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中文
Table of Content
24 January 1999, Volume 20 Issue 1
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Articles
Mechanochemical Synthesis of Nanocrystalline Zinc Ferrite
JIANG Ji-Sen, GAO Lian, YANG Xie-Long, GUO Jing-Kun
1999, 20(1): 1-4.
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Nanocrystalline zinc ferrite(ZnFe
2
O
4
)was synthesized at room temperature(about 25) by mechanochemical reaction of Fe
2
O
3
and ZnO powder under The effectof high energy ball milling.The prepared nanocryst allite was characterized by XRD, TEM, Mossbauer spect roscopy and IR spect rum.The results showed that the as milled nanocryst alline zinc ferrite is non-normal spinel structure and show superparamagnetism.There are many defects in the as milled nanocryst alline zinc ferrite.
Biological Effectof Rare Earth(Ⅰ)-Content and Distribution of Rare Earth in Normal Human Plasma
MENG Lu, DING Lan, CHEN Hang-Ting, ZHAO Da-Qing, NI Jia-Zuan
1999, 20(1): 5-8.
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The content and distribution of rare Earth(RE)in normal human plasma have been in-vestigated by ult rafilt ration, FPL Cand ICP-MS methods.The results showed that there are trace RE in normal human plasma, and Their contents are in accordance with Their abundance.The RE can bond with immunoglobulin G(IgG), transferrin(Tf)and albumin(Alb)species, but mostly bond with if.
The Synthesis,Characterization of New Metal bisdithiole Complexes M-BDT and Indexing on Polycrystalline Xray Diffraction Pattern
HAO Zhi-Feng, YU Xiang-Yang, PANG Shu-Feng, LI Yong-LI, TANG Zong-Xun, SHI Qi-Zhen
1999, 20(1): 9-13.
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Four new M-BDTcomplexes were prepared for the first time(M=Ni, BDT is dithiole with nine Satoms).The study of elementary analysis, IR spectra and UV spect rashows that The molecular formula of The four compounds can be ex pressed as[(CH
3
)
4
N]
2
[Ni(C
5
S
9
)
2
](1), [(C
2
H
5
)
4
N]
2
[Ni(C
5
S
9
)
2
](2), [(C
4
H
9
)
4
N]
2
[Ni(C
5
S
9
)
2
](3), [(C
6
H
5
)(CH
3
)
3
N]
2
[Ni(C
5
S
9
)
2
](4), respectively.The Xray pow der diff raction pattern of compound 1 was deter m ined and its Xray diff raction lines were indexed.The indexing results show that The cryst al be longs to The monoclinic system with a simple monoclinic latice.The cell parameters of The crystal of complex 1:a=0.680 nm, b=0.714 nm, c=2.302 nm, =1114, Z=2.
Hydrothermal Synthesis,Structure,Properties and Quantum Chemistry Calculation of a Novel Bicapped Pseudo Keggin Polymolybdovanadophosphate
XU Yan, XU Ji-Qing, GUO Cun-Xiao, YANG Guo-Yu, WANG Ren-Zhang, SUN Hao-Ran
1999, 20(1): 14-18.
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The novel molybdovanadophosphate, [NH
4
]
4
H[PMo
8
V
4
Ⅳ
V
2
Ⅴ
O
42
]·24H
2
O was synthe sized and charaterized by element ary analysis, EPR, IR, UV spectra and Xray diffraction.The parameters of crystal structure of The compound are tetragonal, space group P4/mnc, a=b=1.2592(2)nm, c=1.7565(4)nm, V=2.7848(8)nm
3
, Z=2, Dc=2.721 g/cm
3
, F(000)=2220, μ=28.64cm
-1
and R=0.0778.The heteropolyanion has a novel bicappedp seudo Keggin structure, in which notonly The eight metalatom positions are randomly dist ributed by four vanadium and four molybdium atoms, but also the central PO
4
tetrahedra andw hole cluster anion are disordered.The electron structure of the cluster anion was discussed byusing EHMO method.
The Study of Molecular Recognition of 5(2-Carboxyphenyl)10,15,20 triphenylporphyrin to Amino Acid Esters
PENG Xiao-Bin, HUANG Jin-Wang, JI Liang-Nian
1999, 20(1): 19-21.
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Using UV-Vis spectroscopic and
1
HNMR methods, we have invest igated The molecu lar recognition of am ino acid esters by 5(2 carbox ypheny l)10, 15, 20 tripheny lporphyrin.The binding const ants between o-TPPCO
2
H and Lphenylalanine ethylester, and Lthreonine ethyl ester were obt ained.The possible recognition mode of The free porphyrin to amino acid esters has been suggested.The hydrogen bond between one of The two hydrogens of pyrroL in o-TPPCO
2
H and The oxygen of The carboxyl group of amino acid ester acts as one point of interaction.Another pointof interaction is The base acid interaction between amino group of amino acid ester and car boxyl group of porphyrin.
The Extraction Equilibrium and the HSAB Rule
YANG Tian-Lin, YANG Yong-Hui, SUN Si-Xiu, SONG Qi-Sheng, SUN Xuan
1999, 20(1): 22-24.
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The extraction equilibrium of Fe(Ⅲ), Be(Ⅱ), Mn(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Pb(Ⅱ)and Cd(Ⅱ)from nit rate medium with di-(2-et hylhexyl)pHospHoric acid (HDEHP)in kerosene were st udied at(298±1)K.The correlation between The extraction equi-librium constants of Metalions and The HSAB rule was discussed.The experimental results indi-cate that Their K
ex
and ΔG ○ are increasing with The increase of hardness of Lewis acid.
Preparation and Characterization of 14T2Cu/MCM41 and 140Cu/MCM41
CAO Xi-Chuan, LI Guo-Dong, CHEN Jie-Sheng, MA Shu-Jie, XU Ru-Ren
1999, 20(1): 25-27.
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MCM-41 m aterials loaded with cupric complexes of 4, 8 bis(2-thienylmethyl 1, 4, 8, 11 tetraazacyclotetradecane 12, 14 dione(14T2Cu)and 1, 4, 8, 11 tet raazacyclotetradecane 12, 14 dione(140Cu)were prepared by mixing The corresponding complexes respectively with silica form of mesoporous molecular sieve MCM-41.The composite materials were characterized by powder XRD, UV-Vis and ESR spect roscopies.The absorption max imum for 14T2Cu/MCM-41 shifts towards The higher frequency by 19 nm in comparison with 14T2 Cu complex in met hanol solution, whereas The absorption for 140Cu/MCM-41 is close to that for 140Cu in methanol.Both 14T2Cu and 140Cu complexes behave anisotropicaly within The channel of MCM-41 material on the basis of ESR spectra.
Determination of Iodine Ion by Differential Pulse Anodic Stripping Voltammetry
TIAN Yuan, SONG Wen-Bo, JIANG Yan-Xia, LIU Ying, CHEN Xu, XU Hong-Ding
1999, 20(1): 28-31.
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I-may be oxidized to form IO
3
-
.On this basis The determination of iodine ion by dif-ferential pulse anodic st ripping voltammetry(DPAS)on Pt ball work Electrode was investigated. For overcoming The absorption of IO
3
-
, The Electrode was washed by Electrochemical method(at+1.3 V)for 120s.This method can detect 5.00×10
-7
mol/L I
-
in 0.1 mol/L KH
2
PO
42
K
2
HPO
4
buffer solution(pH=4).Agood proportionality between The peak currentof DPAS and iodineion concent ration in The range of 5.00×10
-7
～1.50×10
-5
mol/L has been observed. This met hod was successf ully applied to determination of iodine in kelp and edible salt.
Study of Chemical Subgraph Isomorphism Using Genetic Algorithms
CAI Wen-Sheng, SHAO Xue-Guang, PAN Zhong-Xiao
1999, 20(1): 32-36.
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Agenetic algorithm(GA) using integer coding and node based crossover method, and its application in studying The chemical subgraph isomorphism were described in this paper.Aninitial population of random chromosomes representing the mapping betweent arget structure and query structure nodes is evolved by The GA to better solutions until anoptimal solution, the correct mapping, is found.Both The chemical subgraph isomorphism and The multi subgraph isomorphism were implemented.
Purif ication and Characterization of
L-
Amino Acid Oxidase from Agkist rodon Blomhof fii Ussurensis Snake Venom of Changbai Mountains
SUN Ming-Zhong, DING Lan, ZHAO Da-Qing, NI Jia-Zua
1999, 20(1): 37-41.
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The
L-
a.a.oxidase of Agkist rodon blom hoffii ussurensis of Changbai Mountains in northeast of China has been separated by using ion-exchange and gel filtration techniques.This enzyme is composed of two subunits, The molecular weight of one subunit is about 36000, The another is about 57000, determined by sodium dodecyl sulfate-polyacryamide gelelectrophoresis and mat rix assisted laser desorptionion/time of flight mass spect rometry.The activity of
L-
a.a.oxidase determined using
L-
Leu as substrate.The optimal pHof the enzyme is 4.55and 89.The UV-Visible absorption spectrum of
L-
a.a.oxidase shows the characteristics of flavorpro-teins.
An Application of the Wavelet Packets Analysis to Resolution of Multicomponentoverlapping Analytical Signals
SHAO Xue-Guang, CAI Wen-Sheng
1999, 20(1): 42-46.
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Anovel algorithm of the wavelet packets analysis, which is more suitable to process the practical signals in analy ticaLInst rument al analysis, was proposed based on The algorithm of the multiresolution signal decomposition(MRSD).And application of the method to The resolution of The overlapping multicomponent chromatogram was invest igated.It is proved by The results that The method is superior to the MRSD in resolving overlapping chromatograms and There is no need to perform The inverse transform.Comparing with The results by wavelet analysis, The wavelet packets analysis possesses stronger ability in resolving overlapping analytical signals.The linearity of chromatographic signal remains in The resolved results, which ensure the results can be used for quantitative determ ination.
Thiocyanate selective PVC Membrane Electrodes Based on Organotin(Ⅳ)Compounds as Neutral Carriers
LI Zhi-Qiang, SONG Xiao-Ping, YUAN Ruo, YING Min, SHEN Guo-Li, YU Ru-Qin
1999, 20(1): 47-49.
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The paper describes solvent polymeric membrane anion selective electrodes based on t ribenzyltin pHenolates as neutral carriers.The Electrode based on tribenzyltin p-nitrophenolatepossesses excellent potentiomet ric response characteristics and selectivity towards thiocyanate, The linear range is(0.1246)×10
-5
mol/Lwith a slope of -56.8.The Electrode demonst rates anti-Hof meister behavior, and The selectivity sequence observed is:t hiocyanate>benzoate>perchlo-rate>iodide>nitrite>nitrate>acetate>bromide>chloride.The potentiometric response charac-teristics and selectivity have a close relationship with The structure of The carriers, as The substitute in pHenol ring changes from nitro-to hydrogen, then to t-butyl, the potentiometric response characteristics and selectivity to t hiocyanate deteriorate to some extent.The Electrode based on tribenzyltin p-nitrophenolate has a fast response time, fair stability and reproducibility and could be used for The detection of thiocyanate in act ual samples with satisfactory results.
Synthesis of Sila bridged Titanocenes and Desilytion Reaction
WANG Bai-Quan, XU Shan-Sheng, ZHOU Xiu-Zhong
1999, 20(1): 50-53.
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Reactions of lithiat ed sila bridged ligands LI
2
[E(C
5
H
3
SiMe
3
)
2
]with TiCl
4
2T HF lead to The formation of complexes[E(C
5
H
3
SiMe
3
)
2
]TiCl
2
[E=Me
2
SiSiMe
2
(3), Me
2
SiOSiMe
2
(5)]. The unsymmetrical ansat it anocenes[E(C
5
H
4
)(C
5
H
3
SiMe
3
)]TiCl
2
[E=Me
2
SiSiMe
2
(4), Me
2
SiOSiMe
2
(6)]were also isolated simult aneously as desilylation products.Among Them, disilox ane bridged ligand is easier to occur the desilylation reaction.Complexes 36 were character ized by
1
HNMR, mass spectra and elemental analyses.
The Chlorination of O-Alkyl S-Alkyl(aryl)Thiophosphoric(-nic)Acids Derivatives with Phosphorus Oxychloride-A New Method for Synthesis of S-Alkyl(aryl)Thiophosphoro(-no)chloridates
HE Zheng-Jie, CHEN Wen-Bin, MA Fu-Peng, ZHOU Zheng-Hong, TANG Chu-Chi
1999, 20(1): 54-58.
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In The course of investigating The isomerization/chlorination mechanism of O, O-di-alkyl pHospHorot hionate 1 with pHospHorus oxychloride, it was found that The isomerization prod-uctof 1, O, S-dialkyl phosphorothiolate 4, can be smoothly chlorinated with phosphorus oxy-chloride to lead its one alkoxy to be replaced by chlorine atom and give S-alkyl thiophospho-rochloridate 2 and O-alkyl phosphorodichloridate 3.The further investigations indicate that when Risalkyl or pHenyl, R'is alkoxy, aryloxy, alkylthio, arylthio, dialkylamino, nitrogen hetero-cyclic group, pHenyl or methyl respectively and R'is C
1-4
alkyl, this chlorination can also easilytake place and give The desired product in a fair yield.Thus, this constitutes a convenient newmethod for synthesis of asymmet ric pHospHoro(-no)chloridot hiolate 2.
Studies on Structure reactivity Relationship for NAD(P)H Model Compounds-Electronic Effectof the 3Acyls
LU Yun, XIAN Ming, ZHU Xiao-Qing, WANG Kun, MU LIn-Jing, CHENG Jin-Pei
1999, 20(1): 59-63.
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Aseries of 3-
N
-substituted 1, 4-dihydronicotinamide model compounds(1_4)were synthesized.The second order rate const ants of The apparent hydride transfer reactions of these NAD (P)Hmodels with 5-nit roisoquinolinium ion were measured.The redox pot entials were also determined.The results show ed that The 3-acyl group of The dihydropy ridine ring could on one hand delocalize The electrons on The ring nit rogen, and on The other hand the part ially negat ively charged 3-acy loxygen could cause two types of Electrostatic stabilization to the reaction transition state,
i.e
.electrostatic stabilizing interaction with the partialy positively charged 4 carbon with in The model molecule, and intermolecular electrostatic stabilizing interaction with The positively charged subst rate.The Electronic ef fectof The 3carbonyl group on The kinetic reactivities of The NAD(P)Hmodels in relation to their respective Thermodynamic parameters is rationalized by combination of Both effects.
Studies on Stereoselective Synthetic Methods of 2,3,4,5-Tetrasubstituted-cis-2,3-dihydrofurans
DING Wei-Yu, TONG Wei-Qi, ZHAI Yi-An, CAI Zhi-Rong
1999, 20(1): 64-67.
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Three methods for The stereoselective synthesis of 2-carbomet hoxy-3-ary l-4-acethyl-5-methylcis dihydrofurans(7a_7g)were studied.The 1st met hod is proceeded t hrough the reaction of carbomet hoxy methylenet riphenylarsorane(5)with 3 substituted benzal 2, 4-pent adione(6)in benzene at room temperature for 4 h and high yield of the products 7a_7g can be obtained.The 2nd method is started from the reaction of carbomet hoxy methylt riphenylarsonium bromide(4) with K
2
CO
3
in dimethylet hyleneglycol at room temperature, The Ylid 5 formed reacted with 6 in sit u, excellent yield of 7 can be obtained and triphenylarsine recovered quant it at ively.The 3rd met hod is a stepw ise one pot reaction, tripheny larsine(2)and methyl bromoacetate(3)is refluxed in dimethyl et hyleneglycol for 25 h, after cooling, potassium carbonate and 6 are added in and the reaction continued at room temperature for 2d, the overall yield from starting material triph enylarsine is about 65%.Although The 1st method is a very simple process for preparing 2, 3-dihydrofuran derivatives, its application is limited due to the unst ability of Ylid 5 during its prepa ration and storage, so the last two methods seem pref erable.The structures of The products 7a_7g were confirmed by means of IR,
1
HNMR, MS and elementary analysis and their configurations were established through The coupling constants of The two protons on 2-C and 3-C atoms in The dihydrofuran ring.These reactions were alhighly stereoselective and only one kind of stereoiso mer with cis conf iguration was formed.It is notewort hy that these reactions no similar normal Wittig reaction products were detected.
The Chlorination of Organic Ammonium Phosphoro(no)thioates with Phosphorus Oxychloride--A New Convenient Method for Synthesis of Phosphoro(no)chloridothionates
HE Zheng-Jie, LIU Ju-Xiang, ZHOU Zheng-Hong, TANG Chu-Chi
1999, 20(1): 68-71.
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O, O Dialkyl phosphoro(no)thioic acids derivatives are dealkylated with aqueous dimet hylamine to give am monium phosphoro(no)t hioates, which are chlorinated with phospho rus oxychloride to afford phosphoro(no)chloridot hionates.this novel reaction provides a new convenient method for syn The sis of phosphoro(no)chloridot hionates, especially those containing asymmetrical phosphorusatom.The chlorination mechanism is also discussed.
Reactivity of Co(Ⅱ)and Co(Ⅲ)Complexes Towards C=C Bonds
ZHOU Zhi-Ming
1999, 20(1): 72-76.
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Starting from bis(propagyl)amine(1), a new cyclopentadienyl Co(Ⅲ)complex 8 was prepared using CoCl
2
Ph
3
P
via
ClCo(PPh
3
)
2
, and Co(Ⅱ)complex(11)was also prepared using Co
2
(CO)
8
via complex 10.Reactivity of These two colbalt complexes with differentox idation state towards C=C bonds were investigated, a new stable complex 9 was found from the reaction with complex 8, but a pureorganic compound 3 was formed by the reaction of complex 11.The low reactivity of Co(Ⅲ)complex 8 tow ards C=C bonds is explained according to The results of its Xray cryst al structure.
Ansa Metallocene Complexes(Ⅲ)--Synthesis and Application in Ethylene Polymerization of Sila bridged Bis(indenyl and tetrahydroindenyl) Titanium and Zirconium Complexes
WANG Bai-Quan, XU Shan-Sheng, ZHOU Xiu-Zhong, SU LI-Ming, FENG Ru, HE Da-Wei
1999, 20(1): 77-80.
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Tetramethyldisilane bridged bis(1 indenyl and tetrahydroindenyl)Metal ocene dichlorides(Me
2
SiSiMe
2
)Ind
2
MCl
2
[M=Ti(1), Zr(2)]and(Me
2
SiSiMe
2
)[IndH
4
]
2
MCl
2
[M=Ti(3), Zr(4)]were synthesized.Complexes 1-4 were characterized by
1
H NMR, mass spect ra and elemental analyses.Complexes 3 and 4 were used for The polymerization of ethylene after activation with methyl aluminox ane(MAO)at different temperatures and normal pressure.The titanocene 3 shows a lower activity but produces polyet hylene with a higher molecular weight t han zirconocene 4.The catalyst systems show a dependency of the activity and molecular weighton tem perature.
Synthetic Studies of HIV-active Didemnaketal A Analogue--Synthesis of a C8-C15 Fragment
TU Yong-Qiang, LIU Zeng-Lu, WANG Ping-Zhen, JIA Yan-Xing
1999, 20(1): 81-83.
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A C8-C15 fragmentof The HIV-active didemnaketal Aanalogue was synthesized from (+)R-pulegone through 5 steps.One new chiral center, The C12, was successf ully const ructed by The steric induction in this approach.These intermediates were characterized by
1
HNMR.
The Study of Alkali Metal Adductions Technique of Oligosaccharides in Fast Atom Bombardment Mass Spectrometry
ZHAO Fan-Zhi, ZHAI Jian-Jun, CHEN Yao-Zu
1999, 20(1): 84-85.
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In positiveion fast atom bombardment(FAB)mass spectrometry, it is difficult to determine The molecular w eights of oligosaccharides due to the low abundance of[M+H]
+
ion How ever, when oligosaccharides are mixed with an appropriate amountof NaCl and LiCl, two highly abundant peaks[M+LI]
+
and[M+Na]
+
appear in FAB mass spectra and Their mass diff erence is 16.from The adductions, The molecular weights of oligosaccharides can be determineddef initively.this technique has not been reported previously.
Theoretical Research on the Structure and Electronic Spectra of Molecule C
120
O
2
REN Ai-Min, FENG Ji-Kang, GUO Jing-Fu, TIAN Wei-Quan, SUN Xiu-Yun, LI Wei, GE Mao-Fa, HUANG Xu-Ri, SUN Jia-Zhong
1999, 20(1): 86-91.
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The possible structures of the bis-linked fullerene oxide molecule C
120
O
2
have been re-cently investigated carefuly with INDO series methods.The tw o oxygen atoms form a bridge type bond and are connected to The edges of 6/5 rings or 6/6 rings of the fullerene cages, which are linked by adjacent furanoid five-membered rings.The calculation results show that Both con-fig urations are of the C-v symmet ry and the latter seems to be more st able.What is more, The latter electronic spect ra are in bet ter agreement with The experimental dat a in comparison with The former.Formation of the bis-linked ful erene oxide C
120
O
2
notonly lessened the ang le strength of the C
60
O epoxide, but also enhanced The interaction of The two fullerene cages linked by two fura-noid five-membered rings.Although The two fullerene cages show a certain independency, The multiple direct connection draw them nearer and cause a st ronger interaction.At last, C
120
O
2
can be decomposed to form new compounds.
Pentane Reaction over SO
4
2-
/ZrO
2
and SO
4
2
/Al
2
O
32
ZrO
2
Catalysts
XIA Yong-De, HUA Wei-Ming, GAO Zi
1999, 20(1): 92-96.
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The effectof incorporation of ALInto ZrO
2
on The crystallization, surface area, sulf ur content, superacidity and catalytic behavior of SO
4
2-
/ZrO
2
for n-pentane reaction was studied, and The effectof activation temperat ure, reaction temperat ure, Al content and Pt loading on The activity and selectivity of SO
4
2-
/ZrO
2
was investigated as well.The acid strengths of SO
4
2-
/Al2O
32
ZrO
2
catalysts are almost identical with thatof SO
4
2-
/ZrO
2
catalyst, where as the formerhas more superacidic sites than The latter.Before loading with Pt, SO
4
2-
/Al
2
O
32
ZrO
2
catalyst isobviously more active and stable than SO
4
2-
/ZrO
2
for n-pentane conversion reaction.Supporting Pt can improve The isomerization selectivity and stability of The catalysts markedly, but The activi-ties of Pt/SO
4
2-
/Al2O
32
ZrO
2
and Pt/SO
4
2-
/ZrO
2
catalysts for n
2
pentane isomerization are almostidentical, demonst rating that The promoting effectof ALIs not evident in The presence of Pt andhydrogen.
Preparation and Characterization of Self-assembled Monolayers of Trichlorogermanyl Propanoic Acid and Its Derivatives
XU Ran, REN Yan-Zhi, LI Wei, XI Shi-Quan, TIAN Yan-Qing
1999, 20(1): 97-100.
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Self-assembled monolayers(SAMs) of trichlorogermanyl propanoic acid derivatives on hydroxylated silicon subst rates are prepared for The first time.Contac TANGle measurement, ellip-sometry and X-ray photoelectron spectrometry(XPS)are used to characterize these SAMs.It is demonst rated that a quasi 2-D network is formed on the surface of the substrate after molecules ad-sorbed on it.The molecular chains have certain til TANGles to The subst rate surface.The wettabili-ties of The SAMs are various, because The molecules adsorbed and liquids used in The experiment sare different.It can be concluded that trichlorogermanes have similar self-assembly behavior as trichlorosilanes.Four SAMs are st udied togeTher:They are acid, ethyl, butyl and hexyl surfaces whose results are of good consistency.
Mass Spectrometry Study Combined with Theoretical Calculation on the Unimolecular Fragmentation of Tetrahydroimidazole-substituted Methyleneβ-Diketones
WEI Jun-Hua, SHE Yi-Min, XU Wen-Guo, LIU Shu-Ying
1999, 20(1): 101-106.
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Studies of low-energy collision-induced dissociation and isotopic labeling on ionized te-trahydroimidazole-substituted methyleneβ-diketones by tandem mass spectrometry showed that Their unimolecular fragmentations may involve The reactions of intermediate ion/neutral complexes and multistep rearrangements.The corresponding mechanisms were proved by semiemipirical cal-culations of PM3 and AM1 met hods.
Structure Studies on the Bright Nanocrystalline Zinc Deposit
YU Jing-Xian, CHEN Yong-Yan, HUANG Qing-An, YANG Han-Xi
1999, 20(1): 107-110.
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The crystalline defects in the brig ht nanocrystalline zinc deposit were investig ated by using posit ron annihilation lifetime spectroscopy(PLAS), Xray dif fraction and transmission Electron microscope.It has been found that The bright nanocryst alline zinc deposit is a kind of structure betw een polycrysta Line and amorphous structure.The existence oforg anic additives and The hydrogen permeated and The high grain boundaries area in the nanocrystalline zinc deposit lead to a very high concent ration of defects.The organic addit ives and hydrogen mainly exist in The inter f acial domain of zinc nanocryst alline here.
Thermodynamic Analysis for Chemical Vapor Deposition Diamond with the Participation of Chlorine
LIU Zhi-Jie, ZHANG Wei, ZHANG Jian-Yun, WAN Yong-Zhong, WANG Ji-Tao, CAO Chuan-Bao, ZHU He-Sun
1999, 20(1): 111-114.
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Diamond growth condition for C
2
H
2
Cl system is studied by using The non-equilibrium Thermodynamic coupling model.The pHase diagram for diamond growt h is calculated, which is in good agreement with many reported experiments.The experimental observation that diamond film may grow at a higher rate under low temperature and have better qualities due to The addition of chlorine is also discussed according to The Thermodynamic analysis.
The Preparation and Mechanism Studies on Ultrafine Porous Titania
ZHAO Jing-Zhe, WANG Zi-Chen, WANG LI-Wei, XUE LI-Jing, LIU Yan-Hua, YANG Hua, ZHAO Mu-Yu
1999, 20(1): 115-118.
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Ultrafine porous titania pow ders were synthesized by precipitating method with titania sulf ate and ammonia as raw materials and ethanol as dispersing agent.The influences of pHand reaction temperatures on the t ex ture of titania precursor powders were investigated.The causes of surface area reduction with calcining temperat ures are grain growth and phase t ransform ation. Micropores could be sintered as enhancing calcining temperature.from TEM photos space network of porous titania is clearly seen.
The Process Study of SiO
2
Coating onα-FeOOH Particles by Surface Hydrolysis Reaction in Fluidized BED Reactor
ZHU Yi-Hua, LI Chun-Zhong, WU Qiu-Fang, XU Qiang
1999, 20(1): 119-122.
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The process of SiO
2
coating onα-FeOOH particles by dehydration and hydrolysis of te-traethylorthosilicate(TEOS)in fluidized bed reactor has been investigated.The results show that The dehydration of α-FeOOH promote The hydrolysis reaction on The particle surface, which is used to form uniform layer.The effects of The reaction temperature, reaction time, TEOS con-cent ration and The ammonia concent ration, respectively, on The contents of silica were also inves-tigated.Using this technique, The processes of dehydration, coating silica and reduction ofα-FeOOH were carried out by one step, and The SiO
2
coated by Fe
3
O
4
particles with good magnetic properties were obtained.
Studies of the Structures and TPR Properties of Co/ZrO
2
Catalyst
YU Tie-Ming, ZHOU Ren-Xian, TANG Zhong-Min, ZHENG Xiao-Ming
1999, 20(1): 123-126.
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Co/ZrO
2
catalysts were prepared by impregnation met hod.Their structures and TPR properties were st udied by XRD, TPR, and COoxidation as a probe reaction.The results showed that There was a strong interaction between Co and ZrO
2
, which rest rained The growth of fine par-ticles of zirconium oxide and The phase transformation of t-ZrO
2
to m-ZrO
2
By calcination at ahigh temperat ure, partof The cobaltoxide formed a solid solution with zirconium oxide.The formof cobaltoxide is Co
3
O
4
for Co/ZrO
2
catalyst.In addition, The interaction between Co and ZrO
2
raised The dispersion of cobaltoxide on ZrO
2
The activity of CO oxidation increased with The in-creasing of Coloading.
Studies on the Interaction of Rare Earth Ions with BSA
LI Xiao-Jing, ZHANG Shan-Rong, ZHANG Shu-Gong, PEI Feng-Kui
1999, 20(1): 127-131.
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Studies on The bounding character of rare Earth ions with borine serum albumin(BSA) are significant for understanding The state of rare Earth ions in body and Their effects on The struc-ture and function of protein.The fluorescence spectrum and pHpotentiometry showed consistent results of apparent complexion constantof Tb
2
·BSA.The equilibrium dialysis showed that There are two specific binding sites and more than six non-specific binding sites of REions on to BSA molecule with The conditional stable constant s lg
K
1=5.157 and lg
K
2=31435.
23
NaNMR stud-ies revealed that The BSA peptide chain bound to RE ions was expanded and The mobilit y of itsmolecular backbone was increased.
Preparation and Characterization of Monolithic Iron Oxide Aerogels
GAN LI Hua, LI Guang-Ming, YUE Tian-Yi, CHEN Long-Wu, SHEN Jun, ZHOU Bin, WANG Jue
1999, 20(1): 132-134.
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Material synthesis involved addition of aqueous sodium hydroxide to an iron chloride solutionfol owed by thermal dialysis, vacuum dehydration, and supercritical drying.XRD, Mo ssbauer, TEM, BET, DT Astudies of The aerogel samples indicat ed that initially obt ained aerogels were FeOOH, which would be completely converted into monolit hiciron oxide aerogels t hrough heating treat ment at 450.Monolithiciron oxide aerogels were with uniform size and low density, porous materials consisted of nearly spherical, nanometer ult ram icrous Fe
2
O
3
with diametersabout 60 nm.By adjusting molarratio of sodium hydroxide and ferric chloride(OH
-
/Fe
3+
), Thepore structure and specific surface area of The aerogel samples can be controlled.
A Study on the Micelle and Phase Separation Behavior of NIPAM-ODA Copolymer in Aqueous Solution
SHI Xiang-Yang, LI Jun-Bai, SUN Cao-Min WU Shi-Kang
1999, 20(1): 135-139.
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To study the micele and phase separation behavior of amphiphilic copolymer in aqueous solution which is temperat ure-sensit ive, The copolymer of N-isopropylacrylamide(NIPAM)and octadecyl acrylate(ODA)was syn The sized.The micelle behavior of The copolymer was studied by drop weight method and fluorescence probe method respectively.Simultaneously, the phe-nomenon of LCST(Lower Crit ical Solution Temperat ure)of The copolymer in aqueous solution with The increase of temperat ure was also studied by using fluorescence probe met hod.results showed that, the phase separation came into being in The aqueous solution of the copolymer when temperature was increased to its LCST.The P-Aisotherms of The molecule of The copolymer as insoluble monolayer on water surface was obt ained by L-Bmet hod.The abnormal phenomenon that the monolayer of The copolymer got coacervat ive more and more with the increase of The tem-perat ure was observed.It further indicated that The phase separation of the copolymer occured from anoTher met hod.This phenomenon was also discussed in detail.
Studies on Lyotropic and Thermotropic Liquid Crystalline Behavior of Cyanoethylhydroxypropyl Chitosan
DONG Yan-Ming, YUAN Qing, XIAO Zi-Lan, WANG Jian-Wei, MEI Xue-Feng
1999, 20(1): 140-145.
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Cyanoet hylhydroxypropyl chitosan was synthesized by hydroxypropylation of chitosan followed by cyanoet hylation.The degree of hydroxypropylation and cyanoet hylation was 3.2 and 1.0 respectively.Both cyanoet hylhydroxypropyl chitosan(CNHPC'S)and hydroxypropyl chitosan (HPCS)demonst rated lyot ropic liquid crystalline behaviors, and fingerprint texture was observed in Their concent rated solutions implying The presence of cholesteric phase.The critical concent ra-tion of HPCS in DCA(29%)is higher than CNHPCS's(17%), owing to The enhanced chain rigidity cont ributed by The int roduction of cyanoet hylgroup.In The case of CNHPC'S, cholesteric Thermot ropic mesopHase could be observed between its melting point 193℃ and decomposition temperat ure 220℃ measured by Both DSC and polarized light microscope.SALS was employed to determine The pitch of cholesteric phase in CNHPC'S as received film.The results were consis-tent with those of PLM.
An Investigation of Flammability of Intumescent Flame Retardant Polyethylene Containing Starch by Using Cone Calorimeter
LI Bin, SUN Cai-Ying, ZHANG Xiu-Cheng
1999, 20(1): 146-149.
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The behaviour of flammability of linear low density polyet hylene(LLDPE)treated with The int umescent flame retardant containing starch has been investigated by using cone calorimeter at incidenTheat flux of 50kW·m
-2
in this paper.Based upon The parameters, such as peak heat release rate(p k-HRR), total heat release(THR), effective heatof combustion (EHC), peak smoke production rate(pk-SPR), total smoke production(TSP)and mass loss rate (MLR), etc.taken from The cone calorimeter, some results were obtained as follows:Firstly, starch-containing intumescent flame retardant(S-IFR) obviously lowered pk-HRR, THR and EHC,
i.e
., 485 kW·m
-2
, 905kJ, 33.2 MJ·kg
-1
respectively for LLDPE/S-IFR, 1951kW ·m
-2
, 1019 kJ, 44.7MJ·kg
-1
for LLDPE. pk-HRR increased slightly with increasing the percentage of starch in char forming agent s;secondly, S-IFRmade pk-SPR of LLDPE becomelower, however, it significantly enhanced TSP at The end of combustion;finally, S-IFR promot-ed The Thermal degradation of LLDPEearlier, and made The rate of Thermal degradation lower.
Synthesis and Photoconductivity of Fullerenated Polymethylphenylsilane
GU Tao, XU Jian-Min, CHEN Wan-Xi, XU Zhu-De
1999, 20(1): 150-152.
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The fullerenated polymet hylphenylsilane(C
60
-PMPS)was synthesized by two meth-ods. Either PMPS was synthesized via Wurtz type reduced coupling reaction firstly and Then C
60
-PMPS was synthesized by Friedel-Crafts type reaction;or C
60
-PMPS was obtained by directcopolymerization of dichloromet hylpHenylsilane and C
60.
The structure of each type of C
60
-PMPS was characterized by a series of methods such as UV-Vis, GPC and IR.The results show that C
60
bonds with The pendant benzene ring of PMPS in Friedel-Crafts type C
60
-PMPS while C
60
may in
2
corporate into The main chain in The case of copolymerized C
60
-PMPS.The photoconductivity measurement s show that The copolymerized C
60
-PMPS has a good photoconductivity in contrast with pure PMPS and Friedel-Crafts C
60
-PMPS which have hardly any photoconductivities.
Thermotropic Phase Transition of Liquid Crystalline Solution of Chitosan/Dichloroacetic Acid
HU Zhong-Ming, LI Rui-Xia, WU Da-Cheng, SUN Yu-Shan, LIU Hong-Bin, WU LI-Heng
1999, 20(1): 153-155.
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The thermotropic phase transition of liquid crystaLIne solution of chitosan/dichloroacetic acid(DCA) was st udied by means of DSC.When The polymer concentrationc, was higher t han the crit ical one,
c
*
, an clear endothermal peak attributed to The anisot ropicisot ropic phase t ransition of chitosan solution was observed on DSC heating trace.The exothermal peak was obviously observed on DSC trace upon cooling from above the 五笔字型电子计算机汉 clearing-t emperature because of The reverse phase t ransition.It was found that The lyotropic solution of chitosan/DCAcan exhibit Thermotropic behavior and The liquid crystalline phase form ation in solution is also nucleation cont rolled.Similar to The crystaLIne polymer, The thermotropic phasetransition for liquid crystaline solution of chitosan/dichloroacetic acid is influenced by history of the liquid crystalline phase formation.In addition, The Thermotropic phaset ransition was verified by The polarized light microscopy observation as well as by the changes of depolarizing t ransmit tance intensity as The function of temperature.
13CNMR Study of the Sequence Distribution of Styrene Oligomers and Polymers
WANG Song, YAN Xiao-Hu, CHENG Rong-Shi
1999, 20(1): 156-158.
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The comparison of
13
CNMR spect ra of phenyl C
1
carbon reg ion of polystyrenes hav ing molecular weig hts from 10
2
to 10
6
was studied.The spectra were assig ned with The reference of st yrene pentamer hav ing propyl end groups and model compound 1, 3, 5 triphenylhexane.The triad distributions were obtained from spect raLInt egration of phenyl C
1
carbon regions.It is found that The sequence dist ributions are much dif ferent above and below a definite critical molecular weight.The sample with a molecular w eight less than 10
3
hasrrtriad percentage of ca.20%, w hile those with a molecular weight larger than 10
3
have rrtriad percentage from 30%to 40%.The effects of phenyl groups locat ed at end and ex ternal positions on spect ra are discussed quant it atively for lower molecular weight samples.The results are coincident with The kinetic studies of styrene oilgomerization, there The propag ation const ant wil covert to a asym ptote value after molecular weight reaches 10
3
.The polyst yrene samples used in this work were prepared by anionic polymerization of styrene initiated with n butyllithium and terminated with alcohoLIn benzene.
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