二维凝聚体系中分子的取向分布函数性质

对二阶和四阶Legondre多项式构造的取向分布函数进行了仔细研究, 发现该函数适于描述二维凝聚体系中单轴取向分子的四种分布模式, 给出了这四种分布模式对应的序参数〈P_2〉,〈P_4〉的取值区域, 具体讨论了序参数〈P_2〉,〈P_4〉改变时, 分布图形的相应变化.     

CF4等离子体表面氟化PTMSP膜

本文对聚三甲基硅基丙炔(PTMSP)膜进行CF_4等离子体表面氟化研究。改性的PTMSP膜氧氮选择性显著提高(P_(O_2)/P_(N_2)=4-5,P_(O_2)=10~2-10~3barrer)。等离子体改性条件,如处理时间、单体压力、放电功率对PTMSP膜透气性的影响进行了研究。XPS谱分析表明改性后,膜表层化学组成发生了显著变化、碳硅含量大幅度减小,氟含量随着处理程度的增加而增加,氟碳比与膜的选择性有着密切的关系,当 F/C>1时,膜的P_(O_2)/P_(N_2)可达4以上。     

氧族桥原子对类立方烷簇[Mo_4X_4Cp_4′]成键特征的影响(X=O,S,Se,Te;Cp′=Cp or Pr~iCp)

本文用EHMO法对(Mo_4X_4Cp′4](X=0,S,Se,Tc)四个类立方烷型簇合物的电子结构进行了计算,结果表明,桥基X从O到Te,前线区域分子轨道中桥基成分明显增加,能级普遍升高;Mo-Mo间作用有所增强;能隙ΔE(LUMO-HOMO)增大;Mulliken键级P的次序为P_(Mo-Se)>P_(Mo-S)>P_(Mo-Tc)>P_(Mo-o)>P_(Mo-Mo),说明第二过渡系元素Mo更倾向于与较重的se桥结合形成类立方烷型簇合物。     

五硫化二磷含量的化学测定方法

目前,国内五硫化二磷的生产大多采用熔化了的黄磷与液体硫黄按比例流入反应器,严格控制温度在380～420℃的条件下反应而成的。有无硫-磷化合物的异构体存在,取决于反应的温度和硫磷反应时的化合配比。因此,五硫化二磷中的主要杂质成份将是未参与反应的磷或者硫,考虑到P_2S_3,P_4S_3,P_4S_5,     

Solid state synthesis and characterization of iron（Ⅱ） pyrophosphate Fe2P2O7

Offwhite pure Fe_2P_2O_7 was synthesized through solid phase reaction using Fe_2O_3 and NH_4H_2PO_4 in argon atmosphere.The reaction products of Fe_2O_3 and NH4_H_2PO_4 at a series of temperatures from 400 to 900℃were characterized by XRD.Comparison and analysis of XRD patterns of resultant products indicated well-crystallized Fe_2P_2O_7 could be obtained over 630℃and Fe_2P_2O_7 prepared at 700℃was triclinic in cell type.Comparison of the cell parameters proved that the as-prepared Fe_2P_2O_7 belonged toβ- Fe_2P_2O_7 in crystal phase and SEM showed its size distribution was 0.5-2μm.     

三甲基硅烷基丙炔与五甲基二硅烷基丙炔共聚物膜及其气体透过性

研究了三甲基硅烷基丙块与五甲基二硅烷基丙块共聚物〔poly(TMSP-co-PMDSP)〕的成膜特点。poly(TMSP-co-PMDSP)膜的气体透过系数分别为:P_(O2):4×10~3～12×10~3,P_(N2):3×10~3～8×10~3和P_(CO2):2×10~4～4×10~4barrer,气体透过稳定性低,透过行为偏离第二Fick定律,过系数下降,其中溶解系数降低的比例远大于扩散系数的增加比例,在含有凝聚性气体的环境里,膜的气体透过出现表面吸附控制的特征。     

解脱波(EML)与情绪的相关性

本实验采用CNV反馈与解脱波(EML)相结合的实验模式,以14名青年被试者研究了正常人类情绪与EML的相关性。实验分为3项。记录F_2,C_2,P_2,P_2,P_3—T_5连线中点和P_4—T_6连线中点。发现,正情绪与负情绪比较,引起EML潜伏期缩短,波幅升高,5个记录点在正负情绪作用下发生的EML变化一致。讨论了EML的脑内源.在本实验所引发的情绪条件下,EML有可能作为反映其正负属性的ERP指标。     

以Fe_2P_2O_7为前驱体制备LiFePO_4及其电化学性能（英文）

以磷铁废渣(Fe1.5P)和温室效应气体CO_2为原料,以磷酸为补充磷源合成磷酸铁锂(LiFePO_4)的前驱体Fe_2P_2O_7,并研究了其合成过程对LiFePO_4正极材料储能性能的影响。采用SEM观察了LiFePO_4的表面形貌,采用XRD分析了LiFePO_4和Fe_2P_2O_7的晶体结构。进一步对该方法进行优化,发现Fe1.5P与磷酸混合物(nFe1.5P∶nH3PO4=1∶1)在800℃热处理6 h合成的Fe_2P_2O_7对应的LiFePO_4/C电化学性能最好,在0.1C,0.2C,0.5C和1C倍率下的容量分别可达130,126,117和108 m Ah·g~(-1)。     

LaOX-Pr^3^+(X=Cl, Br)体系的荧光特性及其配位场理论解析

LaOX-Pr~(3+)(X=Cl,Br)体系在室温和液氮温度下均只观察到~3P_0能级的发射,其原因在于Pr~(3+)离子的4f5d激发态具有较高能量(>37kK),且~3P_2,~3P_1向~3P_0存在有效的电子弛豫;本文基于DSCPCF配位场模型的计算结果,对该体系的发射光谱和激发光谱进行了理论归属,实测峰位与计算值较好吻合.     

稀土元素的电分析化学研究 Ⅸ.铽—8—羟基喹琳-高氯酸钠的极谱配合吸附波

本文研究了铽-8-羟基喹啉(Ox)-高氯酸钠体系的极谱行为。在高氯酸钠底液中,Ox在单扫示波极谱上有一个稳定的还原波P_1,加入Tb~(3 )后,P_1降低,而在后面出现一个新波P_2。在最佳实验条件(pH4.0～4.5,0.1MNaClO_4-8.0×10~(-5)MOx)下,Tb~(3 )在1.0×10~(-6)～1.0×10~(-5)M范围内与P_1的降低有线性关系;在0.1M NaClO_4~-2.0×10~(-4)MOx下,Tb~(3 )在3.0×10~(-6)～3.0×10~(-5)M范围内与P_2的峰高有线性关系。应用多种极谱技术研究了此体系的电极反应机理,证明它为配位吸附波;写出了电极还原步骤,测定了Ox的离解常数。     

钒取代的Dawson型磷钼酸对酪氨酸酶的抑制作用

采用酶动力学方法研究了5种钒取代的Dawson型磷钼酸H₇[P₂Mo₁₇VO₆₂]、H₈[P₂Mo₁₆V₂O₆₂]、H₉[P₂Mo₁₅V₃O₆₂]、H₈[P₂Mo₁₄V₄O₆₂H₂]和H₉[P₂Mo₁₃V₅O₆₂H₂](分别简写为P₂Mo₁₇V、P₂Mo₁₆V₂、P₂Mo₁₅V₃、P₂Mo₁₄V₄和P₂Mo₁₃V₅)对蘑菇酪氨酸酶二酚酶的抑制作用,结果表明,效应物P₂Mo₁₇V、P₂Mo₁₆V₂和P₂Mo₁₅V₃能够明显地抑制酪氨酸酶的活性,其半抑制浓度(IC₅₀)值分别为0.409、0.386和0.386 mmol/L,且均表现为可逆的竞争型抑制,效应物P₂Mo₁₇V、P₂Mo₁₆V₂和P₂Mo₁₅V₃对游离酶的抑制常数K_I分别为0.234、0.391和0.249 mmol/L。 而效应物P₂Mo₁₄V₄在0~1.0 mmol/L浓度范围内,对酪氨酸酶二酚酶无明显抑制作用,效应物P₂Mo₁₃V₅对酪氨酸酶二酚酶表现为激活作用。     

Facile cyclic ammonium salt with the smallest size for high performance electric double layer capacitors

A novel cyclic ammonium salt, N,N-dimethylpyrrolidinium tetrafluoroborate (P₁₁-BF₄), was successfully synthesized for the first time. The smallest cyclic structure of P₁₁-BF₄ induced high solubility and conductivity in PC, which can easier enter the micropores of activated carbon and occupy more surface area during charge/discharge process.     

Dawson结构的多金属氧酸盐对酪氨酸酶的抑制作用

按文献方法合成了两种Dawson结构的多金属氧酸盐,并对其结构进行紫外光谱和红外光谱分析。以H_6[P_2Mo_(18)O_(62)]和H_8[P_2Mo_(17)Cr(OH_2)O_(61)](简写为P_2Mo_(18)和P_2Mo_(17)Cr)为效应物,采用紫外分光光度法和酶动力学方法研究两种Dawson结构的多金属氧酸盐效应物对蘑菇酪氨酸酶二酚酶活性的抑制作用。结果表明,P_2Mo_(18)和P_2Mo_(17)Cr对酪氨酸酶二酚酶均具有显著的抑制效果,测定抑制酪氨酸酶活力下降50%的抑制浓度(IC_(50))分别为(0.482±0.009)mmol/L和(0.503±0.011)mmol/L。动力学分析表明,P_2Mo_(18)和P_2Mo_(17)Cr对酪氨酸酶的抑制作用均表现为可逆的竞争型,抑制常数K_I分别为0.212和0.249 mmol/L。其中,综合考虑IC_(50)值和抑制常数,P_2Mo_(18)对酪氨酸酶二酚酶活性的抑制效果略优于P_2Mo_(17)Cr。     

Molecular fragmentations : Part XIII. The structures and energies of mass spectral fragments derived from phosphine-3, diphosphine-4, diphosphine-2 and triphosphine-5

Structures and energies have been calculated, in the MNDO approximation, for PH₃, P₂H₄, P₂H₂, and P₃H₅, for their molecular cations, for all the ions in their mass spectra, and for the corresponding neutral mass spectral fragments. With the exception of the conformation of P₂H₄, which is calculated to be anti rather than gauche, the calculated structures and energies are in good agreement with those found experimentally, where these are known. Appearance potentials have been calculated, and allow deductions to be made concerning fragmentation pathways.     

铈(Ⅳ)与焦磷酸盐的配位作用

考察了在焦磷酸盐水溶液中用O₃氧化Ce(Ⅲ),生成的Ce(Ⅳ)与P₂O₇^4-的作用情况,并对不同条件下所得的固体进行了研究。     

A comparative study of species N3 and P3

Calculations on linear and bent structures of N₃ and P₃ show that these species are quite different. N₃ is linear, P₃ is bent almost to a D_3h geometry. The symmetry of P₃ in D_3h is ²E″ but the Jahn-Teller distortion is very small, ≈4°. The many-body expansion of the energy of P_n clusters appears to be only slowly convergent.     

Theoretical study on reaction mechanism of the vinyl radical with nitrogen atom

The complex triplet potential energy surface of the C₂H₃N system is investigated at the UB3LYP and CCSD(T) (single-point) levels in order to explore the possible reaction mechanism of C₂H₃ radical with N(⁴S). Eleven minimum isomers and 18 transition states are located. Possible energetically allowed reaction pathways leading to various low-lying dissociation products are obtained. Starting from the energy-rich reactant C₂H₃+N(⁴S), the first step is the attack of the N atom on the C atom having one H atom attached in C₂H₃ radical and form the intermediate C₂H₃N(1). The associated intermediate 1 can lead to product P₁ CH₂CN+H and P₂ ³CH₂+³HCN by the cleavage of C–H bond and C–C bond, respectively. The most favorable pathway for the C₂H₃+N(⁴S) reaction is the channel leading to P₁, which is preferred to that of P₂ due to the comparative lower energy barrier. The formation of P₃ ³C₂H₂+³NH through hydrogen-abstraction mechanism is also feasible, especially at high temperature. The other pathways are less competitive comparatively.     

磷对泥/煤混燃灰熔融特性的影响及矿物相演变规律

采用灰熔点仪、X射线荧光仪(XRF)研究了无机非金属P2O5对城市污水污泥与烟煤的混烧灰熔融特性的影响,利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)研究在各混烧温度下灰中含磷矿物在晶体和非晶体间的演变。结果表明,对于Al_2O_3含量较多且熔点较高的灰样,磷含量的增加可显著降低其灰熔点,P2O5含量在0-4%时影响最大,使其灰熔点降低126℃;但对碱性含量高的灰样的影响较小。低温灰中主要以磷酸铝(AlPO_4)晶体为主,温度升高后,与硬石膏(CaSO_4)等含钙矿物和赤铁矿(Fe_2O_3)反应生成晶体Ca_3(PO_4)_2和玻璃相(Fe_2O_3)_(0.252)(P_2O_5)_(0.748),磷含量增加可使灰中玻璃相(Fe_2O_3)_(0.252)(P_2O_5)_(0.748)增加,是磷降低灰熔点的主要原因。     

过渡金属-联咪唑-Dawson型钨磷酸盐杂化化合物的酶固定化性能

利用水热法和直接沉淀法, 设计合成了5例由过渡金属(TM)-联咪唑配阳离子与Dawson型钨磷酸阴离子构成的多金属氧酸盐(POM)基有机-无机杂化化合物[Ni(H₂biim)₃]₄[Ni(H₂biim)₂(P₂W₁₈O₆₂)₂]·2H₂O(1), [Co^III(H₂biim)₃]₂[P₂W₁₈O₆₂]·8H₂O(2), [Cu(H₂biim)₂]₃[P₂W₁₈O₆₂]·4H₂O(3), [Co^II(H₂biim)₃]₂H₂[P₂W₁₈O₆₂]·9H₂O(4)和 [Ni(H₂biim)₃]₃[P₂W₁₈O₆₂]·2H₂O(5); 并利用X射线单晶衍射分析(SC-XRD)、 红外光谱(IR)和热重-差热分析 (TG-DTA)等对其进行了表征. 化合物1~5作为载体用于固定辣根过氧化物酶(HRP)时, 显示出了较高的酶固定化能力. 另外, 利用圆二色光谱(CD)和激光扫描共聚焦显微镜(LSCM)等方法评价了固定化酶HRP/1~HRP/5的重复使用性、 储存稳定性和检测过氧化氢(H₂O₂)的性能. 由于该类POMs与HRP间存在强的相互作用, 利用简单的物理吸附法即可实现POMs对HRP的固载. POMs对酶的固定不但提高了HRP对使用及储存环境的耐受性, 同时也拓展了POMs在酶固定化领域的应用.     

Cholesteric liquid crystalline thermosets: synthesis, structure and properties of ChLCTs/precursor polymers

The synthesis of six liquid crystalline monomers M₁-M₆ and three series of side chain cholesteric liquid crystalline polymers P₁-P₃ is described. The chemical structures of the monomers were characterized by FTIR and ¹H NMR spectroscopy. The structure-property relationships of M₁-M₆ and P₁-P₃ are discussed. Their phase behaviour and optical properties were investigated by differential scanning calorimetry and polarizing optical microscopy. The monomers M₁-M₃ exhibited cholesteric phases; M₄-M₆ showed nematic or smectic phases. The polymer series P₁-P₃ showed cholesteric phases. Experimental results demonstrated that the selective reflection of the cholesteric monomers and homopolymers shifted to the shorter wavelength region (blue shift) with increasing length of the flexible spacer. The selective reflection of the copolymers shifted to the longer wavelength region (red shift) with increasing content of nematic units.