The first observation of the REMPI spectra of OCS molecule in the region of 277—285 nm is reported. The laser source is the pulse laser of Nd: YAG pumped tunable dye laser. The total ionization electric charges of OCS gas in the static cell is collected with the parallel electrodes connected to a boxcar averager. The power dependence shows the REMPI is resulted from the two photon resonant, three photon ionization. Comparing with the VUV absorption spectra, the main spectral lines in the REMPI spectra has been assigned preliminarily. The abnormal spectral line at 279.07 nm may be due to the MPI of oxygen atom produced from the photodissociation of OCS molecules.

The scanning tunneling microscope (STM)is a powerful instrument which provide surface topographic images down to the atomic scale and spectroscopic information on the surface density of electronic states. A computerized system based on the IBM Personal Computer Model XT or AT for STM control, data acquisition and display is presented. The high resolution digital-to-analog converter card and analog-to-digital converter card are used for the computer to generate the voltages applied to the STM piezoelectric elements and to measure the tunneling current. A high resolution graphics controller card is used for real-time display of the STM “images”. The software that performs the control, data acquisition and display of the STM has been written in FORTRAN and linded with some ASSEMBLER subroutines for the critical tasks in order to get a fast and compact executable module which works under DOS Version 3.2. Some images anaysis and display tool are included for a posterior image processing.

Li_(0.025)Na_(0.975)NbO_3 undergoes a ferroelectric-ferroelectric phase transition at 180K (on cooling) or 260 K (on heating). The structure determinations of both phases have been carried out by single crystal diffraction analysis. The ferroelectric room-temperature phase is orthorhombic, with space group Pc2_1b; the cell parameters are a=0.5508(3), b=1.5521(6), c=0.5568(2) nm. The structure is same with Li_(0.02)Na_(0.98)NbO_3. The ferroelectric low-temperature phase is also orthorhomhie, a=0.5497(7), b=0.7913(18), c=0.5565(10) nm, V=0.2421 nm, Z=4. There is disordernal position distribution of O(2) atomes in the low-temperature phase. Its “apparent space group” is P2/n2/n2/n. The relation of the ferroelectric properties to the low-temperature phase structure is discussed.

在~(13)C 90.1和62.9MHz观察频率下测定了吗啡(morphine)分子在溶液中的核弛豫参数。用分子不对称旋转模型算得吗啡分子绕X轴的旋转速度为8.6×10~9周秒~(-1),绕Y轴的旋转速度为6.1×10~9周秒~(-1)。NCH_3中甲基的内旋转速度为5.7×10~9周秒~(-1),内旋转位垒为4.59 kcal mol~(-1)。

[Co(H_2O)_4(NCS)_2]·(18-C-6)是本文作者之一最近合成的新王冠醚配合物晶体。我们用CNDO/2方法计算了该配合物原子簇模型的电荷分布, Mulliken键级,电子态密度(DOS)等,研究其成键特性。结果表明, 该配合物中存在稳定的[Co(H_2O)_4(NCS)_2]·(18-C-6)集团, 配合单元[Co(H_2O)_4(NCS)_2]采取四根强度不同的氢键与(18-C-6)相结合, 并较好地解释了实验结果。

合成了二(1-苯基-3-甲基-4-三氟乙酰基吡唑啉酮-5)-(1,10菲啰啉)合钴(Ⅱ)混合配体络合物单晶, 由元素分析确定其组成为Co(C_(12)H_3F_3O_2N_2)_2·(C_(12)H_8N_2)。通过溶解性、摩尔电导, 磁性、中红外光谱、远红外光谱、差热、热重分析研究了该化合物的有关性质。
用四园单晶衍射仪, 测定了该络合物的分子及晶体结构。晶体属单斜晶系, P2_(l/o)空间群,晶胞参数为:a=1.0422(3) nm, b=1.6462(2) nm, c=2.0678(3) nm, β=75.86(1)°, V=3.4402(1.6) nm, Z=4, F(000)=1580, d_(calc)=1.50 g cm~(-3), d_(exp.)=1.492g cm~(-3)。
经最小二乘法修正后, 最终偏差因子R=0.0716。配合物中钴的配位数为六, 分子中有四个氧来自两个双齿配体PMTFP, 两个氮原子由phen所提供。

本文报导了的晶体结构。晶体属三斜晶系, 空间群P_1, 晶胞参数: a=1.0761(2), b=1.3930(4), c=1.5117(4) nm; α=114.74(2)°,β=101.82(2)°,γ=95.85(2)°; Z=1。
标题化合物为四羧基桥的双核铜(II)簇合物, DMF占据端基位置。Cu-Cu距离0.2635(2) nm, 有微弱成键作用。SCC-EHMO计算表明前线轨道38A_g, 37B_u, 21A_u和20B_g能级相当接近, 化合物为顺磁性, μ(eff)=1.82B.M., 根据顺磁谱出现的由三组峰组成的一套谱, 其中在低场的一组峰分裂7条超精细结构峰, 判断化合物顺磁性应是占据38A_g, 和37B_u分子轨道上未配对电子的贡献。Cu-Cu的成键和反键的σ, π和δ型轨道都填满电子, 因此对成键不起作用。Cu-Cu之间的微弱成键作用, 主要是通过铜与羧基桥原子形成的非定域键的34B_u和18A_u分子轨道的贡献。

本文用XPS、DTA、和TG分析了解四苯基铁卟啉和四苯基铁卟啉化学修饰电极的热分解行为。由XPS谱图揭示了玻璃炭与四苯基铁卟啉之间的相互作用, 进而阐述了经热处理的四苯基铁卟啉化学修饰电极的表面结构与电催化稳定性的关系。从四苯基铁卟啉化学修饰电极的XPS价态谱发现Fe中心离子的3d电子在电极的电催化活性中的作用。

制备了几种负载型的钯加氢催化剂, 考察了它们对环戊二烯加氢反应动力学行为的影响。环戊二烯对环戊烯的加氢有抑制作用, 抑制作用的主要原因是环戊二烯的配位能力远大于环戊烯, 催化剂的载体通过其配体效应可以影响两者配位能力之比(K_D/K_E)和反应速度常数之比(k_2/k_4), 从而改变催化剂的选择性和活性。

研究了非流动条件下搅拌对B-Z振荡反应的影响。实验发现即使在氮气保护下, 搅拌仍对振荡行为(振幅和周期等)有明显影响。为解释搅拌的影响作用, 对B-Z反应的Oregonator模型作了修正和补充并依据非平衡态热力学的一般原理将搅拌影响唯象地归结为反应速率常数的相对变化。修正后的模型不仅较好地克服了原模型存在的一些问题, 而且在引入搅拌作用以后得到了与实验现象定性一致的数值模拟结果。

本文采用以EHMO为基础的紧束缚近似方法计算了同分异构复合物1-N-Mci TCNQ_2和2-N-Mci TCNQ_2的能带结构。通过计算谐振稳定能估算复合物中TCNQ的电荷。计算结果表明, 复合物晶体中的给体N-Mci对一维能带的前沿轨道无影响。1-N-Mci和2-N-Mci的几何形状不同, 在晶体堆积能量上影响TCNQ的排列, 使两个复合物的TCNQ堆积方式不同, 能带结构也就不一样了。1-N-Mci TCNQ_2复合物的TCNQ之间π-π轨道迭合较好, 能隙小。LU带色散大, LU轨道上的电子为末充满状态(δ≈1.77), 具有较好的导电性能。2-N-Mci TCNQ_2复合物中TCNQ二聚体之间π-π轨道重叠不好, 能隙大, LU带宽很窄, LU轨道上电子为半充满状态(δ≈1.0), 易于形成磁绝缘体, 其导电性比1-N-Mci TCNQ_2差, 这与实验结果是一致的。

本文利用分子力学计算从理论上估算了酸性有机磷化合物萃取金属离子反应中取代基的空间效应。二烷基磷(膦)酸叔丁酯(Ⅱ)作为萃合物分子的近似模型结构。计算结果表明, 羟基氧在自由萃取剂Ⅰ和Ⅱ中的局部空间张力能之差与烷基的结构有密切的关系, 可近似地用来作为烷基空间效应的量度(E_(s,ex))。并用于一系列有机磷(膦)酸萃取Ni、Co为稀土的多元回归分析。结果表明, E_(s,ex)基本上反映了该萃取过程中的空间效应。

在260～380 K范围内, 用DSC法研究液晶HpBAB的相变。实验查明HpBAB在室温还以玻璃性晶体状态存在。它的玻璃转变、熔化和清亮过程的热力学参数准确地被测到。提出对-正烷氧基亚苄基-对-氨基苯腈同系列中熔化熵和烷基碳原子数的线性关系; 改进Aranow统计模型并估算直线斜率为Rln(3/g)(1

本文研究了TEA CO_2激光诱导SF_6与单晶硅和金属钨的表面化学反应。实验结果表明这些反应的反应率与激光频率之间具有明显的依赖关系, 在频率为942.2 cm~(-1)处反应率呈极大值。对于SF_6-Si体系, 反应率与硅的不同晶面有关, 在相同条件下Si(100)面与SF_6的反应率大于Si(111)面。对于SF_6-W体系, 测定了激光能量密度和脉冲辐照次数与反应率之间的关系, 其反应阈值为1 Jcm~(-2), 并测得该反应的速率与SF_6分压呈一级反应关系。同时, 还讨论了上述反应的机理, 认为气态振动受激的六氟化硫分子与被激光激活的固相表面之间的相互作用是反应的主要过程。

研究Li_2SO_4-EtOH-H_2O体系25 ℃气液平衡及液相的粘度和密度。湿渣法确定平衡固相在整个浓度范围内均为Li_2SO_4·H_2O。用经验公式ln(y/y_0)=K_1x+K_2x~2+K_2x~3对体系的溶解度和密度数据进行关联。硫酸锂加入到液相后由于盐离子静电作用对乙醇-水体系粘度的影响。按Jaques的假二元体系模型, 用WILSON, NRTL方程关联气液平衡数据。

本文提出了一种测定晶体结构位相的系统试差法。它是根据未知反射和已知反射间的相互关系, 按照概率上可测的条件, 把它们划分为可测系统, 并在Sayre公式的基础上建立可测系统的位相超解方程, 再以试差法求解, 从整体上求得未知反射的位相。该方法的特点是可以控制误差和单解。它不仅适用于一般中小分子结构的测定, 也可能为难解结构和大分子结构测定开辟一条新的途径。

本文通过质量作用定律导出的离子交换吸附等温式, 可概括经验的、半经验的Gapon公式、Sips公式、Langmuir公式和Freundlich公式。采用交换吸附是动力学的控制步骤, 可导出交换动力学公式。该式得到海水提铀实验的验证; 且可解释用于证明“颗粒内扩散或液膜扩散机理”的实验数据; 也可解释“颗粒内扩散和液膜扩散联合控制”的实验数据。此外, 本文还讨论了钛胶海水提铀的机理, 为平衡吸铀量的计算提供了理论和方法。

The morphology, size distribution and crystallography of supported nickel on ZSM-5 zeolites have been studied by electron microscopy. The obtained results are in agree with that given by X-ray diffraction. It was shown by bright and dark field microscopy, selected area diffraction that nickel particles aggregate as approximately spherical in shape having normal crystal structure of the bulk metal (f.e.c.) on the surface of carriers.
Some of the factors which have been found to affect the size distribution and the stability of the metal particles are: the type of support, the content of nickel, and the preparation method. etc.
For the impregnation type sample, the...

This paper presented the Mid-IR photoacoustic spectra of polyphenylene sulfide (PPS) which was first measured by us and the group theoretical analyses. By treating the chemical unit, C_6H_4S_2, as the characteristic unit for PPS chains, the group classifications and the normal mode constructions by the internal coordinates and projection operator technique were carried out successfully, also, the correlation analysis between PPS and benzene moleeule was performed to further aid the spectral assignments. This work was the basis upon which further studies of the PPS composites may proceed.

Using a precision static oxygen-bomb calorimeter, the standard energies of combustion at 298.15K of tetra-(p-nitrophenyl)-porphyrin, tetra-(3-pyridinyl)porphyrin were determined to be -27.412±0.012, -32.749±0.011 kJg~(-1), and the corresponding standard enthalpies of formation at 298.15 K were calculated to be 751.0±11.0, 811.8±8.6 kJ mol~(-1), respectively. The uncertainties of the results are given as twice of the final over-all standard deviation of the main.

The adsorption properties of molecules with different polarizabilities, benzene, cyclohexane, n-hexane and water, on aluminophosphate molecular sieve AlPO_4-11 have been investigated by gravimetric method, and compared with those on zeolites NaX and ZSM-5 having high Si/Al ratio.
From adsorption data we have calculated the isosteric heat of adsorption and the differential molar adsorption work and entropy of benzene and cyclohexane on AlPO_4-11. The adsorption isotherms can be described by the theory of volume filling of micropores. The results show that the heat of adsorption of hydrocarbons on AlPO_4-11 mainly depends on the surface energy of dispersion.
AIPO_4-11 favourably...

The characteristics of Mg electrodeposition on Pt in DMF have been investigated by means of cyclic voltammetry and rotating ring-disk electrode technique, The current-potential curves of Mg electrodeposition indicate that this electro deposition process is irreversible. The order of reaction for Mg~(2+) was found to beunity. A rate constant k of 10~(-7) cm s~(-1) was obtained for this electrodeposition process.

For non-centrosymmetric crystal structures, it is usually uses as many specila refletions as possible to define origin and enantiamorph. But in some cases, special reflections may be not enough or may be not in good quality to specify origin and enantiamorph so questions about specifying origin and enantiamorph with general reflections are discussed in this paper. Origin definition reflections of any space groups are differentiated into absolute freedoms and relative freedoms so that the problem of assigning values to the general refection phases for specifying origin is able to be solved. The concept of freedom is also used in enantiamorph specification. Two cases about enantiamorph specification relection related to or not related to origin definition refections are disecussed respectively. In both cases enantiamorph specification can be realized through two steps: (1) Chosing the signs of a certain number of structurral invariants (2) On the basis of step one, making restrictins to the amplitudes and phase signs of the invariant's component reflections.

The stable superconducting phase with T_c 110 K has been prepared in samples of nominal composition (Bi_(2-x)Pb_x)Sr_2Ca_2Cu_3O_y and (Bi_(2-x)Pb_x)Sr_2Ca_3Cu_5O_y x=0.2, 0.4, 0.6. The crystal strucuure of the superconducting phase (Bi_1.8Pb_0.2)Sr_2Ca_2Cu_3O_y with T_c 106.3 K has been determined in the sample of nominal composition (Bi_1.8Pb_0.2)Sr_2Ca_3Cu_5O_y. It is a nine decker perovskite arrangement by incorporating two extra layers CaCuO_2 in each cell of Bi_2Ca_1Cu_2O_y. The plane of CuO_2 is planar in incorporating layer CaCuO_2. Speace group D~1_(2h)-Pmmm was assigned. Adding Pb is in Bi site, and atomic radius and atomic valence in Bi site was modified, so that it is able to stabilize crystal structure and progress superconducting properties.

本文以2,3,5,6-四甲基亚硝基苯(ND)和苯亚甲基叔丁基氮氧化物(PBN)作自由基捕捉剂研究了甲苯基重氮盐及共冠醚络合物光解的自由基历程。ESR结果表明光解可产生相应的甲苯基自由基,并能被ND或PBN所捕获。由共ESR谱可得到甲基取代苯环上的甲基质子通过超共轭作用产生的超精细裂分,共裂分值与苯环上相同位置质子与未偶电子间极化偶合作用引起的裂分值相近。即:α_(p-)~H≈α_(P-)~(CH):α_(o-)~H≈α_(o-)~(CH)3;α_(m-)~H≈α_(m-)~(CH)3.同时还存在下列关系式:α_(p-)~H≈α_(o-)~H>α_(m-)~H.

用单晶X射线衍射分析方法测得1,4-二苯氧基苯(Ⅰ)和1,4-双(4-甲氧基苯氧基)苯(Ⅱ)的晶体结构。它们的晶胞参数分别为:(Ⅰ)α=5.876(2),b=7.832(2),c=1.5455(6)nm, β=95.33(3)°;空间群为P2_1/c,Z=2。(Ⅱ)α=6.017(1),b=7.577(1),c=3.6404(5)nm;空间群为Pcab,Z=4.(Ⅰ),(Ⅱ)的分子构象、键长和键角数据表明氧桥两边的苯环的共轭极化效应不能贯通,而苯氧基只是分子中的一个独立片断。从而也阐明了此类聚苯醚体系的电子吸收光谱的同系直线斜率小的原因。

本文在298K-493K温度范围内,测定了二甲苯在ZSM-5分子筛中的吸附等温线和扩散系数。间二甲苯在HZSM-5分子筛中的吸附是需要较高活化能而为扩散控制的物理吸附,只有在较高温度下(>393K),才能进入分子筛的敛孔,其扩散系数比对二甲苯小三个数量级。对、间二甲苯在HZSM-5分子筛中的吸附量随温度升高而渐趋接近。但HZSM-5经镁改性后,间二甲苯吸附量大幅度下降,而对二甲苯吸附量变化不大,说明孔道结构因素对提高烷基苯转化的对位选择性起着相当重要的作用。增大分子筛的晶粒尺寸,二甲苯的扩散系数变化不大,表明大晶粒ZSM-5之所以能提高对位选择性,原因在于扩散路线的增长导致扩散较慢的间二甲苯异构化为扩散较快的对二甲苯。

循环伏安法研究表明2,2′-联吡啶催化Co(Ⅱ)通过水/硝基苯界面的相转移伴有化学反应发生。水相或有机相的伴随化学反应直接影响Co(Ⅱ)与2,2′-联吡啶逐级配合物的相转移的循环伏安行为,并观察到类似于金属电极/电解质溶液界面出现的不可逆渡,不同的配合物,相转移机制不同。

对包含中间化台物的二元系,若相图中液相线已测定,而化合物的生成熵或生成焓已知,且液相的过剩熵也被测定(或者可以假设为零),那么体系液相的热力学性质可以精确地计算出来。本文给出了包含中间化合物体系的相图与热力学性质间的关系;这一关系表明:大多致情况下,已知以下五个量中的任意三个,可将其它两个计算出来。这五个量是:相图中的液相线,中间化合物的生成焓及生成熵,液相的混合焓及混合熵。

用气液色谱法测量了在不同温度下C_1～C_4醇类的各种异构物在C_(16)～C_(23)正构烷烃、角鲨烷,和角鲨烯中的无限稀活度系数γ_i,偏摩尔过量焓、偏摩尔过量熵。在各种溶剂中γ_i、均大于1,在同一溶剂中γ_i依下列次序减小: 甲醇>乙醇>正丙醇>正丁醇; 正丙醇>异丙醇; 正丙醇>异丁醇>仲丁醇>叔丁醇同一种醇在角鲨烯中的γ_i较在角鲨烷中为低。异构醇类的低于正构醇类。所测的有随的增加而增加的趋势。

用Kretschmer-Wiebe模型结合Hildebrand-Scatchard公式处理含醇体系的活度系γ_i,得到醇类的自身缔合平衡常数K_A和氢键生成焓h_A。在烷烃溶剂中,K_A与烷烃的碳原子数关系不显著。在同一溶剂中,K_A依下列顺序减小: 甲醇>乙醇>正丙醇>正丁醇; 正丙醇>异丙醇; 正丁醇>异丁醇>仲丁醇>叔丁醇。所测醇类的h_A的平均值为:k_A=-24.3±0.6kJmol~(-1),与醇类的碳原子数及异构关系不显著计算出醇类-角鲨烯体系偏离Hildebrand-Scatchard公式的相互作用常数l_(AB),l_(AB)均为负值,|l_(AB)|依下列顺序减小: 甲醇>乙醇>正丙醇>正丁醇; 正丙醇>异丙醇; 正丁醇>异丁醇>仲丁醇>叔丁醇

本文借助于DTA与X射线结构分析研究了PrCl_3-BaCl_2-LiCl三元体系相同。发现本体系内有对应于PrCl_2、α-BaCl_2、β-BaCl_2、LiCl和Ba_2PrCl_3的五个液相面、六条二次结晶线、一个三元低共熔点E(72.1wt%PrCl_3,2.8wt%BaCl_2,25.1wt%LiCl;441℃)和三元转熔点P(62.5wt%PrCl_3,12.5wt%BaCl_2,25.0wt%LiCi;490℃)。同时发现有一固相下形成的不稳定化合物Y(430℃分解)。

本文用酸碱滴定和红外光谱等方法对新型多孔材料——高稳定性层柱粘土分子筛(简称AlR)的表面酸性,催化活性和选择性进行了测定和研究,发现AlR的催化特性与HY和U8Y沸石有明显差别。根据实验研究,可以推测,AlR这种新型催化剂材料适用于有效酸强度较弱的大分子酸催化反应。

测定了25℃时活性炭自水溶液中吸附五种聚乙二醇(PEG)、一种聚丙二醇(PPG)和三种环氧乙烷(EO)-环氧丙烷(PO)嵌段共聚物的吸附等温线。结果表明,各等温线均为Langmuir型的,且在较低浓度时即可达极限吸附。当以g.g~(-1)表示吸附量时,各聚合物的极限吸附量相近。对于PEG系列和EO-PO嵌段共聚物系列,极限吸附时每个分子占据的面积与分子中所含EO数的关系为两条斜率相同的直线。由直线斜率和后一直线的截距可求得每个EO和PO所占的面积分别为26和2.9 nm~2。这些结果支持了分子以其EO和PO链节都平躺在表面上的吸附模型。

本文计算了Brusselator及Oregonator的Lyapunov指数随系统控制参量的变化,依据Lyapunov指数的稳定性理论,确定出上述两模型都是通过Hopf分岔产生极限环的。在Brusselator分岔行为上,Lyapunov指数理论与线性稳定性分析所得的结论是一致的。对Oregonator所代表的化学背景作了分析,指出影响B-Z反应发生分岔的主要因素是Br~-的再生能力与速度。

与机械混合法相比,用KOH水溶液浸渍法制成的K_2O-Fe_2O_3催化剂性能较佳。负载型多元催化剂的性能与C-64I相近。SEM、XPS和EDAX证实,经使用后,上述负载型多元催化剂表面形态明显改变,表面铁/钾原子比上升。连续升温XRD证实,在乙苯脱氢通常所采用的温度区间,载于表面的KOH会迅速和氧化铁相互作用生成K_2Fe_2O_4。本文认为K_3Fe_2O_4可能是活性相并据此对实验结果作出较为合理的解释。

本文利用ESR技术详细研究了室温至150℃范围内CuTAPP在碳表面的行为。提出了铜卟啉在碳表面吸附水膜中的二维扩散机理。对较高温度处理后铜卟啉的ESR也作了简要报道。

本文使用EXAFS方法研究NiO在γ-Al_2O_3的表面上的分散情况。文章讨论了Ni含量为7%、13%、18%、26%、35%的NiO/γ-Al_2O_3体系的径向结构函数图以及Ni含量为13%、26%的NiO/α-Al_2O_3样品的径向结构函数图,认为NiO能在γ-Al_2O_3表面上成单层分散。分散后的Ni-O距离接近NiO晶体的Ni-O距离,表明Ni离子和γ-Al_2O_3表面上的氧有很强的相互作用。

本文应用闪光光解共振荧光技术测量了OH自由基和乙二氧基甲烷气相反应的绝对速率常数,k=(1.68±0.16)×10~(-11)cm~3 molecule~(-1)s~(-1),统计分析求得误差为2σ。实验时系统总压力为25—50Torr(以Ar为稀释气体)。我们曾根据正烷基单醚的动力学测量结果来计算CH_3和CH_2的反应活性值。现发现此活性值此正烷烃对应值约大2倍,但能够精确地估算OH自由基与二乙氧基甲烷气相反应的速率常数。而且表明烷基链中次甲基的位置及数目对其反应活性贡献甚小。

The variation of preoscillatory time and period with initial concentration of every substance in the phenol-BrO_3~--H_2SO_4 batch system has been studied. It is found that the oscillating behavior of the system is very strange: First, the period of the oscillation increases with time, as usual oscillations, then decreases with time in some ranges of concentration. This oscillation is called “period-doublemontonous” oscillation. The phenomena arc first published. The electrode potential of the system exalts likelycatatropy with the concentration of phenol. For BrO~-_3 and H_2SO_4 this phenomenon cannot emerge. This oscillation cannot be explained with FKN or OKN mechanism. Some details will be submitted later.