晶性3，4－聚异戊二烯的结构研究

采用ＷＡＸＤ、ＳＡＸＳ和Ｘ－射线平板照相法研究了不同聚合条件和拉伸倍数下的晶性３，４－聚异戊二烯的结构．结果发现，降低催化体系反应速度有利于产物结晶；不同的含氮类给电子试剂对聚合物的结晶结构影响较大．取向样品随着拉伸倍数的增加结晶度和长周期增大，微晶尺寸变小．ＳＡＸＳ的散射强度计算表明，该聚合物属多分散非均一粒子体系，微孔半径在３．５－１６．４ｎｍ间．     

Oscillation condition for a series piezoelectric sensor. Application to the determination of urease activity in plant seeds

The oscillating conditions for a series piezoelectric quartz crystal (SPQC) are proposed and verified experimentally. The influence of the cell constant and oscillator phase on the oscillational ability of the SPQC was investigated. It is shown that the SPQC possesses excellent oscillational ability in low or high conductivity solutions, but in solution of intermediate conductivity, the oscillational ability decreases with increasing oscillator phase or decreasing cell constant, sometimes resulting in a cease-to-oscillate zone. The SPQC was applied to determine the urease activity in plant seeds with a detection limit of 0.004 U ml⁻¹, based on the change in conductivity.     

Existence and uniqueness for nonlinear boundary value problems in kinetic theory

A boundary value problem for the stationary nonlinear Boltzmann equation in a slab has been examined in a weightedL space. It has been proved that the problem possesses a unique solution for boundary data small enough. The proof is based on the implicit function theorem. It has also been shown that for the linearized problem the Fredholm alternative applies.     

Gap exponents for percolation processes with triangle condition

A study is made of the gap exponents for percolation processes with the triangle condition in the subcritical region. It is show that the gaps are given by _t =2 fort=2, 3,. Scaling theory predicts thatP _p (¦C ₀¦S(p))–(p _c –p) andE _p (1/¦C ₀¦; ¦C ₀¦S(p))–(p _c –p)³, whereS(p) is the typical cluster size. It is found that (p _c –p)P _p (|C ₀S(p) ^1–)(p _c –p)^1–2 and (p _c –p)³E _p (1/|C ₀|;|C ₀|S(p) ^1–))(p _c –p)^3–4.     

Ce(IV) ion initiated graft polymerization of glycidylmethacrylate onto a demineralized bone matrix: effect of reaction parameters

Studies on chemical modification of demineralized bone matrix (DBM) have opened new arenas in the field of clinical orthopedics owing to its potential osteoinductivity with desired chemical functionality. To widen its usage to biomolecular delivery, graft polymerization of glycidylmethacrylate onto DBM was carried out by a free-radical initiating process using ceric ammonium nitrate as an initiator. The evidence of the grafting reaction was examined by chemical analysis using Fourier transform IR spectroscopy. The grafting condition was standardized by regulating the reaction parameters such as the concentrations of the backbone, the monomer and the initiator, the polymerization temperature and time. The optimum polymerization temperature and time to have the maximum grafting yield were 40 °C and 3 h, respectively. The percentage of grafting and the percentage of grafting efficiency were determined as a function of the reaction parameters, and both were found to increasing initially and thereafter decrease in most of the cases. The grafting results are discussed in a detailed fashion and a reaction mechanism is proposed.     

Mathematical Modeling of Multicomponent Nonisothermal Adsorption in Sorbent Particles Under Pressure Swing Conditions

A detailed model for nonisothermal sorption of multicomponent mixtures in a single sorbent particle (monodisperse or bidisperse with negligible intracrystalline mass transport limitations) under pressure swing conditions is developed in this study. The dusty-gas model is used to describe the coupling of the molar fluxes, the temperature, the partial pressures and the partial pressure gradients of the components in the pore space of the particle. The variations of the temperature are described by an energy equation in which both convective and conductive modes of heat transport are accounted for. No limitations are imposed on the number of the components in the mixture and on the type of the adsorption isotherm. The model is applied in the investigation of the industrially important air-zeolite 5A system. Two cases with respect to the surrounding gas phase are examined: infinite environment, which is representative for single particle experiments, and finite environment, which is representative for the situation in packed bed adsorbers. It is found that in an infinite environment the external and internal temperature gradients are equally important while in a finite environment the external heat transport limitations are negligible. It is concluded that in modeling the nonisothermal operation of adsorption processes occurring in packed beds it is not necessary to allow for the temperature differences between the gas phase and the surface of the adsorbing particles. Furthermore, if the temperature gradients within the particles can be neglected, only a single temperature equation is needed to describe the energy transport in the bed.     

Thec logc contribution to the electrolyte conductance and Onsager's reciprocal relation

The differential equations and the boundary conditions for the nonequilibrium binary distribution function of an unsymmetrical binary electrolyte are derived from the Ebeling-Falkenhagen continuity equation. The connection between the Onsager reciprocal relation and the binary distribution functions is shown. Further, Feistel's result for thec logc contribution to the conductance is extended to unsymmetrical binary electrolytes. The reason for the difference between Feistel's and Chen'sc logc term is explained, and the significance of Onsager's reciprocal relation for the calculation ofc logc and higher-concentration contributions of the conductance is discussed.     

D072型树脂脱除过氧化氢中金属阳离子的工艺研究

实验考察D072型阳离子交换树脂在交换柱中脱除过氧化氢中微量金属阳离子的动态行为．通过改变料液流速、高径比、料液中交换离子浓度及料液组成等参数，绘制不同条件下的透过曲线，以此考察D072型树脂对过氧化氢中金属阳离子的动态交换性能，从而确定适宜的工艺条件，为工业化生产提供科学依据．