PC／PBT共混体系的研究：Ⅰ.PC,PBT熔融共混时的酯交换反应

采用红外光谱、核磁共振等测试手段，系统地研究了ＰＣ、ＰＢＴ熔融共混时的酯交换反应，发现ＰＢＴ中残余的Ｔｉ催化剂会对酯交换反应起催化作用。通过加入能和Ｔｉ催化剂络合添加剂，可以控制酯交换程度，这为控制ＰＣ／ＰＢＴ合金的性能提供了一个非常有效的方法。     

Long-range dispersion coefficients for like centrosymmetric linear molecules and an application to H2-H2

The real spherical tensor theory of long-range intermolecular coefficients developed in previous papers is applied to derive explicit formulae for the first three dispersion coefficients for like centrosymmetric linear molecules. The expansion of angle-dependent coefficients in associated Legendre polynomials allows one to identify the isotropic and anisotropic components of the dispersion interaction in terms of London dispersion constants, the treatment of higher coefficients being simplified by the coupling of the elementary (l, l′)-polarizations to resultant angular momenta L_A and L_B onto each molecule. The contributions from all coupling schemes are given explicitly for C₆, C₈, C₁₀, and numerical results are presented for H₂-H₂ using two-term reduced spectra values from the Kaiserlautern group.     

Solar-Driven Artificial Carbon Cycle

Constituting the artificial carbon cycle,for example,through recycling CO₂ and converting CH₄ to value-added fuels and chemicals with solar energy,offers a sustainable future for humankind to tackle the global environmental issues and energy crisis.However,significant bottlenecks remain in such photocatalytic conversion,mainly related to the reaction activity and product selectivity.Herein,we share our efforts and systematic research progress on addressing the double bottlenecks for achieving solar-driven artificial carbon cycle,with specifically focusing on the photocatalytic CO₂ and CH₄ conversion.We further elucidate the common fundamentals behind various designed photocatalytic materials systems.Toward future development,we highlight the opportunities and challenges in the research field.     

高温固相法合成LiNi1/3Mn1/3Co1/3O2及其性能研究

采用高温固相法合成出层状锂离子电池正极材料LiNi_1/3Mn_1/3Co_1/3O₂。通过XRD、ICP、SEM和电化学测试手段对产物的结构、组成、形貌及电化学性能进行了研究。XRD结果表明此方法合成的LiNi_1/3Mn_1/3Co_1/3O₂具有标准的α-NaFeO₂型层状结构，SEM照片显示颗粒粒径大约在500 nm左右，粒径分布较窄。以20 mA·g^-1电流密度放电，充放电电压在2.8～4.4 V之间，其首次放电比容量为170 mAh·g^-1，40次循环容量保持率为85.3%。进一步加入石墨导电剂后，同样条件下首次放电比容量变为179 mAh·g^-1，50次循环容量保持率为89.6%。容量衰减主要发生在前10次循环。XRD和SEM测试表明循环初期容量衰减的原因是由材料本体结构变化和界面反应共同作用的结果。     

X-射线荧光光谱法测定钛铁中的硅、锰、磷、铝

介绍用X-射线荧光光谱仪测定钛铁中Si、Mn、P、Al含量的方法,通过试验确定了合适的研磨时间、压力和保压时间,用压片法制样,建立了各元素的工作曲线,各元素的测定范围分别为Si3.00%～6.00%,Mn1.00%～3.00%,P0.030%～0.070%,Al5.00%～9.00%。通过强度测量得到测定Si、Mn、P、Al的相对标准偏差分别为0.074%、0.308%、0.383%、0.040%,精密度满足测试要求。将该方法测定结果与化学法比对,准确度满足国家标准方法分析误差的要求。     

Photodissociation of Cycloketones by Ultraintense Femtosecond Laser Pulses

ThestudyofphotoionizationandphotodissociationprocessesinducedbyintensefemtosecondlaserpuIses(>lo"W/cm')withpolyatomicmoleculesbecomesofinterestbecausesomenewphenomenahavebeenobserved'-3.Sofar,mostoftheinvestigationsfocusontheexperimentalexplorationofphotoionizationprocesses'-'.Butthephotoionizationmechanismofpolyatomicmoleculesinanintensefslaserfieldisstillambiguous'.,.Incontrasttothephotoionizationprocesses,theunderstandingoffragmentationofmolecularionisevenpoorer.Corkumetal,'.,'reportedthef…     

Reducing a chemical master equation by invariant manifold methods

We study methods for reducing chemical master equations using the Michaelis-Menten mechanism as an example. The master equation consists of a set of linear ordinary differential equations whose variables are probabilities that the realizable states exist. For a master equation with s(0) initial substrate molecules and e(0) initial enzyme molecules, the manifold can be parametrized by s(0) of the probability variables. Fraser's functional iteration method is found to be difficult to use for master equations of high dimension. Building on the insights gained from Fraser's method, techniques are developed to produce s(0)-dimensional manifolds of larger systems directly from the eigenvectors. We also develop a simple, but surprisingly effective way to generate initial conditions for the reduced models.     

Synthesis,structure and DNA-binding studies on the 2-(3-chlorophenyl)imidazo[4,5-f]1,10-phenanthroline-bis(2,2′-bipy ridine)-ruthenium(II) complex

A new polypyridyl ligand, MCP {MCP = 2-(3-chlorophenyl)imidazo[4,5-f]1,10-phenanthroline} and its ruthenium(II) complex, [Ru(bpy)2(MCP)](ClO4)2· 0.5MeCN (bpy = 2,2-bipyridine), have been synthesized and characterized. The structure of the complex was determined by single crystal X-ray diffraction techniques. The MCP ligand is essentially planar and the stacking interactions between the ligands were observed in the crystal. [Ru(bpy)2(MCP)]2+ can strongly bind to Calf thymus DNA through intercalation of MCP ligand. The Cl substitute group has no significant effect on the spectral properties and DNA-binding behaviour of the complex.     

排序集抽样下Inverse Rayleigh分布的Fisher信息量及其在参数估计中的应用

文章分别在简单随机抽样和排序集抽样下研究了Inverse Rayleigh分布中对应样本所含刻度参数θ的Fisher信息量.数值结果表示,同等样本容量的排序集样本比简单随机样本提供更多关于θ的信息.接着分别基于简单随机样本和排序集样本构造了θ的一些优良估计,并对估计结果进行了数值比较.