Strengthening molecular replacement with maximum likelihood in Beast

In molecular replacement we test a series of hypotheses about the position and/or orientation of molecules in the crystal. Likelihood is the natural score for hypothesis testing, and applications to experimental phasing and structure refinement have already demonstrated the value of likelihood in crystallography. A new likelihood function is required for rotation searches, because hypotheses about orientations leave the relative phases of structure factor contributions from symmetry-related molecules undefined. This function can also make good use of information from partial molecular replacement solutions. When multiple choices of model are available, multivariate statistics can be used to generate an ensemble average model, which is particularly powerful in solving structures with NMR models. The likelihood-based approach to molecular replacement will become even more powerful when the targets become more sophisticated, taking account of factors such as anisotropy of diffraction or the presence of non-crystallographic symmetry.     

大功率LED驱动电路研究设计

根据大功率LED的供能要求,从EMI滤波、功率因素校正、半桥谐振转换三个方面着手,以FAN6961和FSFR2100为控制芯片,设计了一款大功率的高效率LED驱动电路,在90～264VAC的线路输入和满载下,功率因数高于93%,效率高于85%,并具有低输入电流谐波失真和低EMI.     

CRITICAL STRESS INTENSITY FACTORS FOR CRACKED HOLLOW PIPES UNDER TRANSIENT THERMAL LOADS

Finite element analyses of a long hollow cylinder having an axisymmetric circumferential internal edge crack, subjected to convective cooling on the inner surface are performed. The transient thermal stress intensity factor is estimated using a domain version of the J-integral method. The effect of the thickness of the cylinder, crack length, and heat transfer coefficient on the stress intensity factor history are studied. The variations of critical normalized stress intensity factor with crack length-to-thickness ratio for different parameters are presented. The results show that if a small inner surface crack begins to grow, its stress intensity factor will increase with increase in crack length, reach a maximum, and then begin to drop. Based on the results, a fracture-based design methodology for cracked hollow pipes under transient thermal loads is discussed.     

Substitution possibilities and determinants of energy intensity for China

This paper measures technological change, factor demand and inter-factor and inter-fuel substitutability measures for China. We use individual fuel price data and a two-stage approach to estimate total factor cost functions and fuel share equations. Both inter-factor and inter-fuel substitution elasticities are calculated and the change in energy intensity is decomposed into its driving forces. The results suggest that energy is substitutable for capital regionally and for labor nationally. Capital substitutes for energy more easily than labor does. Energy intensity changes vary by region but the major drivers seem to be “budget effect” and the adoption of energy-intensive technologies, which might be embodied in high-level energy-using exports and sectors, capital investment and even old technique and equipment imports. Whether the trend in rising energy intensity continues will be significant for China and the rest of the world.     

基于因子分析的内蒙古各盟市文化产业发展的综合评价

文化产业是市场经济条件下繁荣发展社会主义文化的重要载体，也是推动产业结构调整、转变经济发展方式的重要着力点。选取8个反映文化产业发展的有代表性的指标．采用因子分析法．从文化建设投入因子和贡献因子两个方面对内蒙古12个盟市的文化产业进行对比分析，得出各盟市综合评价结果，进而有针对性地提出加快发展文化产业的相应对策。     

Psychometric equivalence of an improved Basic Language Morningness (BALM) Scale using industrial population within comparisons

An existing 13-item composite circadian rhythm ‘morningness’ scale was simplified into a ‘(BA)sic (L)anguage (M)orningness’ (BALM) scale at a seventh grade (12–13 years) reading level. It was given to 150 each of continuously rotating shiftworkers and fixed-schedule dayworkers in an industrial manufacturing plant. Multiple factor analyses confirmed three prior identified factors, morningness/effort, morning alert, and evening. Morningness scores for dayworkers were higher than for shiftworkers (p>000l). The BALM scale revision is suitable for most worker levels. A suggested psychometrically ‘purer’ 9-item morningness scale omits the inconsistent evening factor scale items.     

中国油菜单产增长要素贡献率分析

运用因子分析技术将影响中国油菜单产的众多因素综合为物质费用、劳动力、政策制度和结构与灾害四大因素,并利用Cobb-Douglas型生产函数模型分别测算了四大因素在中国油菜单产增长中的贡献率。根据1990～2004年间的数据计算,物质费用对中国油菜单产增长的贡献率最大,其次是劳动力和政策制度,而同期结构与灾害因子对单产有负向影响。     

基于强度折减法的边坡安全系数求解及精度影响因子分析

本文介绍了FLAC3D中强度折减法的基本原理和边坡安全系数求解的实现过程,基于实例分析,从剪胀角、抗拉强度、网格疏密程度及边界范围四个方面探讨了这些因素对FLAC3D强度折减法计算结果的影响,为FLAC3D边坡稳定性分析中强度指标的选择提供理论依据。     

铁碳微电解法处理水基切削废液

采用铁碳微电解法对水基切削废液进行处理,研究了不同因素对废液CODCr去除率的影响,并通过正交实验得出最佳的工艺处理条件：常温下,当铁碳投加量为0.6g/mL、铁碳质量比为1∶1、反应时间为150min、pH值为1时,水基切削废液CODCr去除率大于93%。