流动注射-氢化物-石墨炉原子吸收光谱法应用研究 Ⅲ.痕量锗的测定

本文采用自制的氢化物-石墨炉自动进样器及流动注射仪,直接测定了一些环境试样中的痕量锗,并研究了测定条件。该方法灵敏度高,线性范围宽,操作简单,速度快,耗样量少。特征质量:5.7 pg/0.0044A;检出限:1.3 pg;测定速度:30个样/h;回收率:99.5％～104％。     

Preparation of 2-phospholene derivatives from zirconacyclopentenes

Zirconacyclopentenes, which are easily prepared from alkynes, alkenes, and zirconocene compounds, reacted with dichlorophenylphosphine to give 2-phospholene in high yields. The reaction was performed conveniently in one-pot from an alkyne, alkene, dichlorophosphine, and zirconocene compounds.     

Nucleophilic addition to 3‐methyl‐1‐(4‐nitrophenyl)‐2‐phenyl‐4,5‐dihydroimidazolium iodide

Reactions of the 1,2‐diaryl 4,5‐dihydroimidazolium, represented by 3‐methyl‐1‐(4‐nitrophenyl)‐2‐phenyl‐4,5‐dihydroimidazolium iodide 1 , with ethylenediamine afforded a benzylidyne unit transferred product, 2‐phenyl‐2‐imidazoline 2 ; a ring‐opened adduct 4 was produced when excess ethylenediamine was used. Reactions of 1 with hydroxylamine, malononitrile, and nitromethane anions produced ring‐opened products, 5 , 7 , and 8 respectively.     

神光Ⅲ原型黑腔物理实验研究

总结了在神光Ⅲ原型激光装置上开展的一系列黑腔物理实验研究,从多个方面研究了黑腔内部等离子体状态和辐射场特性。用真空黑腔能量学研究获得了散射光、辐射温度和不同能段辐射流份额的定标规律,从能量学角度梳理和分析了整个激光黑腔相互作用过程。通过对黑腔中充入低密度低Z气体抑制了腔壁等离子体运动,明显减少了可能造成靶丸预热的金M带辐射流(1.6~4.4keV)份额。针对黑腔内部不同区域等离子体,研究了光斑区等离子体的运动,分析了其与电子热传导限流因子的关系;研究了冕区等离子体的运动,分析了不同充气等离子体条件对其的影响;在同一发次实验中同时测量了光斑区与再发射区的辐射流比值。     

A novel FRET approach for in situ investigation of cellulase–cellulose interaction

A novel real-time in situ detection method for the investigation of cellulase–cellulose interactions based on fluorescence resonance energy transfer (FRET) has been developed. FRET has been widely used in biological and biophysical fields for studies related to proteins, nucleic acids, and small biological molecules. Here, we report the efficient labeling of carboxymethyl cellulose (CMC) with donor dye 5-(aminomethyl)fluorescein and its use as a donor in a FRET assay together with an Alexa Fluor 594 (AF594, acceptor)–cellulase conjugate as acceptor. This methodology was successfully employed to investigate the temperature dependency of cellulase binding to cellulose at a molecular level by monitoring the fluorescence emission change of donor (or acceptor) in a homogeneous liquid environment. It also provides a sound base for ongoing cellulase–cellulose study using cellulosic fiber.     

无粘结后张法预应力框架梁施工技术

介绍了在大跨度钢筋混凝土结构体系中采用无粘结预应力技术完成框架 梁的具体施工做法。     

合金凝固过程中等轴枝晶生长的数学模型

在枝晶晶粒的尺度上，从同时满足溶质守恒与热平衡的原则出发，提出了合金凝固过程中等轴枝晶生长的数学模型。该模型由４个相互联系的微分方程组成，可通过计算机求解，为模拟枝晶合金凝固组织的形成过程奠定了初步基础。     

Improvement of the WENO scheme smoothness estimator

This paper has analyzed the weights of the fifth‐order weighted essentially nonoscillatory scheme suggested by Jiang and Shu and a modified smoothness estimator is suggested to improve the accuracy. Using a function of the minimum and maximum of the original smoothness estimators, the new smoothness estimators have smaller variation among them than the original ones in smooth regions. Hence, as the new weights are closer to the optimal weights, the numerical accuracy is improved. Several numerical experiments are presented to demonstrate the accuracy and robustness of the new scheme. Copyright © 2009 John Wiley & Sons, Ltd.     

关于京津冀产业优化调整的思考

运用C-D生产函数的生产率测定方法,对京津冀各行业的单要素、全要素生产率进行测定分析,着重分析了高耗能产业和装备制造业。结果表明,河北省的整体工业效率应进一步提高,注重节能减排,并将工作重点从高耗能产业向装备制造业转化;北京应转移绝大多数工业产业,着力发展高端服务业,进一步推进产业结构的优化升级;天津应向打造低碳产业链的方向推进。     

Cruciform pi-systems: hybrid phenylene-ethynylene/phenylene-vinylene oligomers

The cruciform pentamers 3a-g were synthesized by a combined Horner-Sonogashira approach; their band gaps vary significantly with emission varying from blue to red depending upon their substituent pattern.