半胱氨酸亚金铵的合成、理化性质及电镀金应用

以半胱氨酸为配体合成一种新型亚金配合物NH4Au(Cys)2,对该配合物进行元素分析、红外光谱、紫外光谱、热失重分析和导电性测量等理化性质研究;以该亚金配合物为金源开展相关的电镀金工艺探索,并通过四因素三水平的正交试验获得其最佳条件参数;采用扫描电子显微镜(SEM)和X线衍射(XRD)对镀金层的表面质量进行探讨。研究结果表明:该目标产物的分子式为NH4Au(Cys)2·2H2O,该配合物中以半胱氨酸的巯基和金配位为成健特征,在170℃以下热稳定性较好,该亚金配合物是一个典型的离子化合物。在电流密度为200~300 A/m2,p H为10.5~12.0,温度为35~45℃,金质量浓度为15~25 g/L的电镀工艺条件下,得到粒度为0.5~1.0μm的单质金,且主要沿着(111)面进行生长。     

随机纳米碳管网络及其渗流性质

数值模拟了实验上构造纳米碳管网络的溶液沉积方法.与一般的随机网络模型不同,将碳管的长度计算在内,而且考虑了不同的空间相交位形.数值模拟发现网络的度分布为高斯分布,平均集聚系数约为0.11.当网络中碳管平均面密度取值在σ0=179 200根/cm2附近时,网络系综达到渗流.在临界点附近,网络的连通概率p、两极之间电导G、...     

Tetraspanin-enriched microdomains regulate digitation junctions

Tetraspanins co-emerged with multi-cellular organisms during evolution are typically localized at the cell–cell interface, and form tetraspanin-enriched microdomains (TEMs) by associating with each other and other membrane molecules. Tetraspanins affect various biological functions, but how tetraspanins engage in multi-faceted functions at the cellular level is largely unknown. When cells interact, the membrane microextrusions at the cell–cell interfaces form dynamic, digit-like structures between cells, which we term digitation junctions (DJs). We found that (1) tetraspanins CD9, CD81, and CD82 and (2) TEM-associated molecules integrin α3β1, CD44, EWI2/PGRL, and PI-4P are present in DJs of epithelial, endothelial, and cancer cells. Tetraspanins and their associated molecules also regulate the formation and development of DJs. Moreover, (1) actin cytoskeleton, RhoA, and actomyosin activities and (2) growth factor receptor-Src-MAP kinase signaling, but not PI-3 kinase, regulate DJs. Finally, we showed that DJs consist of various forms in different cells. Thus, DJs are common, interactive structures between cells, and likely affect cell adhesion, migration, and communication. TEMs probably modulate various cell functions through DJs. Our findings highlight that DJ morphogenesis reflects the transition between cell–matrix adhesion and cell–cell adhesion and involves both cell–cell and cell–matrix adhesion molecules.     

十六位微机教学实验系统分析与改进

本文在分析CCT－88／51／98教学实验系统监控程序的基础上，对该教学实验系统监控程序中存在的问题作出了一些改进。     

Energy input and response from prompt and early optical afterglow emission in gamma-ray bursts

The taxonomy of optical emission detected during the critical first few minutes after the onset of a gamma-ray burst (GRB) defines two broad classes: prompt optical emission correlated with prompt gamma-ray emission, and early optical afterglow emission uncorrelated with the gamma-ray emission. The standard theoretical interpretation attributes prompt emission to internal shocks in the ultra-relativistic outflow generated by the internal engine; early afterglow emission is attributed to shocks generated by interaction with the surrounding medium. Here we report on observations of a bright GRB that, for the first time, clearly show the temporal relationship and relative strength of the two optical components. The observations indicate that early afterglow emission can be understood as reverberation of the energy input measured by prompt emission. Measurements of the early afterglow reverberations therefore probe the structure of the environment around the burst, whereas the subsequent response to late-time impulsive energy releases reveals how earlier flaring episodes have altered the jet and environment parameters. Many GRBs are generated by the death of massive stars that were born and died before the Universe was ten per cent of its current age, so GRB afterglow reverberations provide clues about the environments around some of the first stars.     

用脸谱图对太子河本溪市区段河流沉积物中重金属污染进行评价的研究

本文将沉积学原理及国际上新发展的两种重金属污染评价方法与多变量的图表示法——脸谱图相结合,对太子河本溪市区段河道沉积物中重金属的污染状况及潜在生态危害进行了综合性的评价研究。从脸谱图上可以直观地看出各采样点重金属的污染情况和潜在生态危害程度。从研究结果可以看出,太子河本溪市区段河道沉积物中重金属的污染是很严重的。     

用模糊综合评判法评价变电所所址

变电所选址是电力系统规划的一个重要环节。但与变电所所址有关的因素错综复杂,很难仅凭经验就能确定最佳所址。本文采用模糊综合评判方法对备选所址进行评判,确定其优先次序。在模糊综合评判中,各因素的权重分配对结果起决定性作用,用层次分析法确定与所址密切相关的各个因素相对总体目标而言的权重,使得权重的确定更科学。算例表明该方法是可行的。