从PCB和IC设计领域管理信号完整性

如果你考察我们试图用来获得应力模型或者类似模型的那些“邦迪”式(凑合)的方法,就会发现它可做不到有章可循。这就是为什么我们要花费更多的精力来试图确定需要何种模型,并判断哪种模型将为人们所接受。有待解决的最大的一个问题是,是否继续对器件的曲线来作假设,或者设法从一个确定性光刻的角度来推进问题的解决。EDA行业现在不再对模型采取消极的态度。现在,如果我们得不到所需要的东西,我们的过错将与模型的提供者一样严重。在研究90nm技术并迈向65nm节点的过程中,会出现两个层次上的信号完整性问题。在第一个层面上,你必须在数字域…     

从花生壳中提取天然抗氧化成分的研究

介绍了从花生壳中提取天然抗氧化成分的方法，讨论了溶剂、时间、温度、酸度、固液比等因素对提取效果的影响。结果表明，花生壳的乙醇提取物具有较强的抗氧化性。     

An evaluation of the effects of various parameter weights on typical meteorological years used for building energy simulation

In this paper, we evaluate the influence of different parameter weights in creating “typical year” weather data following the typical meteorological year (TMY) methodology, by studying two sets of 3600 alternate weather files created using different parameter weights for Beijing (China) and New York City (USA). A “typical year” weather file consists of twelve distinctive months, each considered typical for that month of the year. Such a typical month, named “typical meteorological month (TMM),” is commonly identified by using a certain combination of parameter weights, such as 4:4:4:12, for dry bulb temperature, dew point temperature, wind speed, and solar radiation as in the TMY weather files developed by US National Climate Data Center (NCDC), or 4:4:2:10 in the newer TMY2 and TMY3 weather files developed by National Renewable Energy Laboratory (NREL). In this study, we investigate the influence of varying the parameter weights on the TMMs and the resultant new TMY weather files (nTMY). We found that the distribution of new 3600 TMMs tend to cluster within one or a few years for each month, and that the probabilities are very high for significant overlap between the new TMMs and the original TMMs chosen using the TMY/TMY2 weighting. Compared to the TMM data in TMY, the deviations of air temperatures and solar radiation values of the new TMMs and nTMYs derived from the 20-year weather data are less than 10% for both Beijing and New York. This confirms that the creation of “typical year” weather data is not very sensitive to the weighting of the different weather parameters, and that most nTMYs created and evaluated in this study are empirically close to the TMY data intended for use of simulating building energy consumption.     

Participating in Health Issue‐Specific Social Networking Sites to Quit Smoking: How Does Online Social Interconnectedness Influence Smoking Cessation Self‐Efficacy?

This study examined members of health issue-specific social networking sites (SNSs) for smoking cessation, hypothesizing that social identification, bridging and bonding social capital, perceived subjective norms, and social support would impact the relationship between participation and smoking cessation self‐efficacy. Results (N = 252) of an online questionnaire revealed that participation significantly influenced each social factor, which in turn resulted in greater smoking cessation self-efficacy. By applying and extending traditional peer influence theories, a structural model predicting 5 underlying mechanisms of social interconnectedness that influence perceived behavioral control for quitting smoking was tested and supported. Implications for future research on health issue-specific SNSs are discussed.     

Activity and Tissue Expression of Tyrosine Phosphatase PTP-MEG2

Protein tyrosine phosphatases(PTPs) are crucial regulators of signal transduction. Among them,PTP-MEG2 is an intracellular enzyme of 593 amino acid residues with a putative lipid-binding domain at the N-terminus. In the present study, we cloned the full-length form of the enzyme and expressed it in E. coli cells as a 6xHis-tagged protein. The majority of the expressed enzyme was found in the inclusion body of E. coli cell extracts.Upon extraction with a buffer containing urea, the recombinant enzyme was purified to near homogeneity on a single Ni-NTA-agarose column. This procedure resulted in the production of over 100 mg of purified recombinant PTP-MEG2 from 1 L E. coli cell culture. The purified protein displayed a single polypeptide band with expected molecular size on SDS-polyacrylamide gel electrophoresis under reducing conditions. Isolated under denatured conditions in urea, the purified enzyme was re-natured by dialyzing against a refolding buffer. The re-natured enzyme effectively dephosphorylated the common PTP substrate para-nitrophenylphosphate with a specific activity of 2000units/mg. Meanwhile, the denatured enzyme was used to immunize a rabbit to produce antibodies. The resulting antiserum had extremely high sensitivity and specificity. When used for Western blot analysis, the anti-serum revealed a wide expression of PTP-MEG2 in many tissues of mice. Together, we developed a highly effective way to purify a large amount of PTP-MEG2 and generated highly sensitive antibodies that can specifically detect endogenous expression of the enzyme in tissues.