Effects of AlN on the densification and mechanical properties of pressureless-sintered SiC ceramics

In the present work, Si C ceramics was fabricated with Al N using B_4 C and C as sintering aids by a solid-state pressureless-sintered method. The effects of Al N contents on the densification, mechanical properties, phase compositions, and microstructure evolutions of as-obtained Si C ceramics were thoroughly investigated. Al N was found to promote further densification of the Si C ceramics due to its evaporation over 1800 °C,transportation, and solidification in the pores resulted from Si C grain coarsening. The highest relative density of 99.65% was achieved for Si C sample with 15.0 wt% Al N by the pressureless-sintered method at 2130 °C for 1 h in Ar atmosphere. Furthermore, the fracture mechanism for Si C ceramics containing Al N tended to transfer from single transgranular fracture mode to both transgranular fracture and intergranular fracture modes when the sample with 30.0 wt% Al N sintered at 1900 °C for 1 h in Ar. Also, Si C ceramics with 30.0 wt% Al N exhibited the highest fracture toughness of 5.23 MPa m~(1/2) when sintered at 1900 °C.     

几种光产酸剂产酸效率的测定

溴酚兰水溶液的紫外吸收会随着体系中含酸的量发生变化,在440 nm吸收峰处一定浓度范围内溴酚兰水溶液的吸光度与溶液中酸浓度成正比,可由此测定酸浓度.用这种方法测定了3种不同类型的光产酸剂在聚乙二醇膜层中在低压汞灯(254 nm)照射下的产酸量.其中三嗪光产酸剂的光照产酸能力最强.     

太阳电池填充因子随日照强度变化的理论分析与计算

根据太阳电池直流模型和最大功率点数学条件,推出短路电流、开路电压、最大功率点电流和电压 以及填充因子随日照强度变化的数学关系式;并选取２个电池分别计算出在不同日照强度下上述电池参数随日 照强度的变化率。验证了短路电流和最大功率点电流是近似跟日照强度成正比,开路电压和最大功率点电压是 近似跟日照强度的自然对数成正比。并提出了填充因子随日照强度的变化关系不具有简单的函数形式,而对不 同的太阳电池其变化关系也迥异。最后用Multisim的模拟结果检验了理论分析计算的正确性。     

帕累托最优框架下的水电电价模型

将Shapley值分配方法与帕累托最优理论引入到水电电价模型的研究中.通过Shapley值确定水电电价在不同时段的惩罚因子与奖励因子,在帕累托最优的框架下建立能够提供有效的经济信号的有差别水电电价模型,目标为小水电方经济效益减少量与电网线损减少量比值的最小化,在保证对电网运营方与水电方经济效益弱影响的同时,实现电网的低...     

Human metabolic individuality in biomedical and pharmaceutical research

Genome-wide association studies (GWAS) have identified many risk loci for complex diseases, but effect sizes are typically small and information on the underlying biological processes is often lacking. Associations with metabolic traits as functional intermediates can overcome these problems and potentially inform individualized therapy. Here we report a comprehensive analysis of genotype-dependent metabolic phenotypes using a GWAS with non-targeted metabolomics. We identified 37 genetic loci associated with blood metabolite concentrations, of which 25 show effect sizes that are unusually high for GWAS and account for 10-60% differences in metabolite levels per allele copy. Our associations provide new functional insights for many disease-related associations that have been reported in previous studies, including those for cardiovascular and kidney disorders, type 2 diabetes, cancer, gout, venous thromboembolism and Crohn's disease. The study advances our knowledge of the genetic basis of metabolic individuality in humans and generates many new hypotheses for biomedical and pharmaceutical research.     

Method of adaptive PLL bandwidth adjustment without phase slipping

In a system based on the phase lock loop（PLL）, a trade-off must be made between the tracking precision and the dynamic performance if constant parameters are adopted. To overcome this drawback, a new method called no phase slipping adaptive bandwidth（NPS-AB） is proposed, which can adjust the loop bandwidth adaptively for different working conditions. As a result, both the tracking precision and the dynamic performance can be achieved concurrently. NPS-AB has two features to keep the loop stable： one is the capability of quick response to dynamics; the other is a series of additional constraints when the bandwidth is switched. Compared with other methods, there is no phase slipping during the adjustment process for NPS-AB. The phase integer ambiguity can be avoided and the phase value is kept valid. It is meaningful for carrier ranging systems. Simulation results show that NPS-AB can deal with sudden dynamics and keep the pseudo-range value stable in the entire dynamic process.     

我国湿地保护立法研究

湿地被称为“地球之肾”，是地球三大生态系统之一，在促进生态文明建设、构建和谐社会中具有重要作用．然而，近年来我国湿地破坏严重，其原因主要是我国湿地保护法律制度的不健全．我国湿地保护立法缺少中央立法、湿地内涵与外延不明确等，应借鉴发达国家经验提出相关完善建议．     

汾河流域降水量及蒸发量的空间变异性分析研究

借助于地质统计学方法对汾河流域的多年平均降雨量和蒸发量的空间变异性进行了分析,揭示了多年平均降水量和蒸发量的空间变异特征,并应用Kriging方法进行空间插值.分析结果表明,汾河流域多年平均降水量和蒸发量在不同的分割距离范围内有不同的空间相关性,多年平均降水量具有比较明显的地带性,蒸发量分布变化地带性不强.     

WDR34 is a novel TAK1-associated suppressor of the IL-1R/TLR3/TLR4-induced NF-κB activation pathway

Toll-like receptors (TLRs) act as sensors of microbial components and elicit innate immune responses. All TLR signaling pathways activate the nuclear factor-kappaB (NF-κB), which controls the expression of inflammatory cytokine genes. Transforming growth factor-β-activated kinase 1 (TAK1) is a serine/threonine protein kinase that is critically involved in the activation of NF-κB by tumor necrosis factor (TNFα), interleukin-1β (IL-1β) and TLR ligands. In this study, we identified a novel protein, WD40 domain repeat protein 34 (WDR34) as a TAK1-interacting protein in yeast two-hybrid screens. WDR34 interacted with TAK1, TAK1-binding protein 2 (TAB2), TAK1-binding protein 3 (TAB3) and tumor necrosis factor receptor-associated factor 6 (TRAF6) in overexpression and under physiological conditions. Overexpression of WDR34 inhibited IL-1β-, polyI:C- and lipopolysaccharide (LPS)-induced but not TNFα-induced NF-κB activation, whereas knockdown of WDR34 by a RNA-interference construct potentiated NF-κB activation by these ligands. Our findings suggest that WDR34 is a TAK1-associated inhibitor of the IL-1R/TLR3/TLR4-induced NF-κB activation pathway. D. Gao and R. Wang contributed equally to this work.