Glass crystallization making red phosphor for high-power warm white lighting

Rapid development of solid-state lighting technology requires new materials with highly efficient and stable luminescence, and especially relies on blue light p...     

莫斯科中国贸易中心工程防止结构连续倒塌设计

建筑抗倒塌问题近年来在欧美国家得到广泛关注。结合莫斯科中国贸易中心工程的防止结构连续倒塌设计,比较了国外一些相关设计规范和标准之间的相互关系,提出满足俄罗斯规范要求的防止连续倒塌设计计算方法,并将其与正常情况下的结构计算进行比较,找出其中带规律性的问题。     

Characterization of a Thermostable and Surfactant-Tolerant Chondroitinase B from a Marine Bacterium Microbulbifer sp. ALW1

Chondroitinase plays an important role in structural and functional studies of chondroitin sulfate (CS). In this study, a new member of chondroitinase B of PL6 family, namely ChSase B6, was cloned from marine bacterium Microbulbifer sp. ALW1 and subjected to enzymatic and structural characterization. The recombinant ChSase B6 showed optimum activity at 40 °C and pH 8.0, with enzyme kinetic parameters of K_m and V_max against chondroitin sulfate B (CSB) to be 7.85 µg/mL and 1.21 U/mg, respectively. ChSase B6 demonstrated thermostability under 60 °C for 2 h with about 50% residual activity and good pH stability under 4.0–10.0 for 1 h with above 60% residual activity. In addition, ChSase B6 displayed excellent stability against the surfactants including Tween-20, Tween-80, Trion X-100, and CTAB. The degradation products of ChSase B6-treated CSB exhibited improved antioxidant ability as a hydroxyl radical scavenger. Structural analysis and site-directed mutagenesis suggested that the conserved residues Lys248 and Arg269 were important for the activity of ChSase B6. Characterization, structure, and molecular dynamics simulation of ChSase B6 provided a guide for further tailoring for its industrial application for chondroitin sulfate bioresource development.     

第三讲:超高层建筑的施工组织(二)

(续上期)4超高层建筑施工流程4.1施工流程研究的重要意义流程是现代管理理论中非常重要的概念,就是一组将输入转化为输出的相互关联或相互作用的活动集合。相应地,施工流程就是将施工资源转化为建筑工程的相互关联或相     

A Comprehensive Identification and Function Analysis of Serine/Arginine-Rich (SR) Proteins in Cotton (Gossypium spp.)

As one of the most important factors in alternative splicing (AS) events, serine/arginine-rich (SR) proteins not only participate in the growth and development of plants but also play pivotal roles in abiotic stresses. However, the research about SR proteins in cotton is still lacking. In this study, we performed an extensive comparative analysis of SR proteins and determined their phylogeny in the plant lineage. A total of 169 SR family members were identified from four Gossypium species, and these genes could be divided into eight distinct subfamilies. The domain, motif distribution and gene structure of cotton SR proteins are conserved within each subfamily. The expansion of SR genes is mainly contributed by WGD and allopolyploidization events in cotton. The selection pressure analysis showed that all the paralogous gene pairs were under purifying selection pressure. Many cis-elements responding to abiotic stress and phytohormones were identified in the upstream sequences of the GhSR genes. Expression profiling suggested that some GhSR genes may involve in the pathways of plant resistance to abiotic stresses. The WGCNA analysis showed that GhSCL-8 co-expressed with many abiotic responding related genes in a salt-responding network. The Y2H assays showed that GhSCL-8 could interact with GhSRs in other subfamilies. The subcellular location analysis showed that GhSCL-8 is expressed in the nucleus. The further VIGS assays showed that the silencing of GhSCL-8 could decrease salt tolerance in cotton. These results expand our knowledge of the evolution of the SR gene family in plants, and they will also contribute to the elucidation of the biological functions of SR genes in the future.     

铬污染的微生物吸附技术研究进展

近年来,铬在工业生产中得到了广泛的应用,随之而来的含铬污染物对周围环境造成严重的污染和破坏,铬污染的修复已成为亟待解决的环境问题.微生物在铬污染的生物修复中发挥着重要的作用.它因铬污染修复过程中环保有效,安全可靠且无二次污染等优点,引起了相关学者们的广泛关注.首先简述了铬污染危害及传统处理技术,重点综述了微生物作为生物...     

影响挠性印制板插入损耗的几种因素

文章采用三层板叠构对高频通信用挠性印制板(FPCB)的插损进行测试对比,从制造FPCB的材料种类、材料厚度、胶层厚度、仿真设计、信号线过孔类型、盲孔质量,以及信号线阻抗值大小等多个因素总结出对最高频率到20GHz信号插损的影响.     

高精度数控内圆磨床开发设计中的关键技术研究

结构动力学优化设计是提高机床加工精度的有效途径。本文分析了高精度数控内圆磨床开发设计中的几项关键技术。部件结构动力学优化的灵敏度分析，结合面动力学模型修正，主轴系统模型修正与优化的BP神经网络，分布频率的多重调谐阻尼器（MTMD）抑制振动，利用上述技术开发的MK2120A新型数控内圆磨床内孔磨削圆度已达0.0008-0.0011mm。圆柱度0.0015mm，粗糙度Ra0.1μm，消除了表面的磨削振纹，而且整机重量比原磨床有大幅下降。这些技术对相关机床动力学优化设计也具有普遍的指导意义。     

固体推进剂制造工艺危险性的模糊评定方法

建立了一种固体推进剂制造工艺危险性评定的新方法。文中用隶属函数的概念描了阶段等级界限的模糊性，用优化方法确定了影响因素的权重因子集合；并对评判步骤、模糊关系矩阵的确定等问题进行了详细讨论。最后，通过对模糊评定方法与国外现有方法的比较，讨论了新特点。最后，通过对模糊评定方法与国外现有方法的比较，讨论了新方法的特点；通过对典型推进剂的工艺危险性等级的评定计算，说明了新的正确性