常熟华府世家箱形转换层结构设计

常熟华府世家工程是一栋高层建筑,由于在转换梁的布置中有多次梁抬墙的情况,采用整体性好的箱形转换结构。对箱形转换层及其上下若干楼层的受力进行了计算,根据计算结果对箱形转换层进行结构设计。计算结果表明,采用箱形转换层提高了结构的整体性和抗震性能,结构的变形满足规范要求。对箱形转换结构的设计和施工中要注意的问题进行了探讨。     

Sulfated Hyaluronan Binds to Heparanase and Blocks Its Enzymatic and Cellular Actions in Carcinoma Cells

We examined whether sulfated hyaluronan exerts inhibitory effects on enzymatic and biological actions of heparanase, a sole endo-beta-glucuronidase implicated in cancer malignancy and inflammation. Degradation of heparan sulfate by human and mouse heparanase was inhibited by sulfated hyaluronan. In particular, high-sulfated hyaluronan modified with approximately 2.5 sulfate groups per disaccharide unit effectively inhibited the enzymatic activity at a lower concentration than heparin. Human and mouse heparanase bound to immobilized sulfated hyaluronan. Invasion of heparanase-positive colon-26 cells and 4T1 cells under 3D culture conditions was significantly suppressed in the presence of high-sulfated hyaluronan. Heparanase-induced release of CCL2 from colon-26 cells was suppressed in the presence of sulfated hyaluronan via blocking of cell surface binding and subsequent intracellular NF-κB-dependent signaling. The inhibitory effect of sulfated hyaluronan is likely due to competitive binding to the heparanase molecule, which antagonizes the heparanase-substrate interaction. Fragment molecular orbital calculation revealed a strong binding of sulfated hyaluronan tetrasaccharide to the heparanase molecule based on electrostatic interactions, particularly characterized by interactions of (−1)- and (−2)-positioned sulfated sugar residues with basic amino acid residues composing the heparin-binding domain-1 of heparanase. These results propose a relevance for sulfated hyaluronan in the blocking of heparanase-mediated enzymatic and cellular actions.     

"二墙合一"中的地下连续墙接缝的防渗与止水施工

在地下连续墙兼作地下结构外墙的“二墙合一”工程中,为防地下连续墙接缝处的渗漏,采用三重管高压摆喷工艺和压密注浆进行防渗处理,取得了理想的效果。     

NMR Characterization of Long-Chain Fatty Acylcarnitine Binding to the Mitochondrial Carnitine/Acylcarnitine Carrier

The mitochondrial carnitine/acylcarnitine carrier (CAC) transports short-, medium- and long-carbon chain acylcarnitines across the mitochondrial inner membrane in exchange for carnitine. How CAC recognizes the substrates with various fatty acyl groups, especially long-chain fatty acyl groups, remains unclear. Here, using nuclear magnetic resonance (NMR) technology, we have shown that the CAC protein reconstituted into a micelle system exhibits a typical six transmembrane structure of the mitochondrial carrier family. The chemical shift perturbation patterns of different fatty acylcarnitines suggested that the segment A76–G81 in CAC specifically responds to the long-chain fatty acylcarnitine. Molecular dynamics (MD) simulations of palmitoyl-L-carnitine inside the CAC channel showed the respective interaction and motion of the long-chain acylcarnitine in CAC at the cytosol-open state and matrix-open state. Our data provided a molecular-based understanding of CAC structure and transport mechanism.     

粮油中转储备库的加固改造设计

介绍了加固方案的选择、相关构件强度的计算、接点构造的处理等主要加固步骤。实践证明,此方案较经济、合理,且能最大程度地减少施工工作量。     

四川盆西平原区裸土扬尘中Pb、Cd化学形态的生物有效性

为探究四川盆西平原区裸土扬尘中Pb、Cd总质量分数与其生物有效性的规律,在构建的"阳离子型污染物土壤表层运移行为研究系统"内进行模拟起尘试验,对土壤样品进行Pb、Cd模拟污染试验,结果表明:试验条件下,四川盆西平原区裸土扬尘颗粒物中Pb、Cd的总质量分数随着粒径的减小而增大,其中Pb的化学形态以碳酸盐结合态为主(44....     

600MW空冷机组锅炉烟风道优化设计分析

针对600 MW空冷机组原烟风道占地面积大,材料用量多、造价高的问题,结合河北建投沙河发电有限公司2台600 MW超临界空冷机组工程中烟风道的设计,比较分析烟风道采用常规矩形道体和圆形道体的优劣,认为烟风道道体优化形状为圆形,介绍除尘器进口烟道、热一次风道、引风机进口烟道优化布置方案,并进行经济性分析。     

论教育家校长的塑造力——以清华大学“永远的校长”梅贻琦为例

大学需要教育家校长,只有教育家校长才能以其特有的塑造力来创造大学。清华大学老校长梅贻琦正是凭借其大学的塑造力在动荡的时代造就了伟大的清华大学。他在各方面展现自己的塑造力,使清华大学在国内外独树一帜。在当今大学需要教育家办学的时代,我们的大学校长要学习梅贻琦先生,努力成为教育家校长,在各个方面展现出自己对大学的塑造能力,为大学发展贡献自己的力量,为我国造就世界一流大学。     

饱水石灰岩骨架和流体弹性参数的估算

本文利用Niu等提出的基于临界孔隙度模型的组分弹性参数数值计算方法,把测试岩石样品的孔隙度、整体密度、纵波速度和横波速度作为数值计算的输入数据,运用双线性数值计算方法反演求出临界点、流体和骨架的12个弹性参数。具体做法是:基于临界孔隙度模型,给出三组线性关系,即密度—孔隙度,整体剪切模量—孔隙度,整体纵波模量—孔隙度,上述每组线性关系分别以孔隙度作为自变量和因变量得到两个线性方程,再把两个方程计算的结果进行加权平均得到相关的弹性参数估算值,并结合饱水石灰岩样品数据实现了弹性参数估算。数值计算结果表明,由数值计算得到的弹性参数与测试弹性参数的均值和方差相差甚微,特别是密度数据的偏差均值更小,说明文中的数值计算结果是可靠的。     

地道通风在莫高窟游客服务中心空调系统中的应用

莫高窟地处甘肃省西北部的敦煌市,当地全年气候干燥,为自然除湿创造了有利的条件。介绍了莫高窟游客服务中心接待大厅地道通风的地道设计、运行工况、热舒适指标计算,计算结果表明,室内环境的热舒适状况能满足规范要求。