软土层深基槽无支护土方工程实践

石油化工装置地下给排水管道及附属设施工程具有管道口径大、埋设深、管道交叉布置复杂、井及水池等地下构筑物多的特点,而软土区域,具有含水量大、天然孔隙比大压、缩性高、强度低等特点,为深基槽开挖和管道施工带来极大难度.针对扬巴一体化石化项目IPS生产区地下给排水工程,根据地质勘探资料和现场施工条件,采用基槽无支护开挖加轻型井点降水方案,取得了较好的效果.     

In vitro capability of multi-walled carbon nanotubes modified with gonadotrophin releasing hormone on killing cancer cells

Oxidized and polished multi-walled carbon nanotubes (MWCNTs) were dispersed in aqueous solution, providing a highly stable suspension of purified, shortened, and functionalized carboxylic acid nanotubes. A gonadotrophin releasing hormone (GnRH), which was overexpressed in the plasma membrane of several types of cancer cells, was covalently anchored onto the surface of the oxidized MWCNTs via an amide linkage. The MWCNTs modified with GnRH (MWCNTs-GnRH) were characterized by UV-vis and emission spectra, and elemental analysis. Red-shift in the optical spectra consisting of the UV-vis absorption and emission spectra with the attraction of GnRH on the surface of the MWCNTs was observed due to the attraction of GnRH on the surface of the MWCNTs via π stacking, however, there was no property for a direct mixture of MWCNTs and GnRH, supporting the successful modification. Elemental analysis revealed that the sidewall coverage of MWCNTs by the GnRH was about 0.7% of the available surface area. The non toxic GnRH and MWCNTs can separately enter the DU 145 cells. In contrast, GnRH-MWCNTs entered the cells and showed toxicity in the malignant cells. These results showed that the newly formed toxic material had potential ability to kill the malignant cells with just a simple covalent bonding of the two.     

Extraction and characterisation of pectin polysaccharide from soybean dreg and its dispersion stability in acidified milk drink

In this study, pectin polysaccharide (SDPP) was obtained from soybean dreg (26.2% yield), and characteristics of SDPP were compared with those of soybean soluble polysaccharides (SSPS) and citrus pectin (HMP). The galacturonic acid and molecular weight of SSPS, SDPP or HMP were 11.8%, 40.6% or 70.2% and 112, 446, or 440 kDa. SDPP had similar viscosity and protein content to SSPS, and functional groups and linear structure to HMP. SSPS, SDPP or HMP differed in particle size of 260, 467 or 1195 nm and ζ–potential of −5.8, −14.6 or −23.5 mV at pH 4.0. The precipitation of acidified milk drink (AMD) was 6.31% without stabiliser or below 1.75% with 0.4% SDPP at pH 3.6–4.6. These results suggested that SDPP combines the structure and characteristic of HMP and SSPS, and AMD with SDPP had great stabilising behaviour at wider pH range (pH 3.6–4.6).     

Preparation and characterization of transparent Tm:YAG ceramics

Polycrystalline (Y_3−xTm_x)Al₅O₁₂ (x = 0, 0.18, 0.9, 1.5, 3) ceramics were fabricated by a solid-state reaction method using high-purity micrometer-sized powders. Tm-doped ceramics with an almost perfect pore-free structure and high transparency were obtained by advanced ceramic processing. The average grain size and grain boundary width were 15 μm and 1 nm, respectively. The Y_2.82Tm_0.18Al₅O₁₂ (6 at.% Tm:YAG) ceramic slab (5 mm × 5 mm × 3.5 mm) was end-pumped by a Ti:sapphire laser at 785 nm and the maximum output power of 725 mW was obtained with a slope efficiency of 36.2% at 2012 nm.     

无水乙醇注浆成型制备YAG透明陶瓷

以无水乙醇作为分散介质,采用注浆成型工艺和真空烧结技术制备了光学质量良好的YAG透明陶瓷.双面抛光、厚度为3mm的YAG透明陶瓷样品(烧结温度1800℃)在可见光范围内的直线透过率为79%左右,在近红外波段的透过率为80%左右,接近理论透过率84%.样品的平均晶粒尺寸约为30μm,晶界处和晶粒内部均无杂质和第二相存在,也几乎没有气孔的残留.采用无水乙醇做分散剂进行注浆成型是一种很有发展潜力的透明陶瓷成型方法.     

一个异步分布进程通信模型

文中介绍了一个异步分布式通信模型,并利用这个模型,说明通道的语法规则,这些语法规则对通道的行为进行了约束。文中所介绍的模型简称为ＰＣＡＰ（ｐｒｏｃｅｓｓ－ｃｈａｎｎｅｌ－ａｇｅｎｔ－ｐｒｏｃｅｓｓ）模型。ＰＣＡＰ模型与通道语法规划相结合,便成为一个通用、简洁的通信工具,利用这个工具,可以说明和比较不同类型的通道,也可以用它来设计和实现通道应用程序。文中最后用一个层次与Ｆ通道相结合的通道应用阐明了这     

发动机振动主动控制中电磁作动器的设计和性能研究

对电磁作动器的原理及特性作了分析．建立了电磁作动器的力学模型和数学模型,最后通过仿真方法对电磁作动器的结构参数变化,对其性能的影响作了详细的分析,为针对不同发动机选择合适的作动器提供了依据。     

使用外部数据库连接的斜齿轮参数化设计系统

以AutoCAD VBA为开发工具,运用ActiveX和ADO对象,采用Access数据库,以斜齿轮参数化设计为例介绍了采用AutoCAD VBA开发参数化绘图程序的方法、步骤,提出了采用数据库技术获取必要绘图参数的方法。     

基于全基因组序列的污染事件中椰毒假单胞菌酵米面亚种溯源分析

摘 要：目的 对湿米粉与淀粉制品（统称为“湿粉”）及其原料米中分离的椰毒假单胞菌酵米面亚种进行溯源分析。方法 采用GB/T 4789.29—2003在14份湿粉及其原料米中分离出34株唐菖蒲伯克霍尔德氏 菌并进行菌株全基因组重测序,以Burkholderia_gladioli_Co14作为参比基因,基于单核苷酸多态性（SNP）数据构建进化树,分析不同菌株的同源关系。结果 来源于相同产地标识的样品的菌株呈现较好聚类;来源于同一生产企业的湿粉和碎米样品的菌株具有高度同源关系。结论 提示原料米中椰毒假单胞菌酵米面亚种的基因组序列与产地溯源具有较大的相关性,在湿粉生产加工过程中存在椰毒假单胞菌酵米面亚种污染传递的风险。