菌落原位杂交法筛选特定菌种的方法初探

菌落原位杂交法是重组DNA技术中最常用的方法之一,但该方法存在着杂交背景复杂及杂交结果不稳定性等缺点,所以进一步优化杂交体系显得尤为迫切.本研究通过优化杂交体系,最终确定利用溶菌酶处理杂交膜和采用非严紧型洗脱方式洗膜,不仅使得杂交体系的杂交结信号清晰,而且杂交背景较干净.研究结果表明,在探针特异性好的基础上,采用优化的菌落原位杂交体系筛选特定菌种是可行的.     

一种基于母线层的地图综合方法

针对目前地图综合中存在的一些问题，提出了一种基于母线层净数据的地图综合方法。     

PCB技术的革新与进步

文章概述了近几年来在PCB工业中生产技术的革新与进步情况,特别是直流电镀(镀层均匀性、填孔镀等)、表面涂(镀)覆(化学镀镍/钯浸金和直接浸金等)技术的革新与进步,推动了PCB工艺技术的发展。     

基于文档标引图模型的文本相似度策略

文档标引图是一种基于短语的图结构文本特征表示模型,能更加全面、准确地表达文本特征信息,实现渐增的文本聚类和信息处理。该文基于文档标引图特征模型,提出文档相似度计算加法策略和乘法策略,采用变换函数对文档相似度值进行调整,增强文档之间的可区分性,改进文本聚类和分类等处理的性能,实例证明了策略的有效性。     

表面处理工艺的新发展简

文章简述了当下流行的有机涂覆（OSP）、化学镀镍浸金（ENIG）、化学镀镍镀钯浸金（ENEPIG）等表面处理技术的发展现状;并对浸银（IAg）、浸锡（ISn）和直接浸金（DIG）以及自组装单分子（SAM）等新工艺进行了简单讨论,并提出了一些降低工艺成本,改进技术,提高工艺可靠性的方法。     

Tracking the Biological Incorporation of Exogenous Molecules into Cellulose Fibers with Non-Radioactive Iodinated Glucose

Semi-synthetic biological fabrication explores biological systems and their biosynthetic pathways as inspiration for designing precursor analogs that can be metabolized in a similar manner as the natural substrates by organisms to yield new materials with tailored properties. Here we report the biological incorporation of a metabolizing iodinated glucose analog (2-Deoxy-2-iodo-D-glucose, DIG) into Gossypium hirsutum cotton fibers in an ovule in-vitro model. Structural modifications occur at the level of crystallite arrangement and compaction, with amorphization of the fibers and alteration of the H-bond network between the cellulose nanofibrils. We further show that DIG can serve as a non-radioactive micro computed tomography contrast agent (μCT). The fibers act as glucose sinks that accumulate DIG, enabling its detection by μCT. Quantitative analysis shows that the fibers are more oriented when incubated with DIG. This work demonstrates the advantages of using higher organisms for biological in-situ transformation of economically important raw materials over conventional chemical surface modification processes, thereby providing a scientific foundation for implementing future alternatives and sustainable manufacturing strategies towards a bio-based economy.     

直喷汽油(DIG)汽车发动机无声链条系统用温压-高温烧结粉末冶金链轮的开发

作者们以前报导过非直喷汽油 (一般MPI汽油 )发动机滚子链条系统用温压 -常规温度 ( 114 0℃ )烧结的粉末冶金链轮。在这个新开发的项目中 ,研究了几种温压 -高温烧结的粉末冶金钢的力学性能。为测定这些材料的耐磨性 ,用虚拟发动机进行了磨耗试验。最终开发出了可承受严酷磨耗条件的DIG发动机无声链条系统的链轮。使用的基础粉末是混合粉 (DistaloyDC1)。其含 2 %Ni(质量分数 ) ,Ni粉是通过扩散粘结在Fe - 1 5 %Mo(质量分数 )粉末颗粒上的 ,温压是在 130℃下 ,用这种粉末、阴模及模具进行的。烧结温度为 1190℃。链轮还进行了热处理     

Oil Film Stiffness of Double Involute Gears Based on Thermal EHL Theory

Lubrication failure is one of the main failure forms of gear failure.Time varying meshing stiffness is an important factor affecting the dynamic behavior of gears.However,the influence of oil film stiffness is usually ignored in the research process.In this paper,according to the meshing characteristics of double involute gears,based on the non-New-tonian thermal EHL theory,a new calculation method of normal and tangential oil film stiffness for double involute gears is established by the idea of subsection method.The oil film stiffness difference between double involute gears and common involute gears is analyzed,and the influence of tooth waist order parameters,working conditions,and thermal effect on the oil film stiffness are studied.The results reveal that there are some differences between normal and tangential oil film stiffness between double involute gears and common involute gears,but there is little dif-ference.Compared with the torque,rotation speed and initial viscosity of the lubricating oil,the tooth waist order parameters have less influence on the oil film stiffness.Thermal effect has a certain influence on normal and tan-gential oil film stiffness,which indicates that the influence of thermal effect on the oil film can not be ignored.This research proposes a calculation method of normal and tangential oil film stiffness suitable for double involute gears,which provides a theoretical basis for improving the stability of the transmission.     

Development of millimeter wave antennas and associated feed network components using dielectric image guide

The dielectric image guide (DIG) lines have an extremely low loss at the millimeter and sub‐millimeter frequencies. Here, we will demonstrate using a dielectric line with a width that is smaller than its height. Both ferrite and Si materials have been used to fabricate circuits to achieve tunable functions. Different millimeter wave components and radiating structures with this new aspect ratio have been developed, fabricated, and tested. Special emphasis has been placed on demonstrating the components and antennas' operation in the 26–35 GHz range, but the design concepts developed here can be easily extended to sub‐millimeter wave frequencies. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE 2010.