语段分析的功能及其运行方式

语段分析是一种“超句法分析”,它注重句际关系,强调从全局着手去把握说话人的言语动向和引入的新话题。本文基于对语段分析上述特征的分析,论证了语段分析在英语教学中的功用及其运行方式,提出了英语教学的新方法。     

3-D Design and Numerical Simulation of Two-Phase Flow in the Laser Rapid Prototyping Coaxial Powder Delivery System

The metal powder direct and rapid prototyping technology is one of the most developing methods in the laser rapid prototyping technique. The coaxial powder delivery system is the key technique. The purpose of this paper is to introduce a new type of coaxial powder delivery system and simulate the metal powder and shield gas flow in the powder nozzle. 2-D and 3-D model of the new coaxial powder delivery system are established. Then gas-solid two-phase flow model and the k-ε turbulent model are selected to simulate the flow of metal powder in powder nozzle. The Euler-Lagrange method is used in the simulating computation. The results show that the new coaxial powder delivery system has stable performance, uniform powder flux, high cooling efficiency, and long useful life.     

现代物流中心的货物配送问题

为了实现我国物流现代化和提高现代物流中心货物配送的效益 ,本文从现代化物流中心货物配送的定义出发 ,阐述了现代货物配送的特点 ,并对现代物流中心的货物配送作业环节进行了分析 ,提出了我国现代物流的配送体系结构 ;最后对合理组织货物的配送做了简要的分析和阐述 ,重点以货物配送的配装作业环节为例分析了货物的配送问题 ,并应用数学规划知识建立了货物配装模型以优化货物的配装作业 ,从而为解决现代物流合理化配送问题提供了科学的思路 ,同时也为实现我国物流现代化提供了促进作用 .     

设计价值论

设计价值是体现在设计成果里的社会劳动，其构成元素的个性化特征具体表现为有形价值和无形价值。评价设计的好坏程度，有效地提高设计水平，都完全基于设计价值表现的五大基点：基本构成、创造性、表现性、适时性、时代性。面对设计的发展，已不是限于设计表象而评价设计，全面、深刻地理解和把握这五个大基点，能从设计价值的构成本质上正确把握设计内涵和提升设计水平，这是今后发展的首要问题。     

具有同时集送货需求的车辆路径问题的粗粒度并行遗传算法

设计了求解VRPSDP的粗粒度并行遗传算法(CGPGA),其中遗传算法以最优划分法计算适应值,邻域搜索法作为变异算子,定义了群体多样性结构.并行算法以单向环作为连接拓扑,各子群体独立进行遗传操作,迁移算子用于群体间的信息交流,采用多样性替换的方法进行个体替换.论文给出了CGPGA算法在集群系统上的重复非阻塞MPI实现.对典型VRPSDP实例进行测试的结果表明:CGPGA算法在大部分实例上超过了已知最好解,未达到已知最好解的实例与已知最好解的相对误差不超过1.5%.在计算速度方面,CGPGA算法具有接近线性甚至超线性的加速比,提高了遗传算法的求解速度.     

O-硬脂酰化壳聚糖作为DNA的递送载体材料

以邻苯二甲酰基预先保护壳聚糖分子中-NH_2,以硬脂酰氯进行可控酯化,制备O-硬脂酰化壳聚糖.通过超声振荡与溶剂结合制备O-硬脂酰化壳聚糖/λDNA复合物,采用动态激光散射及原子力显微镜分析复合物的粒径分布及形态.凝胶电泳考察该载体与λDNA的结合能力.L929细胞培养对O-硬脂酰化壳聚糖进行细胞毒性评估.FT-IR和~1H NMR结果表明,可以成功制备不同酯化度的O-硬脂酰壳聚糖;O-硬脂酰化壳聚糖与λDNA结合可形成不规则球形复合物,平均粒径可达到86 nm,并且对DNase显示高稳定性.同时O-硬脂酰化壳聚糖具有促L929细胞增殖能力,安全性较高,可作为一种新型的非病毒型基因载体.     

全国文化信息资源共享工程的重要服务模式——联合参考咨询与文献传递网——以哈尔滨市图书馆为例

联合参考咨询与文献传递网将全国优秀的文化信息资源进行数字化加工整合,通过共享工程网络体系,让文化信息资源在最大范围内传递和应用。以哈尔滨市图书馆在联合参考咨询与文献传递网服务中的数据为例,说明了联合参考咨询与文献传递网在共享工程中的显著作用。     

临汾市引沁入汾和川取水输水工程GPS施工控制网的布设与实施

介绍了临汾市引沁入汾和川取水输水工程,对GPS施工控制网的布设、实施野外观测及数据处理等方面进行了论述,为今后在施工控制网测量中采用GPS测量技术总结了一些有益经验。     

新型气相色谱分析样品前处理装置与方法

探索一种新型的样品前处理装置,运用载体、携带体和综合蒸馏技术完成了待测样品中微量成分的提取分离和富集.将冷端接受器设计为可更换结构,所以无样品交叉干扰,适用于痕量组分的富集.在乙酸乙酯中添加了4种微量有机磷农药后进行了前处理其装置能自动将微量组分富集到2mL邻苯二甲酸二甲酯中利用气相色谱分析的结果,研究了样品前处理装置分离富集参数的选择原则.实验证实该方法能最有效地除去蛋白、脂肪、色素等对气相色谱分析有干扰的组分;将待测微量组分的浓度富集150倍以上;回收率92%～117%;相对标准偏差±5.65%;最小检出线为1 ng/mL.有机试剂的回收利用率大于95%,而且操作简单方便,以模拟试样为例说明了方法的实用性.     

Cationic polymeric nanoformulation: Recent advances in material design for CRISPR/Cas9 gene therapy

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat/clustered regularly interspaced short palindromic repeat associated proteins 9) gene editing platform is a promising therapeutic tool for genetic disorders, due to its ability to manipulate the pathogenic gene in genomic level and to easily target specific gene by manipulating single-guide RNA. However, its successful delivery remains a challenge. Up to now, great efforts have been made to explore an effective strategy for CRISPR/Cas9 delivery. But among those delivery methods, physical methods are mainly operated on cultured cells thus limited to laboratorial use; viral vectors are hindered by fetal immunogenic and carcinogenic effects thus dubious in clinical application. Therefore, cationic polymeric vectors, with the ability to interact with CRISPR/Cas9 system to form a nanoformulation as a non-viral approach, are attracting increasing attentions, due to advantages such as well protection of cargos, less limitation in payload size, low immunogenicity or carcinogenicity, potential modifications for further functions, and ease in mass production. In this review, the recent discoveries on polymeric vectors utilized in delivery of CRISPR/Cas9 system will be summarized. With emphasis on advanced features of those polymeric vectors or their nanoformulations to meet the demands of different CRISPR/Cas9 delivery forms (plasmid, mRNA or protein), the detailed illustrations on their disease treatment applications, such as cancer, diabetes or antibiotic-resistant infections, will also be reviewed.