P-F模型的过程复用机制及工具

Ｐ－Ｆ模型是一种利用Ｐｅｔｒｉ Ｎｅｔ与形式化描述相结合描述软件过程的方法。Ｐ－Ｆ模型的模板、模式和元模式概念在不同层次上提供了进行过程复用的方法。模板复用的是过程的内容信息;模式复用的则是过程的结构信息,是更高层的复用;元模式是最小的结构单元,可以设计模式。文章介绍了Ｐ－Ｆ模型中的这三种过程复用方法,及其在Ｐ－Ｆ过程设计工具ＰＳＴｏｏｌｓ中实现的途径。     

多机相关任务均匀衡调度问题的复杂性与新算法

本文讨论了多处理机系统中的一种相关任务均衡调度问题 ,证明了该问题是 NP完全问题 ,并给出了一个新的启发式算法。该算法克服了现有算法的不足。数值实例和仿真结果表明 ,该算法有令人满意的优化效果     

用VB开发多媒体教学软件实践谈

本文结合笔者开发多媒体教学软件的实践经验,通过具体的实例,详细介绍了用ＶＢ开发多媒体教学软件所涉及到的几个关键技术,包括按钮制作、文字和图片处理以及音频、视频文件的播放等等。     

On the small-scale dynamical behavior of lattice BGK and lattice Boltzmann schemes

In this paper, we report some comparative simulations between lattice BGK and lattice Bolzmann schemes for two-dimensional fluid flows. A quantitative assessment of the validity of the lattice BGK and lattice Bolzmann schemes is presented for the two-dimensional weakly compressibleKolmogorov flow. We use this flow to study the difference of the two schemes at small scales. A lowReynolds (R _e 300) number simulation shows the almost identical energy spectra for both schemes except for the small-scale dynamics of lattice Bolzmann which is more noisy. Because of the intrinsic difficulties of nonlinear stability analysis, we use numerical simulations to investigate which scheme is more stable. It turns out the lattice BGK is more stable. It turns out the lattice BGK is more robust than lattice Bolzmann by increasing theReynolds numbers. Detailed comparison with other methods (e.g., spectral method) remains to be done in the near future.     

RDS在ⅡS上的应用和研究

文章介绍了如何在Windows NT中配置ⅡS,以及RDS在ⅡS上的应用和测试。     

Isolation of bacterial metabolites as natural inducers for larval settlement in the marine polychaete Hydroides elegans (Haswell)

The bacterial component of marine biofilms plays an important role in the induction of larval settlement in the polychaete Hydroides elegans. In this study, we provide experimental evidence that bacterial metabolites comprise the chemical signal for larval settlement. Bacteria were isolated from biofilms, purified and cultured according to standard procedures. Bacterial metabolites were isolated from spent culture broth by chloroform extraction as well as by closed-loop stripping and adsorption of volatile components on surface-modified silica gel. A pronounced biological activity was exclusively observed when concentrated metabolites were adsorbed on activated charcoal. Larvae did not respond to waterborne metabolites when prevented from contacting the bacterial film surface. These results indicate that an association of the chemical signal with a sorbent-like substratum may be an essential cofactor for the expression of biological activity. The functional role of bacterial exopolymers as an adsorptive matrix for larval settlement signals is discussed.     

南渡江左岸排涝工程研究

南渡江下游左岸是洪涝灾害十分频繁的洪泛区,一般年份洪水即可入侵农田和村庄,对农业生产造成极大损失.如遇20年一遇洪水,项目区积水深度会超过1 m左右,持续时间达2～3d,为排出防护区内涝水,设计应用ArcGIS分析地形并划分排涝分区,通过调蓄计算确定排涝工程规模.     

陕西省兵工企业管理岗位人岗匹配研究

企业人力资源管理工作的核心就是人岗匹配.文中针对兵工企业行业特征,对员工与岗位进行保密与否区分.在保密管理者可匹配任意管理岗位,而普通管理者只能匹配普通管理岗位的假设下,以管理者的岗位满意度和企业效益最大为目标,建立双目标人岗匹配模型,并用遗传算法分析与求解.尝试探讨兵工企业管理岗位人岗匹配的途径.     

香菇多糖和金针菇多糖的提取及其抑菌活性

为了探索食用菌多糖在抗菌方面的开发和应用,采用菌丝体发酵法,制得金针菇和香菇胞外多糖,采用热水浸提结合微波预处理法,提取香菇菌柄多糖,并采用正交试验方法对提取工艺进行优化,然后采用滤纸片法测试金针菇胞外多糖、香菇胞外多糖和香菇菌柄多糖对大肠杆菌、金黄色葡萄球菌和白色念球菌的抑制活性．结果表明：香菇菌柄多糖提取的最佳工艺为微波预处理3mm（处理过程中微波炉的功率为480w）、料液比为1：30（g：mL）、浸提时间为1．5h和浸提温度为96℃．在8．5mg／mL的浓度下,金针菇胞外多糖,对大肠杆菌、金黄色葡萄球菌和白色念球菌均无抑制作用;在4．8mg／mL的浓度下,香菇胞外多糖和香菇菌柄多糖对大肠杆菌、金黄色葡萄球菌和白色念球菌均有抑制活性．香菇胞外多糖,对大肠杆菌、金黄色葡萄球菌和白色念球菌的最小抑菌浓度分别为0．15、4．8、4．8mg／mL;香菇菌柄多糖,对大肠杆菌、金黄色葡萄球菌和白色念球菌的最小抑菌浓度分别为2．4、4．8、4．8mg／mL．不同浓度的香菇多糖对大肠杆菌、金黄色葡萄球菌和白球念球菌的抑制活性不同;香菇胞外多糖和香菇菌柄多糖对大肠杆菌、金黄色葡萄球菌和白球念球菌的抑制活性存在差异．     

Optical analysis of a hybrid solar concentrating Photovoltaic /Thermal (CPV/T) system with beam splitting technique

A novel hybrid solar concentrating Photovoltaic/Thermal (CPV/T) system with beam splitting technique is presented. In this system, a beam splitter is used to separate the concentrated solar radiation into two parts: one for the PV power generation and the other for thermal utility. The solar concentrator is a flat Fresnel-type concentrator with glass mirror reflectors. It can concentrate solar radiation onto solar cells with high uniformity, which is beneficial to improving the efficiency of solar cells. The thermal receiver is separated to the solar cells, and therefore, the thermal fluid can be heated to a relatively high temperature and does not affect the performance of solar cells. A dimensionless model was developed for the performance analysis of the concentrating system. The effects of the main parameters on the performance of the concentrator were analyzed. The beam splitter with coating materials Nb2O3 /SiO2 was designed by using the needle optimization technique, which can reflect about 71% of the undesired radiation for silicon cell(1.1m < 3m) to the thermal receiver for thermal utility. The performance of this CPV/T system was also theoretically analyzed.