遗传算法和遗传规划对比研究

通过对遗传算法定向搜索机制和遗传规划搜索机制的研究比较,可以看出,依据遗传算法的基本思想设计遗传规划的进化算子时,由于算子空间过大而导致盲目搜索。通过对遗传规划的研究,提出了一套有定向机制的进化算子,进而设计和实现了基于这一套算子的遗传规划算法。     

The PREPL A protein, a new member of the prolyl oligopeptidase family, lacking catalytic activity

The PREPL (previously called KIAA0436) gene encodes a putative serine peptidase from the prolyl oligopeptidase family. A chromosomal deletion involving the PREPL gene leads to a severe syndrome with multiple symptoms. Homology with oligopeptidase B suggested that the enzyme cleaves after an arginine or lysine residue. Several PREPL splice variants have been identified, and a 638-residue variant (PREPL A) was expressed in Escherichia coli and purified. Its secondary structure was similar to that of oligopeptidase B, but differential-scanning calorimetry indicated a higher conformational stability. Dimerization may account for the enhanced stability. Unexpectedly, the PREPL A protein did not cleave peptide substrates containing a P1 basic residue, but did slowly hydrolyse an activated ester substrate, and reacted with diisopropyl fluorophosphate. These results indicated that the catalytic serine is a reactive residue. However, the negligible hydrolytic activity suggests that the function of PREPL A is different from that of the other members of the prolyl oligopeptidase family.     

基于长白山臭冷杉胶合板强度的水性异氰酸酯胶黏剂配比

用水性异氰酸酯胶黏剂压制长白山臭冷杉胶合板,通过检测胶合板的胶合强度,分析聚乙烯醇(PVA)质量分数、甲苯二异氰酸酯(TDI)质量分数、乳化剂用量等因素对水性异氰酸酯胶黏剂胶合性能的影响.利用正交试验方差分析得出各影响因素间的主次关系为TDI质量分数PVA质量分数乳化剂质量分数.当PVA质量分数为10%、TDI质量分数为5%、乳化剂质量分数为30%时,水性异氰酸酯胶黏剂的胶合性能最好,胶合强度达到了0.79 MPa.     

广植柠条,恢复植被--关于在我国西北地区大力发展柠条林的建议

我国是世界上环境问题最为突出的国家之一,包括晋、陕、蒙、甘、宁、青、新七省区在内的西北部地区,既是我国水土流失、风沙等生态灾难最严重的地区,也是我国大面积集中连片的社会经济贫困地区。每年流入黄河的１６亿ｔ泥沙,每年以２４６０ｋｍ２速率扩展的沙漠,主要发生在这一地区。水土流失和土地沙化造成的生态环境恶化直接阻碍着当地的社会经济发展,吞噬着人们辛勤劳动的成果,危及着人们的生存安全,从而使这一地区成为我国环境与发展的矛盾最为尖锐的地区。要解决这里的发展问题,必须首先解决环境问题,在解决环境问题的过程中…     

氯化锂-乙醇-水溶液稀释热

使用LKB2107型流动式微量热计-微机数据采集系统测量了288.15 K、298.15 K和308.15K下LiCl-C     

Optimal pricing and inventory policy with order cancelations under the cash-on-delivery payment scheme

Considering a periodic review system where the online seller allows the customers to pay when the products are delivered to them（referred as cash-on-delivery payment scheme in this paper）,the authors investigate the seller＇s joint pricing and inventory control policy with a finite planning horizon.In particular,the authors incorporate the customers＇ possible order cancellation behavior with the cash-on-delivery scheme.It can be proven that the base-stock list price policy is optimal under mild conditions.The authors also analyze the impact of the customers＇ forward looking behavior on the optimal policy.     

浅析企业人力资源管理机制的创新

随着市场经济的发展,企业间的竞争越来越激烈,高素质的人力资源成为企业生存发展的根本保证。有效的人力资源管理机制将为企业获得更多的人才,以提高企业的核心竞争力。笔者针对目前企业人力资源管理机制中存在的一些问题,探寻出几点新的对策。     

如何在工程竣工结算过程中控制工程造价

随着我国经济建设的发展,建筑企业的规模越来越大,工程结算又是决定工程造价最关键的一步,如何在这最关键的一步控制好工程造价。工程造价直接关系着建设单位和施工单位效益的问题,这就需要双方共同努力,所以文章就作者在这几年工作中总结的几点经验进行论述。     

Growth of Magnetite Nanoparticles under Magnetic Fields

1 Introduction Over the past several years, the preparation and characterization ofnanoscale magnetic materials, especially one-dimensional (1D) nanostructure, have attracted much attention as the nanomaterials would allow investigating the fundamental aspects of magnetic-ordering phenomena in magnetic materials with reduced dimensions and could lead to new potential applications such as data storage technology[1-6].     

线路病害整治措施探讨

文章针对线路路基轨道的病害,论述了当前快速化、重载化运输的条件下,根治翻浆冒泥病害的方法以及整治措施.