330 research outputs found
黑洞超吸积与伽玛射线暴
黑洞超吸积模型是伽玛射线暴中心引擎的有力候选者之一.将结合纷繁复杂的伽玛射线暴、引力波及其电磁对应体等爆发现象,简述该模型的一系列理论研究成果.同时,提供部分黑洞超吸积的常用工具类结论和公式,为相关工作提供理论支持.国家重点基础研究发展计划(2014CB845800);;国家自然科学基金项目(11822304、11473022)资
Design and Implementation of News Release Management System for an Enterprise
随着科技的进步,信息时代的快速发展,生活节奏日益加快,通过纸质期刊、杂志、报纸等方式获取信息已经不能满足当前的需要,因此通过互联网获得更多更详细的信息成为当前更多人的首选方式,而目前一些企业的门户网站或新闻发布网站发布信息是以静态页面手动添加的方式进行的,但是随着信息量的逐渐以几何式增加,通过手动添加页面的方式很不利于管理人员的工作,为了使得管理员的工作更为有效便捷,搭建一套企业新闻发布管理系统是很有必要的。 本文将当前应用较为广泛的管理系统的管理模式、开发方式、实现过程进行了解和研究,其次对系统的业务需求、功能需求进行调研分析,确定系统的主要开发目标;最后通过采用J2EE相关技术,开发平台...With the progress of science and technology, the rapid development of information age, quickening the pace of life, through the paper journals, magazines, newspapers and other ways to obtain information already cannot satisfy the needs of the current, so get more detailed information via the Internet has become one of the preferred means of more people, and now some of the enterprise portal websit...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201323058
Central Engine of Gamma-Ray Bursts: Models of Neutrino-Dominated Accretion Flows around Black Holes
γ射线暴(Gamma-RayBurst,本文统一简记为GRB)是一种来自宇宙空间的γ射线在短时间内突然增强的现象,是目前观测到的宇宙中最剧烈的爆发现象。在过去的十年间,GRBs的观测和理论研究取得了很大的进展。用来解释GRBs及其余辉的火球-激波模型已经被普遍地接受,但是相对论火球的中心能源机制仍不清楚,相关的模型大多借助于黑洞的超吸积过程。 本文综述了GRBs到目前为止所取得的观测和理论成果,并介绍了本人在攻读博士学位期间对超吸积模型之一—中微子主导吸积流(neutrino-dominatedaccretionflow,本文统一简记为NDAF)模型的研究成果。本文包括三部分:综述部分(第一...The gamma-ray burst (GRB) is the most drastic burst in the universe known so far. In the past decade, lots of remarkable progresses have been made in observations and theoretical researches of GRBs. The fireball-shock model has been widely accepted to interpret the gamma-ray and afterglow radiation of GRBs, though the central engine of the relativistic fireball is not yet well understood, but most...学位:理学博士院系专业:物理与机电工程学院物理学系_理论物理学号:2005140302
Salary system redesign for X Real Estate Company
摘要 薪酬激励是现代人力资源管理的重要组成部分,它对提高企业的竞争力有着不容忽视的作用。怎样建立科学的薪酬激励机制,发挥薪酬的最佳激励效果,吸引和留住人才,造就一支高效、团结、富有战斗力的员工队伍,实现企业可持续发展,是企业人力资源管理的一项非常重要的工作。同时它更是稀缺人才的物业管理行业首要关注的问题。因为员工所得到的薪酬既是对过去工作的肯定和补偿,也是他们未来努力工作可得到报酬的预期。在员工心目中,薪酬不仅仅是自己的劳动所得,还代表着员工自身的价值、代表企业对员工工作的认同。所以,薪酬激励不单单是金钱激励,实质上是一种复杂的企业薪酬激励方式,它包含着成就激励、地位激励等等。因此,薪酬激励...Abstract Salary motivation is an important part of modern human resources management. Its role in strengthening a company’s competitive status is not to be ignored. A key issue for human resources management of a company is how to set up a scientific salary motivation system and how to bring forth the best result of the system so as to attract and retain the talents and to bring up an efficient,u...学位:工商管理硕士院系专业:管理学院企业管理系_外国语言文学学号:20041542
十字花科与豆科作物对微囊藻毒素耐受性差异的比较
[目的]研究十字花科与豆科作物对微囊藻毒素(MC)耐受性的差异。[方法]以十字花科作物典型作物油菜、小白菜、甘蓝与豆科典型作物黄豆、豌豆、蚕豆为材料,检测它们在不同浓度MC暴露条件下的生长发育情况,检测指标包括发芽率、株高、叶绿素等。[结果]十字花科作物中油菜与小白菜受MC影响较大,甘蓝受影响较小,而豆科作物普遍受影不大。[结论]豆科作物比十字花科作物对MC耐受性更强,在受微囊藻毒素污染地区可以优先种植豆科作物
小股东权益与公司治理绩效改善——基于产权理论的分析
目前关于公司治理的不同研究结果之间实际上形成了一个悖论 :控制性股东对小股东利益的侵占是公司治理绩效改善的必要代价。对此 ,本文通过分析 ,首先指出公司治理关注的基本代理问题应该是广大小股东与控制性股东之间的代理冲突 ,而不是普遍认识上的股东与经理之间的代理冲突 ;其次 ,本文指出控制性股东对小股东利益的侵占是一个普遍存在的问题 ,并尝试运用产权分析的方法从公司所有权安排的角度具体考察控制性股东及小股东的实际权利 ,分析的结果表明 :小股东在公司所有权安排中遭到歧视 ,从而为控制性股东盲目追求控制权的私下收益提供了较大的可行空间 ;最后 ,本文就过分强调“搭便车”对小股东监督行为的影响的观点提出批驳 ,认为只要在所有权安排过程中能够保证权利在各个参与主体之间的合理分配和有效制衡 ,在此基础上 ,通过一定的制度安排就可以确保小股东在很大程序上克服“搭便车”问题 ,并对控制性股东进行有效的监督 ,从而同时实现保护小股东权益和改善公司治理绩效这两个一度被视为是相互排斥的目标
微囊藻毒素对水稻、高粱和玉米毒性的研究
以水稻、高粱和玉米为研究对象,考察了微囊藻毒素对受试作物的毒性差异,研究了不同浓度MC对萌发及萌发初期生长发育的影响,不同灌溉时期对受试作物生长发育的影响,检测指标包括发芽率、株高、鲜重、叶绿素、根系活力等。结果表明,受试作物对微囊藻毒素毒性并不一致,水稻发芽率受到明显抑制,高粱发芽率基本不受影响,玉米出现了低浓度促进、高浓度抑制的现象;MC对水滔、高粱和玉米的光合作用、株高和鲜重没有抑制作用,反而有一定的促进效果;不同灌溉时间条件下的研究结果表明,萌发前对高粱和玉米染毒会明显抑制植株根系活力,萌发结束后在染毒则对植株根系活力有明显的促进作用
复合图书馆信息资源建设和服务策略
在建设数字图书馆的热潮中,我们应冷静的注意到,复合图书馆是当前图书馆的主体形态,应立足实际开展信息资源建设和信息服务工作
Optimization of β-Cyclodextrin Inclusion Technology of Volatile Oil from Pueraria Compound by Orthogonal Design
目的优选葛根复方挥发油的包合工艺,提高制剂的稳定性。方法采用饱和水溶液法制备包合物,以挥发油中藁本内酯、桂皮醛、甲基丁香酚包合率及包合物得率为综合评价指标,采用正交试验法考察挥发油与β-环糊精的比例、包合时间、包合温度对包合工艺的影响,优化得到葛根复方中挥发油的最优包合工艺。结果葛根复方中挥发油的最佳包合工艺条件为挥发油与β-环糊精比例为1∶8,包合温度为30℃,包合时间为1h,验证试验中,藁本内酯、桂皮醛及甲基丁香酚的包合率为别为86.58%±0.009%,73.34%±0.001%,68.89%±0.020%,包合物得率为67.98%±0.047%。结论所确定的包合工艺挥发油的包合率高、工艺稳定可行。Objective To obtain the optimized technology of volatile oil from Pueraria Compound with β-Cyclodextrin( β-CD). Methods The inclusion compound was prepared by saturated peroxide solution method. In order to optimize inclusion technology,orthogonal design was performed,with the content of multi-target ingredient,such as ligustilide,cinnamic aldehyde,methyleugenol and the yield of inclusion as comprehensive evaluation indexes. Three factor was performed,the ratio of volatile oil( m L) to β-CD( g),the inclusion temperature and the inclusion time. Results The optimum conditions for inclusion process were as follow: the ratio of volatile oil( m L) to β-CD( g) was 1: 8,the inclusion temperature was 30℃ and the inclusion time was 1h. With the optimum inclusion condition,the content of ligustilide,cinnamic aldehyde and methyleugenol and the yield of inclusion were 86. 58% ± 0. 009%,73. 34% ± 0. 001%,68. 89% ± 0. 020%,and 67. 98% ± 0. 047%,respectively.Conclusion The optimum inclusion condition was stable and reproducible with a high inclusion yield.国家自然科学基金(No.81270901);上海市教委基金(No.15cxy21
The relationship between EEG band power, cognitive processing and intelligence in school-age children
To investigate the differences in event-related potential parameters related to children’s intelligence and cognitive ability, 24 individuals from an experimental class of intellectually gifted children and 23 intellectually average children as the control group from a regular class were selected in the present study and the main neural mechanism pertaining tohigh intelligence was investigated. The electroencephalogram (EEG) was recorded and the relationship between different percentages of Delta, Theta, Alpha1, Alpha2, Beta1 and Beta2 and intelligence and cognitive ability were analyzed. The results
suggested that Delta power activity in brighter individuals was more than that in normal individuals, and Alpha2 and Beta1 power activity in higher intelligence individuals were less than that in normalindividuals. In high ability group, Alpha1 was significantly correlated with visual search ability, and Theta band correlated with simple abstract matching significantly. While in the normal group, Delta band related significantly with short term memory abilities. Spectral EEG parameters could be regarded as neural bases for fast reaction and a good tool todiscriminate high intelligent children from the average. 
- …