全文获取类型
收费全文 | 200篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
化学 | 46篇 |
力学 | 5篇 |
综合类 | 3篇 |
数学 | 72篇 |
物理学 | 82篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 16篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 10篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 4篇 |
2005年 | 14篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有208条查询结果,搜索用时 93 毫秒
41.
本文发展了一种对3D形式的2D NOE分析软件,提出了一种可表达2D NOE与3D NOE-NOE峰值之间关系的数学模型,并考虑了存储空间与CPU时间的平衡. 相似文献
42.
43.
针对自动测试软件平台的通用化和智能化,把软件测试中的模型驱动思想应用于硬件自动化测试系统中,提出了通用测试集成环境(GTIE)的概念,并进行了详细研究与设计,包括软件分析、软件设计以及软件实现过程。充分利用了UML思想对整个软件系统进行建模,其中包括软件的功能、静态结构、动态行为等,使软件的开发标准化。所实现的GTIE可有效提高测试程序的开发效率,降低开发成本,并使测试程序具有非常好的通用性。 相似文献
44.
45.
46.
晶体结构是《材料科学基础》课程的重中之重,是学好后续专业知识的基础,此部分内容概念抽象,需要很强的空间想象能力,传统的二维图片很难表达离子/原子的三维空间排布。本文以钙钛矿(CaTiO3)结构教学为例,借助Diamond软件和网络数据库构建立体性和可操作性三维晶体结构模型,利用此模型可以清晰直观的看到晶体结构内部原子的排列。通过改变立方体位置和配位体中心原子构建不同的晶体结构模型,采用坐标系法、最紧密堆积法和多面体的连接方式三种方法,对钙钛矿的晶体结构进行全面的描述,有助于提高学生的学习兴趣和效率。 相似文献
47.
Sanjeev Singh 《Fiber and Integrated Optics》2019,38(1):43-75
In this article, a comparative performance analysis of three (03) different algorithms operating in the control plane of the three (03) varied architectures such as Physically Distributed, Logically Distributed, and Physically Centralized Architecture has been done. The paper also elucidates the working and implementation of the three proposed architectures with suitable block diagram of system model. Besides, in these architecture models OpenFlow (OF) governed various MATLAB components have been designed such as Application Controller, Optical Transport Network Controller, SDOWN Controller, Ethernet switch-1 and 2, ROADM and Wi-Fi access point with suitable interfaces. Pseudo codes of the algorithms operating in above said MATLAB components are duly explained with flowcharts. Mathematical analysis of three different architecture in respect of latency is carried out, and results and discussions with suitable figures have also been represented. The results obtained show that out of three (03) aforesaid architectures the Physical Centralized Architecture has better performance upto 45 Km in terms of Q-factor, SNR, BER, Jitter and Latency. 相似文献
48.
In this paper, we consider an inventory system whose products share a common hardware platform but are differentiated by two types of software. Choice of different software results in different installation cost and different selling price of the whole product. Product with different software also faces different customer demand. We investigate the optimal proportion of an order to be installed with software 1 or 2, that maximizes expected profit in the single and multiple period scenarios, respectively. The optimal policy is analytically obtained and proved to be an order-up-to policy in each scenario. Our investigation reveals that whether to replenish, and how much to replenish each product depend not only on its own initial inventory level, and system parameters, but also the initial inventory level of the other product. We perform numerical experiments using the optimal policies we have derived in the paper. 相似文献
49.
Oliver Koch 《Nachrichten aus der Chemie》2009,57(12):1211-1213
50.
This paper presents a general-purpose software framework dedicated to the design and the implementation of evolutionary multiobjective optimization techniques: ParadisEO-MOEO. A concise overview of evolutionary algorithms for multiobjective optimization is given. A substantial number of methods has been proposed so far, and an attempt of conceptually unifying existing approaches is presented here. Based on a fine-grained decomposition and following the main issues of fitness assignment, diversity preservation and elitism, a conceptual model is proposed and is validated by regarding a number of state-of-the-art algorithms as simple variants of the same structure. This model is then incorporated into the ParadisEO-MOEO software framework. This framework has proven its validity and high flexibility by enabling the resolution of many academic, real-world and hard multiobjective optimization problems. 相似文献