全文获取类型
收费全文 | 6923篇 |
免费 | 202篇 |
国内免费 | 432篇 |
专业分类
电工技术 | 172篇 |
综合类 | 299篇 |
化学工业 | 129篇 |
金属工艺 | 199篇 |
机械仪表 | 443篇 |
建筑科学 | 161篇 |
矿业工程 | 93篇 |
能源动力 | 46篇 |
轻工业 | 33篇 |
水利工程 | 13篇 |
石油天然气 | 64篇 |
武器工业 | 48篇 |
无线电 | 632篇 |
一般工业技术 | 205篇 |
冶金工业 | 43篇 |
原子能技术 | 56篇 |
自动化技术 | 4921篇 |
出版年
2024年 | 4篇 |
2023年 | 15篇 |
2022年 | 39篇 |
2021年 | 65篇 |
2020年 | 71篇 |
2019年 | 48篇 |
2018年 | 76篇 |
2017年 | 118篇 |
2016年 | 125篇 |
2015年 | 178篇 |
2014年 | 311篇 |
2013年 | 231篇 |
2012年 | 331篇 |
2011年 | 514篇 |
2010年 | 342篇 |
2009年 | 315篇 |
2008年 | 422篇 |
2007年 | 493篇 |
2006年 | 480篇 |
2005年 | 501篇 |
2004年 | 400篇 |
2003年 | 459篇 |
2002年 | 345篇 |
2001年 | 258篇 |
2000年 | 248篇 |
1999年 | 226篇 |
1998年 | 166篇 |
1997年 | 113篇 |
1996年 | 124篇 |
1995年 | 90篇 |
1994年 | 74篇 |
1993年 | 65篇 |
1992年 | 57篇 |
1991年 | 39篇 |
1990年 | 20篇 |
1989年 | 23篇 |
1988年 | 21篇 |
1987年 | 19篇 |
1986年 | 14篇 |
1985年 | 19篇 |
1984年 | 17篇 |
1983年 | 19篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1974年 | 3篇 |
排序方式: 共有7557条查询结果,搜索用时 15 毫秒
41.
文中讨论了一种基于窗口的对象用户界面设计思想及方法,详细描述了各种类的定义。在DOS环境下运用WatcomC++语言在微机上开发运行。它可以使用户方便地进行再开发工作,界面运用事件处理方式由窗口、弹出菜单、图标、按钮等组成。效果良好。 相似文献
42.
本文主要介绍Sun Openwindows Developer’s Guide3.0.1软件的简单使用和主要特点。 相似文献
43.
We introduce a probability model for populations of cells and viruses that interact in the presence of an anti-viral agent. Cells can be infected by viruses, and their longevity and ability to avoid infection are modified if they survive successive attacks by viruses. Viruses that survive the effect of the anti-viral agent may find that their ability to survive a future encounter with molecules of the anti-viral agent is modified, as is their ability to infect a healthy cell. Additionally, we assume that the anti-viral agents can be a cocktail with different proportions of agents that target different strains of the virus. In this paper, we give the state equations for the model and derive its analytical solution in steady state. The solution then provides insight into the appropriate mix or “cocktail” of anti-viral agents that can be designed to deal with the virus' ability to mutate. In particular, the analysis shows that the concentration of anti-viral agent by itself does not suffice to ultimately control the infection, and that it is important to dose a mix of anti-viral agents so as to target each strain of virus in a specific manner, taking into account the ability of each virus strain to survive in the presence of the anti-viral agents. Models of this kind may eventually lead to the computer aided design of therapeutic protocols or drug design. 相似文献
44.
J. S. Karn S. Syed-Abdullah A. J. Cowling M. Holcombe 《Behaviour & Information Technology》2007,26(2):99-111
The aim of the research described in this paper is to gain a qualitative understanding of how cohesiveness relates to personality type, performance and adherence to a particular software engineering methodology (XP). A variety of research methods were employed including ethnographic methods, questionnaires and interviews. An online personality test based on the Myers-Briggs Type Indicator (MBTI) was used to ascertain the personality types, and questionnaires were used throughout the project to measure levels of cohesiveness. Examples of how the teams worked together throughout the project are described, and whether and how this relates to the personality types of the individual members. The results indicate that certain teams were found to work consistently well over the project due to homogeneity in personality type and others were found to be very cohesive due to a mixture of types. 相似文献
45.
This paper proposes an efficient method to develop requirement specifications for Plant Control Software (PCSW) using software-component-based prototypes. Prior to this proposal, domain analyses were conducted on existing PCSWs, and their functions were classified into “similar functions” and “individual functions”. Then PCSW Software Components (PSC: PCSW Software Component, PSCs: PCSW Software Components) were developed to correspond to these functions. PSCs as parameter-style components were developed in order to satisfy the clients’ (we define clients as owners, managers and operators of plants) requirements. A support environment for developing requirement specifications was developed. The environment consists of the Prototype Development Tool (PDT), the Behavior Check Simulator (BCS) and the Requirement Specification Development Tool (RSDT). The method consists of four steps. In the first step, PDT is used to define the parameters to customize PSCs and to compose a PCSW prototype by setting these parameters to PSCs. In the second step, BCS is used to execute the composed PCSW prototype and check its behavior and relevancy against the clients’ expectations. In the third step, steps 1 and 2 are repeated until the behavior of the PCSW prototype satisfies the clients’ requirements. Finally, a requirement specification is developed from the PCSW prototype which fully reflects the clients’ requirements. In order to evaluate the proposed method, it has been applied in five development cases. A Requirement Coverage of 91%, a Requirement Revision Rate of 6%, a PSC Reuse Rate of 92% and a LOC Reuse Rate of 83% have been achieved. In addition, a reduction of 55% in the amount of time required to develop requirement specifications has been achieved. These results indicate that the proposed method has sufficient capability to develop an exhaustive and an adequate PCSW requirement specification. And the developed PSCs have sufficient functions and capability to compose PCSW prototypes, and the support environment is capable of shortening the time taken to develop requirement specifications. 相似文献
46.
基于MSP430F413 MCU的IC卡煤气表的设计与实现 总被引:1,自引:0,他引:1
提出了以TI公司MSP430系列MCU为基础的IC卡煤气表的设计思想,给出了总体设计,硬件电路设计,软件流程设计及主要模块的编程框架,讨论了低功耗问题。同时,对IC卡煤气表设计中一些应注意的问题也进行了简要的阐述。 相似文献
47.
伏安特性测量技术有着广泛用途。本文介绍一种用8098单片机为控制核心的智能化通用伏安特性测量系统的设计要点。包括系统的硬件和软件设计,以及针对实际问题所采用的一些设计技巧。成果分析表明,采用8098单片机有着独特的优越性和推广价值。 相似文献
48.
地化-气测录井仪将地化、气测二种成熟的技术,有机地结合在一起.地化、气测数据在同一软件下运行,可达到技术互补的优势,克服了单一录井方法录取资料单一片面的缺陷,有利于提高油气层的发现率和解释成功率,为实现录井仪器和录井服务向综合型发展的战略创造了条件。该文主要介绍了仪器的构成、功能及计算机软件的特色,并阐述了该仪器的技术装备优势及应用前景。 相似文献
49.
符丁 《电脑与微电子技术》2012,(11):29-32,40
针对隐藏于组织业务海量数据中的隐性软件需求获取提出一种方法。该方法的基本思想是:组织业务海量数据中隐含软件需求,它是以隐性知识形式存在于海量数据中的,隐性知识利用的解决方案就是组织及利益相关者对待开发软件系统的要求(软件需求)。首先,构建一个完整的、无冲突的、正确的待开发软件系统目标及其关系模型,并在待开发系统目标指导下,利用数据挖掘技术对数据进行挖掘,从中发现隐性知识;然后,识别知识的有用性和可用性;最后为可用性知识的利用提供解决方案。进而获取隐藏于大量数据中的隐性软件需求. 相似文献
50.
郑慧君 《电脑与微电子技术》2012,(6):20-23
目前国内对软件质量评估还没有明确的准则和衡量标准,难以实现定量评价,运用软件度量的最新研究成果,针对中小型软件进行质量指标分析,确定度量指标体系,建立定量度量模型,最终开发软件系统,进行案例分析。 相似文献