全文获取类型
收费全文 | 1345篇 |
免费 | 210篇 |
国内免费 | 82篇 |
专业分类
电工技术 | 58篇 |
综合类 | 113篇 |
化学工业 | 131篇 |
金属工艺 | 57篇 |
机械仪表 | 54篇 |
建筑科学 | 118篇 |
矿业工程 | 66篇 |
能源动力 | 31篇 |
轻工业 | 86篇 |
水利工程 | 35篇 |
石油天然气 | 56篇 |
武器工业 | 4篇 |
无线电 | 118篇 |
一般工业技术 | 73篇 |
冶金工业 | 67篇 |
原子能技术 | 1篇 |
自动化技术 | 569篇 |
出版年
2024年 | 9篇 |
2023年 | 8篇 |
2022年 | 18篇 |
2021年 | 13篇 |
2020年 | 22篇 |
2019年 | 26篇 |
2018年 | 34篇 |
2017年 | 47篇 |
2016年 | 51篇 |
2015年 | 48篇 |
2014年 | 76篇 |
2013年 | 70篇 |
2012年 | 70篇 |
2011年 | 59篇 |
2010年 | 62篇 |
2009年 | 49篇 |
2008年 | 74篇 |
2007年 | 89篇 |
2006年 | 52篇 |
2005年 | 64篇 |
2004年 | 71篇 |
2003年 | 89篇 |
2002年 | 123篇 |
2001年 | 90篇 |
2000年 | 81篇 |
1999年 | 55篇 |
1998年 | 44篇 |
1997年 | 35篇 |
1996年 | 19篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 14篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1637条查询结果,搜索用时 15 毫秒
81.
王浩 《国外电子测量技术》2015,34(5):61-65
为了使生成的汇编代码具有更高的执行效率,设计并实现了一种基于GCC的 TMS320C67xx汇编指令级的代码优化算法。首先,将汇编指令按照功能划分为不同的指令类型,并将汇编指令链接到链表中。然后,针对每一个寄存器建立对该寄存器的读写操作指令链表。最后,通过对指令类型的判断和对寄存器读写操作指令链表的分析,完成了冗余代码的删除和指令合并。实验结果表明,经过代码优化后,TMS320C67xx汇编代码的执行效率提高了20%左右,较中间代码级的优化算法执行效率提高了15%左右。 相似文献
82.
83.
Mozhgan Chimeh Paul Cockshott Susanne B. Oehler Ashkan Tousimojarad Tian Xu 《Concurrency and Computation》2015,27(17):5060-5075
Intel's XeonPhi is a highly parallel x86 architecture chip made by Intel. It has a number of novel features which make it a particularly challenging target for the compiler writer. This paper describes the techniques used to port the Glasgow Vector Pascal Compiler to this architecture and assess its performance by comparisons of the XeonPhi with 3 other machines running the same algorithms. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
84.
Effect of running‐in process on friction behaviour of carbon nitride (CNx) coating in N2 gas stream was investigated with a newly introduced two‐step ball‐on‐disk friction test, where the rubbed Si3N4 ball in the pre‐sliding (step 1) was replaced by a new CNx‐coated Si3N4 ball in the subsequent sliding stage under N2 gas (step 2). The two‐step friction test is clarified to be a simple but effective technique for obtaining contact material combination of self‐mated CNx coatings and for achieving stable and low frictions of CNx coatings. Friction coefficients of CNx/CNx in N2 gas stream decrease greatly from 0.07 without pre‐sliding to less than 0.025 in two‐step friction tests. The minimum friction coefficient of 0.004 was obtained by introducing 500 cycles of pre‐sliding in ambient air. These stable and low frictions are attributed to the generation of self‐mated CNx coatings and the formation of a lubricious layer on the disk surface. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
85.
Nick Blismas Christine Pasquire Alistair Gibb 《Construction Management & Economics》2013,31(2):121-130
Evaluating to what extent a component or building system should be produced off‐site is inadequate within the industry. The potential benefits of off‐site production (OSP) are commonly cited when justifying an OSP approach, yet holistic and methodical assessments of the applicability and overall benefit of these solutions, to a particular project, have been found to be deficient. Common methods of evaluation simply take material, labour and transportation costs into account when comparing various options, often disregarding other cost‐related items such as site facilities, crane use and rectification of works. These cost factors are usually buried within the nebulous preliminaries figure, with little reference to the building approach taken. Further, softer issues such as health and safety, effects on management and process benefits are either implicit or disregarded within these comparison exercises. Yet it is demonstrated that these issues are some of the most significant benefits of OSP. A series of case studies demonstrated that evaluation focus is almost solely on direct material and labour costs of components, without explicit regard for the wider cost or soft issue implications of OSP on a project. The paper argues that until evaluation is more holistic and value‐based rather than cost‐based, OSP uptake in construction will be slow. 相似文献
86.
结合体外预应力加固和粘钢加固的优点,介绍一种新的加固普通钢筋混凝土桥梁的方法——预应力粘钢加固法。通过实验及实际施工,证明了预应力粘钢加固法是可行的,能显著提高普通混凝土梁正常使用阶段的刚度和承载能力。 相似文献
87.
88.
通过对循环冷却水系统腐蚀、结垢的原因分析,得出化学清洗预膜过程在循环水处理中的必要性,并结合武汉乙烯第二循环冷却水场的清洗预膜实际操作,及清洗预膜前后效果对比,证实了清洗预膜在新建循环冷却水场的必要性及在循环水处理中的重要作用。 相似文献
89.
以磷铵生产工艺指标中和料浆中N与P物质的量比为例,对比分析了预控法与均值极差图应用效果差异,发现在标准偏差较小的数据分析时,应用预控法效果更佳。 相似文献
90.
CHARLES W. GARDINER 《Software》1996,26(10):1087-1096
Many programmers find that the logical structure of data defined in ASA.1 is simple enough, but the physical representation requires painfully careful attention to lots of detail. ASN.1 'compilers' which we had used required a programmer ot know the intricacies of both ASN.1 and the generated code. Furthermore those which generated 'C' code were prone to 'memory leaks' and produced bulky code. Two features of object orientiation led us to develop a code generator that procues 'C++'. First Class inheritance permits a small number of functions to operate on objects of any derived class. Second, the destructors of such objects can be designed to prevent memory leaks automatically. Our own use of the system shows that within a few days programmers withh no pair exposure to ASN.1 can start writing applications using only the ASN.1 specification for reference. The generated code is compact and well protected anainst memory leaks. This paper describes the capabilies of the code generator, the library of functions for handling all ASN.1 objects so generated, and the interior structure of these objects which allows the library functions to navigate any hierarchy. The las section discusses our experience in using the system. 相似文献