全文获取类型
收费全文 | 5219篇 |
免费 | 236篇 |
国内免费 | 132篇 |
专业分类
电工技术 | 43篇 |
综合类 | 302篇 |
化学工业 | 994篇 |
金属工艺 | 1950篇 |
机械仪表 | 559篇 |
建筑科学 | 110篇 |
矿业工程 | 73篇 |
能源动力 | 36篇 |
轻工业 | 453篇 |
水利工程 | 17篇 |
石油天然气 | 13篇 |
武器工业 | 11篇 |
无线电 | 69篇 |
一般工业技术 | 241篇 |
冶金工业 | 619篇 |
自动化技术 | 97篇 |
出版年
2024年 | 13篇 |
2023年 | 38篇 |
2022年 | 138篇 |
2021年 | 162篇 |
2020年 | 161篇 |
2019年 | 92篇 |
2018年 | 75篇 |
2017年 | 114篇 |
2016年 | 135篇 |
2015年 | 114篇 |
2014年 | 309篇 |
2013年 | 301篇 |
2012年 | 416篇 |
2011年 | 430篇 |
2010年 | 344篇 |
2009年 | 362篇 |
2008年 | 299篇 |
2007年 | 371篇 |
2006年 | 356篇 |
2005年 | 271篇 |
2004年 | 163篇 |
2003年 | 159篇 |
2002年 | 140篇 |
2001年 | 141篇 |
2000年 | 119篇 |
1999年 | 98篇 |
1998年 | 49篇 |
1997年 | 62篇 |
1996年 | 39篇 |
1995年 | 33篇 |
1994年 | 22篇 |
1993年 | 14篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有5587条查询结果,搜索用时 31 毫秒
11.
Ernest Marco‐Urrea Xavier Gabarrell Gloria Caminal Teresa Vicent C Adinarayana Reddy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(9):1190-1196
BACKGROUND: Trichloroethylene (TCE) and perchloroethylene (PCE) are considered among the most important groundwater pollutants around the world. These compounds are usually found together in polluted environments but little is known about the ability of microorganisms to simultaneously degrade TCE and PCE. RESULTS: Data showed that several species of white‐rot fungi, including Trametes versicolor, Ganoderma lucidum, and Irpex lacteus, degrade substantial levels of TCE in pure culture. T. versicolor was chosen for further study since it degraded higher levels of TCE than the other organisms. Initial glucose concentration and reoxygenation of samples increased the amount of TCE dechlorination, but no significant difference in percentage TCE degradation was observed. T. versicolor was able to degrade 34.1 and 47.7% of PCE and TCE added as mixtures (containing 5 and 10 mg L−1, respectively). CONCLUSIONS: The degradation ability of TCE was extended to other species of white‐rot fungi. Percentage degradation as well as chloride release from mixtures of TCE and PCE showed that T. versicolor degrades mixtures of TCE and PCE almost as well as its ability to degrade individually added TCE or PCE. The results suggest the potential promise of T. versicolor for bioremediation of TCE and PCE in the environment. Copyright © 2008 Society of Chemical Industry 相似文献
12.
13.
Yoo‐Seong Kim Woong‐Sik Kim Hak‐Nyun Choi Tae‐Geum Koh Yong‐Seog Kim 《Journal of the Society for Information Display》2007,15(3):199-204
Abstract— Among various barrier‐rib manufacturing processes, the mold‐pattern‐transfer method has potential to reduce processing cost as well as the manufacture of high‐resolution pixels. In this study, the effects of major processing variables of the mold‐pattern‐transfer process on the formation of air‐trapped pores within barrier ribs were examined. The results indicated that with an optimum combination of the processing variables, barrier ribs without trapped defects can be produced, demonstrating the possibility of reducing the number of processing steps and costs of barrier ribs. 相似文献
14.
通过对Internet上模具知识特点的分析,提出通过修改模具论坛的发贴模板的方法来获取论坛贴子的标签,然后利用"七步法"构建Internet上模具知识本体,并初步提出语义搜索概念模型,为基于Internet模具知识的搜索引擎的实现提供理论和实践基础。 相似文献
15.
叙述胀砂与缩孔、缩松的关系,说明提高砂型刚度对防止胀砂、缩孔、缩松的重要性。指出型砂强度和砂型的紧实程度是常温下影响湿砂型刚度的主要因素。对影响湿砂型浇注时的刚度的各种因素进行了分析。 相似文献
16.
R.Babaei N.Hatami K.Asgari N.Varahram P.Davami 《铸造》2006,55(4):373-377
铸造过程中熔融金属内的固体渣粒的运动轨迹是非常重要的。文中给出了粒子传输轨迹的数学模型,该数学模型采用显示法来确定粒子的位置。模拟研究结果与用其它数学模型的模拟结果比较,吻合良好。该模型可用于固体粒子位置的确定,并应用到SUTCAST软件中。 相似文献
17.
Mensuration and simulation of mold filling process in semi-solid die-cast of aluminum alloy 总被引:1,自引:0,他引:1
To understand the flow trace of semi-solid slurry in mold cavity, some thermocouples were inserted in mold cavity, and the reaction timing of thermocouples showed the arrival of fluid. The filling time and rate were estimated by comparison between the experiment and calculation. The introduction of computer simulation technique based on ADSTEFAN was to predict injectionforming process and to prevent defects during trial manufacture of various parts. By comparing the formed appearance of parts in experiment and in simulation, and observing the relationship between internal defects inspected by X-ray or microscope and the flow field obtained in simulation, it was indicated that both have quite good agreement in simulation and experiment. Right predictions for cast defects resulted from mold filling can be carried out and proper direction was also proposed. The realization of numerical visualization for filling process during semi-solid die-cast process will play an important role in optimizing technology plan. 相似文献
18.
模具敏捷制造系统研究 总被引:5,自引:0,他引:5
针对模具设计制造过程复杂、条件苛刻和单件或小批量生产的特点 ,论述了模具产业发展敏捷制造技术的必要性。提出了模具敏捷制造系统框架和基于STEP与特征技术实现信息集成与过程集成的运行机制。阐述了基于Internet/Intranet的开放式可视化协同工作平台的模具敏捷制造实施方案。 相似文献
19.
为了适应火车全面调速后货运高度的要求,提出了有效的铸模改进方案。对铸模改造前后的使用寿命进行了分析。通过改造达到了降低铝锭垛高的目的,同时延长了铸模的使用寿命。 相似文献
20.