全文获取类型
收费全文 | 11906篇 |
免费 | 1054篇 |
国内免费 | 746篇 |
专业分类
电工技术 | 975篇 |
技术理论 | 1篇 |
综合类 | 1470篇 |
化学工业 | 985篇 |
金属工艺 | 503篇 |
机械仪表 | 712篇 |
建筑科学 | 1416篇 |
矿业工程 | 460篇 |
能源动力 | 349篇 |
轻工业 | 582篇 |
水利工程 | 554篇 |
石油天然气 | 717篇 |
武器工业 | 70篇 |
无线电 | 690篇 |
一般工业技术 | 741篇 |
冶金工业 | 1515篇 |
原子能技术 | 80篇 |
自动化技术 | 1886篇 |
出版年
2024年 | 59篇 |
2023年 | 167篇 |
2022年 | 328篇 |
2021年 | 350篇 |
2020年 | 388篇 |
2019年 | 314篇 |
2018年 | 289篇 |
2017年 | 322篇 |
2016年 | 373篇 |
2015年 | 397篇 |
2014年 | 688篇 |
2013年 | 637篇 |
2012年 | 816篇 |
2011年 | 971篇 |
2010年 | 722篇 |
2009年 | 711篇 |
2008年 | 679篇 |
2007年 | 840篇 |
2006年 | 780篇 |
2005年 | 682篇 |
2004年 | 599篇 |
2003年 | 528篇 |
2002年 | 415篇 |
2001年 | 362篇 |
2000年 | 241篇 |
1999年 | 191篇 |
1998年 | 153篇 |
1997年 | 111篇 |
1996年 | 100篇 |
1995年 | 78篇 |
1994年 | 83篇 |
1993年 | 49篇 |
1992年 | 33篇 |
1991年 | 22篇 |
1990年 | 26篇 |
1989年 | 34篇 |
1988年 | 15篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 13篇 |
1965年 | 9篇 |
1964年 | 9篇 |
1962年 | 7篇 |
1961年 | 7篇 |
1960年 | 6篇 |
1959年 | 12篇 |
1958年 | 7篇 |
1957年 | 6篇 |
1955年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
淀粉液化液灭酶方法的研究 总被引:5,自引:1,他引:4
某些情况下淀粉液化液需要严格控制液化的程度 ,因此需要及时终止残余淀粉酶的活性。实验用降低液化液 pH值、升高温度、以及两者并用等 3种方法结束液化反应过程 ,实验结果可作为工业生产过程参考。 相似文献
2.
William E Acree Jr Michael H Abraham 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(8):1441-1446
The contentions made in an earlier paper [J Chem Technol Biotechnol 80 : 133–137 (2005)] that the coefficients of the Abraham solvation equation do not provide meaningful information on the molecular properties of ionic liquid solvents is refuted. The objections noted in the earlier paper disappear when the solvation equation model is correctly applied to the experimental data. It is further shown that the coefficients of the Abraham solvation equations can be used to characterize ionic liquids and can be used to select solvents for the solubility of gaseous solutes. Copyright © 2006 Society of Chemical Industry 相似文献
3.
介绍了热水采暖系统运行及调整的注意事项,分析了立支管阀门、集气罐的作用,提出了使热水采暖系统的调节和集排气操作达到理想程度的有效措施,以实现良好的供暖效果。 相似文献
4.
James Rodgers Kaye Wolf Norm Willis Don Hamilton Ralph Ledbetter Curtis Stewart 《Color research and application》1994,19(5):322-331
A multiplant Quality Improvement Team [QIT] was firmed to develop and implement an evaluation program for various color measurement .systems as potential replacements for the then-current aging systems. The emphasis qf this article is the analytical methodology utilized to evaluate the various color systems. The evaluation program consisted cf two phases. Phase I was a general overview/review of several systems, while Phase II was an extensive internal comparative evaluation measurement systems. These were Milton-Roy's ColorMate HDS, HunterLab's Ultrascan, Datacolor's CS-5, and BYK-Gardner's The Color Sphere [TCS]. The main comparison criteria were interinstrument agreement [agreement between two instruments ofthe same system], user-friendly software and computer interface capability, vendor amenability to a long-term logistical and maintenance relationship, and price. All systems were evaluated by duplicate measurements on various color tiles, yarns, and polymer flakes-over 1600 measurements on each system. The systems were compared with an instrument matrix, a decision matrix, and a product matrix. The instrument matrix was a comparison qfinstrument parameters, software/math treatments, and economics. The decision matrix was a forced ranking of each system by each criteria category [1–4 scale, with 1 representing the best and 4 representing the worst]. The product matrix accentuated the relative importance ofone criterion category over another by multiplying the forced ranking by the criticality of the category. The criticality of a given category wus determined by consensus within the QIT. Thr combination qf the three matrices allowed the evaluator[.s] t o select the color rneasuremmt system that best satixfied the color measurement needs and requirements of their facility and their products. For this evaluation, all ofthe evaluated systems were superior to the then-current agingsystems. As a result of this methodology, one instrument emerged as clearly superior. © 1994 John Wrley & Sons, Inc. 相似文献
5.
介绍Ф210mm/Ф500mm× 800mm四辊液压轧机厚度预控系统中采用人机界面实现参数在线调整的方法,能大大提高预控参数的控制精度,减少轧机产品的厚度误差,是厚度自动控制的一项创新. 相似文献
6.
在热媒温度控制系统中以熔体温度作为主参数,组成串极调节系统。投入运行后,熔体温度稳定,调节阀动作平稳,效果良好。 相似文献
7.
《Information & Management》2014,51(8):1031-1042
Customer relationship management (CRM) has become one of the most influential technologies in the world, and companies are increasingly implementing it to create value. However, despite significant investment in CRM technology infrastructure, empirical research offers inconsistent support for its positive impact on performance. This study develops and tests a research model analyzing the process through which CRM technology infrastructure translates into organizational performance, drawing on the resource-based view (RBV) and the knowledge-based view (KBV) of the firm. Based on an international sample of 125 hotels, the results suggest that organizational commitment and knowledge management fully mediate this process. 相似文献
8.
Permeability of a polymer plays an important role in conferring the protective ability of organic coating to the steel surface against atmospheric corrosion. Although the relationship between structure of polymers and their permeability has been extensively studied in various applications like membranes, packaging, etc., such detailed study is lacking in the area of coatings. The systematic study of structure–permeability relationship of polymers in clear coatings can give guidelines in selecting the binder for the required application. This article deals with the effect of introduction of structural defects into a straight chain aliphatic polyesters on the protective ability of their clear coatings against corrosion. The mild steel panels coated with clear coatings based on the polyesters were exposed to humidity in humidity chamber. A novel technique of detecting the onset of corrosion was used instead of conventional methods that detect the failure of the coating due to corrosion. It was observed that even at 1–10% mole defect introduced by replacement of straight chain diols with branched diols, the protective ability of clear coatings was affected drastically. 相似文献
9.
王会云 《煤炭加工与综合利用》2004,(1):13-15
辛置选煤厂针对原煤煤质变化后的特点 ,采用有压给料三产品重介旋流器为核心的高效选煤工艺系统分选 5 0~ 0mm原煤 ;对旋流器一段及二段中心管的直径和插入深度、二段底流口的直径等进行了优化调整 ,同时调整了介质泵的工作频率及悬浮液密度等参数 ,取得了分选效率高、产品质量稳定等显著效果 相似文献
10.
王彦 《浙江工业大学学报》2009,(2):232-235
大学职能的发展历经了从教学主导到教学科研并举的演变。教学与科研在大学的发展历程和具体运作过程中存在着不可避免的矛盾。二者结合是优化资源配置、发展创新教育的最佳途径,对大学进行有效的分层定位是协调二者关系的关键。具体包括在宏观战略上明确定位,同时加强组织重构、分类管理等。此外,大学文化之于教学与科研和谐也十分重要。 相似文献