全文获取类型
收费全文 | 233683篇 |
免费 | 3956篇 |
国内免费 | 587篇 |
专业分类
电工技术 | 3783篇 |
综合类 | 190篇 |
化学工业 | 36801篇 |
金属工艺 | 10811篇 |
机械仪表 | 7505篇 |
建筑科学 | 5786篇 |
矿业工程 | 2234篇 |
能源动力 | 5430篇 |
轻工业 | 15042篇 |
水利工程 | 3191篇 |
石油天然气 | 7819篇 |
武器工业 | 25篇 |
无线电 | 23572篇 |
一般工业技术 | 50485篇 |
冶金工业 | 39447篇 |
原子能技术 | 6817篇 |
自动化技术 | 19288篇 |
出版年
2021年 | 2576篇 |
2020年 | 2043篇 |
2019年 | 2569篇 |
2018年 | 4374篇 |
2017年 | 4387篇 |
2016年 | 4878篇 |
2015年 | 3007篇 |
2014年 | 4774篇 |
2013年 | 10600篇 |
2012年 | 7290篇 |
2011年 | 9261篇 |
2010年 | 7312篇 |
2009年 | 7909篇 |
2008年 | 8303篇 |
2007年 | 8076篇 |
2006年 | 6967篇 |
2005年 | 6301篇 |
2004年 | 5658篇 |
2003年 | 5436篇 |
2002年 | 5103篇 |
2001年 | 4784篇 |
2000年 | 4418篇 |
1999年 | 4485篇 |
1998年 | 10393篇 |
1997年 | 7381篇 |
1996年 | 5715篇 |
1995年 | 4515篇 |
1994年 | 3970篇 |
1993年 | 4214篇 |
1992年 | 3308篇 |
1991年 | 3189篇 |
1990年 | 3187篇 |
1989年 | 3136篇 |
1988年 | 3108篇 |
1987年 | 2761篇 |
1986年 | 2824篇 |
1985年 | 3130篇 |
1984年 | 2932篇 |
1983年 | 2782篇 |
1982年 | 2516篇 |
1981年 | 2456篇 |
1980年 | 2504篇 |
1979年 | 2523篇 |
1978年 | 2525篇 |
1977年 | 2612篇 |
1976年 | 2991篇 |
1975年 | 2313篇 |
1974年 | 2168篇 |
1973年 | 2254篇 |
1972年 | 1992篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Kore Ekanath K. Shahane Guruling S. Mulik Ramesh N. 《Journal of Materials Science: Materials in Electronics》2022,33(13):9815-9829
Journal of Materials Science: Materials in Electronics - The Co1?xZnxFe2O4 (Co–Zn) ferrite nanoparticles with x varying from 0.0 to 0.4 have been manufactured by facile chemical... 相似文献
2.
Cristiano Silva do Nascimento Brenda N. Santos Sueli Rodrigues 《International Journal of Food Science & Technology》2022,57(8):5186-5194
In the present study, a prebiotic acerola juice containing gluco-oligosaccharides and dextran was produced and processed by high-intensity ultrasound (HIUS). After a simulated in vitro digestion, the gluco-oligosaccharides and dextran maintained 90% and 80% of their initial concentration in all prebiotic’s juices. At the same time, Vitamin C and phenolic compounds concentration increased significantly by 19% and 7% (P < 0.05). After the in vitro digestion, the prebiotic juice HIUS processed by 10 min showed the highest increase in gluco-oligosaccharides and bioactive compound concentrations. The HIUS processing imparted some dextran hydrolysis and improved its fermentability by Lacticaseibacillus casei. Gluco-oligosaccharides were extensively consumed as substrate in simulated intestinal conditions, promoting the L. casei NRRL B-442 growth and production of organic acids and short-chain organic acids. The prebiotic juice HIUS processed for 6 min showed the best responses regarding the metabolism of L. casei NRRL B-442. The results showed high-intensity ultrasound processed acerola juices containing gluco-oligosaccharides and dextran as a prebiotic food. 相似文献
3.
Kuznetsov I. V. Budin O. N. Shchepin A. S. Kalenova M. Yu. Mel’nikova I. M. Saprykin R. V. Al’zhev N. I. 《Inorganic Materials》2022,58(6):651-660
Inorganic Materials - We have studied the effect of annealing on the chemical and physical properties of mineral-like host matrices for immobilization of the rare-earth–actinide fraction from... 相似文献
4.
Hemavathi N. Sriranjani R. Arulmozhi Parvathy Meenalochani M. Deepak R. U. 《Wireless Personal Communications》2022,122(2):931-946
Wireless Personal Communications - Breast cancer is one of the rapid spreading diseases resulting in the death of younger age group of women. Unfortunately, as the detection of cancer is at later... 相似文献
5.
Brennan Michael C. Howard Marylesa Marzouk Youssef Dresselhaus-Marais Leora E. 《Journal of Materials Science》2022,57(31):14890-14904
Journal of Materials Science - We develop several inference methods to estimate the position of dislocations from images generated using dark-field X-ray microscopy (DFXM)—achieving... 相似文献
6.
Parkhomenko M. P. Kalenov D. S. Eremin I. S. Fedoseev N. A. Kolesnikova V. M. 《Journal of Communications Technology and Electronics》2022,67(9):1127-1133
Journal of Communications Technology and Electronics - A modified resonator method for determining the complex permittivity of materials based on the theory of small perturbations where a resonator... 相似文献
7.
Volkov K. N. Emelyanov V. N. Karpenko A. G. 《Journal of Engineering Physics and Thermophysics》2022,95(1):80-89
Journal of Engineering Physics and Thermophysics - A simulation of the vibroacoustic processes proceeding in a long pipe with an obstacle in the form of a circular cylinder, in which a fluid flows,... 相似文献
8.
Cognitive and metabolic workload assessment techniques: A review in automotive manufacturing context
Ergonomics assessment in the automotive industry has, to date, focused mainly on physical ergonomics, for example, manual handling and posture. However, workload and, in particular, metabolic and cognitive workload, contributes to worker efficiency but has not received sufficient attention to yield practical guidance for industry. Successful workload assessment requires in-depth understanding of the context in which it will be conducted and of the various assessment techniques which will be applied, with consideration given to factors such as feasibility, resources, and skill of the assessor. These requirements are met with challenges within large and complex organizations and are often dealt with in a piecemeal and isolated matter (i.e., reactive workload assessment). The present paper explores these challenges within the automotive manufacturing industry and aims to develop a decision matrix to guide effective selection of workload assessment techniques focused on metabolic and cognitive demands. It also presents the requirements for time, equipment, and knowledge to implement these techniques as part of a participatory ergonomics approach. Early findings suggest that most assessment techniques reviewed require further development, for example, to establish the acceptance criteria for the specific workload scenario. However, five methods (Garg, Borg RPE, IPAQ, SWAT, and NASA-TLX) are ready to use in certain applications. Ultimately, the findings suggest that it is possible to implement a participatory workload evaluation program within large and complex manufacturing plants. 相似文献
9.
Stumpo Vittorio Sebök Martina van Niftrik Christiaan Hendrik Bas Seystahl Katharina Hainc Nicolin Kulcsar Zsolt Weller Michael Regli Luca Fierstra Jorn 《Magma (New York, N.Y.)》2022,35(1):29-44
Magnetic Resonance Materials in Physics, Biology and Medicine - Innovative physiologic MRI development focuses on depiction of heterogenous vascular and metabolic features in glioblastoma. For this... 相似文献
10.
Bermeshev T. V. Zhereb V. P. Bundin M. P. Yasinsky A. S. Yushkova O. V. Voroshilov D. S. Samoilo A. S. Mazurova E. V. Zaloga A. N. Yakivyuk O. V. Bespalov V. M. 《Inorganic Materials》2022,58(6):604-611
Inorganic Materials - We have studied the effect of isothermal holding of a melt containing 78 mol % Bi2O3 and 22 mol % SiO2 and various melt cooling schedules on the morphology, microstructure,... 相似文献