全文获取类型
收费全文 | 3208篇 |
免费 | 130篇 |
国内免费 | 63篇 |
专业分类
电工技术 | 127篇 |
综合类 | 90篇 |
化学工业 | 479篇 |
金属工艺 | 138篇 |
机械仪表 | 158篇 |
建筑科学 | 129篇 |
矿业工程 | 49篇 |
能源动力 | 76篇 |
轻工业 | 219篇 |
水利工程 | 21篇 |
石油天然气 | 155篇 |
武器工业 | 6篇 |
无线电 | 349篇 |
一般工业技术 | 512篇 |
冶金工业 | 582篇 |
原子能技术 | 95篇 |
自动化技术 | 216篇 |
出版年
2024年 | 8篇 |
2023年 | 36篇 |
2022年 | 48篇 |
2021年 | 86篇 |
2020年 | 58篇 |
2019年 | 47篇 |
2018年 | 70篇 |
2017年 | 77篇 |
2016年 | 70篇 |
2015年 | 81篇 |
2014年 | 89篇 |
2013年 | 134篇 |
2012年 | 125篇 |
2011年 | 143篇 |
2010年 | 142篇 |
2009年 | 112篇 |
2008年 | 137篇 |
2007年 | 159篇 |
2006年 | 115篇 |
2005年 | 129篇 |
2004年 | 88篇 |
2003年 | 76篇 |
2002年 | 81篇 |
2001年 | 66篇 |
2000年 | 49篇 |
1999年 | 74篇 |
1998年 | 233篇 |
1997年 | 173篇 |
1996年 | 118篇 |
1995年 | 75篇 |
1994年 | 61篇 |
1993年 | 71篇 |
1992年 | 28篇 |
1991年 | 37篇 |
1990年 | 19篇 |
1989年 | 26篇 |
1988年 | 26篇 |
1987年 | 18篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 22篇 |
1983年 | 16篇 |
1982年 | 24篇 |
1981年 | 16篇 |
1980年 | 17篇 |
1978年 | 12篇 |
1977年 | 6篇 |
1976年 | 19篇 |
1974年 | 6篇 |
1972年 | 6篇 |
排序方式: 共有3401条查询结果,搜索用时 0 毫秒
91.
92.
93.
Ke Fang Yuki Murakami Seiji Kanda Takaki Shimono Anh Tuan Dang Mitsuaki Ono Toshimasa Nishiyama 《International journal of molecular sciences》2022,23(14)
Osteoporosis is a common bone disease, particularly in menopausal women. Herein, we screened four Kampo medicines (Unkeito (UKT), Kamishoyosan (KSS), Kamikihito (KKT), and Ninjinyoeito (NYT)), frequently used to treat menopausal syndromes, for their effects on receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast differentiation in RAW 264 cells. Considering that UKT exhibited the most potent effect, we examined its effect on RANKL-induced osteoclastogenesis, the induction of osteoclast apoptosis, and the mechanisms underlying its effects. UKT inhibits RANKL-induced osteoclast differentiation in the early stage and decreases osteoclast-related genes, including tartrate-resistant acid phosphatase (Trap), dendritic cell-specific transmembrane protein (Dcstamp), matrix metalloproteinase-9 (Mmp9), and cathepsin K (Ctsk). Specifically, UKT inhibits the nuclear factor of activated T cells 1 (NFATc1), which is essential for osteoclastogenesis. UKT increases Bcl6, which antagonizes NFATc1 and Dc-stamp, thereby blocking the progression of osteoclasts to maturation. UKT also decreased nuclear translocation by downregulating the activity of p65/NF-κB. In addition, UKT enhances mononuclear osteoclast apoptosis via activation of caspase-3. Herein, we demonstrate that UKT suppresses RANKL-mediated osteoclastogenesis via the Blimp1–Bcl6 and NF-κB signaling pathways and enhances mononuclear osteoclast apoptosis. Furthermore, UKT prevents bone loss in OVX mice. Thus, UKT might be a potential therapeutic agent for postmenopausal osteoporosis. 相似文献
94.
国内汽车起重机用钢丝绳现状 总被引:1,自引:1,他引:0
简述汽车起重机的概况,以国内外汽车起重机的部分型号为例,介绍国内汽车起重机用钢丝绳的需求现状。重点介绍提升用钢丝绳、变幅用钢丝绳、伸缩臂用钢丝绳的结构、规格的选用,以期全面提高我国汽车起重机用钢丝绳的使用性能和寿命。 相似文献
95.
18×7类不旋转钢丝绳结构特点 总被引:4,自引:4,他引:0
指出18×7类不旋转钢丝绳用途的广泛性,通过对18×7类不旋转钢丝绳结构特点的认识,分析钢丝绳的稳定性及产品缺陷,举例说明提高钢丝绳实物质量的措施和行业内急需解决的技术难题。 相似文献
96.
97.
水泥行业属于高污染、高能耗行业,将清洁生产的理念运用到水泥工业意义重大。根据水泥工业的现状,详细阐述了水泥工业清洁生产的内容和技术途径,包括合理有效地利用自然资源和能源,控制污染物的产生和排放,有效利用废弃物,改善工艺和操作过程以及提高管理水平等。 相似文献
98.
The double-inlet pulse tube refrigerator that has a diaphragm inserted in a bypass-tube, which enabled it to transmit a pressure oscillation whereas to obstruct a DC gas flow, was manufactured and tested. The oscillating flow behavior inside of the refrigerator was studied by using a smoke-wire flow visualization technique. It was found that if the diaphragm was optimized, the performance would be improved more than that of the refrigerator with a bypass valve due to the increase in the P–V work of the gas and the decrease in the convective heat loss caused by a secondary flow. 相似文献
99.
Luzhen Jing Yu Liu Jinmei Gao Meijuan Xu Min Gou Hao Jiang Guoquan Zhang Wenhao Li 《International Journal of Food Science & Technology》2019,54(9):2668-2678
The normal and waxy corn starch gels were subjected to repeated freeze–thaw treatment at 0, 1, 2, 3, 4,5 and 6 cycles with an interval of 24 h, and the effects on structural, physicochemical and digestible properties were investigated. The normal starch gels formed a honeycomb structure while waxy starch gels exhibited a lamellar structure, and the number of holes and lamellas increased with increasing cycles. The X-ray analysis showed that the A-type pattern of starches was converted into the B-type after treatment, and their relative crystallinity increased with the number of increased freeze–thaw cycles. The hardness increased in both normal and waxy starch. The solubility and pasting breakdown viscosity decreased in normal starch while they increased in waxy starch. The pasting peak time, peak viscosity, and setback viscosity increased in normal starch but decreased in waxy starch. The rapidly digested starch (RDS) and slowly digested starch (SDS) content in normal starch increased and non-digestible starch (RS) content decreased whereas the RDS, SDS and RS content in waxy starch was almost unchanged as the freeze–thaw cycles increased. In the meantime, the molecular weight of both normal and waxy starch decreased with freeze–thaw treatment. Therefore, the repeated freeze–thaw treatment can change the physicochemical and digestible properties which could be a basis for starch-based food processing. 相似文献
100.