全文获取类型
收费全文 | 10437篇 |
免费 | 972篇 |
国内免费 | 517篇 |
专业分类
电工技术 | 573篇 |
综合类 | 600篇 |
化学工业 | 1532篇 |
金属工艺 | 728篇 |
机械仪表 | 530篇 |
建筑科学 | 722篇 |
矿业工程 | 448篇 |
能源动力 | 265篇 |
轻工业 | 538篇 |
水利工程 | 196篇 |
石油天然气 | 1275篇 |
武器工业 | 83篇 |
无线电 | 1303篇 |
一般工业技术 | 1200篇 |
冶金工业 | 564篇 |
原子能技术 | 88篇 |
自动化技术 | 1281篇 |
出版年
2025年 | 1篇 |
2024年 | 172篇 |
2023年 | 225篇 |
2022年 | 358篇 |
2021年 | 491篇 |
2020年 | 405篇 |
2019年 | 341篇 |
2018年 | 341篇 |
2017年 | 359篇 |
2016年 | 326篇 |
2015年 | 439篇 |
2014年 | 491篇 |
2013年 | 613篇 |
2012年 | 655篇 |
2011年 | 747篇 |
2010年 | 603篇 |
2009年 | 565篇 |
2008年 | 501篇 |
2007年 | 519篇 |
2006年 | 562篇 |
2005年 | 502篇 |
2004年 | 349篇 |
2003年 | 283篇 |
2002年 | 253篇 |
2001年 | 206篇 |
2000年 | 230篇 |
1999年 | 279篇 |
1998年 | 216篇 |
1997年 | 173篇 |
1996年 | 164篇 |
1995年 | 139篇 |
1994年 | 123篇 |
1993年 | 72篇 |
1992年 | 71篇 |
1991年 | 48篇 |
1990年 | 26篇 |
1989年 | 24篇 |
1988年 | 18篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Chan Lu Jun Ye Yuanqing Chang Zeyuan Mi Shuai Liu Donghao Wang Zhezhi Wang Junfeng Niu 《International journal of molecular sciences》2022,23(17)
SWEETs (sugars will eventually be exported transporters), a well-known class of sugar transporters, are involved in plant growth and development, sugar transport, biotic and abiotic stresses, etc. However, to date, there have been few investigations of SWEETs in Orchidaceae. In this study, 23 SWEET genes were identified in Bletilla striata for the first time, with an MtN3/saliva conserved domain, and were divided into four subgroups by phylogenetic tree. The same subfamily members had similar gene structures and motifs. Multiple cis-elements related to sugar and environmental stresses were found in the promoter region. Further, 21 genes were localized on 11 chromosomes and 2 paralogous pairs were found via intraspecific collinearity analysis. Expression profiling results showed that BsSWEETs were tissue-specific. It also revealed that BsSWEET10 and BsSWEET18 were responsive to low temperature and oxidative stresses. In addition, subcellular localization study indicated that BsSWEET15 and BsSWEET16 were localized in the cell membrane. This study provided important clues for the in-depth elucidation of the sugar transport mechanism of BsSWEET genes and their functional roles in response to abiotic stresses. 相似文献
15.
针对互联网音频大数据的高速检索问题,结合音频指纹技术与过滤-提纯思想,提出一种面向音频大数据的鲁棒高效检索方法.在经典的Philips音频指纹基础上,提出了一种基于bag-of-features(BoF)的音频中间过滤指纹用于快速缩小检索范围,与Fibonacci Hashing检索相比提高检索速度约130倍;并设计了一种基于阈值的固定间隔抽样匹配方法,大幅减少匹配计算量,进一步提高检索速度可达140倍.实验结果显示:使用该方法在约10万首音频中对不同时长的音频片段进行批量检索,平均检索时间均小于1s;对音频进行MP3转换、重采样、随机剪切后再检索,召回率均在99.47%以上,理论准确率接近100%. 相似文献
16.
17.
Diluted magnetic semiconductors (DMSs) that possess both properties of semiconductors and ferromagnetism, have attracted a lot of attentions due to its potential applications for spin-sensitive electronic devices. Recently, a series of bulk form DMSs isostructural to iron-based superconductors have been reported, which can be readily investigated by microscopic experimental techniques such as nuclear magnetic resonance (NMR) and muon spin rotation (μSR). The measurements have demonstrated that homogeneous ferromagnetism is achieved in these DMSs. In this review article, we summarize experimental evidences from both NMR and μSR measurements. NMR results have shown that carriers facilitate the interactions between distant Mn atoms, while μSR results indicate that these bulk form DMSs and (Ga,Mn)As share a common mechanism for the ferromagnetic exchange interactions. 相似文献
18.
Due to the quantum confinement effect, atomically thin two-dimensional (2D) monolayer materials possess distinct characteristics from their corresponding bulk materials, which have received wide attention from science and industry. Among all the 2D materials, elemental 2D materials with the simplest components are most striking. As an emerging group-VIA elemental 2D monolayer material, tellurene exhibits many exciting fundamental properties, such as chemical and mechanical stabilities, bandgap and high carrier mobilities compared to phosphorene, graphene and MoS2, respectively. Besides, in further exploration, it was found that tellurene or tellurene-based device presents excellent thermoelectric properties, piezoelectric properties, quantum Hall effects, and superb optical properties especially nonlinear optics characteristics, etc. The properties of tellurene can be modulated by virtue of strain, defects, edges, and heterojunction effects. In view of so many unique properties, it has drawn significant interest since tellurene was predicted and fabricated successfully in 2017. In this paper, we review the 2D tellurene allotropes, experimental preparation, excellent properties, performance modulation and future development. 相似文献
19.
Long Wang Zhang Ting-An Lv Guo-Zhi Dou Zhi-He Zhang Wei-Guang Niu Li-Ping 《Russian Journal of Non-Ferrous Metals》2019,60(1):52-60
Russian Journal of Non-Ferrous Metals - The extraction of valuable elements from high-alumina fly ash was carried out using two methods, the carbochlorination method and the carbothermic method.... 相似文献
20.
Peiwen Zhang Yuxu He Shuang Wu Xinrong Li Xutao Lin Mailin Gan Lei Chen Ye Zhao Lili Niu Shunhua Zhang Xuewei Li Li Zhu Linyuan Shen 《International journal of molecular sciences》2022,23(14)
Mammalian adipose tissue can be divided into white and brown adipose tissue based on its colour, location, and cellular structure. Certain conditions, such as sympathetic nerve excitement, can induce the white adipose adipocytes into a new type of adipocytes, known as beige adipocytes. The process, leading to the conversion of white adipocytes into beige adipocytes, is called white fat browning. The dynamic balance between white and beige adipocytes is closely related to the body’s metabolic homeostasis. Studying the signal transduction pathways of the white fat browning might provide novel ideas for the treatment of obesity and alleviation of obesity-related glucose and lipid metabolism disorders. This article aimed to provide an overview of recent advances in understanding white fat browning and the role of BAT in lipid metabolism. 相似文献