全文获取类型
收费全文 | 29560篇 |
免费 | 2216篇 |
国内免费 | 1255篇 |
专业分类
电工技术 | 1426篇 |
技术理论 | 6篇 |
综合类 | 1960篇 |
化学工业 | 5174篇 |
金属工艺 | 1875篇 |
机械仪表 | 1821篇 |
建筑科学 | 2275篇 |
矿业工程 | 808篇 |
能源动力 | 801篇 |
轻工业 | 1707篇 |
水利工程 | 521篇 |
石油天然气 | 1978篇 |
武器工业 | 159篇 |
无线电 | 3206篇 |
一般工业技术 | 3716篇 |
冶金工业 | 1583篇 |
原子能技术 | 397篇 |
自动化技术 | 3618篇 |
出版年
2024年 | 111篇 |
2023年 | 479篇 |
2022年 | 749篇 |
2021年 | 1078篇 |
2020年 | 829篇 |
2019年 | 689篇 |
2018年 | 787篇 |
2017年 | 858篇 |
2016年 | 856篇 |
2015年 | 1016篇 |
2014年 | 1352篇 |
2013年 | 1663篇 |
2012年 | 1699篇 |
2011年 | 1942篇 |
2010年 | 1760篇 |
2009年 | 1710篇 |
2008年 | 1603篇 |
2007年 | 1443篇 |
2006年 | 1437篇 |
2005年 | 1308篇 |
2004年 | 979篇 |
2003年 | 1012篇 |
2002年 | 1066篇 |
2001年 | 1039篇 |
2000年 | 802篇 |
1999年 | 875篇 |
1998年 | 732篇 |
1997年 | 582篇 |
1996年 | 522篇 |
1995年 | 434篇 |
1994年 | 377篇 |
1993年 | 269篇 |
1992年 | 209篇 |
1991年 | 156篇 |
1990年 | 120篇 |
1989年 | 106篇 |
1988年 | 76篇 |
1987年 | 51篇 |
1986年 | 55篇 |
1985年 | 24篇 |
1984年 | 29篇 |
1983年 | 27篇 |
1982年 | 20篇 |
1981年 | 19篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 5篇 |
1976年 | 13篇 |
1970年 | 6篇 |
1966年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Multiplexed Bioassays: Dual‐Encoded Microbeads through a Host–Guest Structure: Enormous,Flexible, and Accurate Barcodes for Multiplexed Assays (Adv. Funct. Mater. 34/2016) 下载免费PDF全文
103.
Fei Wei Pengyun Chen Hongliang Jian Lu Sun Xiaoyan Lv Hengling Wei Hantao Wang Tingli Hu Liang Ma Xiaokang Fu Jianhua Lu Shiyun Li Shuxun Yu 《International journal of molecular sciences》2022,23(9)
As one of the most important factors in alternative splicing (AS) events, serine/arginine-rich (SR) proteins not only participate in the growth and development of plants but also play pivotal roles in abiotic stresses. However, the research about SR proteins in cotton is still lacking. In this study, we performed an extensive comparative analysis of SR proteins and determined their phylogeny in the plant lineage. A total of 169 SR family members were identified from four Gossypium species, and these genes could be divided into eight distinct subfamilies. The domain, motif distribution and gene structure of cotton SR proteins are conserved within each subfamily. The expansion of SR genes is mainly contributed by WGD and allopolyploidization events in cotton. The selection pressure analysis showed that all the paralogous gene pairs were under purifying selection pressure. Many cis-elements responding to abiotic stress and phytohormones were identified in the upstream sequences of the GhSR genes. Expression profiling suggested that some GhSR genes may involve in the pathways of plant resistance to abiotic stresses. The WGCNA analysis showed that GhSCL-8 co-expressed with many abiotic responding related genes in a salt-responding network. The Y2H assays showed that GhSCL-8 could interact with GhSRs in other subfamilies. The subcellular location analysis showed that GhSCL-8 is expressed in the nucleus. The further VIGS assays showed that the silencing of GhSCL-8 could decrease salt tolerance in cotton. These results expand our knowledge of the evolution of the SR gene family in plants, and they will also contribute to the elucidation of the biological functions of SR genes in the future. 相似文献
104.
介绍了某型导弹发控盒电路板综合测试系统的硬件和软件设计,该系统以PC计算机为平台,采用总线式设计思想,实现了对电路板检测的自动化、快速化和智能化. 相似文献
105.
汽车已经成为现代物质文明的一种象征和人类生活中不可缺少的部分,而汽车在一个国家的普及程度,也成为衡量其工业化的重要标志.本文论述了国内外汽车产品发展状况和汽车产品的开发体系. 相似文献
106.
Thomas G. Kannampallil Kevin Waicekauskas Daniel G. Morrow Kathryn M. Kopren Wai-Tat Fu 《Cognition, Technology & Work》2013,15(2):121-131
Medication adherence—taking medication as prescribed—is critical for successful self-care, especially among older adults. Adherence depends on developing and implementing plans for taking medications. Age-related cognitive declines that affect adherence may be mitigated using external tools that support patient-provider collaboration needed to develop these adherence plans. We tested the effectiveness of structured collaborative medication tools to support better medication planning and adherence practices. Evidence for benefits of collaborative tools has been mixed in terms of their usefulness for medication-scheduling tasks, perhaps because the tools have not been explicitly designed to support patient-provider collaboration. A total of 144 community-dwelling older adults participated in pairs and performed the role of a patient or provider in a simulated patient-provider medication-scheduling task. Each pair worked with a structured (MedTable? and e-MedTable) or unstructured (Medcard) scheduling tool and completed four problems (2 simple and 2 complex). Performance was measured using the following: problem-solving (medication schedule) accuracy, problem-solving time, solution (schedule) optimality, tool usability, collaborative effectiveness, and subjective workload involved in creating the medication schedules. Participants using structured tools produced more accurate and optimal schedules. They also rated subjective workload as lower and thought that the structured tools were easier to use, reduced subjective workload associated with creating the schedules. There was also suggestive evidence that participants using the structured tools rated more highly the quality of their collaboration. Structured medication-scheduling tools have the potential to improve medication adherence among older adults because they support collaborative planning and reduce the cognitive load involved in creating these adherence plans. 相似文献
107.
男同性恋群体的城市空间分布及文化生产:以沈阳为例 总被引:3,自引:0,他引:3
From the pespective of space-culture, this paper explores how gay people's body, behavior and social relations are organized, represented and understood in Shenyang city by adopting participating observation, in-depth individual interview and historical literature review. Through the interaction between the urban space and the gay groups' inner characteristics, this paper finds out that the urban space constructs a dynamic platform for the mobilization of homosexual behavior, emotion and identity. 相似文献
108.
Hsien-Chin Chiu Chao-Hung Chen Che-Kai Lin Jeffrey S. Fu 《Microelectronics Reliability》2011,51(8):1337-1341
The InAlAs/InGaAs metal-oxide-semiconductor metamorphic high electron mobility transistors (MOS-mHEMTs) were demonstrated by using liquid-phase HBr treatment technology to form a high-quality gate insulator layer. In this study, liquid-phase HBr treatment technology was used instead of traditional plasma-assisted chemical vapor deposition (PECVD) because the proposed technology can prevent the device from plasma-induced damage. The novel HBr + ultraviolet (UV) illumination treated InGaAs provided a lower surface states such that MOS structure can be efficiently obtained. Besides, based on the atomic force microscopy (AFM) measurement, the native oxides film formed by HBr + UV illumination treatment also provided a better surface roughness compared to traditional NH4OH and only HBr treatment solutions. It is beneficial for reducing the surface traps and lowering the leakage current in MOS-mHEMTs. Based on the flicker noise and load-pull power measurement results, HBr + UV treatment mHEMT achieved a low flicker noise at high current level and the power-added efficiency can be enhanced up to 9%. Therefore, the novel liquid phase method of HBr + UV illumination treatment exhibited a highly potential for low noise microwave power device applications. 相似文献
109.
Song Fu Osmo Kauppila Matti Mottonen 《The International Journal of Advanced Manufacturing Technology》2011,57(9-12):1079-1086
In 100% inspection, measurement errors are unavoidable. Due to these errors, acceptable products are sometimes rejected (overkill) and defective products are accepted (escape). Overkill increases production costs, while escape is a source of customer dissatisfaction. This study presents a model for calculating overkill and escape rates using process and measurement system performance data. A practical example of applying the model is also presented to calculate gage reproducibility and repeatability requirements for different production settings. Industrial managers and quality engineers can utilize the results of this study to calculate escape and overkill rates of their production systems, and to assess and improve their processes. 相似文献
110.
应用型本科院校担负着为地方以及周边地区培养具有生产、经营、管理、教学等知识和技能的专门性人才的艰巨任务,非英语专业大学英语课程是应用型本科院校开设的一门必修课程和公共性课程.无论在规模上还是在权重上,大学英语课程都占据极其重要的地位.从学力理论的发展性学力视角探究该课程的承载者,无论对教学对象本身、英语教师的教学以及教学管理来说都具有极其重要的参考价值. 相似文献