全文获取类型
收费全文 | 290214篇 |
免费 | 21622篇 |
国内免费 | 11171篇 |
专业分类
电工技术 | 15504篇 |
技术理论 | 31篇 |
综合类 | 17474篇 |
化学工业 | 50286篇 |
金属工艺 | 16991篇 |
机械仪表 | 18475篇 |
建筑科学 | 22931篇 |
矿业工程 | 9543篇 |
能源动力 | 7974篇 |
轻工业 | 16680篇 |
水利工程 | 4811篇 |
石油天然气 | 20357篇 |
武器工业 | 2245篇 |
无线电 | 31516篇 |
一般工业技术 | 34488篇 |
冶金工业 | 15310篇 |
原子能技术 | 2866篇 |
自动化技术 | 35525篇 |
出版年
2024年 | 1222篇 |
2023年 | 4691篇 |
2022年 | 7966篇 |
2021年 | 11515篇 |
2020年 | 8569篇 |
2019年 | 7296篇 |
2018年 | 8199篇 |
2017年 | 9234篇 |
2016年 | 8051篇 |
2015年 | 11201篇 |
2014年 | 13814篇 |
2013年 | 16496篇 |
2012年 | 17801篇 |
2011年 | 19458篇 |
2010年 | 16800篇 |
2009年 | 15946篇 |
2008年 | 15481篇 |
2007年 | 15133篇 |
2006年 | 16028篇 |
2005年 | 14171篇 |
2004年 | 9069篇 |
2003年 | 7923篇 |
2002年 | 7324篇 |
2001年 | 6500篇 |
2000年 | 7118篇 |
1999年 | 8519篇 |
1998年 | 6863篇 |
1997年 | 5830篇 |
1996年 | 5459篇 |
1995年 | 4514篇 |
1994年 | 3767篇 |
1993年 | 2632篇 |
1992年 | 2145篇 |
1991年 | 1602篇 |
1990年 | 1176篇 |
1989年 | 936篇 |
1988年 | 761篇 |
1987年 | 524篇 |
1986年 | 389篇 |
1985年 | 265篇 |
1984年 | 183篇 |
1983年 | 120篇 |
1982年 | 130篇 |
1981年 | 88篇 |
1980年 | 70篇 |
1979年 | 24篇 |
1978年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Yufei Zhao Yuxia Zhang Zhiyu Yang Yiming Yan Kening Sun 《Science and Technology of Advanced Materials》2013,14(4)
AbstractScientists increasingly witness the applications of MoS2 and MoO2 in the field of energy conversion and energy storage. On the one hand, MoS2 and MoO2 have been widely utilized as promising catalysts for electrocatalytic or photocatalytic hydrogen evolution in aqueous solution. On the other hand, MoS2 and MoO2 have also been verified as efficient electrode material for lithium ion batteries. In this review, the synthesis, structure and properties of MoS2 and MoO2 are briefly summarized according to their applications for H2 generation and lithium ion batteries. Firstly, we overview the recent advancements in the morphology control of MoS2 and MoO2 and their applications as electrocatalysts for hydrogen evolution reactions. Secondly, we focus on the photo-induced water splitting for H2 generation, in which MoS2 acts as an important co-catalyst when combined with other semiconductor catalysts. The newly reported research results of the significant functions of MoS2 nanocomposites in photo-induced water splitting are presented. Thirdly, we introduce the advantages of MoS2 and MoO2 for their enhanced cyclic performance and high capacity as electrode materials of lithium ion batteries. Recent key achievements in MoS2- and MoO2-based lithium ion batteries are highlighted. Finally, we discuss the future scope and the important challenges emerging from these fascinating materials. 相似文献
992.
993.
994.
Yongsong Luo Benhai Yu Youchao Tu Ying Liang Yonggang Zhang Jinping Liu Jialin Li Zhijie Jia 《Materials Research Bulletin》2008,43(8-9):2166-2171
Cu2O nanocactuses were synthesized via a simple, low-temperature, and no time-consuming wet chemical route. The synthesized products were systematically studied by X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the formation of Cu2O nanocactuses was strongly depended on the addition of CTAB and NaOH. The structural evolution of the cactuslike Cu2O was found to follow dissolution and recrystallization processes. It is noteworthy that the stepwise synthetic procedure was crucial to the growth of the final nanoarchitectures. UV–vis spectrum was also used to estimate the absorption and photodegradation ability of the nanocactuses. 相似文献
995.
996.
Le Zhang Zhichen Wang Lei Wang Zhe Zhang Xu Chen Lin Meng 《Digital Communications & Networks》2021,(4):551-558
Many large-scale and complex structural components are applied in the aeronautics and automobile industries.However,the repeated alternating or cyclic loads in ... 相似文献
997.
Yingying Zhang Shuang Wang Lu Wang Xiaoyan Chang Yongxiao Fan Meiqing He Dawei Yan 《International journal of molecular sciences》2022,23(10)
Plasmodesmata (PD) are plant-specific channels connecting adjacent cells to mediate intercellular communication of molecules essential for plant development and defense. The typical PD are organized by the close apposition of the plasma membrane (PM), the desmotubule derived from the endoplasmic reticulum (ER), and spoke-like elements linking the two membranes. The plasmodesmal PM (PD-PM) is characterized by the formation of unique microdomains enriched with sphingolipids, sterols, and specific proteins, identified by lipidomics and proteomics. These components modulate PD to adapt to the dynamic changes of developmental processes and environmental stimuli. In this review, we focus on highlighting the functions of sphingolipid species in plasmodesmata, including membrane microdomain organization, architecture transformation, callose deposition and permeability control, and signaling regulation. We also briefly discuss the difference between sphingolipids and sterols, and we propose potential unresolved questions that are of help for further understanding the correspondence between plasmodesmal structure and function. 相似文献
998.
Li Yanzhe Gai Jianing Zhang Xiaofei Zhao dongfeng Guo Yadong Yu Gengxing Zhao Chaocheng Liu Fang Zhao Ruiyu Liu Chunshuang 《中国炼油与石油化工》2022,(1):129-134
In this study,the nitrogen removal performance of partial denitrificaiton/anammox(PDA) process was investigated by using an UASB reactor.High total nitrogen(TN) removal efficiency(91.97%) was achieved at an influent nitrogen loading rate of 0.64 kg/(m3·d).Anammox bacteria did execute the function of converting nitrate to nitrite in PDA system according to 15N isotope labeling experiments and the contribution was approximately 36.3%.Candidatus_Brocadia,Candidatus_Kuenenia an... 相似文献
999.
In situ selective carbothermic reactions and vacuum sintering were used to prepare iron-based friction material directly from vanadium-bearing titanomagnetite c... 相似文献
1000.
摘 要:目的 建立蔬菜农药多残留的筛查方法。方法 使用国家标准方法规定的QuEChERS法净化蔬菜样品,结合静电场轨道阱高分辨质谱法(orbitrap high resolution mass spectrometry)开展809种农药的快速非靶向筛查。结果 62种阳性农药的筛查限(screening detection limit, SDL)为0.005~0.010 mg/kg,定量限(limits of quantitation, LOQ)为0.01 mg/kg,线性范围为0.01~0.20 mg/kg,线性相关系数(r2)为0.9917~0.9997,日内精密度为2.77%~6.98% (n=5),日间精密度为4.82%~10.8% (n=5)。200批次样品共检出62种农药,不合格样品28批次,不合格率为14.0%。豇豆的不合格情况比较突出,不合格样品22批次,主要的不合格项是灭蝇胺和噻虫胺。结论 方法快速、准确、分析通量高,在无标准品的情况下实现了蔬菜中809种农药的非靶向快速筛查,可为蔬菜农药残留风险监测和质量控制提供支撑。 相似文献