全文获取类型
收费全文 | 122280篇 |
免费 | 10716篇 |
国内免费 | 5182篇 |
专业分类
电工技术 | 7382篇 |
技术理论 | 7篇 |
综合类 | 7878篇 |
化学工业 | 21187篇 |
金属工艺 | 6770篇 |
机械仪表 | 7610篇 |
建筑科学 | 9894篇 |
矿业工程 | 3515篇 |
能源动力 | 3648篇 |
轻工业 | 8437篇 |
水利工程 | 2235篇 |
石油天然气 | 7513篇 |
武器工业 | 917篇 |
无线电 | 13839篇 |
一般工业技术 | 14798篇 |
冶金工业 | 5506篇 |
原子能技术 | 1402篇 |
自动化技术 | 15640篇 |
出版年
2024年 | 479篇 |
2023年 | 2044篇 |
2022年 | 3608篇 |
2021年 | 5155篇 |
2020年 | 3876篇 |
2019年 | 3296篇 |
2018年 | 3554篇 |
2017年 | 4107篇 |
2016年 | 3449篇 |
2015年 | 4985篇 |
2014年 | 6006篇 |
2013年 | 7139篇 |
2012年 | 7859篇 |
2011年 | 8448篇 |
2010年 | 7349篇 |
2009年 | 7010篇 |
2008年 | 6761篇 |
2007年 | 6346篇 |
2006年 | 6572篇 |
2005年 | 5683篇 |
2004年 | 3871篇 |
2003年 | 3367篇 |
2002年 | 3142篇 |
2001年 | 2839篇 |
2000年 | 3012篇 |
1999年 | 3202篇 |
1998年 | 2694篇 |
1997年 | 2307篇 |
1996年 | 2116篇 |
1995年 | 1841篇 |
1994年 | 1474篇 |
1993年 | 1056篇 |
1992年 | 861篇 |
1991年 | 671篇 |
1990年 | 493篇 |
1989年 | 434篇 |
1988年 | 351篇 |
1987年 | 233篇 |
1986年 | 151篇 |
1985年 | 87篇 |
1984年 | 55篇 |
1983年 | 37篇 |
1982年 | 60篇 |
1981年 | 38篇 |
1980年 | 32篇 |
1979年 | 11篇 |
1978年 | 3篇 |
1965年 | 3篇 |
1959年 | 8篇 |
1951年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Lili Chen Nanami Fujisawa Masato Takanohashi Mazaya Najmina Koichiro Uto Mitsuhiro Ebara 《International journal of molecular sciences》2021,22(5)
This study demonstrates the rational fabrication of a magnetic composite nanofiber mesh that can achieve mutual synergy of hyperthermia, chemotherapy, and thermo-molecularly targeted therapy for highly potent therapeutic effects. The nanofiber is composed of biodegradable poly(ε-caprolactone) with doxorubicin, magnetic nanoparticles, and 17-allylamino-17-demethoxygeldanamycin. The nanofiber exhibits distinct hyperthermia, owing to the presence of magnetic nanoparticles upon exposure of the mesh to an alternating magnetic field, which causes heat-induced cell killing as well as enhanced chemotherapeutic efficiency of doxorubicin. The effectiveness of hyperthermia is further enhanced through the inhibition of heat shock protein activity after hyperthermia by releasing the inhibitor 17-allylamino-17-demethoxygeldanamycin. These findings represent a smart nanofiber system for potent cancer therapy and may provide a new approach for the development of localized medication delivery. 相似文献
22.
Yu-Xuan Li Ping Li Yu-Zhe Wu Zhen-Liang Xu Ming-Ling Huang 《Ceramics International》2021,47(2):2180-2186
A novel TiO2 thin film was prepared on the ceramic hollow fiber by the sol-gel method using poly(vinylpyrrolidone) (PVP) and polyvinyl alcohol (PVA) as additives. SEM images verified the formation of TiO2 layer with various thickness using different composition of titania sols. The effect of the PVP and PVA contents on the TiO2 sol properties, the separation and the antifouling performance of the ultrafiltration membranes were investigated thoroughly. When the contents of PVP and PVA were 1.0 wt% and 0.8 wt%, respectively, the resultant membrane showed a thickness of 0.55 μm with a pure water flux of 255 L m?2 h?1. In addition, the adherent foulant bovine serum albumin was applied to evaluate the antifouling performance. During the three fouling-recovery cycles, the flux recovery ratio and the flux decay ratio maintained about 99% and 30%. The BSA flux and rejection were still 169 L m?2 h?1 and 96.9% after the cycles, indicating a superior antifouling property. 相似文献
23.
Lili Hao Jiaxiang Li Peng Wang Zongliang Wang Zhenxu Wu Yu Wang Zixue Jiao Min Guo Tongfei Shi Qigang Wang Yoshihiro Ito Yen Wei Peibiao Zhang 《Advanced functional materials》2021,31(15):2009661
The degradation behavior of implants is significantly important for bone repair. However, it is still unprocurable to spatiotemporally regulate the degradation of the implants to match bone ingrowth. In this paper, a magneto-controlled biodegradation model is established to explore the degradation behavior of magnetic scaffolds in a magnetothermal microenvironment generated by an alternating magnetic field (AMF). The results demonstrate that the scaffolds can be heated by magnetic nanoparticles (NPs) under AMF, which dramatically accelerated scaffold degradation. Especially, magnetic NPs modified by oleic acid with a better interface compatibility exhibit a greater heating efficiency to further facilitate the degradation. Furthermore, the molecular dynamics simulations reveal that the enhanced motion correlation between magnetic NPs and polymer matrix can accelerate the energy transfer. As a proof-of-concept, the feasibility of magneto-controlled degradation for implants is demonstrated, and an optimizing strategy for better heating efficiency of nanomaterials is provided, which may have great instructive significance for clinical medicine. 相似文献
24.
Nengbing Long Yanqing Fu Tianxiang Xu Dashuang Ding Shaoqian Zhang Shengzhi Sun Shiliang Kang Tiefeng Xu Shixun Dai Qiuhua Nie Changgui Lin 《Journal of the European Ceramic Society》2021,41(8):4584-4589
The confinement of CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs) in a stabilized inorganic glass matrix is a new strategy for improving their long-term stability and promoting their applications in the optoelectronic field. Here, in situ nanocrystallization strategy is developed to precipitate CsPbBr3?xIx NCs with arbitrary I/Br ratio among an elaborately designed GeS2–Sb2S3-based chalcogenide glass matrix. Spherical CsPbBr3?xIx NCs are homogeneously distributed in the glass matrix after thermal treatment. The photoluminescence (PL) spectra show that the emission peaks of CsPbBr3?xIx NCs can be tuned from 570 nm to 722 nm with the replacement of Br by I. The fs transient absorption (TA) spectra reveal that there exists some structural defects in the NCs, leading to short PL decay life. This work would shed light on confining CsPbX3 NCs into glassy matrices, facilitating their future applications in photoelectronic fields. 相似文献
26.
唐英,清代沈阳人,隶属汉军正白旗。《陶人心语》是清代督陶官唐英撰写的诗集。该诗集内容丰富,表达了唐英对皇帝的感恩之情,以及他的赤城之心;对制陶事业的热爱之情;对亲人的思念关爱之情,体恤百姓的疾苦,关心百姓等。此书具有丰富的文学价值和历史价值。 相似文献
27.
28.
To overcome the drawbacks of solid microporous materials for CO2 capture, this proof‐of‐concept study demonstrates a low‐cost and rapid method for producing composites consisting of hypercrosslinked polymers (HCP) with a polyethyleneimine (PEI) binder. The resulting materials capture CO2 through physical and chemical absorption simultaneously. Compared with HCP, the composites exhibit higher CO2 uptake, higher volumetric density, and improved tolerance to water which is attributed to the PEI binder. 相似文献
29.
Ting Cui Ling Xu Feng Ding Ahmed Alsaedi Tasawar Hayat 《International Journal of Adaptive Control and Signal Processing》2020,34(11):1658-1676
Parameter estimation plays an important role in the field of system control. This article is concerned with the parameter estimation methods for multivariable systems in the state-space form. For the sake of solving the identification complexity caused by a large number of parameters in multivariable systems, we decompose the original multivariable system into some subsystems containing fewer parameters and study identification algorithms to estimate the parameters of each subsystem. By taking the maximum likelihood criterion function as the fitness function of the differential evolution algorithm, we present a maximum likelihood-based differential evolution (ML-DE) algorithm for parameter estimation. To improve the parameter estimation accuracy, we introduce the adaptive mutation factor and the adaptive crossover factor into the ML-DE algorithm and propose a maximum likelihood-based adaptive differential evolution algorithm. The simulation study indicates the efficiency of the proposed algorithms. 相似文献
30.