全文获取类型
收费全文 | 208547篇 |
免费 | 31034篇 |
国内免费 | 10695篇 |
专业分类
电工技术 | 14365篇 |
技术理论 | 3篇 |
综合类 | 14552篇 |
化学工业 | 40628篇 |
金属工艺 | 11507篇 |
机械仪表 | 12797篇 |
建筑科学 | 15827篇 |
矿业工程 | 5636篇 |
能源动力 | 6084篇 |
轻工业 | 17991篇 |
水利工程 | 4380篇 |
石油天然气 | 8562篇 |
武器工业 | 2073篇 |
无线电 | 26906篇 |
一般工业技术 | 28473篇 |
冶金工业 | 7902篇 |
原子能技术 | 2264篇 |
自动化技术 | 30326篇 |
出版年
2024年 | 484篇 |
2023年 | 2204篇 |
2022年 | 4506篇 |
2021年 | 6861篇 |
2020年 | 6289篇 |
2019年 | 6794篇 |
2018年 | 7302篇 |
2017年 | 8283篇 |
2016年 | 8360篇 |
2015年 | 10864篇 |
2014年 | 12636篇 |
2013年 | 15328篇 |
2012年 | 15379篇 |
2011年 | 15765篇 |
2010年 | 15343篇 |
2009年 | 14777篇 |
2008年 | 14003篇 |
2007年 | 13403篇 |
2006年 | 12140篇 |
2005年 | 10201篇 |
2004年 | 8057篇 |
2003年 | 7747篇 |
2002年 | 8189篇 |
2001年 | 7170篇 |
2000年 | 4968篇 |
1999年 | 3531篇 |
1998年 | 1856篇 |
1997年 | 1629篇 |
1996年 | 1403篇 |
1995年 | 1107篇 |
1994年 | 875篇 |
1993年 | 628篇 |
1992年 | 493篇 |
1991年 | 381篇 |
1990年 | 323篇 |
1989年 | 256篇 |
1988年 | 193篇 |
1987年 | 129篇 |
1986年 | 105篇 |
1985年 | 49篇 |
1984年 | 46篇 |
1983年 | 27篇 |
1982年 | 36篇 |
1981年 | 25篇 |
1980年 | 34篇 |
1979年 | 17篇 |
1978年 | 11篇 |
1976年 | 7篇 |
1959年 | 18篇 |
1951年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Feng Wenran Li Zhen Chen Yingying Chen Jinyang Lang Haoze Wan Jianghong Gao Yan Dong Haitao 《Journal of Materials Science》2022,57(3):1881-1889
Journal of Materials Science - Although chalcogenide materials continue to generate considerable interest due to great potentials for various optoelectronic devices, annealing for a long time in... 相似文献
3.
Ligang Yu Yong Li Yukun Yang Caixia Guo Meiping Li 《International Journal of Food Science & Technology》2022,57(7):4646-4655
This study investigated the inhibitory effects of curcumin and piperine on fluorescent advanced glycation end products (fAGEs) formation in a bovine serum albumin (BSA)–fructose model. Model systems of BSA and fructose were prepared, and curcumin or piperine was added. fAGEs and BSA oxidation product (dityrosine, kynurenine and N'-formylkynurenine) contents were determined. The results showed that fAGEs content decreased with increasing concentration of curcumin and piperine (P < 0.05). Addition of curcumin and piperine at 160 µg mL−1 could inhibit fluorescent AGEs by 100% and 93% respectively. Dityrosine and N'-formylkynurenine contents decreased as curcumin and piperine concentration increased (P < 0.05). Furthermore, the result of principal component analysis indicated that curcumin and piperine markedly impeded BSA oxidation, resulting in a lower level of fAGEs in model systems. Therefore, adding curcumin and piperine may facilitate reduced fAGEs levels in BSA–fructose model. 相似文献
4.
5.
Qian Wu Xiangmei Liu Bo Li Lei Tan Yong Han Zhaoyang Li Yanqin Liang Zhenduo Cui Shengli Zhu Shuilin Wu Yufeng Zheng 《材料科学技术学报》2021,67(8):70-79
Pathogens pose a serious challenge to environmental sanitation and a threat to public health.The frequent use of chemicals for sterilization in recent years has not only caused secondary damage to the environment but also increased pathogen resistance to drugs,which further threatens public health.To address this issue,the use of non-chemical antibacterial means has become a new trend for environmental disinfection.In this study,we developed red phosphorus nanoparticles(RPNPs),a safe and degradable photosensitive material with good photocatalytic and photothermal properties.The red phosphorus nanoparticles were prepared using a template method and ultrasonication.Under the irradiation of simulated sunlight for 20 min,the RPNPs exhibited an efficiency of 99.98%in killing Staphylococcus aureus due to their excellent photocatalytic and photothermal abilities.Transmission electron microscopy and ultraviolet–visible spectroscopy revealed that the RPNPs exhibited degradability within eight weeks.Both the RPNPs and their degradation products were nontoxic to fibroblast cells.Therefore,such RPNPs are expected to be used as a new type of low-cost,efficient,degradable,biocompatible,and eco-friendly photosensitive material for environmental disinfection. 相似文献
6.
Photoresponsive biomaterials are experiencing a transition from in vitro models to in vivo demonstrations that point toward clinical translation. Dynamic hydrogels for cell encapsulation, light-responsive carriers for controlled drug delivery, and nanomaterials containing photosensitizers for photodynamic therapy are relevant examples. Nonetheless, the step to the clinic largely depends on their combination with technologies to bring light into the body. This review highlights the challenge of photoactivation in vivo, and presents strategies for light management that can be adopted for this purpose. The authors’ focus is on technologies that are materials-driven, particularly upconversion nanoparticles that assist in “direct path” light delivery through tissue, and optical waveguides that “clear the path” between external light source and in vivo target. The authors’ intention is to assist the photoresponsive biomaterials community transition toward medical technologies by presenting light delivery concepts that can be integrated with the photoresponsive targets. The authors also aim to stimulate further innovation in materials-based light delivery platforms by highlighting needs and opportunities for in vivo photoactivation of biomaterials. 相似文献
7.
恶意代码数量已经呈现爆炸式增长,对于恶意代码的检测防护显得尤为重要.近几年,基于深度学习的恶意代码检测方法开始出现,基于此,提出一种新的检测方法,将恶意代码二进制文件转化为十进制数组,并利用一维卷积神经网络(1 Dimention Convolutional Neural Networks,1D CNN)对数组进行分类和识别.针对代码家族之间数量不平衡的现象,该算法选择在分类预测上表现良好的XGBoost,并对Vision Research Lab中的25个不同恶意软件家族的9458个恶意软件样本进行了实验.实验结果表明,所提的方法分类预测精度达到了97%. 相似文献
8.
Tao Feng Mingde Tong Shuotian Yao Hejun Li Shifeng Wen Hongjiao Lin 《Journal of the European Ceramic Society》2021,41(1):158-166
Composites based on hafnium carbide and reinforced with continuous naked carbon fiber with and without PyC interface were prepared at low temperature by precursor infiltration and pyrolysis and chemical vapor deposition method. The microstructure, mechanical property, cyclic ablation and fiber bundle push-in tests of the composites were investigated. The results show that after three times ablation cycles, the bending strength of samples without PyC interface decreased by 63.6 %; the bending strength of samples with PyC interface only decreased by 37.8 %. The force displacement curve of the samples with PyC interface presented a well pseudoplastic deformation state. The mechanical behavior difference of two kinds of composites was due to crucial function of PyC interface phase including protection of fiber and weakening of fiber/matrix interface. 相似文献
9.
10.
Bijan Nasri‐Nasrabadi Akif Kaynak Shayan Seyedin Zahra Komeily‐Nia Abbas Z Kouzani 《Polymer International》2019,68(5):922-928
Recent advances in three‐dimensional (3D) printing have enabled the fabrication of interesting structures which are not achievable using traditional fabrication approaches. The 3D printing of carbon microtube composite inks allows fabrication of conductive structures for practical applications in soft robotics and tissue engineering. However, it is challenging to achieve 3D printed structures from solution‐based composite inks, which requires an additional process to solidify the ink. Here, we introduce a wet 3D printing technique which uses a coagulation bath to fabricate carbon microtube composite structures. We show that through a facile nanogrooving approach which introduces cavitation and channels on carbon microtubes, enhanced interfacial interactions with a chitosan polymer matrix are achieved. Consequently, the mechanical properties of the 3D printed composites improve when nanogrooved carbon microtubes are used, compared to untreated microtubes. We show that by carefully controlling the coagulation bath, extrusion pressure, printing distance and printed line distance, we can 3D print composite lattices which are composed of well‐defined and separated printed lines. The conductive composite 3D structures with highly customised design presented in this work provide a suitable platform for applications ranging from soft robotics to smart tissue engineering scaffolds. © 2019 Society of Chemical Industry 相似文献