全文获取类型
收费全文 | 152663篇 |
免费 | 7048篇 |
国内免费 | 3054篇 |
专业分类
电工技术 | 4331篇 |
技术理论 | 10篇 |
综合类 | 6264篇 |
化学工业 | 23443篇 |
金属工艺 | 8525篇 |
机械仪表 | 7428篇 |
建筑科学 | 8109篇 |
矿业工程 | 2563篇 |
能源动力 | 3243篇 |
轻工业 | 7841篇 |
水利工程 | 2363篇 |
石油天然气 | 4713篇 |
武器工业 | 534篇 |
无线电 | 17558篇 |
一般工业技术 | 25084篇 |
冶金工业 | 6183篇 |
原子能技术 | 1137篇 |
自动化技术 | 33436篇 |
出版年
2024年 | 871篇 |
2023年 | 1370篇 |
2022年 | 1938篇 |
2021年 | 2658篇 |
2020年 | 2184篇 |
2019年 | 1787篇 |
2018年 | 16086篇 |
2017年 | 15332篇 |
2016年 | 11800篇 |
2015年 | 3265篇 |
2014年 | 3496篇 |
2013年 | 4095篇 |
2012年 | 7343篇 |
2011年 | 13743篇 |
2010年 | 12046篇 |
2009年 | 9155篇 |
2008年 | 10329篇 |
2007年 | 11316篇 |
2006年 | 3947篇 |
2005年 | 4519篇 |
2004年 | 3391篇 |
2003年 | 3140篇 |
2002年 | 2454篇 |
2001年 | 1844篇 |
2000年 | 1924篇 |
1999年 | 2078篇 |
1998年 | 1859篇 |
1997年 | 1511篇 |
1996年 | 1462篇 |
1995年 | 1090篇 |
1994年 | 1045篇 |
1993年 | 723篇 |
1992年 | 560篇 |
1991年 | 462篇 |
1990年 | 329篇 |
1989年 | 262篇 |
1988年 | 250篇 |
1987年 | 154篇 |
1986年 | 106篇 |
1985年 | 81篇 |
1984年 | 38篇 |
1982年 | 42篇 |
1968年 | 43篇 |
1966年 | 42篇 |
1965年 | 44篇 |
1959年 | 37篇 |
1958年 | 37篇 |
1957年 | 36篇 |
1955年 | 63篇 |
1954年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Xinyu Wang Hutailong Zhu Jiayin Hu Haobin Li Suhan Guo Bin Chen Changxiao Liu Guangji Wang Fang Zhou 《International journal of molecular sciences》2022,23(21)
Nephrotoxicity is the dose-limiting factor of cisplatin treatment. Magnesium isoglycyrrhizinate (MgIG) has been reported to ameliorate renal ischemia–reperfusion injury. This study aimed to investigate the protective effect and possible mechanisms of MgIG against cisplatin-induced nephrotoxicity from the perspective of cellular pharmacokinetics. We found that cisplatin predominantly accumulated in mitochondria of renal tubular epithelial cells, and the amount of binding with mitochondrial DNA (mtDNA) was more than twice that with nuclear DNA (nDNA). MgIG significantly lowered the accumulation of cisplatin in mitochondria and, in particular, the degree of target-binding to mtDNA. MgIG notably ameliorated cisplatin-induced changes in mitochondrial membrane potential, morphology, function, and cell viability, while the magnesium donor drugs failed to work. In a mouse model, MgIG significantly alleviated cisplatin-caused renal dysfunction, pathological changes of renal tubules, mitochondrial ultrastructure variations, and disturbed energy metabolism. Both in vitro and in vivo data showed that MgIG recovered the reduction of NAD+-related substances and NAD+-dependent deacetylase sirtuin-3 (SIRT3) level caused by cisplatin. Furthermore, SIRT3 knockdown weakened the protective effect of MgIG on mitochondria, while SIRT3 agonist protected HK-2 cells from cisplatin and specifically reduced platinum-binding activity with mtDNA. In conclusion, MgIG reduces the target-binding amount of platinum to mtDNA and exerts a protective effect on cisplatin-induced renal injury through SIRT3, which may provide a new strategy for the treatment of cisplatin-induced nephrotoxicity. 相似文献
92.
Hua Yang Weiwei Chen Renkai Zhu Jiafu Wang Jianghui Meng 《International journal of molecular sciences》2022,23(17)
Chronic itch is one of the most prominent clinical characteristics of diverse systematic diseases. It is a devastating sensation in pathological diseases. Despite its importance, there are no FDA-labelled drugs specifically geared toward chronic itch. The associated complex pathogenesis and diverse causes escalate chronic itch to being one of the top challenges in healthcare. Humanized antibodies against IL-13, IL-4, and IL-31 proved effective in treatment of itch-associated atopic dermatitis but remain to be validated in chronic itch. There are still no satisfactory anti-itch therapeutics available toward itch-related neuropeptides including GRP, BNP, SST, CGRP, and SP. The newly identified potential itch targets including OSM, NMB, glutamate, periostin, and Serpin E1 have opened new avenues for therapeutic development. Proof-of-principle studies have been successfully performed on antagonists against these proteins and their receptors in itch treatment in animal models. Their translational interventions in humans need to be evaluated. It is of great importance to summarize and compare the newly emerging knowledge on chronic itch and its pathways to promote the development of novel anti-itch therapeutics. The goal of this review is to analyze the different physiologies and pathophysiologies of itch mediators, whilst assessing their suitability as new targets and discussing future therapeutic development. 相似文献
93.
Li Huang Lei Zhu Hua Xie Jeffery Shawn Goodwin Tanu Rana Lan Xie Chin-Ho Chen 《International journal of molecular sciences》2022,23(17)
COVID-19, caused by the highly transmissible severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has rapidly spread and become a pandemic since its outbreak in 2019. We have previously discovered that aloperine is a new privileged scaffold that can be modified to become a specific antiviral compound with markedly improved potency against different viruses, such as the influenza virus. In this study, we have identified a collection of aloperine derivatives that can inhibit the entry of SARS-CoV-2 into host cells. Compound 5 is the most potent tested aloperine derivative that inhibited the entry of SARS-CoV-2 (D614G variant) spike protein-pseudotyped virus with an IC50 of 0.5 µM. The compound was also active against several other SARS-CoV-2 variants including Delta and Omicron. Results of a confocal microscopy study suggest that compound 5 inhibited the viral entry before fusion to the cell or endosomal membrane. The results are consistent with the notion that aloperine is a privileged scaffold that can be used to develop potent anti-SARS-CoV-2 entry inhibitors. 相似文献
94.
95.
Chenyu Lu Jingyu Kuang Tong Shao Sisi Xie Ming Li Lingyun Zhu Lvyun Zhu 《International journal of molecular sciences》2022,23(17)
Prime editing (PE), as a “search-and-replace” genome editing technology, has shown the attractive potential of versatile genome editing ability, which is, in principle, currently superior to other well-established genome-editing technologies in the all-in-one operation scope. However, essential technological solutions of PE technology, such as the improvement of genome editing efficiency, the inhibition of potential off-targets and intended edits accounting for unexpected side-effects, and the development of effective delivery systems, are necessary to broaden its application. Since the advent of PE, many optimizations have been performed on PE systems to improve their performance, resulting in bright prospects for application in many fields. This review briefly discusses the development of PE technology, including its functional principle, noteworthy barriers restraining its application, current efforts in technical optimization, and its application directions and potential risks. This review may provide a concise and informative insight into the burgeoning field of PE, highlight the exciting prospects for this powerful tool, and provide clues for questions that may propel the field forward. 相似文献
96.
In this paper, density functional theory (DFT) was used to study the possibility of low-dimensional (2D, 1D, 0D) boron nitride nanomaterials to catalyze acetylene acetate reaction, and further explore the possible source of this catalytic activity. It is found that the catalytic activity of boron nitride nanomaterials for acetylene acetate reaction will change with the change of the geometric structure (dimension) and reaction site of the catalyst. From the geometric structure, the reaction components and the zero-dimensional BN catalyst can form chemical bonds and form complexes, while only physical adsorption occurs on the surface of the one-dimensional and two-dimensional BN catalysts. From the reaction site, the properties of different C sites on the B12N12NC-C2H2 complexes are different. Namely, a C atom connected with a B atom is more likely to have an electrophilic reaction with H+, and a C atom connected with an N atom is more likely to have a nucleophilic reaction with CH3COO−. Through the study of three kinds of BN nanomaterials with low dimensions, we found that the zero-dimensional B12N12 nanocage broke the inherent reaction inertia of BN materials and showed good catalytic activity in an acetylene acetate reaction, which is very likely to be a non-metallic catalyst for the acetylene gas-phase preparation of vinyl acetate. 相似文献
97.
98.
Yunlong Pang Chunxia Liu Meng Lin Fei Ni Wenhui Li Jin Cai Ziliang Zhang Huaqiang Zhu Jingxian Liu Jiajie Wu Guihua Bai Shubing Liu 《International journal of molecular sciences》2022,23(17)
Wheat stripe (yellow) rust is a worldwide disease that seriously reduces wheat grain yield and quality. Adult-plant resistance (APR) to stripe rust is generally more durable but usually controlled by multiple genes with partial resistance. In this study, a recombinant inbred line population was developed from a cross between a Chinese wheat landrace, Tutoumai, with APR to stripe rust, and a highly susceptible wheat cultivar, Siyang 936. The population was genotyped by genotyping-by-sequencing and phenotyped for APR to stripe rust in four consecutive field experiments. Three QTLs, QYr.sdau-1BL, QYr.sdau-5BL, and QYr.sdau-6BL, were identified for APR to stripe rust, and explained 8.0–21.2%, 10.1–22.7%, and 11.6–18.0% of the phenotypic variation, respectively. QYr.sdau-1BL was further mapped to a 21.6 Mb region using KASP markers derived from SNPs identified by RNA-seq of the two parents. In the QYr.sdau-1BL region, 13 disease-resistance-related genes were differently expressed between the two parents, and therefore were considered as the putative candidates of QYr.sdau-1BL. This study provides favorable gene/QTL and high-throughput markers to breeding programs for marker-assisted selection of the wheat stripe rust APR genes. 相似文献
99.
100.
Binwen Tan Miaomiao Wang Li Cai Sanyue Li Wei Zhu Lili Xu Yi Wang Jian Zeng Xing Fan Lina Sha Dandan Wu Yiran Cheng Haiqin Zhang Guoyue Chen Yonghong Zhou Houyang Kang 《International journal of molecular sciences》2022,23(18)
Powdery mildew caused by Blumeria graminis f. sp. tritici is a devastating disease that reduces wheat yield and quality worldwide. The exploration and utilization of new resistance genes from wild wheat relatives is the most effective strategy against this disease. Psathyrostachys huashanica Keng f. ex P. C. Kuo (2n = 2x = 14, NsNs) is an important tertiary gene donor with multiple valuable traits for wheat genetic improvement, especially disease resistance. In this study, we developed and identified a new wheat—P. huashanica disomic addition line, 18-1-5—derived from a cross between P. huashanica and common wheat lines Chinese Spring and CSph2b. Sequential genomic and multicolor fluorescence in situ hybridization analyses revealed that 18-1-5 harbored 21 pairs of wheat chromosomes plus a pair of alien Ns chromosomes. Non-denaturing fluorescence in situ hybridization and molecular marker analyses further demonstrated that the alien chromosomes were derived from chromosome 7Ns of P. huashanica. The assessment of powdery mildew response revealed that line 18-1-5 was highly resistant at the adult stage to powdery mildew pathogens prevalent in China. The evaluation of agronomic traits indicated that 18-1-5 had a significantly reduced plant height and an increased kernel length compared with its wheat parents. Using genotyping-by-sequencing technology, we developed 118 PCR-based markers specifically for chromosome 7Ns of P. huashanica and found that 26 of these markers could be used to distinguish the genomes of P. huashanica and other wheat-related species. Line 18-1-5 can therefore serve as a promising bridging parent for wheat disease resistance breeding. These markers should be conducive for the rapid, precise detection of P. huashanica chromosomes and chromosomal segments carrying Pm resistance gene(s) during marker-assisted breeding and for the investigation of genetic differences and phylogenetic relationships among diverse Ns genomes and other closely related ones. 相似文献