全文获取类型
收费全文 | 1584篇 |
免费 | 116篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 97篇 |
综合类 | 4篇 |
化学工业 | 428篇 |
金属工艺 | 26篇 |
机械仪表 | 33篇 |
建筑科学 | 62篇 |
矿业工程 | 6篇 |
能源动力 | 49篇 |
轻工业 | 119篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
无线电 | 137篇 |
一般工业技术 | 280篇 |
冶金工业 | 129篇 |
原子能技术 | 7篇 |
自动化技术 | 315篇 |
出版年
2023年 | 45篇 |
2022年 | 60篇 |
2021年 | 88篇 |
2020年 | 74篇 |
2019年 | 65篇 |
2018年 | 62篇 |
2017年 | 60篇 |
2016年 | 64篇 |
2015年 | 49篇 |
2014年 | 83篇 |
2013年 | 110篇 |
2012年 | 77篇 |
2011年 | 105篇 |
2010年 | 56篇 |
2009年 | 66篇 |
2008年 | 67篇 |
2007年 | 58篇 |
2006年 | 57篇 |
2005年 | 37篇 |
2004年 | 28篇 |
2003年 | 34篇 |
2002年 | 29篇 |
2001年 | 17篇 |
2000年 | 6篇 |
1999年 | 21篇 |
1998年 | 42篇 |
1997年 | 40篇 |
1996年 | 12篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 20篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 10篇 |
1972年 | 4篇 |
1943年 | 4篇 |
1942年 | 3篇 |
1940年 | 3篇 |
排序方式: 共有1702条查询结果,搜索用时 0 毫秒
31.
Felix T.S. Chan H.K. Chan 《The International Journal of Advanced Manufacturing Technology》2005,25(9-10):998-1006
Supply chain management (SCM) has become one of the most important strategies for achieving competitive advantage in different industries in the last decade. Researchers have investigated various processes in the planning and development of supply chains. However, increasing attention has been placed on performance, design and analysis of supply chain models. A supply chain is a complex model that is very difficult to analyze, in particular, with respect to performance. Simulation is one of the effective tools to evaluate the control mechanism for a supply chain. In this paper, five common supply chain models have been built and tested with the aid of simulation. Various performance measures such as transportation cost, resources utilization, inventory level, and order cycle time will be calculated for comparative indications. The methodology that is presented in this paper can be extended to any real life applications in SCM. 相似文献
32.
Simon K. Krebs Marlitt Stech Felix Jorde Nathanaël Rakotoarinoro Franziska Ramm Sophie Marinoff Sven Bahrke Antje Danielczyk Doreen A. Wüstenhagen Stefan Kubick 《International journal of molecular sciences》2022,23(22)
Recombinant immunotoxins (RITs) are an effective class of agents for targeted therapy in cancer treatment. In this article, we demonstrate the straight-forward production and testing of an anti-CD7 RIT based on PE24 in a prokaryotic and a eukaryotic cell-free system. The prokaryotic cell-free system was derived from Escherichia coli BL21 StarTM (DE3) cells transformed with a plasmid encoding the chaperones groEL/groES. The eukaryotic cell-free system was prepared from Chinese hamster ovary (CHO) cells that leave intact endoplasmic reticulum-derived microsomes in the cell-free reaction mix from which the RIT was extracted. The investigated RIT was built by fusing an anti-CD7 single-chain variable fragment (scFv) with the toxin domain PE24, a shortened variant of Pseudomonas Exotoxin A. The RIT was produced in both cell-free systems and tested for antigen binding against CD7 and cell killing on CD7-positive Jurkat, HSB-2, and ALL-SIL cells. CD7-positive cells were effectively killed by the anti-CD7 scFv-PE24 RIT with an IC50 value of 15 pM to 40 pM for CHO and 42 pM to 156 pM for E. coli cell-free-produced RIT. CD7-negative Raji cells were unaffected by the RIT. Toxin and antibody domain alone did not show cytotoxic effects on either CD7-positive or CD7-negative cells. To our knowledge, this report describes the production of an active RIT in E. coli and CHO cell-free systems for the first time. We provide the proof-of-concept that cell-free protein synthesis allows for on-demand testing of antibody–toxin conjugate activity in a time-efficient workflow without cell lysis or purification required. 相似文献
33.
Wenya Wang Xi Zheng Anca Azoitei Axel John Friedemann Zengerling Felix Wezel Christian Bolenz Cagatay Günes 《International journal of molecular sciences》2022,23(22)
TKS5 promotes invasion and migration through the formation of invadopodia in some tumour cells, and it also has an important physiological function in cell migration through podosome formation in various nontumour cells. To date, the role of TKS5 in urothelial cells, and its potential role in BC initiation and progression, has not yet been addressed. Moreover, the contribution of TKS5 to ploidy control and chromosome stability has not been reported in previous studies. Therefore, in the present study, we wished to address the following questions: (i) Is TKS5 involved in the ploidy control of urothelial cells? (ii) What is the mechanism that leads to aneuploidy in response to TKS5 knockdown? (iii) Is TKS5 an oncogene or tumour-suppressor gene in the context of BC? (iv) Does TKS5 affect the proliferation, migration and invasion of BC cells? We assessed the gene and protein expressions via qPCR and Western blot analyses in a set of nontumour cell strains (Y235T, HBLAK and UROtsa) and a set of BC cell lines (RT4, T24, UMUC3 and J82). Following the shRNA knockdown in the TKS5-proficient cells and the ectopic TKS5 expression in the cell lines with low/absent TKS5 expression, we performed functional experiments, such as metaphase, invadopodia and gelatine degradation assays. Moreover, we determined the invasion and migration abilities of these genetically modified cells by using the Boyden chamber and wound-healing assays. The TKS5 expression was lower in the bladder cancer cell lines with higher invasive capacities (T24, UMUC3 and J82) compared to the nontumour cell lines from human ureter (Y235T, HBLAK and UROtsa) and the noninvasive BC cell line RT4. The reduced TKS5 expression in the Y235T cells resulted in augmented aneuploidy and impaired cell division. According to the Boyden chamber and wound-healing assays, TKS5 promotes the invasion and migration of bladder cancer cells. According to the present study, TKS5 regulates the migration and invasion processes of bladder cancer (BC) cell lines and plays an important role in genome stability. 相似文献
34.
Elena García-Martín Jos A. G. Agúndez Javier Gmez-Tabales Julin Benito-Len Jorge Milln-Pascual María Díaz-Snchez Patricia Calleja Laura Turpín-Fenoll Hortensia Alonso-Navarro Esteban García-Albea Jos Francisco Plaza-Nieto Felix Javier Jimnez-Jimnez 《International journal of molecular sciences》2022,23(23)
Several recent works have raised the possibility of the contribution of the lymphocyte activation gene 3 (LAG3) protein in the inflammatory processes of multiple sclerosis (MS). Results of studies on the possible association between LAG3 gene variants and the risk of MS have been inconclusive. In this study, we tried to show the possible association between the most common single nucleotide variants (SNVs) in the CD4 and LAG3 genes (these two genes are closely related) and the risk of MS in the Caucasian Spanish population. We studied the genotypes and allelic variants CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 in 300 patients diagnosed with MS and 400 healthy patients using specific TaqMan-based qPCR assays. We analyzed the possible influence of the genotype frequency on age at the onset of MS, the severity of MS, clinical evolutive subtypes of MS, and the HLADRB1*1501 genotype. The frequencies of the CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 genotypes and allelic variants were not associated with the risk of MS and were unrelated to gender, age at onset and severity of MS, the clinical subtype of MS, and HLADRB1*1501 genotype. The results of the current study showed a lack of association between the CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 SNVs and the risk of developing MS in the Caucasian Spanish population. 相似文献
35.
36.
37.
Charlotte Szewczykowski Christian Mardin Marianna Lucio Gerd Wallukat Jakob Hoffmanns Thora Schrder Franziska Raith Lennart Rogge Felix Heltmann Michael Moritz Lorenz Beitlich Julia Schottenhamml Martin Herrmann Thomas Harrer Marion Ganslmayer Friedrich E. Kruse Martin Krter Jochen Guck Robert Lmmer Matthias Zenkel Andreas Gießl Bettina Hohberger 《International journal of molecular sciences》2022,23(13)
Long COVID (LC) describes the clinical phenotype of symptoms after infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Diagnostic and therapeutic options are limited, as the pathomechanism of LC is elusive. As the number of acute SARS-CoV-2 infections was and is large, LC will be a challenge for the healthcare system. Previous studies revealed an impaired blood flow, the formation of microclots, and autoimmune mechanisms as potential factors in this complex interplay. Since functionally active autoantibodies against G-protein-coupled receptors (GPCR-AAbs) were observed in patients after SARS-CoV-2 infection, this study aimed to correlate the appearance of GPCR-AAbs with capillary microcirculation. The seropositivity of GPCR-AAbs was measured by an established cardiomyocyte bioassay in 42 patients with LC and 6 controls. Retinal microcirculation was measured by OCT–angiography and quantified as macula and peripapillary vessel density (VD) by the Erlangen-Angio Tool. A statistical analysis yielded impaired VD in patients with LC compared to the controls, which was accentuated in female persons. A significant decrease in macula and peripapillary VD for AAbs targeting adrenergic β2-receptor, MAS-receptor angiotensin-II-type-1 receptor, and adrenergic α1-receptor were observed. The present study might suggest that a seropositivity of GPCR-AAbs can be linked to an impaired retinal capillary microcirculation, potentially mirroring the systemic microcirculation with consecutive clinical symptoms. 相似文献
38.
静态安全约束下基于Benders分解算法的可用传输容量计算 总被引:22,自引:8,他引:22
在电力市场环境下,可用传输容量(ATC)是反映输电线路可用于交易的剩余容量的重要指标。文中以最优潮流为基础,采用Benders分解方法将考虑静态安全约束的ATC计算问题分解为一个基态主问题和一系列与各预想事故有关的子问题。主问题用来处理基态潮流和相应约束以及由子问题所返回的Benders割(cut)约束,而各子问题用来处理各预想事故和形成相应的静态安全约束。文章给出了相应的数学模型,并提出了两种改进的求解策略。4节点和IEEE30节点系统的计算结果表明了该方法和求解策略的有效性。 相似文献
39.
40.