首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   956篇
  免费   57篇
  国内免费   2篇
电工技术   3篇
综合类   1篇
化学工业   378篇
金属工艺   38篇
机械仪表   21篇
建筑科学   24篇
矿业工程   6篇
能源动力   36篇
轻工业   64篇
无线电   51篇
一般工业技术   149篇
冶金工业   68篇
原子能技术   6篇
自动化技术   170篇
  2024年   5篇
  2023年   14篇
  2022年   98篇
  2021年   120篇
  2020年   26篇
  2019年   25篇
  2018年   48篇
  2017年   41篇
  2016年   51篇
  2015年   27篇
  2014年   57篇
  2013年   61篇
  2012年   53篇
  2011年   63篇
  2010年   48篇
  2009年   33篇
  2008年   30篇
  2007年   24篇
  2006年   25篇
  2005年   23篇
  2004年   21篇
  2003年   16篇
  2002年   4篇
  2001年   9篇
  2000年   3篇
  1999年   8篇
  1998年   9篇
  1997年   7篇
  1996年   6篇
  1995年   5篇
  1994年   3篇
  1993年   2篇
  1988年   3篇
  1987年   6篇
  1985年   4篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   5篇
  1977年   1篇
  1976年   5篇
  1975年   3篇
  1974年   4篇
  1973年   1篇
  1972年   2篇
  1971年   2篇
  1968年   1篇
  1967年   1篇
排序方式: 共有1015条查询结果,搜索用时 15 毫秒
1.
We investigate the challenges of building an end-to-end cloud pipeline for real-time intelligent visual inspection system for use in automotive manufacturing. Current methods of visual detection in automotive assembly are highly labor intensive, and thus prone to errors. An automated process is sought that can operate within the real-time constraints of the assembly line and can reduce errors. Components of the cloud pipeline include capture of a large set of high-definition images from a camera setup at the assembly location, transfer and storage of the images as needed, execution of object detection, and notification to a human operator when a fault is detected. The end-to-end execution must complete within a fixed time frame before the next car arrives in the assembly line. In this article, we report the design, development, and experimental evaluation of the tradeoffs of performance, accuracy, and scalability for a cloud system.  相似文献   
2.
3.
4.
Rapeseed containing up to 1 ppm malathion and ≤ 10% moisture was stored for up to 32 weeks at 10, 20 and 30°C to determine the time required to reach residue levels of 0.1 ppm. Malathion levels < 0.1 ppm were found only in seed at 20°C, 7.7% moisture content by 32 weeks and at 30°C, 7.1% moisture content by 16 weeks. The malathion degradation rates were related to calculated safe storage times to determine acceptable storage conditions. An improved analytical method of malathion extraction from rapeseed was developed. Manipulation of temperature ≤ 60°C for short periods was ineffective in lowering malathion residues to 0.1 ppm.  相似文献   
5.
OBJECTIVE: The purpose of our study was to evaluate the effectiveness of MR imaging for showing the intrinsic anatomy of a peripheral nerve. Cadaver wrist specimens that included the median nerve were imaged with MR imaging at 3 T, then sectioned, stained, and inspected grossly and microscopically. The size, shape, and signal intensity of the sheath and axonal structures in the median nerve were identified in MR images by comparison with anatomic sections. CONCLUSION: This study suggests that MR imaging with sufficiently high-resolution techniques shows the internal structure of peripheral nerves. These results suggest that MR imaging may be a means to distinguish neuritis, tumor, degeneration, or fatty proliferation in a peripheral nerve and to evaluate the nerve before microsurgical anastomosis.  相似文献   
6.
Blood platelets’ adenosine receptors (AR) are considered to be a new target for the anti-platelet therapy. This idea is based on in vitro studies which show that signaling mediated by these receptors leads to a decreased platelet response to activating stimuli. In vivo evidence for the antithrombotic activity of AR agonists published to date were limited, however, to the usage of relatively high doses given in bolus. The present study was aimed at verifying if these substances used in lower doses in combination with inhibitors of P2Y12 could serve as components of dual anti-platelet therapy. We have found that a selective A2A agonist 2-hexynyl-5’-N-ethylcarboxamidoadenosine (HE-NECA) improved the anti-thrombotic properties of either cangrelor or prasugrel in the model of ferric chloride-induced experimental thrombosis in mice. Importantly, HE-NECA was effective not only when applied in bolus as other AR agonists in the up-to-date published studies, but also when given chronically. In vitro thrombus formation under flow conditions revealed that HE-NECA enhanced the ability of P2Y12 inhibitors to decrease fibrinogen content in thrombi, possibly resulting in their lower stability. Adenosine receptor agonists possess a certain hypotensive effect and an ability to increase the blood–brain barrier permeability. Therefore, the effects of anti-thrombotic doses of HE-NECA on blood pressure and the blood–brain barrier permeability in mice were tested. HE-NECA applied in bolus caused a significant hypotension in mice, but the effect was much lower when the substance was given in doses corresponding to that obtained by chronic administration. At the same time, no significant effect of HE-NECA was observed on the blood–brain barrier. We conclude that chronic administration of the A2A agonist can be considered a potential component of a dual antithrombotic therapy. However, due to the hypotensive effect of the substances, dosage and administration must be elaborated to minimize the side-effects. The total number of animals used in the experiments was 146.  相似文献   
7.
Polymeric hydrogels play an increasingly important role in medicine, pharmacy and cosmetology. They appear to be one of the most promising groups of biomaterials due to their favorable physicochemical properties and biocompatibility. The objective of the presented study was to synthesize new poly(chitosan-ester-ether-urethane) hydrogels and to study the kinetic release of genistein (GEN) from these biomaterials. In view of the above, six non-toxic hydrogels were synthesized via the Ring-Opening Polymerization (ROP) and polyaddition processes. The poly(ester-ether) components of the hydrogels have been produced in the presence of the enzyme as a biocatalyst. In some cases, the in vitro release rate of GEN from the obtained hydrogels was characterized by near-zero-order kinetics, without “burst release” and with non-Fickian transport. It is important to note that developed hydrogels have been shown to possess the desired safety profile due to lack of cytotoxicity to skin cells (keratinocytes and fibroblasts). Taking into account the non-toxicity of hydrogels and the relatively highly controlled release profile of GEN, these results may provide fresh insight into polymeric hydrogels as an effective dermatological and/or cosmetological tool.  相似文献   
8.
Neoplasms derived from follicular tissue are extremely rare. Clinically, they are reported as non-symptomatic, slow-growing nodules. These lesions are mainly benign, but the malignant type can occur. Mainly middle-aged people (50–60 years of age) are affected. These carcinomas are mainly localized on the head and neck or torso. They can be locally aggressive and infiltrate surrounding tissue and metastasize to regional lymph nodes. In the minority of cases, distant metastases are diagnosed. Quick and relevant diagnosis is the basis of a treatment for all types of tumors. The patient’s life expectancy depends on multiple prognostic factors, including the primary tumor size and its mitotic count. Patients should be referred to a specialized skin cancer center to receive optimal multidisciplinary treatment. This article tries to summarize all the information that is currently available about pathogenesis, diagnosis, and treatment methods of follicular tumors.  相似文献   
9.
Staphylococcus aureus is one of the most prevalent pathogens associated with several types of biofilm-based infections, including infections of chronic wounds. Mature staphylococcal biofilm is extremely hard to eradicate from a wound and displays a high tendency to induce recurring infections. Therefore, in the present study, we aimed to investigate in vitro the interaction between S. aureus biofilm and fibroblast cells searching for metabolites that could be considered as potential biomarkers of critical colonization and infection. Utilizing advanced microscopy and microbiological methods to examine biofilm formation and the staphylococcal infection process, we were able to distinguish 4 phases of biofilm development. The analysis of staphylococcal biofilm influence on the viability of fibroblasts allowed us to pinpoint the moment of critical colonization—12 h post contamination. Based on the obtained model we performed a metabolomics analysis by 1H NMR spectroscopy to provide new insights into the pathophysiology of infection. We identified a set of metabolites related to the switch to anaerobic metabolism that was characteristic for staphylococcal biofilm co-cultured with fibroblast cells. The data presented in this study may be thus considered a noteworthy but preliminary step in the direction of developing a new, NMR-based tool for rapid diagnosing of infection in a chronic wound.  相似文献   
10.
Electrochemical properties of poly(3,4-ethylenedioxythiophene) doped with hexacyanoferrate(II,III) ions (PEDOT(HCF)) were studied in the presence of Cu2+ ions. Voltammetric and EDAX studies revealed retention of hexacyanoferrate anions in the polymer film and accumulation of Cu(II) cations, as well as formation of solid copper hexacyanoferrate near the polymer surface.Accumulation of Cu2+ ions was found to be advantageous from the point of view of PEDOT(HCF) applications as a solid contact (ion-to-electron transducer) in all-solid-state Cu2+-selective electrodes with solvent polymeric polyvinyl chloride (PVC) based membrane, containing Cu2+-selective ionophore. Binding of Cu2+ ions in the conducting polymer layer results in analyte ions flux into the transducer phase. Thus, pronounced enhancement of selectivity of the all-solid-state Cu2+-selective electrode or lower detection limit of the potentiometric response range was achieved, reaching under optimised conditions 10−7 M CuSO4.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号