全文获取类型
收费全文 | 1999篇 |
免费 | 146篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 22篇 |
综合类 | 1篇 |
化学工业 | 558篇 |
金属工艺 | 77篇 |
机械仪表 | 58篇 |
建筑科学 | 69篇 |
矿业工程 | 3篇 |
能源动力 | 60篇 |
轻工业 | 409篇 |
水利工程 | 33篇 |
石油天然气 | 18篇 |
无线电 | 101篇 |
一般工业技术 | 352篇 |
冶金工业 | 183篇 |
原子能技术 | 12篇 |
自动化技术 | 192篇 |
出版年
2024年 | 5篇 |
2023年 | 21篇 |
2022年 | 66篇 |
2021年 | 111篇 |
2020年 | 57篇 |
2019年 | 73篇 |
2018年 | 91篇 |
2017年 | 100篇 |
2016年 | 88篇 |
2015年 | 53篇 |
2014年 | 87篇 |
2013年 | 164篇 |
2012年 | 126篇 |
2011年 | 158篇 |
2010年 | 108篇 |
2009年 | 110篇 |
2008年 | 110篇 |
2007年 | 95篇 |
2006年 | 70篇 |
2005年 | 48篇 |
2004年 | 43篇 |
2003年 | 35篇 |
2002年 | 24篇 |
2001年 | 23篇 |
2000年 | 17篇 |
1999年 | 23篇 |
1998年 | 46篇 |
1997年 | 32篇 |
1996年 | 28篇 |
1995年 | 20篇 |
1994年 | 21篇 |
1993年 | 14篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1973年 | 3篇 |
1964年 | 1篇 |
排序方式: 共有2148条查询结果,搜索用时 15 毫秒
71.
Rejane Martins Fernandes Canha Kenneth de Borja Jaguaribe Ana Lúcia Homce de Cresce El Debs Mounir Khalil El Debs 《Engineering Structures》2009,31(3):788-798
This paper presents a theoretical and experimental analysis of socket base connections of precast concrete structures with regard to the behavior of transverse walls. The experimental program included seven specimens, for which the type of interface in contact with cast-in-place concrete, the load eccentricities and the embedded lengths were all varied. A design model was proposed to calculate the reinforcements of the transverse walls. Based on the obtained results, some conclusions can be drawn: (a) The top of the transverse wall on the compression side of the smooth connections and the top of the two transverse walls of the rough connections are submitted to a bending-tension and this tension prevails on the bending; (b) The design model proposed for the calculation of the reinforcement of the transverse wall on the compression side provides the best prediction of the experimental results for all specimens when compared to the current design models; (c) For rough interfaces, the top of the transverse wall on the tension side is more requested than the top of transverse wall on the compression side; (d) The results of the proposed design model for the reinforcement of the transverse wall on the tension side of rough connections were in close agreement with the experimental results. 相似文献
72.
73.
Alan P. O. da Silva Cicilia R. M. Leite Larry McMillan Carlos A. Paz de Araujo Marcelo A. C. Fernandes ANA M. G. Guerreiro 《Integrated ferroelectrics》2015,159(1):23-33
In this work we propose the implementation of boolean logic through artificial neurons with Ferroelectric Capacitor (FeCapacitor) as its basic unit on a reconfigurable hardware platform. Two neurons were implemented: the Perceptron and the Spiking Neuron model. Both neurons use the phenomenon of the hysteresis loop as an activation function and were embedded on a Field Gate Programmable Gate Array (FPGA) hardware platform. The implementations were carried out by Simulink models and hardware synthesizable blocks from DSP Builder software and the results are shown in the form of the models and the boolean functions implemented by them. 相似文献
74.
Incorporation of Alpha‐Linolenic Acid and Enhancement of n‐3 Fatty Acids in Nile Tilapia: a Factorial Design
下载免费PDF全文
![点击此处可从《Journal of the American Oil Chemists](/ch/ext_images/free.gif)
Vanessa Vivian Almeida Schneider Fabiana Carbonera Paula Fernandes Montanher Ana Paula Lopes Makoto Matsushita Jesuí Vergílio Visentainer 《Journal of the American Oil Chemists' Society》2015,92(5):693-700
A 22 factorial design (two factors at two levels, in triplicate) was performed to investigate the influence of factors A (time of treatment, 15 and 30 days) and B (chia oil content in a supplemented diet, at 2.1 and 4.2 %) in three responses of interest referring to: (a) the incorporation of alpha‐linolenic acid (LNA) in lipids of Nile tilapia fillet; (b) the enhancement of n‐3 fatty acids; and (c) the decrease in the omega‐6/omega3 (n‐6/n‐3) ratio in fish. Factors A and B were significant in the three regression models obtained and the interaction AB was a significant contributor to the LNA and n‐6/n‐3 ratio. Analysis of variance suggested three significant and predictive mathematical models. Response surfaces analyses from designs indicated higher LNA and n‐3 contents and a lower n‐6/n‐3 ratio using both factors A and B in the higher levels (30 days of treatment and 4.2 % of chia oil in the diet for fish) chosen for this study. 相似文献
75.
76.
77.
Microencapsulation of red and white thyme oil in poly(lactic‐co‐glycolic) acid: Assessment of encapsulation efficiency and antimicrobial capacity of the produced microcapsules
下载免费PDF全文
![点击此处可从《加拿大化工杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
78.
Metformin Reduces Lipogenesis Markers in Obese Mice Fed a Low-Carbohydrate and High-Fat Diet
下载免费PDF全文
![点击此处可从《Lipids》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Karla Nayara de Oliveira Santana Deborah Farias Lelis Keila Lopes Mendes Jamille Fernandes Lula Alanna Fernandes Paraíso João Marcus Oliveira Andrade John David Feltenberger Junio Cota Diego Vicente da Costa Alfredo Mauricio Batista de Paula André Luiz Sena Guimarães Sérgio Henrique Sousa Santos 《Lipids》2016,51(12):1375-1384
Lipogenesis is the process by which fatty acids are synthesized. In metabolic syndrome, an insulin resistant state along with high plasma levels of free fatty acids (FFA) and hyperglycemia may contribute to the lipogenic process. The aim of the present study was to investigate the effects of oral administration of metformin on the expression of lipogenic genes and glycemic profile in mice fed with low‐carbohydrate high‐fat diet by evaluating their metabolic profile. SWISS male mice were divided into 4 groups (N = 7) that were fed with standard (ST), standard plus metformin (ST + MET), low‐carbohydrate high‐fat diet (LCHFD) and low‐carbohydrate high‐fat diet plus metformin (LCHFD + MET) (100 mg kg?1 diet) diets respectively. Food intake, body weight and blood parameters, such as glucose tolerance, insulin sensitivity, glucose, HDL‐c, total cholesterol, triglycerides, ASL and ALT levels were assessed. Histological analyses were performed on hematoxylin and eosin‐stained epididymal adipose tissue histological specimens. The expression levels of peroxisome proliferator‐activated receptor (PPARγ), sterol regulatory element‐binding protein 1 (SREBP1), fatty acid synthase (FAS) and acetyl‐CoA carboxylase (ACC), were assessed by RT‐PCR. This study showed that metformin decreased adipocyte area, body weight and food consumption in obese animals when compared to the standard group. Furthermore, the expression of lipogenic markers in adipose tissue were diminished in obese animals treated with metformin. This data showed that oral administration of metformin improved glucose and lipid metabolic parameters in white adipose tissue by reducing the expression of lipogenesis markers, suggesting an important clinical application of MET in treating obesity‐related diseases in metabolic syndrome. 相似文献
79.
A Quinacrine Analogue Selective Against Gastric Cancer Cells: Insight from Biochemical and Biophysical Studies
下载免费PDF全文
![点击此处可从《ChemMedChem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ana Gomes Dr. Iva Fernandes Dr. Cátia Teixeira Prof. Nuno Mateus Prof. M. J. Sottomayor Prof. Paula Gomes 《ChemMedChem》2016,11(24):2703-2712
One of the earliest synthetic antimalarial drugs, quinacrine, was recently reported as interesting for the treatment of acute myeloid leukemia. Inspired by this and similar findings, we evaluated a set of quinacrine analogues against gastric (MKN‐28), colon (Caco‐2), and breast (MFC‐7) cancer cell lines and one normal human fibroblast cell line (HFF‐1). All the compounds, previously developed by us as dual‐stage antimalarial leads, displayed antiproliferative activity, and one of the set stood out as selective toward the gastric cancer cell line, MKN‐28. Interestingly, this compound was transported across an in vitro MKN‐28 model cell line in low amounts, and approximately 80 % was trapped inside those cells. Nuclear targeting of the same compound and its interactions with calf thymus DNA were assessed through combined fluorescence microscopy, spectroscopy, and calorimetry studies, which provided evidence for the compound's ability to reach the nucleus and to interact with DNA. 相似文献
80.
Stephen Buckman Mara Latorre M. Martin Bosman Neveen Nawawy Bomin Koh 《Papers in Regional Science》2019,98(2):679-699
As cities are compelled to compete for new sources of investment and revenue, arts-based economic development strategies have become the norm. The purpose of this paper is to revisit and reevaluate some of the conventional claims about the arts as an important economic development strategy by exploring a case study called “The Space at 2106 Main” in a rapidly gentrifying neighbourhood called West Tampa. The results of this study suggest that the arts are indeed assuming a greater role in economic policy under the auspices of West Tampa community redevelopment areas (CRA) and the direct actions of various arts related entrepreneurs. The results however, point to a mixed picture that raises difficult questions about the medium to long-term effects of this urban redevelopment strategy, especially on the poor and mostly minority residents of West Tampa. 相似文献