全文获取类型
收费全文 | 910篇 |
免费 | 76篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 18篇 |
综合类 | 10篇 |
化学工业 | 192篇 |
金属工艺 | 26篇 |
机械仪表 | 35篇 |
建筑科学 | 44篇 |
矿业工程 | 6篇 |
能源动力 | 57篇 |
轻工业 | 108篇 |
水利工程 | 16篇 |
石油天然气 | 7篇 |
无线电 | 81篇 |
一般工业技术 | 184篇 |
冶金工业 | 24篇 |
原子能技术 | 7篇 |
自动化技术 | 178篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 22篇 |
2021年 | 52篇 |
2020年 | 60篇 |
2019年 | 45篇 |
2018年 | 94篇 |
2017年 | 56篇 |
2016年 | 89篇 |
2015年 | 43篇 |
2014年 | 75篇 |
2013年 | 137篇 |
2012年 | 62篇 |
2011年 | 55篇 |
2010年 | 46篇 |
2009年 | 29篇 |
2008年 | 14篇 |
2007年 | 27篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有993条查询结果,搜索用时 0 毫秒
21.
22.
Pia Fahlbusch Aleksandra Nikolic Sonja Hartwig Sylvia Jacob Ulrike Kettel Cornelia Kllmer Hadi Al-Hasani Stefan Lehr Dirk Müller-Wieland Birgit Knebel Jrg Kotzka 《International journal of molecular sciences》2022,23(12)
Alterations in mitochondrial function are an important control variable in the progression of metabolic dysfunction-associated fatty liver disease (MAFLD), while also noted by increased de novo lipogenesis (DNL) and hepatic insulin resistance. We hypothesized that the organization and function of a mitochondrial electron transport chain (ETC) in this pathologic condition is a consequence of shifted substrate availability. We addressed this question using a transgenic mouse model with increased hepatic insulin resistance and DNL due to constitutively active human SREBP-1c. The abundance of ETC complex subunits and components of key metabolic pathways are regulated in the liver of these animals. Further omics approaches combined with functional assays in isolated liver mitochondria and primary hepatocytes revealed that the SREBP-1c-forced fatty liver induced a substrate limitation for oxidative phosphorylation, inducing enhanced complex II activity. The observed increased expression of mitochondrial genes may have indicated a counteraction. In conclusion, a shift of available substrates directed toward activated DNL results in increased electron flows, mainly through complex II, to compensate for the increased energy demand of the cell. The reorganization of key compounds in energy metabolism observed in the SREBP-1c animal model might explain the initial increase in mitochondrial function observed in the early stages of human MAFLD. 相似文献
23.
Motion estimation is one of the critical parts in video compression standards with a high computational load. Many motion estimation algorithms have been developed to reduce the number of search points compared to a full-search algorithm without losing the quality considerably. Most of them use fixed search patterns in their first step which may suffer from trapping into local minima or searching unnecessary blocks due to inappropriate size and type of search patterns. In this paper, a new dynamic search pattern using motion vectors of spatial and temporal neighboring blocks is proposed. The motion vectors of neighboring blocks are prioritized, in order to efficiently use of halfway stop technique. The simulation results indicate that proposed algorithm is very close to the full-search algorithm in quality, compared to other rivals. Moreover, the average number of searches is often less than other algorithms. 相似文献
24.
Hybrid Paper–Plastic Microchip for Flexible and High‐Performance Point‐of‐Care Diagnostics 下载免费PDF全文
Mohamed Shehata Draz Maryam Moazeni Manasa Venkataramani Harini Lakshminarayanan Ecem Saygili Nivethitha Kota Lakshminaraasimulu Kamyar Mehrabi Kochehbyoki Manoj Kumar Kanakasabapathy Shirin Shabahang Anish Vasan Mohamad Ali Bijarchi Adnan Memic Hadi Shafiee 《Advanced functional materials》2018,28(26)
A low‐cost and easy‐to‐fabricate microchip remains a key challenge for the development of true point‐of‐care (POC) diagnostics. Cellulose paper and plastic are thin, light, flexible, and abundant raw materials, which make them excellent substrates for mass production of POC devices. Herein, a hybrid paper–plastic microchip (PPMC) is developed, which can be used for both single and multiplexed detection of different targets, providing flexibility in the design and fabrication of the microchip. The developed PPMC with printed electronics is evaluated for sensitive and reliable detection of a broad range of targets, such as liver and colon cancer protein biomarkers, intact Zika virus, and human papillomavirus nucleic acid amplicons. The presented approach allows a highly specific detection of the tested targets with detection limits as low as 102 ng mL?1 for protein biomarkers, 103 particle per milliliter for virus particles, and 102 copies per microliter for a target nucleic acid. This approach can potentially be considered for the development of inexpensive and stable POC microchip diagnostics and is suitable for the detection of a wide range of microbial infections and cancer biomarkers. 相似文献
25.
Reza Parvizi Jalil Vahdati Khaki Mohammad Hadi Moayed Mohammad Rezaei Ardani 《Metallurgical and Materials Transactions B》2012,43(6):1269-1276
In this study, the Taguchi design method was employed to determine the optimum experimental parameters in extraction of vanadium by NaOH leaching of oil-fired fly. Prior to designed experiments, the raw precipitates were mechanicallly milled using a high-energy planetary ball mill. Experimental parameters were investigated as follows: mechanical milling (MM) times (2 and 5?hours), NaOH (1 and 2 molar concentration) as reaction solution (RS), powder to solution (P/S) ratios (100/400 and 100/600?mg/mL), temperature (T) of reaction system (303 K and 333?K [30?°C and 60?°C]), stirring times (ST) of reaction media (4 and 12?hours), stirring speed (SS) being adjusted to 400 and 600?rpm, and rinsing times (RT) of remained filtrates (1 and 3?hours). Statistical analysis of signal-to-noise ratio followed by analysis of variance was performed in order to estimate the optimum levels and their relative contributions. Data analysis is carried out using L8 orthogonal array consisting of seven parameters each with two levels. The optimum conditions were MM1 (3?hours), RS2 (2 molar NaOH), P/S2 (100/600?mg/mL), T2 (333?K [60?°C]), ST2 (12?hours), SS1 (400?rpm), and RT1 (1?hour). Finally, from environmental and economical points of view, the process is faster and better organized by employing this analytical design method. 相似文献
26.
27.
Yonghyun Jo Hanyoung Jang Yeon-Ho Kim Joon-Kee Cho Hadi Moradi 《Advanced Robotics》2013,27(4):301-308
This paper presents an octree-based map building algorithm for mobile home-service robots. The robot is equipped with a time-of-flight camera, which produces point clouds of the environment surfaces. Given the successive input of point clouds, a 3D map is incrementally computed in real time. The map is accurate and memory-efficient because the octree nodes containing points on a plane are merged and represented simply by an index to the plane. The real-time performance is achieved largely due to the parallel processing capability of the many-core Graphics Processing Unit used for plane extraction. 相似文献
28.
Amir Hossein Alavi Amir Hossein Gandomi Hadi Chahkandi Nejad Ali Mollahasani Azadeh Rashed 《Neural computing & applications》2013,23(6):1771-1786
Providing precise estimations of soil deformation modulus is very difficult due to its dependence on many factors. In this study, gene expression programming (GEP) and multi-expression programming (MEP) systems are presented to derive empirical equations for the prediction of the pressuremeter soil deformation modulus. The employed expression programming (EP) systems formulate the soil deformation modulus in terms of the soil physical properties. Selection of the best models is on the basis of developing and controlling several models with different combinations of the affecting parameters. The proposed EP-based models are established upon 114 pressuremeter tests on different soil types conducted in this study. The generalization capabilities of the models are verified using several statistical criteria. Contributions of the variables influencing the soil modulus are evaluated through a sensitivity analysis. The GEP and MEP approaches accurately characterize the soil deformation modulus resulting in a very good prediction performance. The result indicates that moisture content and soil dry unit weight can efficiently represent the initial state and consolidation history of soil for determining its modulus. 相似文献
29.
Mehdi Salih Shihab Abbas Hadi Alshukrawi Wedad Hamad Aldahhan 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(6):1086-1092
In the present work, sodium 4-[(4-formylbenzylidene) amino] benzoiate (4) was synthesized and its structure was confirmed using spectroscopic techniques. Prepared compound was successfully applied as a corrosion inhibitor for C1010 carbon steel in 3.5% NaCl solution at 25°C. Different electrochemical measurements such as linear polarization resistance (LPR), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) were used to evaluate the suggested inhibitor (4). The results of different electrochemical measurements show that inhibition efficiencies obtained from EIS curves are in consistence with the results of potentiodynamic polarization and LPR measurements due to increase corrosion inhibition efficiency by increasing the concentration of organic inhibitor (4). Semi-empirical calculations with PM3 method were used to find relationship between molecular structure and inhibiting effect of suggested inhibitor (4). 相似文献
30.
Majid Ghashang Hadi Taghrir Mohammad Najafi Biregan Negar Heydari Fateme Azimi 《Journal of Sulfur Chemistry》2016,37(1):61-69
An eco-friendly procedure for synthesis of 2-(2-oxo-2H-chromen-4-yl)-3-arylthiazolidin-4-one derivatives by three-component reaction of 2-oxo-2H-chromene-4-carbaldehydes, aromatic amines and thioglycolic acid, with tetramethylbutane-1,4-diammonium acetate as a low-cost ionic liquid catalyst under reflux condition is described. The use of an ionic liquid as a catalyst has the advantages of high yields, short reaction time and environmentally friendly reaction media. 相似文献