全文获取类型
收费全文 | 618篇 |
免费 | 51篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 19篇 |
化学工业 | 158篇 |
金属工艺 | 14篇 |
机械仪表 | 23篇 |
建筑科学 | 37篇 |
矿业工程 | 2篇 |
能源动力 | 40篇 |
轻工业 | 83篇 |
水利工程 | 10篇 |
石油天然气 | 12篇 |
无线电 | 52篇 |
一般工业技术 | 89篇 |
冶金工业 | 26篇 |
原子能技术 | 9篇 |
自动化技术 | 105篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 16篇 |
2021年 | 38篇 |
2020年 | 34篇 |
2019年 | 47篇 |
2018年 | 62篇 |
2017年 | 41篇 |
2016年 | 52篇 |
2015年 | 38篇 |
2014年 | 42篇 |
2013年 | 83篇 |
2012年 | 48篇 |
2011年 | 58篇 |
2010年 | 23篇 |
2009年 | 23篇 |
2008年 | 12篇 |
2007年 | 6篇 |
2006年 | 14篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有679条查询结果,搜索用时 15 毫秒
41.
42.
In this paper, the remaining creep life of SA-304L stainless steel at elevated temperatures is studied. The small punch creep tests (SPCT) were performed on SA-304L virgin and aged materials at constant loads. Times to fracture and the minimum deflection rate in SPCTs were recorded, and the time-temperature parametric analysis was performed, based on experimental results. The constants of the Larson–Miller parameter and the Monkman–Grant relationship were obtained for different consumed creep life ratios, and eventually the equations were established to explain the variation of constants of the Larson–Miller parameter and the Monkman-Grant relationship with respect to the consumed creep life ratio. 相似文献
43.
This study examined the generalizability of direct and mediated links posited in objectification theory among internalization of sociocultural standards of beauty, body surveillance, body shame, and eating disorder symptoms with a sample of Deaf women. The study also examined the role of marginal Deaf cultural identity attitudes within this framework. Data from 177 Deaf women indicated positive relations among internalization, body surveillance, body shame, and eating disorder symptomatology. Consistent with tenets of objectification theory, body shame mediated the links of internalization and body surveillance with eating disorder symptoms. In addition, marginal Deaf identity attitudes (but not hearing, immersion, or bicultural attitudes) were linked uniquely with eating disorder constructs and had significant indirect relations through internalization with body surveillance, body shame, and eating disorder symptoms. Implications for practice and future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
Regarding to the variations of the load and unmodeled dynamic, robot manipulators are known as a nonlinear dynamic system. Overcoming such problems like uncertainties and nonlinear characteristics in the model of two-link manipulator is the principal goal of this paper. To approach to this aim, a neural network is combined with a linear robust control in which the result has the advantages of, the first, approximated nonlinear elements and the second, the guaranteed robustness. To design the proposed controller, at first, multivariable feedback linearization is employed to convert the nonlinear model to linear one. Second, the unknown parameters of the system are identified by neural network based on a new proposed learning rule. Third, Mixed linear feedback-H?∞? robust control method is proposed to stabilize the closed loop system. The closed loop system based on the proposed controller is analyzed and some numerical simulations are performed. Results show suitable responses of the closed loop system. 相似文献
45.
In the present work, compressive strength of geopolymers made from seeded fly ash and rice husk–bark ash has been predicted by adaptive network-based fuzzy inference systems (ANFIS). Different specimens, made from a mixture of fly ash and rice husk–bark ash in fine and coarse forms and a mixture of water glass and NaOH mixture as alkali activator, were subjected to compressive strength tests at 7 and 28 days of curing. The curing regimes were different: one set of the specimens were cured in water at room temperature until 7 and 28 days and the other sets were oven-cured for 36 h at the range of 40–90°C and then cured at room temperature until 7 and 28 days. A model based on ANFIS for predicting the compressive strength of the specimens has been presented. To build the model, training and testing using experimental results from 120 specimens were conducted. The used data as the inputs of ANFIS models are arranged in a format of six parameters that cover the percentage of fine fly ash in the ashes mixture, the percentage of coarse fly ash in the ashes mixture, the percentage of fine rice husk–bark ash in the ashes mixture, the percentage of coarse rice husk–bark ash in the ashes mixture, the temperature of curing, and the time of water curing. According to these input parameters in the ANFIS models, the compressive strength of each specimen was predicted. The training and testing results in ANFIS models showed a strong potential for predicting the compressive strength of the geopolymeric specimens. 相似文献
46.
Ayoub Moradi Laurent Metivier Olivier de Viron Stephane Calmant Catherine Mering 《International journal of remote sensing》2013,34(16):6060-6075
Moderate-Resolution Imaging Spectroradiometer (MODIS) optical and infrared data are used to monitor changes in the Caspian Sea coastline. The information extracted from MODIS images is converted into total water volume and mean lake level by combining a digital elevation model (DEM) with remote-sensing data. The elevation estimates were enhanced by reprocessing the MODIS data at the sub-pixel scale. The water volume variations estimated from MODIS data along with DEM are compared to other estimations derived from altimetry data sets, and show fair agreement. 相似文献
47.
Ali Farsi Vahid Shadravan Seyed Soheil Mansouri Gholamreza Zahedi Zainuddin Abdul Manan 《国际能源研究杂志》2013,37(2):129-152
A new and very promising application of auto‐thermal reactors is the coupling of endothermic and exothermic reactions where the product of the endothermic reaction is the desired one. Therefore, in this work, a reactor in which oxidative coupling of methane (OCM) and steam re‐forming of methane (SRM) reactions take place simultaneously was modeled. The results were obtained in a wide range of different conditions such as inlet feed, inlet temperature, portions of OCM and SRM catalysts, and inlet velocity. In selection of the catalysts, more attention was drawn to prevent re‐forming of OCM products. The main parameters of each reaction under different conditions such as conversion of the feed components, products selectivity and yield, temperature in the length of reactor, and component's concentration in the reactor were considered in course of this study. The results revealed that simultaneous OCM and SRM reactions in one reactor will tend to be auto‐thermal, and the waste of energy will be reduced. The results also show that complete conversion of water and majority of methane and oxygen will decrease the amount of unwanted products at the reactor's discharge–a constraint that exists in single reactors of each reaction specially OCM. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
48.
Noorossadat Seyyedi Fatemeh Farjadian Ali Farhadi Gholamreza Rafiei Dehbidi Reza Ranjbaran Farahnaz Zare Mohammad Ali Okhovat Negin Nikouyan Abbas BehzadBehbahani 《IET nanobiotechnology / IET》2020,14(7):555
Gold nanoparticles (AuNPs) are commonly used in biosensors of various kinds. However, its application to extract DNA from cancer tissues has not been extensively studied. The purification of DNA from cancer tissues is an important step in diagnostic and therapeutic development. Almost, all cervical cancer cases are associated with high‐risk human papillomavirus (HR‐HPV) infection. Accurate viral diagnosis has so far relied on the extraction of adequate amounts of DNA from formalin‐fixed, paraffin‐embedded (FFPE) tissue samples. Till now, no specific and sensitive DNA purification method has been introduced for the extraction of HR‐HPV from FFPE tissue. Since the commercially available purification kits are not sensitive and specific enough for HR‐HPV DNA targets, in this study, a DNA purification method was designed based on AuNPs to purify sufficient amounts of HR‐HPV DNA from cervical cancer tissue samples. AuNPs were coated with a series of oligonucleotide probes to hybridize to specific DNA sequences of HR‐HPV genotypes. Results showed that 733 out of 800 copies of type‐specific HPV DNA were recovered with complete specificity, compared to 36 copies with a standard commercial kit (Qiagen FFPE). The high yield of DNA (91.6%) is the main advantage of the AuNPs‐probe purification method.Inspec keywords: cancer, biological tissues, microorganisms, gold, DNA, lab‐on‐a‐chip, gynaecology, purification, biochemistry, molecular biophysics, nanoparticles, nanomedicine, cellular biophysicsOther keywords: specific extraction method, cervical cancer tissue samples, high‐risk human papillomavirus infection, paraffin‐embedded tissue samples, specific DNA purification method, sensitive DNA purification method, FFPE tissue, HR‐HPV DNA targets, specific DNA sequences, HR‐HPV genotypes, type‐specific HPV DNA, AuNP‐probe purification method, gold nanoparticle‐based DNA isolation method, oligonucleotide, human papillomaviruse genotypes, clinical samples, Au 相似文献
49.
50.
Through this study, a method is presented to estimate moment-rotation (M-) curve of I beam-to-the concrete filled tube (CFT) connections. This method is based on the components method in which components are analyzed and modeled as different mechanical models. These components are considered as springs with specific mechanical properties of stiffness, strength, and rigid bars. Their force-displacement relationship is assumed bi-linear and 3-linear. The connection behavior is assumed through assembling the stiffness of different components. In this study, connection of I beam-to-CFT column with bolted endplate connection under monotonic loading, which has been tested in the laboratory, is evaluated. It must be mentioned that those bolts which penetrated into the column depth have been used in order to create continuity between flanges of the column. The suggested method has been compared with the experimental test and the advanced finite element model in terms of stiffness, strength, and rotational capacity; moreover, its operation was satisfactory. 相似文献