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81.
Jian Wang Bing-Lin Yue Yong-Zhen Huang Xian-Yong Lan Wu-Jun Liu Hong Chen 《International journal of molecular sciences》2022,23(5)
Exosomes are a subset of nano-sized extracellular vesicles originating from endosomes. Exosomes mediate cell-to-cell communication with their cargos, which includes mRNAs, miRNAs, lncRNAs, and circRNAs. Exosomal RNAs have cell specificity and reflect the conditions of their donor cells. Notably, their detection in biofluids can be used as a diagnostic marker for various diseases. Exosomal RNAs are ideal biomarkers because their surrounding membranes confer stability and they are detectable in almost all biofluids, which helps to reduce trauma and avoid invasive examinations. However, knowledge of exosomal biomarkers remains scarce. The present review summarizes the biogenesis, secretion, and uptake of exosomes, the current researches exploring exosomal mRNAs, miRNAs, lncRNAs, and circRNAs as potential biomarkers for the diagnosis of human diseases, as well as recent techniques of exosome isolation. 相似文献
82.
作为一种案例导向的研究方法,定性比较分析(QCA)于最近的二十多年中在社会科学研究领域得到普及和应用。本文对这一方法的研究逻辑、适用情境进行了介绍及分析,并就其在新闻传播研究中的应用前景予以展望,提出了四个话题方向。文章同时介绍了该方法的操作步骤,以期将其引入到新闻传播学的研究中,拓展现有的方法论体系。 相似文献
83.
To construct efficient emitters suitable for non-doped devices and deeply understand the relationship between structures and performances, we designed and synthesized two heteroleptic iridium(III) complexes based on 1,2-diphenyl-1H-benzoimidazole (PBI) ligands whose substituents are varied simply from methyl (complex 2) to tert-butyl groups (complex 3). The parent complex 1 with non-substituent on PBI ligand has also been presented for a better comparison. Their photophysical, electrochemical and electroluminescent (EL) performances are investigated systematically. Despite their structural modification, all complexes exhibit almost identical emission and excited-state characters, which are rationalized by the quantum-chemical calculations. However, the obvious differences on device performances are found. Non-doped device employing 3 as emitting layer displays the highest EL performance with maximum current efficiency (ηc, max) of 18.6 cd A−1 and power efficiency (ηp, max) of 16.2 lm W−1 accompanied by low efficiency roll-off values, which is much higher than those of complexes 1 and 2. The obtained results herein suggest that introduction of the simple substituent into PBI ligand is an effective and feasible approach to develop highly efficient non-doped phosphors. 相似文献
84.
The series and parallel bimorph actuators were investigated to identify the limiting factors at high voltage operations. In the static condition, the series and parallel bimorph exhibit polarization-shaped and three-looped hysteresis curve, respectively. The parallel bimorph shows much larger magnitude of saturated and remnant polarization than the series bimorph. The series bimorph is mainly restricted by the breakdown voltage in contrast to the parallel bimorph, which is limited by the domain reorientation. In the dynamic condition, both types of actuators are mainly limited by the maximum stress and domain reorientation. The actuator tends to fracture at the location of maximum stress near the resonance when the voltage is increased to a certain degree. Further increasing the voltage, domain reorientation may happen at frequencies lower than the resonance. Comparatively, the series bimorph has higher resistance to the domain reorientation than the parallel bimorph. 相似文献
85.
《Energy Policy》2014
The grasslands of Inner Mongolia are not only the source of the necessary resources for the survival and development of herdsmen, but also represent a significant green ecological barrier in North China. Coal-mining production is important in maintaining GDP growth in Inner Mongolia. However, over-exploitation has created serious problems, such as pollution of the environment and significant decreases in grassland ecosystem services, in addition to impacting the well-being of herdsmen and other humans. Based on questionnaires survey performed among 864 herdsmen addressing the relationship between coal exploitation in grasslands and human well-being in Xilinguole League in Inner Mongolia, we found that (1) coal resource exploitation in these grasslands does not benefit the herdsmen by increasing their income; (2) the rapid development of this resource has not obviously materially improved the life of the herdsmen; and (3) these activities have increased the risks that herdsman will have to endure in the future. Overall, coal resource exploitation in grasslands has more negative than positive effects on the well-being of herdsmen. We propose the conservation of coal resources and improvement of ecological compensation should be carried out without blindly pursuing economic growth, instead of focusing on economic development and structural adjustments. 相似文献
86.
介绍了金融业对辽阳经济发展的支持情况,剖析了存在的问题,提出了对策和建议。 相似文献
87.
《Journal of power sources》2006,153(2):265-273
Electrolytic manganese dioxide (EMD) is made in aqueous sulfuric acid and neutralized or ion exchanged with aqueous lithium hydroxide before use in Li batteries. Solid state Li NMR studies show that Li is present on surface and vacancy sites and migrates into Mn (III) related sites after heat treatment to remove water. During heat treatment the MnO2 rearranges from ramsdellite/pyrolusite intergrowth EMD to a defect pyrolusite heat-treated manganese dioxide (HEMD). EMD exhaustively treated with lithium hydroxide solution has 40–50% of the protons in EMD exchanged for Li ions to produce a structurally unchanged γ-MnO2. Li magic angle spinning (MAS) NMR reveals that this lithiated material contains lithium in cation vacancy and Mn (III) related sites in the MnO2 lattice in addition to ionic Li on the surface. During heat treatment, the vacancy lithium content prevents the ramsdellite to pyrolusite rearrangement in HEMD formation. Instead, an ordered ramsdellite/pyrolusite intergrowth of lithiated manganese dioxide (LiMD) is formed with an approximate composition of 50% ramsdellite and 50% pyrolusite. Li MAS NMR of LiMD shows Li resonances near 280 and 560 ppm, consistent with Li transition from surface and cation vacancy sites into the ramsdellite lattice.LiMD discharged against lithium shows two processes, one near 3.1 V, the other about 2.8 V. Li MAS NMR studies show the initial reduction results a lithium resonance near 560 ppm associated with Li near a mixed valence Mn (III/IV) environment followed by appearance of a resonance near 100 ppm consistent with a Li environment near Mn (III). TEM studies of the reduced material show initial expansion of the ramsdellite lattice accompanied by a loss in crystallinity in the 3.1 V discharge process followed by disappearance of the pyrolusite content via conversion to ramsdellite in the second discharge process. 相似文献
88.
《Materials Letters》2007,61(19-20):4128-4130
BaMgAl10O17:Eu2+ doped with 0–6% additional Mg2+ were synthesized by co-precipitation method. Their photoluminescence and thermal stability were investigated under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation. The additional Mg2+-doped samples exhibited stronger emission intensity and better thermal stability than the sample without additional Mg2+ under 254 or 147 nm excitation. After thermal degradation, the 4% additional Mg2+-doped sample had the highest emission intensity which was 12.7% and 16.6% stronger than that of the sample without additional Mg2+ under 254 and 147 nm excitation, respectively. Moreover, the improvement mechanisms on emission intensity and thermal stability were discussed. 相似文献
89.
Rapid determination of soil organic matter content based on soil colour obtained by a digital camera
Caiwu Wu Jianxin Xia Yue Yang Yuecong Zhang Fuwei Cheng 《International journal of remote sensing》2013,34(20):6557-6571
ABSTRACTSoil organic matter (SOM) is an important component of soil and a significant criterion in determining the dynamics of soil quality. A rapid, low-cost method to measure SOM content is needed to support the development of precision agriculture. This article studied the quantitative relationship between SOM and soil colour using a digital camera, which is relatively inexpensive and easy to operate, as a portable tool for obtaining colour information of the soil surface. The results show that mixed samples with different soil particle sizes reduce the noise of the image and are more suitable than uniform soil samples for predicting the SOM. Among the three bands of red, green, and blue (RGB), the red band had the best correlation with SOM, and its reciprocal correlation coefficient (r) reached 0.75. The reciprocal regression model of the RGB colour model provided good prediction results for mixed soil samples, with a coefficient of determination (R2) of 0.76 and a root mean square error (RMSE) of 0.55, and the validation result had an excellent predictive ability (R2val = 0.85 and RMSEval = 0.53). The single-variation predictive model of CIELa*b* colour space model through transformation of the RGB colour space model performed well. The model built by colour intensity values had a strong stability and forecasting capacity. Thus, a digital camera can be used as an alternative tool to rapidly measure SOM. 相似文献
90.