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1.
《International Journal of Hydrogen Energy》2022,47(95):40379-40390
TiO2 quantum dots-sensitized Cu2S (Cu2S/TiO2) nanocomposites with varying concentration of TiO2 QDs are synthesized via a facile two-stage hydrothermal-wet impregnation method. X-ray diffraction analysis confirms the formation of Cu2S and TiO2with chalcocite and anatase phases, respectively. The observed shoulder-like absorption peaks indicate the UV–visible light-driven properties of the composite. Morphological analysis reveals that the fabricated Cu2S/TiO2 composite consists of Cu2S with a nano rod-like shape (average length and width of ~856 and ~213 nm, respectively) and nanosheets-like structures (average length and width of ~283 and ~289 nm, respectively), whereas the TiO2 is formed as quantum dots with a size range of 8.2 ± 0.4 nm. Chemical state analysis shows the presence of Cu+, S2?, Ni2+, and O2? in the nanocomposite. The H2 evolution rate over the optimized photocatalyst is found to be ~45.6 mmol h?1g?1cat under simulated solar irradiation, which is around 5 and 2.4-fold higher than that of the pristine TiO2 and Cu2S, respectively. Continuous H2 production for 30 h is achieved during time-on-stream experiments, demonstrating the excellent stability and durability of the Cu2S/TiO2 photocatalyst for large-scale applications. 相似文献
2.
渤中13-2大型潜山地区是渤海海域发现的首个亿吨级深层变质岩潜山油藏。通过已钻井的岩心、薄片、测试、测井等资料,从构造演化、成岩作用、古地貌特征等方面,阐述了研究区潜山储集空间类型、裂缝发育主控因素及分布规律,为研究区的高效开发奠定基础。研究结果表明:①多期次构造运动是导致裂缝形成的主控因素,风化淋滤和裂缝充填是造成储层纵向差异的主要原因。②利用结构张量场与绕射波耦合属性可以有效指导研究区储层平面预测,根据最大似然属性体能够较好地预测潜山裂缝走向。③平面上靠近大断层附近裂缝发育较好,纵向上风化带裂缝好于内幕带裂缝,渤中13-2地区主力层段风化带储层可划分为4类,Ⅰ类储层最好,主要位于构造高部位;Ⅱ类储层次之,主要位于构造腰部; Ⅲ类储层较差,主要位于距离断层较近区域的构造翼部; Ⅳ类储层最差,主要位于距离大断层较远处。 相似文献
3.
《Ceramics International》2022,48(3):3362-3367
The influence of high-energy ball milling on structural, microstructural, and optical properties of TiO2 by modifying the nanoparticle size was studied. Five samples were extracted at different milling times (0, 2, 4, 8, and 13 h). The average particle sizes estimated by dynamic light scattering (DLS) were 205, 155.8, 116.8, 82.9, and 82.7 nm at 0, 2, 4, 8, and 13 h, respectively. X-ray diffraction analysis confirmed progressive broadening of the peaks as the milling time elapsed. Besides, a correlation was found between d spacing and the average crystal size. The UV–Vis diffuse reflectance spectra of TiO2 revealed a decrease in reflectance due to particle size reduction. Similarly, an alteration of the bandgap transition energy was presented, whose values gradually decreased from 2.966 eV to 2.861 eV for the sample without and with the maximum duration milling performed (13 h), respectively. Likewise, the SEM analysis showed a distribution in nanoparticle size that became more homogeneous and smaller average grain size as the milling duration was longer. 相似文献
4.
《Ceramics International》2022,48(12):16730-16736
Recently, all-inorganic cesium lead-halide perovskites have shown their promise for light emission applications, due to the excellent optical performance. Herein, we report that the initially nonphosphorescent undoped lead-halide Cs4PbBr6 single crystals (SCs) exhibit an ultralong phosphorescence emission under X-ray excitation at low temperatures. It is shown that the dramatic change has been taken place in radioluminescence spectra and the broad-band emission gradually appeared with the decrease of temperature. Below 210 K, the radioluminescence spectra can be deconvoluted into one narrow peak located at 530 nm and two broad peaks centered at 595 nm and 672 nm respectively. Subsequently, the time-dependent radioluminescence spectra in undoped lead-halide Cs4PbBr6 SCs were investigated. The ultralong phosphorescence emission can persist over 120 min at 70 K. We consider that ultralong phosphorescence originates from defect-related emission. To the best of our knowledge, our finding is the first time that undoped Cs4PbBr6 SCs exhibit the phosphorescence emission, which will offer a paradigm to motivate revolutionary applications on perovskite. 相似文献
5.
在执行API SPEC 5L管线规范的过程中,当使用X射线数字检测方法对钢管焊缝进行无损检测时,检测标准应采用API SPEC 5L规范的引用标准ISO 10893-7,该标准未对双丝像质计的使用频次等工艺要求进行明确,因此还需要参考其引用标准ISO 17636-2的相关要求执行。为了使X射线数字检测方法的工艺文件编制及工艺执行更加严谨和完善,以ISO 10893-7—2019为主,将其与ISO 17636-2—2013的相关内容进行对比,并对两者的主要差异进行了分析,以便为X射线数字检测的工艺执行提供参考和依据。 相似文献
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8.
为了探究GH4169合金低周疲劳试样加工过程中表面残余应力的变化及残余应力对低周疲劳性能的影响,采用X射线衍射法对“车 磨 抛”不同加工工艺的试样表面残余应力进行表征及对成品试样进行残余应力层深度测试,通过中子衍射法对试样内部进行残余应力测试。采用电液伺服万能试验机进行了低周疲劳试验。结果表明:GH4169合金低周疲劳试样加工表面残余应力随着切削量的增加由表面残余压应力变为残余拉应力。根据残余应力层深度测试,机加工对试样表面造成残余应力层深度小于0.01 mm,内部残余拉应力减小;根据疲劳试验结果,GH4169合金疲劳寿命与表面轴向残余压应力呈正相关关系。 相似文献
9.
《Ceramics International》2022,48(12):16877-16884
Oxygen selective membrane on the base of cermet δ-Bi2O3/Ag with an interpenetrating structure has the maximum potential efficiency of air separation. However, the degradation processes, including the phase degradation of fluorite δ-Bi2O3, do not make it possible to create a membrane with the required perfection and durability. In this work, the ordering of oxygen vacancies with the transformation of fluorite into the rhombohedral phase (S.G. R-3) was studied by powder HT XRD in situ at 600 °C on dense Bi0.78Er0.2Hf0.02O1.51 ceramics. Fast regeneration of disordered fluorite occurs at T = 640–700 °C. The phase degradation of fluorite due to the segregation of dopants at the second stage leads into stable phases - sillenite, tetragonal or rhombohedral phase (S.G. R-3m), depending on the composition of δ-Bi2O3. Fast regeneration of fluorite occurs when heated to 820 °C, which is unacceptable for membranes. Analysis of all available data allows us to propose approaches to optimize the composition of δ-Bi2O3 and technical solutions for creating durable oxygen selective membranes with promising use in distributed multigeneration. As a result of the analysis, a new solid electrolyte with better parameters was obtained. 相似文献
10.
利用X射线光电子能谱(XPS)及深度剖析技术,定量研究了SnO和SnO2在不同氩离子束能下化学损伤。0.5、1、2 keV的离子束能溅射后,SnO2无明显化学损伤;而SnO则出现不同程度的还原,分别产生了7.0%、15.3%、20.6%的Sn单质。实验还表明,同离子束能不同电流下,Sn2+还原程度相差无几。因而利用XPS及深度剖析技术对Sn焊料进行表面分析时,须选用尽可能低的束能以减少化学损伤。定性讨论了Sn价带,4d和3d电子层的图谱特征,并确定了用Sn 3d5图谱进行Sn价态的定量分析。利用获得的Sn0、Sn2+、Sn4+图谱参数,以模拟波峰焊的锡铜焊料为例,定量分析了Sn价态随深度的变化,结果表明,氧化层最表面主要为SnO2并逐步过渡到SnO。 相似文献