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排序方式: 共有651条查询结果,搜索用时 15 毫秒
1.
为了给海面溢油污染识别检测提供理论基础,根据菲涅尔反射公式的偏振反射系数,结合偏振双向反射率因子和粗糙海面的概率密度分布函数,建立了完善的pBRDF模型,仿真在不同太阳入射角度、不同探测器观测角度以及不同海面风速风向等条件下海水和油膜的偏振反射分布函数。结果表明:海水和油膜太阳天顶角为53°和56°时P偏振反射率分别为1.0×10^-5和2.5×10^-5,S偏振反射率随着太阳天顶角的增加而增加;海面风速越大偏振反射率峰值越小;海面风向只改变pBRDF的空间位置;海水和油膜线偏振度空间分布有明显差异。搭建实验平台相机以40°拍摄时,得出海水和油膜的线偏振度分别在0.2~0.4, 0.5~0.7之间,同时表明利用偏振探测获取目标场景的偏振度和偏振角图可提高图像质量。 相似文献
2.
广义系统一类鲁棒观测器的设计 总被引:3,自引:0,他引:3
本文讨论了用观测器消除广义系统中由于模型误差、非线性因素、参数不确定及输入输
出噪声产生的量测误差的可能性,给出了这类鲁棒观测器的存在条件,得到了相应的算法. 相似文献
3.
4.
起重搬运作业的安全风险分析 总被引:2,自引:1,他引:1
用安全系统的理论和方法 ,以起重作业为研究对象 ,通过危险识别 ,对造成人员损伤的危险事件发生的可能性和导致伤害后果的严重程度 ,进行了定性的风险分析 ,介绍了我国采取的针对性综合管理对策 相似文献
5.
Quantification of trace amounts of impurities in high purity cobalt by high resolution inductively coupled plasma mass spectrometry 总被引:2,自引:0,他引:2
XIE Hualin HUANG Kelong NIE Xidu TANG Yougen 《稀有金属(英文版)》2007,26(3):286-291
An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au, and Pb) in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects because of the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the deter- mination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 μg?g?1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results. 相似文献
6.
ICP-MS法测定陶瓷容器中重金属元素的研究 总被引:2,自引:0,他引:2
采用电感耦合等离子体—质谱(ICP—MS)法同时测定了陶瓷容器中重金属元素PB、CA、Cr、Ni,对影响其测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件。结果表明,方法的检出限为0.002—0.008μg/L,回收率为90.0%-110.0%,RSD小于9.21%。该法准确、快速、简便,应用于陶瓷容器中重金属元素的测定,结果满意。 相似文献
7.
水泥中硫的高频红外分析方法研究 总被引:1,自引:0,他引:1
采用高频红外吸收法测定了水泥中硫的含量,并对样品作测定前的预处理(物理处理),在测定中选用复合型助熔剂,解决了高频感应炉中因顶吹氧气流的作用而导致的样品喷溅问题。该法可准确测定水泥中0.001%~5%的硫,回收率为98.6%~102.5%,RSD为0.78%~1.35%。 相似文献
8.
With 3‐aminopropyltriethoxysilane (APTES) as coupling agent, poly(lactic acid) (PLA)/SiO2 hybrid material was prepared to produce poly(lactic acid)/SiO2 hybrid microspheres (PLAHs) with porous structure bythe oil‐in‐water, single‐emulsion solvent evaporation method. Field scanning electron microscopy results show that the PLAHs were porous microspheres about 20 μm in diameter. The holes in the PLAHs opened outside and were not complicated. A nitrogen adsorption–desorption experiment showed that the nitrogen adsorbed in the holes was easily desorbed, and the specific surface area of the PLAHs was calculated to be 6.87 m2/g according to the Brunauer–Emmett–Teller equation. Fourier transform infrared spectroscopy results show that PLA was amidated with APTES successfully and formed a kind of organic–inorganic hybrid material by hydrolysis and con‐condensation with tetraethoxysilane. Moreover, the molecular structure of the hybrid material was confirmed by X‐ray photoelectron spectroscopy. Differential scanning calorimetry results show that the melting point ofthe PLAHs was higher than that of PLA by about 11.2°C. These PLAHs may be used in the controlled release of drugs by the embedding of the drugs in the holes of the PLAHs, and the drug loading amount can be controlled by the size and number of holes in the PLAHs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 679–683, 2006 相似文献
9.
蒋华林 《重庆科技学院学报(社会科学版)》2010,(4):136-139
把重庆大学建设成为一所综合性的世界高水平研究型大学,既有历史积淀的因素,更是国内外经济社会、科技教育发展的必然要求。阐述了重庆大学学科综合性建设的历史与现实背景,回顾了重庆大学学科综合性的发展历程。根据综合性大学的内涵界定与特征表现,梳理了重庆大学学科综合性建设的制约因素,提出了“既追求‘综合性’,又必须表现出自身的差异性,强化办学特色”的学科综合性建设思路和基本路径。 相似文献
10.
Lingzhan Pan Huawei He Zhiwen Yao Zhiqing Chen Jingsong Liu Hualin Zhang Jun Yang 《武汉理工大学学报(材料科学英文版)》2010,25(3):484-486
A novel nano-hydroxyapatite (HA)/konjac glucomannan composite scaffold with high porosity was developed by blending nano-HA
particles with konjac glucomannan in alkaline solution. The scanning electron microscopy, porosity measurement, X-ray diffraction(XRD),
and Fourier transformed infrared(FTIR) spectroscopy were used to analyze the physical and chemical properties of the composite
scaffolds. The pure konjac glucomannan scaffolds and composite scaffolds were similar in their macroscopic morphology, however,
the microscopic morphology on porewall surfaces was quite different. The diffraction patterns of XRD revealed the presence
of konjac glucomannan and HA in the composite scaffolds. In addition, the results of FTIR also showed the existence of the
functional group of HA. These results reveal that the newly developed nano-HA/konjac glucomannan composite scaffold may serve
as a good three-dimensional substrate in bone tissue engineering. 相似文献