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51.
该文从城市设计的视角,分析新加坡河沿河建筑形态、街区尺度、交通系统、景观系统等方面所采用的设计手法,并提出新加坡河沿河地区的城市设计采用"面向河道"的更新策略.在分析过程中,注重考察和研究这些设计手法对社会经济的发展、传统文化的保护、城市环境的提升所产生的综合效益. 相似文献
52.
珠江三角洲大都市地区高密集城中村的形成——一个分析框架 总被引:1,自引:0,他引:1
从改革开放后珠江三角洲外向型乡村工业化入手,分析其对区域空间的影响,并从区域增长与制度供给层面、华南宗族聚居特征与重商传统等角度探讨其与城中村建设的关系,从而搭建一个对珠江三角洲大都市地区高密集城中村形成的大致分析框架。 相似文献
53.
介绍了国内外水源热泵技术发展概况,研究了以黄浦江水为冷热源的水源热泵技术在上海十六铺地区综合改造工程中的应用,评价了该系统的能效、经济性及环境效益,并展望了水源热泵技术在国内的开发应用前景。 相似文献
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Viganò L Arillo A Buffagni A Camusso M Ciannarella R Crosa G Falugi C Galassi S Guzzella L Lopez A Mingazzini M Pagnotta R Patrolecco L Tartari G Valsecchi S 《Water research》2003,37(3):501-518
Comprehensive and contemporary evaluations of physical, chemical and toxicological endpoints have been performed on bed sediments of the Po River, the major Italian watercourse. Two extensive sampling campaigns were conducted in summer and winter low-flow conditions. Composite sediment samples were collected from ten reaches of the main river: the first was located in the upper region (ambient control), and the others downstream of the confluences of nine principal tributaries. The two sampling programs were paralleled by contemporary investigations on the macroinvertebrate community. The particle-size composition along the Po River showed a relatively uniform distribution of fine sand, a progressive downstream decrease of coarse sands and a corresponding increase of fine materials. The levels of polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), extractable organo halides (EOX), Cd, Cr, Cu, Hg, Ni, Pb and Zn were determined in sediment fine particles (< 63 microm), and showed marked changes across the ten river reaches. Their longitudinal trends, as those of organic carbon and total nitrogen, were very similar and largely independent of the survey season. Sediment quality benchmarks were used to evaluate sediment chemistry, and, although the overall level of contamination was from moderate to low, the reaches located downstream of the tributaries Dora Riparia, Dora Baltea, Lambro and Oglio were considered to be at risk. Sediments were tested for toxicity on Oncorhynchus mykiss, Ceriodaphnia dubia, Raphidocelis subcapitata and Vibrio fischeri. The toxicity tests were conducted both with sediment extracts and whole samples. Sediment extracts showed toxic potentials that were consistent with the spatial distribution of contaminants. Whole-sediment toxicity showed moderate/low effects which also included false positives and negatives. Alterations of the macroinvertebrate community were found for many kilometers downstream of Dora Riparia, and with a seasonal dependence, also in other reaches of the Italian river. Principal component analysis (PCA) was used to describe the longitudinal and temporal changes of the Po River, and allowed the selection of the most useful and discriminating indicators. 相似文献
58.
基于城市河流半自然化的生态防洪对策——河滨缓冲带与柔性堤岸设计导引 总被引:6,自引:0,他引:6
旨在将城市河流半自然化与生态防洪对策落实到城市设计层面。根据观测水位、防洪、防潮标准确定缓冲带鼓励淹没范围、堤顶控制点标高,结合亲水性活动、适宜土地利用方式及景观要素,给出8种典型缓冲带断面设计及相应护岸生态工法。设计导引以海河下游为例,采用绩效控制、示例设计方法,主要内容包括目标-策略表、控制要点与编制方法表、示例设计图、应用索引图等。导引有助于消除防洪设施带来的视线遮挡、增强河滨缓冲带土地利用复合性与公共性,缓解防洪与亲水性、城市区生态用地与河滨土地稀缺性等矛盾,以保持河滨持久性活力。 相似文献
59.
Surface water and sediments from the St Lawrence River system (Québec region) were analysed for genotoxicity using the SOS Chromotest, as well as for their chemical concentrations of polycyclic aromatic hydrocarbons and heavy metals. Additionally, chlorobenzenes, polychlorinated biphenyls, organochlorinated pesticides, ammonia and nitrite concentrations in sediments were determined. Water and sediments sampled from twenty-five sites were initially partitioned into their aqueous and particulate phases by tangential flow filtration and centrifugation, respectively. Organic contaminants were extracted from the fractions with dichloromethane. For surface water, fifteen extracts of filtered water and seven of particulates, and for sediments one extract of pore water and three of particulates proved to be weakly genotoxic. All but one of the genotoxic responses observed in the surface water were obtained from samples taken from the highly industrial portion of the St Lawrence River system, with the strongest responses observed in Lake St Louis. Surface water genotoxicants partitioning favours the particulate fraction. Bottom particulates genotoxicity was 1000-fold weaker than suspended particulates, on a per unit weight basis. Additionally, whole sediments were extracted with a 10% dimethylsulfoxide-saline solution. The observed distributions of genotoxicity values did not correlate with observed concentrations of demonstrated SOS inducers, mutagens and/or carcinogens, nor with the presence of other toxic chemicals. 相似文献
60.
我国的城市大型桥梁及隧道正处在起步发展的阶段,由于这些领域的弱电控制系统具有一定的复杂性、特殊性,故在确定弱电方案时必须充分考虑大型桥梁、隧道等工程长距离、大范围、设备分散性、控制复杂等特点。 相似文献