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排序方式: 共有5163条查询结果,搜索用时 46 毫秒
1.
Liu Yang Pengfei Yu Wenyuan Li Fengliang Cao Xin Jin Sheng Xue Xianglong Zhang Tingwei Zhang Mingbo Wu Wenting Wu 《American Institute of Chemical Engineers》2022,68(9):e17760
Hydrogen peroxide (H2O2) has been listed as one of the 100 most important chemicals in the world. However, huge amount of residual H2O2 is hard to timely decomposed into O2 and H2O under acidic condition, easily resulting in explosion hazard. Here, we reported a core–shell structure catalyst, that is graphene with Co N structure encapsulated Co nanoparticles. Co N graphene shell serves as the active site for the H2O2 decomposition, and Co core further enhance this decomposition. Benefiting from it, the H2O2 decomposition were close to 100% after 6 cycles without pH adjustment, which increased 6 orders of magnitude compared with no catalyst. At the same time, the O2 generation reached 99.67% in 2 h with little metal leaching, and ·OH has been greatly inhibited to only 0.08%. This work can cleanly remove H2O2 with little deep oxidation and protect the process of H2O2 utilization to achieve a safer world. 相似文献
2.
3.
Tao Yang Jiasong Zhong Jianwen Liu Yongjun Yuan Dexin Yang Qinan Mao Xinyue Li Zaiping Guo 《Advanced functional materials》2021,31(13):2009433
Due to its suitable working voltage and high theoretical storage capacity, antimony is considered a promising negative electrode material for lithium-ion batteries (LIBs) and has attracted widespread attention. The volume effect during cycling, however, will cause the antimony anode to undergo a severe structural collapse and a rapid decrease in capacity. Here, a general in situ self-template-assisted strategy is proposed for the rational design and preparation of a series of M Sb (M = Ni, Co, or Fe) nanocomposites with M N C coordination, which are firmly anchored on Swiss-cheese-like nitrogen-doped porous carbon as anodes for LIBs. The large interface pore network structure, the introduction of heteroatoms, and the formation of strong metal N C bonds effectively enhance their electronic conductivity and structural integrity, and provide abundant interfacial lithium storage. The experimental results have proved the high rate performance and excellent cycling stability of antimony-based composite materials. Electrochemical kinetics studies have demonstrated that the increase in capacity during cycling is mainly controlled by the diffusion mechanism rather than the pseudocapacitance contribution. This facile strategy can provide a new pathway for low-cost and high-yield synthesis of Sb-based composites with high performance, and is expected to be applied in other energy-related fields such as sodium-/potassium-ion batteries or electrocatalysis. 相似文献
4.
5.
介绍了上海前滩10-01地块(办公及住宅)高层建筑上下相邻双层大跨度钢桁架施工技术。结合项目桁架结构特点,分析讨论了双层桁架的支撑措施布设及安装过程中的注意要点,解决了±0m楼板不能满足双层桁架荷载要求的问题,提出了待下层桁架支撑卸载后,利用下层桁架布设上层桁架支撑,完成上层桁架安装的方案。同时通过有限元计算分析,对桁架施工过程进行计算模拟,研究施工过程的结构位形及内力,保证施工质量与安全。 相似文献
6.
Abstract. The concentration of dissolved organic carbon (DOC) in the Berkeley pit lake water ranges from 2 to 4 mg/L, and is comparable
to that of its inflow waters. On the dates sampled, the DOC concentrations decreased towards the surface of the lake, in a
manner similar to the concentration of dissolved Fe. This may reflect adsorption of DOC onto newly formed ferric precipitates
in the epilimnion of the lake. The total organic carbon (TOC) content of the lake sediment is 0.20 to 0.33%, and is on the
low end of TOC in natural aquatic sediments. In contrast, the DOC concentrations of sediment pore waters are unusually high,
ranging from 50 to 380 mg/L, and are much higher than DOC values of pore waters from typical marine or lacustrine sediments.
The high DOC concentrations are explained by release of adsorbed organic carbon from ferric precipitates as they age and recrystallize,
coupled with the relative scarcity of heterotrophic bacteria in the acidic and heavy metal-rich waters that would otherwise
consume DOC through reduction of sulfate. 相似文献
7.
Jorge?OyarzúnEmail author Hugo?Maturana Andrzej?Paulo Anna?Pasieczna 《Mine Water and the Environment》2003,22(3):155-161
Abstract.
Active sediments from the Elqui River in Chile were
sampled 4 times at 10 sites during 2000. Concentrations of Ag,
Ba, Cd, Co, Cr, Hg, Mn, Mo, Ni, Pb, Sr, Ti, V, Al, Ca, Fe, K,
Mg, Na, P, and S were normal. Zinc levels were clearly high, and
those of Cu (hundred to thousands ppm) and As (tens to hundreds
ppm) were highly anomalous. Dissolved Cu (0.1-12.7 ppm) and Zn
(0.2-2.2 ppm) levels were also very high. The anomalies of the
upper tributaries are due to the El Indio–Tambo Au-Cu-As
district and large hydrothermal alteration zones at altitudes
between 3500–4500 m. Lower on the river, old and active tailing
waste deposits and on-going mining operations in the Talcuna Cu
(Pb) district are responsible. Partially eroded tailing deposits
in the alluvial plain of the Elqui River and its tributaries,
and especially in the El Indio-Tambo district, after mine
closure in 2000, warrant special attention. 相似文献
8.
Abstract In many regions of the world, flooded mines are a potentially cost-effective option for heating and cooling using geothermal
heat pump systems. For example, a single coal seam in Pennsylvania, West Virginia, and Ohio contains 5.1 x 1012 L of water. The growing volume of water discharging from this one coal seam totals 380,000 L/min, which could theoretically
heat and cool 20,000 homes. Using the water stored in the mines would conservatively extend this option to an order of magnitude
more sites. Based on current energy prices, geothermal heat pump systems using mine water could reduce annual costs for heating
by 67% and cooling by 50% over conventional methods (natural gas or heating oil and standard air conditioning). 相似文献
9.
John J. Metesh 《Mine Water and the Environment》2006,25(2):108-113
Abstract. Nearly 10,000 miles (16,000 km) of underground mine workings began flooding on April 22, 1982 when the large pumps used to
dewater the mines of Butte, Montana were shut off. In the first few months, water levels in the workings rose hundreds of
meters. Flooding continues to this day at a slower rate, nearly 25 years later. An early evaluation of the water chemistry
in the flooding mines suggested that the initially poor water quality was the result of flushing of a reservoir of stored
acidity and metals. However, a detailed water balance for the Berkeley pit, underground workings, and associated mining features
suggests an alternative explanation. During the early period of mine flooding, acidic surface water from the deactivated heap
leach operations and nearby acid rock drainage were routed into the empty Berkeley Pit, and thence drained downward and outward
into the underground mine workings, causing widespread degradation of water quality in the underlying workings. After 21 months,
the hydraulic gradients in the system reversed, causing a change in the direction of ground water flow and a gradual improvement
in water quality of the mine shafts. 相似文献
10.
针对临江门车站隧道跨度大、高差大、工序多且受力复杂等施工特点,必须有一套适应满足其施工特点并能确保施工质量及施工安全的隧道衬砌施工技术。着重介绍了轨行式模板台车衬砌施工技术,对浅埋暗挖、大跨隧道衬砌施工,有一定的参考价值。 相似文献