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1.
某铅锌矿原矿铅含量为1.26%,含锌6.53%,含硫30.38%。生产上采用“铅锌依次优先浮选-中矿顺序返回”工艺流程,生产指标为铅精矿铅品位50.69%,含锌12.61%,铅回收率75.53%,锌精矿锌品位48.77%,含铅1.59%,锌回收率73.91%。铅锌互含较高,锌精矿指标不理想。为了解决该问题,本文在了解现场生产工艺流程及矿石性质的基础上,针对该铅锌矿开展了详细的选矿工艺优化试验,通过对部分药剂制度进行优化,采用特效捕收剂BK-LY11,同时在锌浮选回路采用中矿再磨工艺,显著改善了铅锌互含情况,有效提高了铅锌选别指标,并成功应用于生产实践,优化后获得的铅、锌回收率分别提高了5.83、8.46个百分点。 相似文献
2.
本文以工业纯铝和混合稀土RE(Ce和La)为原料,制备出Al-8RE、Al-10RE和Al-15RE中间合金,并探讨了Al-RE中间合金对变形铝合金3102的细化机理。结果表明:Al-RE中间合金由α-Al、Al11RE3(Al11Ce3和Al11La3)、Ce和La组成,不同稀土含量Al-RE中间合金微观组织形貌不同,Al-8RE、Al-10RE和Al-15RE中间合金组织分别为亚共晶组织,伪共晶组织和过共晶组织,随稀土含量增加,Al-RE中间合金中Al11RE3相数量增多,尺寸增大;Al-RE中间合金对3102合金具有显著的细化效果,其中Al-10RE中间合金的细化效果最好;添加Al-RE中间合金可以提高产品性能,当添加10%RE时,性能提升最大。 相似文献
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Alexander Van-Brunt Patrick E. Farrell Charles W. Monroe 《American Institute of Chemical Engineers》2022,68(5):e17599
We present the Onsager–Stefan–Maxwell thermodiffusion equations, which account for the Soret and Dufour effects in multicomponent fluids. Unlike transport laws derived from kinetic theory, this framework preserves the structure of the isothermal Stefan–Maxwell equations, separating the thermodynamic forces that drive diffusion from the force that drives heat flow. The Onsager–Stefan–Maxwell transport-coefficient matrix is symmetric, and the second law of thermodynamics imbues it with simple spectral characteristics. This new approach allows for heat to be considered as a pseudo-species and proves equivalent to both the intuitive extension of Fick's law and the generalized Stefan–Maxwell equations popularized by Bird, Stewart, and Lightfoot. A general inversion process facilitates the unique formulation of flux-explicit transport equations relative to any choice of convective reference velocity. Stefan–Maxwell diffusivities and thermal diffusion factors are tabulated for gaseous mixtures containing helium, argon, neon, krypton, and xenon. The framework is deployed to perform numerical simulations of steady three-dimensional thermodiffusion in a ternary gas. 相似文献
5.
Hua Yang Shi-Xiao Wei Han Chen Lang Chen Chak-Tong Au Ting-Liang Xie Shuang-Feng Yin 《American Institute of Chemical Engineers》2022,68(10):e17810
A high-throughput (105.5 g/h) passive four-stage asymmetric oscillating feedback microreactor using chaotic mixing mechanism was developed to prepare aggregated Barium sulfate (BaSO4) particles of high primary nanoparticle size uniformity. Three-dimensional unsteady simulations showed that chaotic mixing could be induced by three unique secondary flows (i.e., vortex, recirculation, and oscillation), and the fluid oscillation mechanism was examined in detail. Simulations and Villermaux–Dushman experiments indicate that almost complete mixing down to molecular level can be achieved and the prepared BaSO4 nanoparticles were with narrow primary particle size distribution (PSD) having geometric standard deviation, σg, less than 1.43 when the total volumetric flow rate Qtotal was larger than 10 ml/min. By selecting Qtotal and reactant concentrations, average primary particle size can be controlled from 23 to 109 nm as determined by microscopy. An average size of 26 nm with narrow primary PSD (σg = 1.22) could be achieved at Qtotal of 160 ml/min. 相似文献
6.
《Ceramics International》2022,48(1):130-136
A two-step mechanical milling followed by a reactive sintering process was used to synthesize Nano TiC-Graphene-Cu composites from a mixture of Cu, Ti, and Graphene (GN) powders in four different compositions, and effects of reinforcements content on the microstructure and mechanical properties were studied. The results showed that a part of GN reacted with Ti atoms in the matrix, leading to the successful formation of hybrid nanocomposites. Uniform distribution of in-situ TiC with nanometer size and unreacted GN in the nanostructured Cu (Ti) solid solution were obtained. Addition of high percentage of the reinforcements led to an increase in the porosity and microhardness, coarsening of TiC nanoparticles, and decreasing the grain size of the matrix after sintering. The simultaneous presence of GN and TiC nanoparticles in the Cu matrix improved the hardness and wear resistance and reduced the friction coefficient by self-lubricating behavior. The nanocomposite with the nominal composition of Ti-40 vol % TiC showed the highest wear resistance and the lowest friction coefficient. 相似文献
7.
《Journal of the European Ceramic Society》2022,42(6):2892-2904
Graphene nanoplatelets (GNPs) as reinforcement in the ceramic matrix is rising continuously due to their outstanding mechanical and lubricative properties. Herein, different compositions of GNPs (0.5–2 wt%) reinforced alumina-titania coatings were prepared using atmospheric plasma spraying. The relative density of AT coating increased from 83% to 94% with just (1.5 wt%) addition of GNP. Consequently, mechanical properties i.e. hardness and elastic modulus were improved by ~77% and ~69% respectively. Fracture toughness also increased from 2.65 ± 0.95 MPa.m1/2 to 5.85 ± 1.07 MPa.m1/2. Furthermore, the seawater wear test, using a ball-on-disc tribometer revealed that the wear rate of AT coating decreased from ~11 × 10?14 m3/Nm to ~4 × 10?14 m3/Nm, whereas the coefficient of friction reduced from 0.33 ± 0.05–0.16 ± 0.03. The mechanisms involved to improve these properties, viz. GNP sandwiching, crack bridging, crack arrest, etc. GNP’s multi-layers facilitated long-term lubricity and enhanced the wear resistance properties of the coatings. 相似文献
8.
甫沙4井位于塔里木盆地塔西南坳陷昆仑山前冲断带的柯东构造带上,北部和东部分别发育有柯克亚和柯东1井油气田。为研究甫沙4井原油来源与充注过程,对原油样品和连续抽提后的含油砂样各组分(游离态、束缚态、包裹体)进行GC、GC?MS和 GC?IRMS分析,与柯克亚凝析油气田油样进行油—油对比。结果表明:甫沙4井晚期充注原油组分具有C29?32重排藿烷、重排甾烷和Ts相对含量高,C27?29甾烷ααα 20R分布呈反“L”型,以及正构烷烃单体碳同位素值较低等特征,与柯克亚凝析油气田来源于二叠系普司格组(P2?3p)烃源岩的主体原油(I类)地球化学特征一致。而早期充注的原油组分具有重排藿烷、重排甾烷和Ts相对含量较低,C27?29甾烷ααα 20R分布呈“V”型,以及正构烷烃单体碳同位素值较高等特征,与柯克亚凝析油气田来源于中—下侏罗统湖相泥岩的II类原油地球化学特征一致。甫沙4井经历3个阶段成藏过程:①在上新世,二叠系烃源岩于生油晚期阶段生成的I类原油运移至柯克亚构造带或柯东构造带深部形成油藏;②在更新世早期,侏罗系烃源岩于生油早—中期生成的II类原油运移至甫沙4井白垩系储层;③在第四纪,强烈的构造作用使深部I类原油沿断裂调整进入甫沙4井白垩系储层。最终造成甫沙4井白垩系储层II类原油先充注,I类原油后充注的特殊现象。 相似文献
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为研究地铁施工风险耦合机理和地铁施工系统的脆弱性,提高地铁施工系统的安全性。结合脆弱性理论,归纳地铁施工安全风险因素,构建系统脆弱性模型;并对国内2008-2020年的地铁施工事故进行搜集整理,选取风险致因因素完整的130起事故,运用N-K模型计算不同耦合方式下的风险发生概率以及风险耦合值,获得影响系统脆弱性的关键风险耦合方式。结果表明:系统中的风险因素越多,事故发生的概率越大;人员因素、管理因素与环境因素完全耦合时,地铁施工安全系统脆弱性较大。研究明确系统中脆弱性的关键耦合风险,为地铁施工安全控制方面提供了参考价值。 相似文献