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41.
Leon M. Hermans 《Water Resources Management》2011,25(1):373-393
International experiences with water policy and governance arrangements are shared through various international meetings and reports. The underlying assumption is that these experiences provide useful information to policy makers who are looking for ways to improve water resources management in their home country or region. However, little has been written about analytical support for these potentially interested policy makers. They have to reach informed decisions about whether or not to initiate a process of policy transfer, about which foreign experiences to consider and about what parts of those experiences to copy, adapt, or reject. Providing such analytical support is complicated by the involvement of multiple actors in water resources management, who do not necessarily agree on these decisions. This paper outlines an approach to offer analytical support to these multiple actors in the initial phase of a policy transfer process. The approach is applied to the case of the Büyük Menderes river basin in Turkey, where local policy makers were engaged in a policy transfer process related to the EU Water Framework Directive. It is concluded that the outlined approach can be used to inform local policy makers, as it yielded new and valid information in the case. In the absence of overriding political concerns, such information would lead to different decisions in various phases of policy transfer, when compared to a process that lacks this analytical support. 相似文献
42.
43.
Dr.‐Ing. Andrea Ohle Michael Obst Prof. Dr.‐Ing. Norbert Mollekopf Prof. Dr.‐Ing. Leon Urbas 《化学,工程师,技术》2014,86(5):640-648
Modularization has been identified as one of the research fields of the ?50 % idea”?. A development methodology for modules must consider both the economies of scale for investment costs and costs of operation and maintenance. In this paper, the impact of an absorber module, which is offered as discretized diameter scaling, on the total process is investigated at the example of the CO2 separation from biogas. The simulation shows the effect of this approach to the stripper diameter and the energy demand of the process. The calculations form the basis for applying cost models. 相似文献
44.
Leon B. Levy 《应用聚合物科学杂志》1996,60(13):2481-2487
The lengths of polymerization induction periods for butyl acrylate (BA) in the presence of air were measured at temperatures from 54 to 122.5°C. The kinetics of MEHQ and oxygen consumption at 80 and 100°C are characterized by their own induction periods followed by sharply accelerated rates immediately prior to the BA polymerization. It is proposed that these phenomena are consistent with an “intrinsic” BA radical formation rate that is extremely slow compared to the ultimate rate of radical production from the decomposition of peroxides. These oligomeric peroxides build up during the induction period and, at its end, rapidly decompose with a resulting “radical cascade effect,” causing the accelerated inhibitor and oxygen consumption followed rapidly by BA polymerization. Thus, confirmation that a supply of BA has a normal MEHQ concentration may not be sufficient to ensure its stability. Strict adherence to the storage conditions and shelf life recommended by the supplier6 is absolutely vital to storage safety, especially because uncontrolled poly-merization of BA has the potential to be violent (polymerization exotherm rates higher than 1000°C/min were observed). © 1996 John Wiley & Sons, Inc. 相似文献
45.
An interesting problem in the oil and gas industry is the visualization of the movement of oil and gas in porous media. An example of such a medium is a rock sample with some distribution of holes (pores) connected by channels (pore throats), the solid parts of the rock are called grains. In our work we have simulated the porous medium using a pointer-based octree, representing these pores and grains. This data structure allows us to model the connectivity of the pores and thus visualize fluid penetration within the medium. Whereas earlier models represent a serious simplifications or two dimensional homogeneous layers, our model provides us with a statistically accurate distribution in three dimensions and a more accurate representation of the connectivity. In this paper we present our data structure and the techniques which were used to create models of porous media and their porous networks. Next, we present algorithms for connectivity in octrees and we show how to apply them to modelling and visualization of fluid penetration in porous media. 相似文献
46.
Leon Wehrhan Prof. Dr. Alexander Hillisch Dr. Stefan Mundt Dr. Adrian Tersteegen Dr. Katharina Meier 《ChemMedChem》2020,15(21):2010-2018
Target druggability assessment is an integral part of the early target characterization and selection process in pharmaceutical industry. Here, we investigate a set of five different serine proteases from the blood coagulation cascade. The aim of this study is twofold. Firstly, leveraging the wealth of available in-house high-throughput screening (HTS) data, we analyze HTS hit rates and discuss their predictive value for the development of small molecule (SMOL) candidates. Purely structure-activity relationship (SAR) based druggability ratings are compared with computational protein-structure based druggability assessments. Secondly, we evaluate the impact of using conformational ensembles from molecular dynamics (MD) simulations instead of single static crystal structures as basis for computational druggability assessments. Based on this study, we recommend incorporating molecular dynamics routinely into the early target characterization process, especially if only a single X-ray structure is available. 相似文献
47.
Preparation and Use of a Boron Nitride Precursor as Binder for the Densification of Boron Nitride 总被引:1,自引:0,他引:1
A precursor of boron nitride was prepared through the partial condensation of 2,4,6-trichloroborazine and bis-(trimethylsilyl)acetylene. This reaction was conducted at 100°C and is catalyzed by AlCl3 . The condensation product pyrolyzed at 800°C, producing trimethylsilyl chloride as a volatile product and a boron nitride rich residue containing 54 wt% of the initial weight. Mixtures of the precursor and commercial boron nitride were made and hot-pressed at 800°C and 27.6 MPa. A maximum density of 1.84 g/cm3 is reached at a loading corresponding to the deposition of 13 wt% residue derived from the precursor. Examination by analytical electron microscopy, including X-ray energy dispersive spectroscopy and electron energy loss spectroscopy analyses, revealed the location of material derived from the precursor in BN-binder composites through the presence of residual aluminum, silicon, and carbon. Crystallization of boron nitride from the precursor appears to have taken place, as deduced from the morphology of the phases observed and association with residual elements present in the binder. 相似文献
48.
Four carbon nanotube (CNT)‐filled polymer blends, i.e., CNT‐filled polyethylene terephthalate (PET)/polyvinylidene fluoride, PET/nylon 6,6, PET/polypropylene, and PET/high‐density polyethylene blends, have been injection‐molded and characterized in terms of their microstructures, electrical conductivities, and mechanical properties. The distribution of CNTs in the polymer blends has been examined based on their wetting coefficients and minimization of the interfacial energy. The electrical conductivity and mechanical properties have been related to the cocontinuous polymer blends, the conductive path formed by CNTs, the CNT distribution, and the intrinsic properties of the constituent polymers. It is found that to obtain a CNT‐filled polymer composite with both high electrical conductivity and good mechanical properties, it is preferred that most CNTs distribute in one polymer phase, while the other polymer phase(s) remain neat. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 477–488, 2006 相似文献
49.
The distribution of total and free fatty acids as well as the acids from the glycerides, sterol esters and phospholipids of
polar bear liver lipids was ascertained and found to contain somewhat higher levels of unsaturated components as compared
to those of such mammals as the pig. Saponification of the liver lipids yielded the hydrocarbons, alcohols and sterols which
were analyzed by GLC. The hydrocarbons occurred at an overall level of 55 mg/kg liver or 57.9 mg/100 g total lipids, of which
pristane and other saturated hydrocarbons, mainly normal homologs, comprised 2.6 and 5.3 mg/100 g, respectively; the remainder
contained squalene (37.7 mg/100 g) and other unsaturated types (12.3 mg/100 g). As based on the total lipids, the levels of
fatty alcohols, sterol and glyceryl ethers amounted to 1.65%, 5.9% and 0.03%, respectively. The fatty alcohols displayed about
31 peaks of C12 to C30, of which the hexadecanol and a branched C20 component were prominent. 相似文献
50.
Manganese(II) acetate reacts with phthalic acid (phH(2)) to give [Mn(ph)].0.5H(2)O (1). Reaction of 1 with 1,10-phenanthroline produces [Mn(ph)(phen)].2H(2)O (2) and [Mn(ph)(phen)(2)(H(2)O)].4H(2)O (3). Reaction of isophthalic acid (isophH(2)) with manganese(II) acetate results in the formation of [Mn(isoph)].2H(2)O (4). The addition of the N,N-donor ligands 1,10-phenanthroline or 2,2'-bipyridine to 4 leads to the formation of [Mn(2) (isoph)(2)(phen)(3))].4H(2)O (5), [(Mn(phen)(2)(H(2)O)(2)](2)(isoph)(2)(phen).12H(2)O (6) and {[Mn(isoph)(bipy)](4).2.75 biby}(n) (7), respectively. Molecular structures of 3, 6 and 7 were determined crystallographically. In 3 the phthalate ligand is bound to the manganese via just one of its carboxylate groups in a monodentate mode with the remaining coordination sites filled by four phenanthroline nitrogen and one water oxygen atoms. In 6 the isophthalates are uncoordinated with the octahedral manganese center ligated by two phenanthrolines and two waters. In 7 the Isophthalate ligands act as bridges resulting in a polymeric structure. One of the carboxylate groups is chelating a single manganese with the other binding two metal centres in a bridging bidentate mode. The phthalate and isophthalate complexes, the metal free ligands and a number of simple manganes salts were each tested for their ability, to inhibit the growth of Candida albicans. Only the "metal free" 1,10-phenanthroline and its manganese complexes were found to be active. 相似文献