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981.
Henning?M.?Beier Martin?Bujard Klaus?Diedrich Horst?Dreier Helmut?Frister Heribert?Kentenich Hartmut?Kre? Jan-Steffen?Krüssel Annika?K.?Ludwig Eva?Schumann Thomas?Strowitzki Jochen?Taupitz Christian?J.?Thaler Petra?Thorn Claudia?WiesemannEmail author Hans-Peter?Zenner 《Ethik in der Medizin》2018,30(2):153-158
982.
The molecular structure of anionic species of 2,4,5,7‐tetranitrofluorescein as studied by electrospray ionisation,nuclear magnetic resonance and X‐ray techniques 下载免费PDF全文
Nikolay O. Mchedlov‐Petrossyan Klaus Steinbach Natalya A. Vodolazkaya Denis V. Samoylov Sergey V. Shekhovtsov Irina V. Omelchenko Oleg V. Shishkin 《Coloration Technology》2018,134(5):390-399
Among the fluorescein dyes, the behaviour of their nitro derivatives in solution is most unusual, and yet at the same time rarely studied. In this study, their 13C nuclear magnetic resonance and electrospray spectra are reported, which confirm, in concert with their ultraviolet‐visible spectra, the molecular structures of the neutral and ionic species of 2,4,5,7‐tetranitrofluorescein observed in different solvents and at various pH values. A peculiar property of this dye consists in its lactonisation of the double‐charged anion, contrary to the well‐known coloured and fluorescent dianions of fluorescein, eosin, etc. Also, this dianion‐lactone exhibits high ability for opening the pyran ring. This cleavage takes place at much lower pH values as compared with those for fluorescein and its halogen derivatives. The ruptured species can be formed as either lactone or carbinol; the latter appears as a result of the nucleophilic attack of a HO? on the central carbon atom. The corresponding molecular structures are identified via the electrospray method and X‐ray analysis. The behaviour of some other nitrofluoresceins in alkaline media is also considered. 相似文献
983.
Kevin Bethke Sinem Palantöken Marcel Roß Vikram Singh Raghuwanshi Frieder Kettemann Kim Greis Julius B. Stückrath Suresh Valiyaveettil Klaus Rademann 《Advanced functional materials》2018,28(23)
As the most abundant natural polymer, cellulose presents a unique advantage for large‐scale applications. To fully unlock its potential, the introduction of desired functional groups onto the cellulose backbone is required, which can be realized by either chemical bonding or physical surface interactions. This review gives an overview of the chemistry behind the state‐of‐the‐art functionalization methods (e.g., oxidation, esterification, grafting) for cellulose in its various forms, from nanocrystals to bacterial cellulose. The existing and foreseeable applications of the obtained products are presented in detail, spanning from water purification and antibacterial action, to sensing, energy harvesting, and catalysis. A special emphasis is put on the interactions of functionalized cellulose with heavy metals, focusing on copper as a prime example. For the latter, its toxicity can either have a harmful influence on aquatic life, or it can be conveniently employed for microbial disinfection. The reader is further introduced to recent sensing technologies based on functionalized cellulose, which are becoming crucial for the near future especially with the emergence of the internet of things. By revealing the potential of water filters and conductive clothing for mass implementation, the near future of cellulose‐based technologies is also discussed. 相似文献
984.
Klaus Zöll Artur Benisek Edgar Dachs Volker Kahlenberg Andreas Saxer Peter Tropper Johan de Villiers 《Journal of the American Ceramic Society》2018,101(9):4193-4202
In a systematic study on silico‐ferrites of calcium aluminum and magnesium (SFCA phases) this investigation focuses on synthesis of silicon‐free SFCA‐type compounds with low‐MgO contents (~1.00 apfu—atoms per formula unit). Previous studies revealed the existence of iron‐rich SFCA phases similar to the SFCA‐I structure with the chemical composition Ca3MgAl6Fe10O28 (Metall Mater Trans B. 2017;48:2207). The experimental results in the quaternary Fe2O3‐CaO‐Al2O3‐MgO system confirm large stability fields of 2 silicon‐free ferrites FCAM‐I and FCAM‐III, which are members of the homologous series M14+6nO20+8n (n = 1, 2). Starting with compositions corresponding to Ca3MgAlxFe16‐xO28 (with increasing aluminum content from x = 0‐12 apfu), it was possible to synthesize these phases with an x‐value ≥2 apfu, which corresponds to Al2O3 contents ≥7.14 wt%. Synthesis of pure silicon‐free ferrites with n = 1 (FCAM‐I) and 2 (FCAM‐III) and silicon‐bearing ferrites with n = 0 (SFCA) was possible. Samples were characterized by electron probe microanalysis, powder diffraction, and subsequently studied using relaxation calorimetry measurements in combination with differential scanning calorimetry for determination of the heat capacities and standard entropies S°(298). The corresponding values are S°(298) = 650.3 ± 4.6 J/mol·K for SFCA, S°(298) = 864.5 ± 6.1 J/mol·K for FCAM‐I, and S°(298) = 1206.2 ± 8.4 J/mol·K for FCAM‐III. These thermodynamic data are a step toward a rigorous quantitative thermodynamic modeling of the iron ore sintering process. 相似文献
985.
Vergleich von Nachweisverfahren für Stutzen in Zylinderschalen unter Innendruck und äußeren Lasten 下载免费PDF全文
Klaus Benitz 《化学,工程师,技术》2018,90(7):998-1004
Various methods for the verification of nozzles in cylindrical shells are described and the results of an example are compared. The example is carried out according to DIN EN 13445‐3, Sect. 16.5, in which the maximum permissible loads from internal pressure, axial force as well as moments in the longitudinal and circumferential direction are calculated. The results are compared with finite element computations performed with a 3D shell model, both with linear‐elastic material behavior and as limit‐load analyzes with ideal‐elastic ideal‐plastic material behavior. 相似文献
986.
Simultaneous Multiple MS Binding Assays for the Dopamine,Norepinephrine, and Serotonin Transporters 下载免费PDF全文
Patrick Neiens Dr. Angela De Simone Dr. Georg Höfner Prof. Dr. Klaus T. Wanner 《ChemMedChem》2018,13(5):453-463
In this work, we present label‐free, mass‐spectrometry‐based binding assays (MS Binding Assays), targeting the human dopamine, norepinephrine, and serotonin transporters (hDAT, hNET, and hSERT) in simultaneous binding experiments. Using a validated LC–ESI‐MS/MS method for quantification of the selective dopamine transporter inhibitor (R,R)‐4‐(2‐benzhydryloxyethyl)‐1‐(4‐fluorobenzyl)piperidin‐3‐ol ((R,R)‐D‐84), the selective norepinephrine transporter inhibitor (S,S)‐reboxetine, and the selective serotonin reuptake inhibitor (S)‐citalopram, binding affinities at the three monoamine transporters could be characterized simultaneously in a single binding experiment. The performed simultaneous saturation and competition experiments yielded results that are in good accordance with those determined in MS Binding Assays addressing the monoamine transporters individually. The results obtained from this study underscore the potential of MS Binding Assays for simultaneous affinity determination at different targets, which is difficult to accomplish with conventional radioligand binding assays. 相似文献
987.
Synthesis of a Series of Structurally Diverse MB327 Derivatives and Their Affinity Characterization at the Nicotinic Acetylcholine Receptor 下载免费PDF全文
Sebastian Rappenglück Sonja Sichler Dr. Georg Höfner Dr. Thomas Wein Karin V. Niessen Dr. Thomas Seeger Prof. Dr. Franz F. Paintner Prof. Dr. Franz Worek Prof. Dr. Horst Thiermann Prof. Dr. Klaus T. Wanner 《ChemMedChem》2018,13(17):1806-1816
A novel series of 30 symmetric bispyridinium and related N‐heteroaromatic bisquaternary salts with a propane‐1,3‐diyl linker was synthesized and characterized for their binding affinity at the MB327 binding site of nicotinic acetylcholine receptor (nAChR) from Torpedo californica. Compounds targeting this binding site are of particular interest for research into new antidotes against organophosphate poisoning, as therapeutically active 4‐tert‐butyl‐substituted bispyridinium salt MB327 was previously identified as a nAChR re‐sensitizer. Efficient access to the target compounds was provided by newly developed methods enabling N‐alkylation of sterically hindered or electronically deactivated heterocycles exhibiting a wide variety of functional groups. Determination of binding affinities toward the MB327 binding site at the nAChR, using a recently developed mass spectrometry (MS)‐based Binding Assay, revealed that several compounds reached affinities similar to that of MB327 (pKi=4.73±0.03). Notably, the newly prepared lipophilic 4‐tert‐butyl‐3‐phenyl‐substituted bispyridinium salt PTM0022 ( 3 h ) was found to have significantly higher binding affinity, with a pKi value of 5.16±0.07, thus representing considerable progress toward the development of more potent nAChR re‐sensitizers. 相似文献
988.
Klaus M. Zwilsky Nicholas J. Grant 《JOM Journal of the Minerals, Metals and Materials Society》1957,9(10):1197-1201
Utilizing relatively coarse copper powders and several sizes of silica and alumina powders, alloys containing up to 10 volume pct of oxide were made. The alloys were prepared by mechanical mixing of powders, followed by cold hydrostatic pressing, sintering, and hot extrusion. Measurements were made of room temperature tensile properties, recrystallization temperature, creep rupture properties from 250° to 450°C, and resistivity. In addition, metallographic studies were made of the resultant structures. Of particular interest was the stability of the structure with respect to temperature, time, and stress. 相似文献
989.
Archimedes’ principle was applied to strand lengths of up to 14 m of round 177 mm diameter billets to determine cavity volume V (in cm3/m) for a series of tubemaking steels. Under steady state casting conditions, V depends primarily on the chemical composition and solidification behaviour of the steels. Averages ranged up to in an extreme case (bearing steel; vC = 2.0 m/min). Stopping the strand and abrupt lowering of withdrawal speed made it possible to artificially induce individual shrinkage cavities with peak values of V = 45 cm3/m. In the round mould, subsequent necking of the liquid crater is initiated in this process. Whisker-like and icicle-like dendrites can be observed in horizontally formed macroscopic shrinkage cavities. The liquid crater is broken off by periodic bridging (the mini-lingot model). As permeability decreases, the bridges deflect downward in a U-shape under the ferrostatic load. The residual inter-dendritic melt is squeezed out in this plastic deformation process. Some bridges ultimately break. This interpretation is based on comprehensive CMA studies and concentration maps. Cores taken from the centre of a strand of bearing steel were submitted to various heat treatments between 1100 and 1350°C. Homogenization occurs below solidus (T < 1225°C). Carbides dissolve and sulfides become globular. Spatial segregation, on the other hand, increases, above solidus. In the extreme case at 1350°C/30 h, the residual melt at the grain boundaries migrates practically completely from the surface zone to the centre of the cylindrical sample (40 mm diameter). The propellent forces for this macro-heterogenization are provided by the activity gradient from the cylindrical surface to the centre and minimization of interface energy γ/I. 相似文献
990.
Electrochemically Active Polymers for Rechargeable Batteries 总被引:3,自引:0,他引:3