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991.
Processing of biobased feedstock materials may lead to formation of multicomponent azeotropic mixtures. Reactive separations provide an opportunity to circumvent azeotropes by changing the substance properties through chemical reactions. Exemplarily several effluents from black liquor processing contain aqueous mixtures of low molecular weight fatty acids such as formic acid and acetic acid. These mixtures form inseparable azeotropes. Separation of the system formic acid–acetic acid–water by esterification with methanol was investigated. Reactive distillation experiments in batch and continuous mode confirmed complete removal of formic acid in a first step. Acetic acid may then be isolated by distillation or by reactive distillation. 相似文献
992.
Claudia Gordin Christelle Delaite Sophie Bistac Daniela Rusu Mihai Rusu 《Polymer Bulletin》2009,63(4):517-529
Poly(vinyl chloride)/poly(ε-caprolactone)/poly(ε-caprolactone)-b-poly(dimethylsiloxane) [PVC/PCL/(PCL-b-PDMS)] blends were
prepared by solvent casting from tetrahydrofuran. The content of PVC was kept constant (60 wt%); the PCL and PCL-b-PDMS contents
were varied by replacing different amounts of PCL [0–20 wt% from the PVC/PCL (60/40) blend] with PCL-b-PDMS copolymer having
different molecular weights of the PCL blocks. The thermal properties of prepared blends were investigated by differential
scanning calorimetry in order to analyse miscibility (through glass transition temperature) and crystallinity. Differential
scanning calorimetry analyses show that the PVC/PCL/PCL-b-PDMS blends are multi-phase materials which contain a PVC plasticized
with PCL phase, a block copolymer PCL-b-PDMS phase (with crystalline and amorphous PCL and PDMS domains) and a PCL phase (preponderantly
crystalline). 相似文献
993.
Khac‐Minh Thai Dr. Andreas Windisch Daniela Stork Dr. Anna Weinzinger Dr. Andrea Schiesaro Robert H. Guy Prof. Dr. Eugen N. Timin Prof. Dr. Steffen Hering Prof. Dr. Gerhard F. Ecker Prof. Dr. 《ChemMedChem》2010,5(3):436-442
The inner cavity of the hERG potassium ion channel can accommodate large, structurally diverse compounds that can be trapped in the channel by closure of the activation gate. A small set of propafenone derivatives was synthesized, and both use‐dependency and recovery from block were tested in order to gain insight into the behavior of these compounds with respect to trapping and non‐trapping. Ligand–protein docking into homology models of the closed and open state of the hERG channel provides the first evidence for the molecular basis of drug trapping. 相似文献
994.
Porcelloni M D'Andrea P Rossi C Sisto A Ettorre A Madami A Altamura M Giuliani S Meini S Fattori D 《ChemMedChem》2008,3(7):1048-1060
The NK(2) receptor belongs to the family of tachykinin neurotransmitters. It has been reported to be involved in several pathological conditions, and selective antagonists are potentially useful drugs for the treatment of asthma, irritable bowel syndrome, cystitis, and depression. Starting from in-house capped dipeptide libraries, we were able to identify a number of molecules with sub-nanomolar binding affinity for the hNK(2) receptor. All were characterized by a rigid core structure with a strong constraint induced by an alpha,alpha-cyclopentaneglycine fragment. Herein we report the further elaboration of three initial basic structures. The planar benzothiophene group was substituted with a series of biphenyl and heterobiphenyl moieties that are well tolerated in terms of receptor affinity. The new compounds also maintained good antagonist potency in an in vitro functional assay, and a number of them showed significant in vivo activity after intravenous administration in our guinea pig model. 相似文献
995.
996.
Manzoni L Belvisi L Arosio D Bartolomeo MP Bianchi A Brioschi C Buonsanti F Cabella C Casagrande C Civera M De Matteo M Fugazza L Lattuada L Maisano F Miragoli L Neira C Pilkington-Miksa M Scolastico C 《ChemMedChem》2012,7(6):1084-1093
We report the synthesis of novel chelates of Gd and (68)Ga with DPTA, DOTA, HP-DOA3, as well as with AAZTA, a novel chelating agent developed by our research group. These chelating agents were appropriately conjugated, prior to metal complexation, with DB58, an RGD peptidomimetic, conformationally constrained on an azabicycloalkane scaffold and endowed with high affinity for integrin α(ν)β(3) . Because α(ν)β(3) is involved in neo-angiogenesis in solid tumors and is also directly expressed in cancer cells (e.g. glioblastomas, melanomas) and ovarian, breast, and prostate cancers, these constructs could prove useful as molecular imaging probes in cancer diagnosis by MRI or PET techniques. Molecular modeling, integrin binding assays, and relaxivity assessments allowed the selection of compounds suitable for multiple expression on dendrimeric or nanoparticulate structures. These results also led us to an exploratory investigation of (68)Ga complexation for the promising (68)Ga-PET technique; the AAZTA complex 15((68)Ga) exhibited uptake in a xenograft model of glioblastoma, suggesting potentially useful developments with new probes with improved affinity. 相似文献
997.
Plant volatiles play an important role in the lives of phytophagous insects, by guiding them to oviposition, feeding and mating
sites. We tested the effects of different host-plant volatiles on attraction of Lobesia botrana males to the female-produced sex pheromone, in a wind tunnel. Addition of volatile emissions from grapevines or individual
plant volatiles to pheromone increased the behavioral responses of L. botrana males over those to pheromone alone. At a low release rate (under-dosed) of pheromone, addition of (E)-β-caryophyllene, (Z)-3-hexenyl acetate, 1-hexanol, or 1-octen-3-ol increased all behavioral responses, from activation to pheromone source contact,
while addition of (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-β-farnesene, (Z)-3-hexenol, or methyl salicylate affected only the initial behavioral responses. Dose–response experiments suggested an optimal
release ratio of 1:1000 (sex pheromone: host plant volatile). Our results highlight the role of plant volatiles in the sensory
ecology of L. botrana. 相似文献
998.
Simona Bonollo Daniela Lanari Tommaso Angelini Ferdinando Pizzo Assunta Marrocchi Luigi Vaccaro 《Journal of Catalysis》2012,285(1):216-222
Although its intriguing features, such as uniform functionalization through the entire beads and a very high-loading capacity are suitable candidates for solid-phase synthesis and reagent-scavenging, the use of Rasta resin as support for organocatalysis has been little explored. In this contribution, Rasta polymer has been used to preparation of high-loading Rasta-TBD. This catalyst has been able to efficiently promote several organic transformations with constantly good and promising results. 相似文献
999.
de Souza Magossi Maiara Fernandes Daniela Silvestrini dos Santos Franco Fernanda dos Santos Felipe Alexsandro de Vicente Fábio Simões do Carmo Devaney Ribeiro 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(10):4093-4102
Journal of Inorganic and Organometallic Polymers and Materials - In this work, it describes the preparation of Titanium and Zirconium functionalized MCM-41 and subsequent chemical modification with... 相似文献
1000.
Maass S Sievers S Zühlke D Kuzinski J Sappa PK Muntel J Hessling B Bernhardt J Sietmann R Völker U Hecker M Becher D 《Analytical chemistry》2011,83(7):2677-2684
Knowledge on absolute protein concentrations is mandatory for the simulation of biological processes in the context of systems biology. A novel approach for the absolute quantification of proteins at a global scale has been developed and its applicability demonstrated using glucose starvation of the Gram-positive model bacterium Bacillus subtilis and the pathogen Staphylococcus aureus as proof-of-principle examples. Absolute intracellular protein concentrations were initially determined for a preselected set of anchor proteins by employing a targeted mass spectrometric method and isotopically labeled internal standard peptides. Known concentrations of these anchor proteins were then used to calibrate two-dimensional (2-D) gels allowing the calculation of absolute abundance of all detectable proteins on the 2-D gels. Using this approach, concentrations of the majority of metabolic enzymes were determined, and thus a quantification of the players of metabolism was achieved. This new strategy is fast, cost-effective, applicable to any cell type, and thus of value for a broad community of laboratories with experience in 2-D gel-based proteomics and interest in quantitative approaches. Particularly, this approach could also be utilized to quantify existing data sets with the aid of a few standard anchor proteins. 相似文献