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101.
Activity of Fluorine‐Containing Analogues of WC‐9 and Structurally Related Analogues against Two Intracellular Parasites: Trypanosoma cruzi and Toxoplasma gondii 下载免费PDF全文
María N. Chao Catherine Li Melissa Storey Dr. Bruno N. Falcone Dr. Sergio H. Szajnman Prof. Dr. Sergio M. Bonesi Prof. Dr. Roberto Docampo Prof. Dr. Silvia N. J. Moreno Prof. Dr. Juan B. Rodriguez 《ChemMedChem》2016,11(24):2690-2702
Two obligate intracellular parasites, Trypanosoma cruzi, the agent of Chagas disease, and Toxoplasma gondii, an agent of toxoplasmosis, upregulate the mevalonate pathway of their host cells upon infection, which suggests that this host pathway could be a potential drug target. In this work, a number of compounds structurally related to WC‐9 (4‐phenoxyphenoxyethyl thiocyanate), a known squalene synthase inhibitor, were designed, synthesized, and evaluated for their effect on T. cruzi and T. gondii growth in tissue culture cells. Two fluorine‐containing derivatives, the 3‐(3‐fluorophenoxy)‐ and 3‐(4‐fluorophenoxy)phenoxyethyl thiocyanates, exhibited half‐maximal effective concentration (EC50) values of 1.6 and 4.9 μm , respectively, against tachyzoites of T. gondii, whereas they showed similar potency to WC‐9 against intracellular T. cruzi (EC50 values of 5.4 and 5.7 μm , respectively). In addition, 2‐[3‐ (phenoxy)phenoxyethylthio]ethyl‐1,1‐bisphosphonate, which is a hybrid inhibitor containing 3‐phenoxyphenoxy and bisphosphonate groups, has activity against T. gondii proliferation at sub‐micromolar levels (EC50=0.7 μm ), which suggests a combined inhibitory effect of the two functional groups. 相似文献
102.
The activity and mechanism of uranium oxide catalysts for the oxidative destruction of volatile organic compounds 总被引:8,自引:0,他引:8
Stuart H. Taylor Catherine S. Heneghan Graham J. Hutchings Ian D. Hudson 《Catalysis Today》2000,59(3-4):249-259
Uranium oxide based catalysts have been investigated for the oxidative destruction of volatile organic compounds (VOCs) to carbon oxides and water. The catalysts have been tested for the destruction of a range of organic compounds at space velocities up to 70 000 h−1. Destruction efficiencies greater than 99% can be achieved over the appropriate uranium based catalyst in the temperature range 300–450°C. Volatile organic compounds investigated include benzene, butylacetate, cyclohexanone, toluene, methanol, acetylene, butane, chlorobutane and chlorobenzene. The catalysts are thermally stable, destroy low concentrations and mixtures of VOCs and lifetime studies indicate that deactivation during oxidation of chlorinated VOCs did not occur. A temporal analysis of products (TAPs) reactor is used to investigate the mechanism of oxidation of VOCs by uranium oxide catalysts. Studies indicated that VOCs were oxidised directly to carbon oxides on the catalyst surface. A combination of TAP pulse experiments with oxygen present and absent in the gas phase has indicated that the lattice oxygen from the catalyst is responsible for the total oxidation activity. This has been confirmed by studies using isotopically labelled oxygen which indicates that the catalyst operates by a redox mechanism. 相似文献
103.
Philippe Allongue Catherine Henry de Villeneuve Sylvie Morin Rabah Boukherroub Danial D. M. Wayner 《Electrochimica acta》2000,45(28):4591
The reasons why ideally flat H–Si(111) surface can be prepared by NH4F etching are investigated from correlation between AFM observations and experimental conditions used for etching. It is shown that pitting may be completely suppressed if a one side polished wafer is immersed in an oxygen free solution. An analytical electrochemical study of the (111) and rough face of the same n-Si wafer is presented to yield insight into observations. 相似文献
104.
Sharon Rose Aarons Catherine R. O’Connor Hossein M. Hosseini Cameron J. P. Gourley 《Nutrient Cycling in Agroecosystems》2009,84(1):81-92
In grazing systems dung is an important source of nutrients which can increase soil fertility and contribute to nutrient cycling
through increased pasture production. Changes in soil chemical and biological properties and pasture production were measured
below and around dung pads created in the field. Almost 65% of the total dung P remained after 45 days and about two-thirds
of the pad fresh weight had disappeared in that time, indicating that physical degradation is the mechanism of incorporation
of dung P. All the pads bar one were completely degraded by 112 days. At this time, soil pH and EC increased under dung pads
as did Olsen extractable inorganic phosphorus (Pi) and total phosphorus (Pt), with these changes observed at 0–5 and 5–10 cm
depths. Bicarbonate extractable soil organic phosphorus (Po) was not affected by dung and the observed differences in soil
Po:Pi ratios were largely influenced by the substantial addition of inorganic P from dung. Dung increased the P buffering
capacity of the 0–5 cm soil samples collected at the end of the experiment, potentially contributing to the increased extractable
soil P measured under the pads. Dung also changed soil properties in 0–10 cm samples with increases in soil pH, EC, Colwell
P and Colwell K recorded even long after the dung had completely disappeared. Microbial biomass carbon increased under dung
pads in the 0–10 cm soil samples in the first 45 days after pads were applied. Total herbage production and ryegrass biomass
increased significantly under and around the pads by 112 days after dung was applied. The botanical composition changed significantly
with increased ryegrass contents observed, but only under the dung pads. This experiment demonstrated that increases in pasture
around dung pads in the field are not solely due to animal rejection. 相似文献
105.
Jonathon E. Beves Edwin C. Constable Catherine E. Housecroft Markus Neuburger Silvia Schaffner 《Inorganic chemistry communications》2009,12(9):898-901
The synthesis and characterization of three new bis(2,2′:6′,2′-terpyridine) (tpy) ligands containing different hydrazone spacers between the metal-binding domains are described. Treatment of 1,4-benzenedicarbaldehyde bis(2,2′:6′,2′′-terpyridin-4′-ylhydrazone) (1) with [(tpy)RuCl3] in the presence of N-ethylmorpholine results in the formation of [(tpy)Ru(μ-1)Ru(tpy)]4+. Single crystal X-ray diffraction data for [(tpy)Ru(μ-1)Ru(tpy)][PF6]4·8MeCN confirm the ability of the hydrazone-based ligand to bridge two ruthenium(II) centres, providing proof-of-principle for the application of this class of flexible ligand in the design of coordination polymers. 相似文献
106.
107.
Dynameomics: design of a computational lab workflow and scientific data repository for protein simulations 总被引:1,自引:0,他引:1
Simms AM Toofanny RD Kehl C Benson NC Daggett V 《Protein engineering, design & selection : PEDS》2008,21(6):369-377
Dynameomics is a project to investigate and catalog the native-state dynamics and thermal unfolding pathways of representatives of all protein folds using solvated molecular dynamics simulations, as described in the preceding paper. Here we introduce the design of the molecular dynamics data warehouse, a scalable, reliable repository that houses simulation data that vastly simplifies management and access. In the succeeding paper, we describe the development of a complementary multidimensional database. A single protein unfolding or native-state simulation can take weeks to months to complete, and produces gigabytes of coordinate and analysis data. Mining information from over 3000 completed simulations is complicated and time-consuming. Even the simplest queries involve writing intricate programs that must be built from low-level file system access primitives and include significant logic to correctly locate and parse data of interest. As a result, programs to answer questions that require data from hundreds of simulations are very difficult to write. Thus, organization and access to simulation data have been major obstacles to the discovery of new knowledge in the Dynameomics project. This repository is used internally and is the foundation of the Dynameomics portal site http://www.dynameomics.org. By organizing simulation data into a scalable, manageable and accessible form, we can begin to address substantial questions that move us closer to solving biomedical and bioengineering problems. 相似文献
108.
Catherine Fernandez Yogan Monnier Elena Ormeño Virginie Baldy Stéphane Greff Vanina Pasqualini Jean-Philippe Mévy Anne Bousquet-Mélou 《Journal of chemical ecology》2009,35(8):970-979
We investigated changes in the occurrence of allelochemicals from leachates of different Pinus halepensis organs taking into account the stages of pine stand age (i.e., young < 15-years-old, middle age ± 30-years, and old > 60-years-old).
GC-MS analysis of aqueous extracts revealed approx. 59 components from needles and roots. The major constituents were divided
into different phytochemical groups—phenolics (50%), fatty acids (44%), and terpenoids. Further analyses were carried out
to characterize the distribution of allelochemicals in different organs and P. halepensis successional stages. Roots and needles had two distinct chemical profiles, while needle leachates were composed mainly of
oxygenated terpenoids (e.g., α-eudesmol, α-cadinol, and α-terpineol). Roots mainly contained fatty acids. Needles from young
pine stands had the highest content of monoterpenes, suggesting their role as potential allelochemicals that could help young
pine stands to establish. Pooling the different functional chemical groups showed that needles and, to a lesser extent, old
roots, had higher chemical diversity than the roots of young and medium-aged pines. The highest diversity in phenolic constituents
and fatty acids was in young needles (Dchem = 2.38). Finally, caffeic acid, a compound that has allelopathic properties was found in aqueous extracts at high concentrations
in both young needles and old roots. The role of this compound in mediation of biological interactions in P. halepensis ecosystem functioning is discussed. 相似文献
109.
Hai-Dong Wang Catherine Hui Niu Mei Yang Liang-Yin Chu 《Chemical engineering science》2009,64(7):1462-1473
The concept of chiral ligand exchange is employed in the present study to achieve the chiral resolution of tryptophan (Trp) enantiomers by using chitosan (CS) membrane in a sorption resolution mode and copper(II) ion as the complexing ion. CS porous membranes are prepared by freeze-drying method (CS-LT) and sol-gel process at high temperature (CS-HT), respectively, to investigate their sorption resolution characteristics. The proposed CS chiral ligand exchange membranes exhibit good chiral resolution capability. Meanwhile the sorption selectivity of the CS membranes is found to be reversed from L-selectivity at low copper(II) ion concentration to D-selectivity at high copper(II) ion concentration, which is attributable to the stability difference between the copper(II)-L-Trp and copper(II)-D-Trp complexes. Moreover, the CS-HT membrane shows better performance with respect to both sorption selectivity and sorption capability than the CS-LT membrane, which mainly results from its more amorphous structures compared with the more crystalline structures of the CS-LT membrane. The superiority of sorption capability of the CS-HT membrane is also attributable to its larger specific surface area than that of the CS-LT membrane. The results obtained in this study are conducive to the design and fabrication of chiral ligand exchange membranes for enantiomer separation in sorption mode. 相似文献
110.
Duhamel Cécilie Caballero Jacqueline Couvant Thierry Crépin Jérôme Gaslain Fabrice Guerre Catherine Le Hong-Thaï Wehbi Mickaël 《Oxidation of Metals》2017,88(3-4):447-457
Oxidation of Metals - The present work focuses on the intergranular oxidation of Alloy 600 and its weld material Alloy 82 after exposure in simulated primary water at 340–360 °C... 相似文献