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41.
K. D. Carlson A. Chaudhry R. E. Peterson M. O. Bagby 《Journal of the American Oil Chemists' Society》1990,67(8):495-498
To conduct product development research onLesquerella seed oils, we explored methods to obtain >100 g quantities of lesquerolic (14-hydroxy-cis-11-eicosenoic) acid. Preliminary experiments with open-column silica gel chromatography showed thatL. fendleri oil could be separated into 3 triglyceride (TG) fractions. The first (10%) contained nonhydroxy 16-(13%) and 18-carbon acids
(65% 18∶1,2,3). The second fraction (15%) contained monolesquerolins (39% lesquerolic acid). The major TG fraction (73%) was
mainly dilesquerolins (66% lesquerolic acid) showing that a hydroxy acid-enriched TG oil was obtainable by this procedure.
Silica gel chromatography easily separatedL. fendleri fatty acid methyl esters (FAME) into a hydroxy-free ester fraction (40–44%) consisting largely of 18∶1 (39%), 18∶2 (19%)
and 18∶3 (31%), and a hydroxy ester fraction (56–60%) that was largely methyl lesquerolate (94%) with small amounts of auricolate
(5%) (14-hydroxy-cis-11,cis-17-eicosadienoate) and traces of 18-carbon hydroxy esters. This process for isolating the hydroxy FAME ofLesquerella oil was scaled up 15-to 100-fold with a preparative high performance liquid chromatograph. Thirty-gram samples ofL. gordonii FAME were dissolved in eluting solvent, pumped onto the high performance liquid chromatography (HPLC) silica column and eluted
with 97∶3 hexane/ethyl acetate. In an 8-hr period, up to 200 g of methyl lesquerolate could be obtained with a purity >98%,
the only contaminants being methyl auricolate and methyl ricinoleate.
Presented at the AOCS meeting in Phoenix, AZ, May 1988.
The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of
Agriculture over other firms or similar products not mentioned. 相似文献
42.
Oliveira TW Leandro CG de Jesus Deiró TC dos Santos Perez G da França Silva D Druzian JI Couto RD Barreto-Medeiros JM 《Lipids》2011,46(11):1071-1074
The main goal of the present study was to evaluate the long-term effects of a perinatal palatable high-fat diet on the food
intake and cholesterol profile of adult rats. Male Wistar rats (aged 22 days) were divided into two groups according to their
mother’s diet during gestation and lactation (C
p, n = 10; pups from control mothers; and HLp
n = 10; pups from mothers fed a palatable high-fat diet). At the 76th day, pups were housed individually for 14 days, and daily
food consumption was determined during a period of 6 days. Blood from 100-day-old rats was sampled by cardiac puncture. Fasting
(12 h) serum glucose, total cholesterol, LDL-C, HDL-C, triglycerides (TG), and VLDL-C levels were determined. The measurement
of food intake was higher in the animals submitted to a hyperlipidic diet during the perinatal period. Serum total cholesterol,
LDL-C, HDL-C, TG, VLDL-C and glycemia were increased in the HLp group compared to the control group. Our findings show that an early life environment with a high-fat diet can contribute
to metabolic disease in later life. 相似文献
43.
The loss of enzymatic activity of lactate dehydrogenase was studied in several ascorbate, iron and hydrogen peroxide metal catalyzed oxidation solutions in which the initial concentration of each reactant was varied independently. Nonmonotonic concentration dependencies of enzymatic inactivation were observed for all three reactants. with minimum activity levels occurring in the 0·1 to 8 mM range. A first effort has been made to predict these concentration dependencies with a mathematical simulation model. The model consisted of the most commonly reported reactions and assumed that protein damage occurred through reaction with the hydroxyl radical. The simulation predicted nonmonotonic concentration dependencies of enzyme inactivation on each of the reactants. The predicted concentrations of the minima differed from the experimentally observed points by a factor of 2 to 4. Mathematically the minima occurred because each reactant was reported to react with hydroxyl radicals and form less reactive compounds. The plausibility that competition caused or contributed to the extrema was further explored with experimental competition studies between peroxide and the radical scavenger dimethylsulfoxide. A point of maximum hydroxyl radical formation was observed with increasing peroxide concentration. This maxima corresponded to the point of maximum lactate dehydrogenase damage observed with increasing peroxide concentration. 相似文献
44.
Michaela K. Thielen Cody K. Vaneerd Dr. Manibarsha Goswami Prof. Dr. Erin E. Carlson Prof. Dr. John F. May 《Chembiochem : a European journal of chemical biology》2020,21(24):3500-3503
One promising strategy to combat antibiotic-resistant bacteria is to develop compounds that block bacterial defenses against antibacterial conditions produced by the innate immune system. Salmonella enterica, which causes food-borne gastroenteritis and typhoid fever, requires histidine kinases (HKs) to resist innate immune defenses such as cationic antimicrobial peptides (CAMPs). Herein, we report that 2-aminobenzothiazoles block histidine kinase-dependent phenotypes in Salmonella enterica serotype Typhimurium. We found that 2-aminobenzothiazoles inhibited growth under low Mg2+, a stressful condition that requires histidine kinase-mediated responses, and decreased expression of the virulence genes pagC and pagK. Furthermore, we discovered that 2-aminobenzothiazoles weaken Salmonella’s resistance to polymyxin B and polymyxin E, which are last-line antibiotics and models for host defense CAMPs. These findings raise the possibilities that 2-aminobenzothiazoles can block HK-mediated bacterial defenses and can be used in combination with polymyxins to treat infections caused by Salmonella. 相似文献
45.
First year growth of preterm infants fed standard compared to marine oil n−3 supplemented formula 总被引:9,自引:0,他引:9
Very low birth weight (VLBW) infants (748–1390 g, n=65) were randomly assigned to receive control or marine oil-supplemented
formula when they achieved intakes >454 kJ (110 kcal)/kg/d of a formula designed for VLBW infants. Study formulas with or
without marine oil were provided until 79 wk of postconceptional age (PCA), first in a formula designed for preterm infants
followed by a formula designed for term infants. Infants were studied at regular intervals through 92 wk PCA. Weight, length,
and head circumference were determined by standardized prodedures and normalized to the National Center for Health Statistics
figures for growth of infants born at term of the same age and gender. Mean normalized weight, weight-to-length, and head
circumference were greatest at 48 wk and decreased thereafter. The decline in normalized weight was greater in infants fed
the marine oil-supplemented formula. Beginning at 40 wk, marine oil-supplemented infants compared to controls had significantly
poorer Z-scores for weight, length and head circumference. In addition, birth order (negatively) and maternal height (positively)
influenced weight and length achievement in infancy as shown previously in infants born at term.
Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990. 相似文献
46.
Paulo Romano Cruz Correia Ingrid Graça Ramos Arão Cardoso Viana Artur José Santos Mascarenhas Antônio Euzébio Goulart Sant'ana Henrique Fonseca Goulart Janice Izabel Druzian 《应用聚合物科学杂志》2018,135(5)
Composite membranes consisting of biodegradable poly(butylene adipate‐co‐terephthalate (PBAT) and zeolite Y (0–10 wt %) were produced by extrusion. Zeolite Y is well dispersed in the membrane up to 5 wt %, but tends to agglomerate at higher contents. The presence of zeolite Y in the composite resulted in an improvement of the thermal stability, mechanical properties, and increased the barrier properties. The interaction of the composite membranes with rhynchophorol was investigated by different techniques, showing that the semiochemical progressively lixiviates PBAT monomers, causing thermal and mechanical properties to decrease. However, no interaction seemed to occur between the rhynchophorol and the zeolite. Studies of diffusion of pheromone through membranes have shown that the addition of the zeolite Y has not contributed significantly to a decrease in the release rate of rhynchophorol, but the presence of the zeolite Y helps to increase chemical, mechanical, and thermal stabilities of the membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45757. 相似文献
47.
Ashot Khrimian Matthew S. Siderhurst Grant T. Mcquate Nicanor J. Liquido Janice Nagata Lori Carvalho Filadelfo Guzman Eric B. Jang 《Journal of chemical ecology》2009,35(2):209-218
Oriental fruit fly, Bactrocera dorsalis (Hendel), males are highly attracted to the natural phenylpropanoid methyl eugenol (ME). They compulsively feed on ME and
metabolize it to ring and side-chain hydroxylated compounds that have both pheromonal and allomonal functions. Side-chain
metabolic activation of ME leading to (E)-coniferyl alcohol has long been recognized as a primary reason for hepatocarcinogenicity of this compound in rodents. Earlier,
we demonstrated that introduction of a fluorine atom at the terminal carbon of the ME side chain significantly depressed metabolism
and specifically reduced formation of coniferyl alcohol but had little effect on field attractiveness to B. dorsalis. In the current paper, we demonstrate that fluorination of ME at the 4 position of the aromatic ring blocks metabolic ring-hydroxylation
but overall enhances side-chain metabolism by increasing production of fluorinated (E)-coniferyl alcohol. In laboratory experiments, oriental fruit fly males were attracted to and readily consumed 1,2-dimethoxy-4-fluoro-5-(2-propenyl)benzene
(I) at rates similar to ME but metabolized it faster. Flies that consumed the fluorine analog were as healthy post feeding
as ones fed on methyl eugenol. In field trials, the fluorine analog I was ∼50% less attractive to male B. dorsalis than ME.
相似文献
Ashot KhrimianEmail: |
48.
必需脂肪酸在美容化妆品中的应用 总被引:4,自引:0,他引:4
必需脂肪酸(EFAs)可以使皮肤增益,加强细胞膜结构与功能,维持并恢复皮肤天然屏障,预防皮肤刺激和炎症,以及增强细胞膜的通透性。详述了必需脂肪酸的新陈代谢过程和其在美容化妆品中的应用。 相似文献
49.
Decomposition of Bt and Non-Bt Corn Hybrid Residues in the Field 总被引:1,自引:0,他引:1
David D. Tarkalson Stephen D. Kachman Johannes M. N. Knops Janice E. Thies Charles S. Wortmann 《Nutrient Cycling in Agroecosystems》2008,80(3):211-222
Results of a previous laboratory study indicated that six transgenic crops expressing the Cry1Ab insecticidal protein from
Bacillus thuringiensis (Bt) decomposed at a slower rate than their respective non-Bt isolines. Consequently, litter decomposition rates, nitrogen
cycling, and carbon pools may change in agricultural systems as the result of the widespread use of Bt crops. In this study,
we assessed the decomposition rates and chemical composition of commonly grown hybrids of Bt and non-Bt isolines of corn (Zea mays L.) in the field. Leaves, stalks, and cobs from two Bt corn hybrids (Pioneer 34N44 Bt and NC+ 4990 Bt) and their non-Bt isolines
(Pioneer 34N43 and NC+ 4880) were analyzed for biomass fractions (soluble, hemicellulose, cellulose, and lignin) and total
C and N content. Litterbags containing these residues were buried at a depth of 10 cm in a Holdrege silt loam (fine-silty,
mixed, mesic Typic Argiustolls) soil and recovered 5, 11, 17, and 23 months after placement in the field. There were no differences
in the rates of decomposition and mass of C remaining over time between the Bt and non-Bt corn residues. Plant parts differed
in decomposition rates where leaves > stalks > cobs. There were differences in total C, total N, biomass fractions, and C:N
ratios between initial Bt and non-Bt corn residues, and between companies (NC+ and Pioneer), however, these differences did
not result in differences in their rates of decomposition or mass of C remaining over time. For each plant part, there were
no differences in lignin content between the Bt and non-Bt residues. These data suggest that the Bt and non-Bt corn hybrids
used in this study should not cause differences in carbon sequestration when their residues decompose under similar environmental
conditions. 相似文献
50.
We report on the electrooxidation of hydrazine catalyzed by single-walled carbon nanotube (SWCNT) functionalized with cobalt phthalocyanine (CoPc) which shows that the presence of the single-walled carbon nanotubes enhances the catalytic activity of the CoPc itself without any change in the reaction mechanism. A synergistic effect, in terms of reactivity when the new nanocomposite material was adsorbed on the GC electrode, was observed. The obtained hybrid electrodes were tested under hydrodynamic conditions, showing two different oxidation processes, which suggest the presence of two different types of active sites on the electrode surface catalyzing the reaction. Electrochemical impedance spectroscopy (EIS) analyses in the presence of [Fe(CN)6]3−/4− as a redox probe revealed that the GC/SWCNT + CoPc showed much lower electron-resistance (Ret) confirming the synergistic effect of the composite mentioned above. Atomic force microscopy (AFM) images showed the clear differences in surface roughness for each film, confirming the different compositions of the hybrid electrodes used in this study. 相似文献