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81.
Tharnath Nanthirudjanar Hidehiro Furumoto Jiawen Zheng Young‐Il Kim Tsuyoshi Goto Nobuyuki Takahashi Teruo Kawada Si‐Bum Park Akiko Hirata Nahoko Kitamura Shigenobu Kishino Jun Ogawa Takashi Hirata Tatsuya Sugawara 《Lipids》2015,50(11):1093-1102
Hydroxy and oxo fatty acids were recently found to be produced as intermediates during gut microbial fatty acid metabolism. Lactobacillus plantarum produces these fatty acids from unsaturated fatty acids such as linoleic acid. In this study, we investigated the effects of these gut microbial fatty acid metabolites on the lipogenesis in liver cells. We screened their effect on sterol regulatory element binding protein‐1c (SREBP‐1c) expression in HepG2 cells treated with a synthetic liver X receptor α (LXRα) agonist (T0901317). The results showed that 10‐hydroxy‐12(Z)‐octadecenoic acid (18:1) (HYA), 10‐hydroxy‐6(Z),12(Z)‐octadecadienoic acid (18:2) (γHYA), 10‐oxo‐12(Z)‐18:1 (KetoA), and 10‐oxo‐6(Z),12(Z)‐18:2 (γKetoA) significantly decreased SREBP‐1c mRNA expression induced by T0901317. These fatty acids also downregulated the mRNA expression of lipogenic genes by suppressing LXRα activity and inhibiting SREBP‐1 maturation. Oral administration of KetoA, which effectively reduced triacylglycerol accumulation and acetyl‐CoA carboxylase 2 (ACC2) expression in HepG2 cells, for 2 weeks significantly decreased Srebp‐1c, Scd‐1, and Acc2 expression in the liver of mice fed a high‐sucrose diet. Our findings suggest that the hypolipidemic effect of the fatty acid metabolites produced by L. plantarum can be exploited in the treatment of cardiovascular diseases or dyslipidemia. 相似文献
82.
We have successfully synthesized novel polyurethanes where PU1 contains a [3]rotaxane that consists of N-3,5-di-tert-butylbenzyl-N-3-hydroxypropylammonium hexafluorophosphate (AOH1) and N,N′-Dimethyl-N,N′-bis(dibenzo-24-crown-8)-terephthalamide (BisC) as well as PU2 contains a [2]rotaxane that consists of AOH1 and dibenzo-24-crown-8 ether. Diphenylmethanediisocyanate (MDI), 1,4-butanediol (BD) and poly(ε-caprolactone)diol (PCL) were used as an isocyanate, chain expander, and soft segment, respectively. A polyurethane without any rotaxane structures (PU0) were also prepared as a reference polymer. The existence of the rotaxanes in the polyurethanes was confirmed by 1H NMR spectroscopy and TGA measurement. ATR-FT-IR spectral measurement revealed that the rotaxanes disturb the formation of hydrogen bonding between the polyurethane chains. From the DSC result, the rotaxanes retard the recrystallization of the PCL unit whereas no influence on the glass transition temperatures of the polyurethanes was observed. The retarding effect appeared remarkably with PU1. These thermal behaviors of the polyurethanes were also supported by viscoelastic measurement. In tensile test, the tensile strength and break of strain of PU1 were larger than those of PU2. 相似文献
83.
Docosahexaenoic acid (DHA) supply to the fetal brain depends upon the dam’s dietary intake of n-3 fats. In this study, we
measured the incorporation of DHA into the fetal brain and liver in n-3 fatty acid deficient (0.1% alpha-linolenate) mice
upon switching to an n-3 fatty acid adequate (2.1% alpha-linolenate) diet. Second generation mice raised and maintained on
an n-3 deficient diet during mating were switched to an n-3 adequate diet on embryonic day 1 (ED 1) or ED 13. Fatty acid analysis
was performed on fetal brains and livers and on maternal serum on ED 13, 15, 17, and 19. Although fetal brain and liver DHA
began at a very low level (both exhibited an 85% decline), recovery was nearly complete by ED 15 in the group switched near
conception but thereafter diverged. The maternal serum and fetal liver were very similar in their DHA and docosapentaenoic
acid time courses. However, when repletion began on ED 13, brain DHA recovery was only about 44%. These results suggest that
a nutritional intervention with alpha-linolenic acid can nearly but incompletely rescue the mouse fetal DHA deficiency if
began at the time of conception but that the third trimester is too late, thus leaving a large DHA gap. 相似文献
84.
Akiko Nakahashi Eisuke Miyoshi Kensuke Naka Yoshiki Chujo 《Journal of Inorganic and Organometallic Polymers and Materials》2009,19(1):55-66
Radical reaction of bis(4-prop-2-ynyloxyphenyl) disulfide (1) with 2,2′-azobis(isobutyronitrile) as an initiator provided a polymer with dithioalkene units (2). The 1H and 13C NMR spectra of 2 showed that 2 had mainly E-form dithioalkene structure. The radical reactions of 1 and diphenyl diselenide (3) or diphenyl ditelluride (5) were also carried out. At higher temperature than 70 °C, polymers were obtained with less amount of AIBN than in the case
of the homopolymerization of 1. Addition of 3 or 5 in the reaction mixture appeared to promote the radical reaction. Moreover, the obtained structure has high contents of thio-seleno
alkene or thio-telluro alkene than expected, which is due to difference of the chalcogen radical reactivity and difference
of capture ability of the dichalcogenide.
相似文献
Yoshiki Chujo (Corresponding author)Email: |
85.
Hisahiro Nakayama Takahiro Moriya Jiro Kasahara Akiko Matsuo Yuya Sasamoto Ikkoh Funaki 《Combustion and Flame》2012,159(2):859-869
The detonation propagation phenomena in curved channels were experimentally studied in order to determine the stable propagation condition. A stoichiometric ethylene–oxygen mixture gas and five types of rectangular-cross-section curved channels with different inner radii of curvature were employed. The detonation waves propagating through the curved channels were visualized using a high-speed video camera. Multi-frame short-time open-shutter photography (MSOP) was developed in the present study to simultaneously observe the front shock shape of the detonation wave and the trajectories of triple points on the detonation wave. The detonation wave became more stable under the conditions of a higher filling pressure of the mixture gas and/or a larger inner radius of curvature of the curved channel. The critical condition under which the propagation mode of the detonation wave transitioned from unstable to stable was having an inner radius of curvature of the curved channel (ri) equivalent to 21–32 times the normal detonation cell width (λ). In the stable propagation mode, the normal detonation velocity (Dn) increased with the distance from the inner wall of the curved channel and approached the velocity of the planar detonation propagating through the straight section of the curved channel (Dstr). The smallest Dn was observed on the inner wall and decreased with decreasing ri/λ. The distribution of Dn on the detonation wave in the stable mode was approximately formulated. The approximated Dn given by the formula agreed well with the experimental results. The front shock shape of the detonation wave could be reconstructed accurately using the formula. The local curvature of the detonation wave (κ) nondimensionalized by λ decreased with increasing distance from the inner wall. The largest λκ was observed on the inner wall and increased with increasing ri/λ. Dn/Dstr decreased with increasing λκ. This nondimensionalized Dn–κ relation was nearly independent of ri/λ. 相似文献
86.
Sawai H Wada M Kouda T Nakamura Ozaki A 《Chembiochem : a European journal of chemical biology》2006,7(4):605-611
5'-pACUG tetraribonucleotides containing 2'-5' or 3'-5' linkages self-condensed on 2'-5'- or 3'-5'-linked complementary decaribonucleotide (5'-CAGUCAGUCA) templates. CD and UV melting studies showed that helix formation took place in all four possible combinations of linkage isomers of the substrate tetramer and the template decamer under the ligation conditions. The hybridization ability followed the order: [3'-5' tetramer with 3'-5' decamer] > [2'-5' tetramer with 3'-5' decamer] > [2'-5' tetramer with 2'-5' decamer] > or = [3'-5' tetramer with 2'-5' decamer]. Each tetramer condensed on the complementary decaribonucletide template to form the corresponding octamer, but the ligation efficiency varied considerably, depending on the types of linkage in the tetramer substrate and the template decamer. The yields of the octamers obtained by the template-directed ligation followed the order: [2'-5' substrate: 2'-5' template] > [3'-5':3'-5'] > [2'-5':3'-5'] > [3'-5':2'-5']. The results demonstrate that a homo-linkage system is preferable for the template-directed synthesis of RNA. The resulting linkage of the octamer formed from the 2'-5'-linked substrate and the 2'-5'-linked template is mainly 2'-5'. 相似文献
87.
High corrosion resistance of magnesium coated with hydroxyapatite directly synthesized in an aqueous solution 总被引:1,自引:0,他引:1
Anticorrosion coatings are crucial for practical applications of magnesium alloys, which are used to reduce the weight of vehicles, aircraft, electronics enclosures etc. Hydroxyapatite (HAp) potentially offers high corrosion resistance and no environmental toxicity because its thermodynamic structural stability is high and it is a basic component of bone. However, direct synthesis of HAp on magnesium in aqueous solutions has been a scientific challenge because Mg ions prevent HAp crystallization. A new method of direct synthesis of HAp on magnesium was developed using a Ca chelate compound, which can maintain a sufficiently high concentration of Ca ions on the magnesium surface to overcome prevention of HAp crystallization with Mg ions. Highly crystallized HAp coatings were successfully formed on pure magnesium and AZ series alloys. Corrosion behavior of HAp-coated pure magnesium was examined by cyclic dry and wet tests with 1 g m−2 NaCl on the surface and polarization tests in a 3.5 wt% NaCl solution. A HAp-coated pure magnesium showed no noticeable corrosion pits after the dry and wet test. HAp-coated specimens showed 103-104 times lower anodic current density than as-polished specimen in the polarization test. The results demonstrate the remarkable anticorrosion performance of HAp coatings on magnesium for the first time. 相似文献
88.
In comparison with dietary high-linoleate safflower oil, high α-linolenate perilla oil decreased alkylacyl-and alkenylacyl-glycerophosphocholine
(GPC) content in rat kidney by roughly 30 and 25%, respectively. The fatty acid composition was also modified by high α-linolenate
oil; arachidonic acid (AA) level in alkylacyl-GPC, a platelet-activating factor (PAF) precursor, decreased by 30% along with
concomitant increases in the n-3 fatty acid levels. PAF contents under resting conditions were similarly low in the two dietary
groups. Fifteen minutes after endotoxin administration, PAF and lyso-PAF contents increased significantly, and the PAF content
in the high α-linolenate group was 60% lower than in the high linoleate group; the lyso-PAF contents also tended to be lower.
Lyso-PAF acetyltransferase and CoA-independent transacylase activities in kidney microsomes increased significantly after
endotoxin administration, while PAF acetylhydrolase activity in the cytosol was relatively unchanged. The lyso-PAF acetyltransferase
and PAF acetylhydrolase activities did not differ between the two dietary groups, but the CoA-independent, transacylase activity
was roughly 30% lower in the high α-linolenate group. In agreement with in vitro study, our present study demonstrates that dietary high α-linolenate suppresses PAF production in rat kidney during systemic
endotoxemia, and which is mainly due to the decrease in alkylacyl-GPC content, altered fatty acid compositions of the precursor
lipids and lower CoA-independent transacylase activity. 相似文献
89.
Mehedi Masud M Ozaki-Nakamura A Kuwahara M Ozaki H Sawai H 《Chembiochem : a European journal of chemical biology》2003,4(7):584-588
A thymidine analogue bearing a methyl ester at the C5 position was accepted as a substrate by the thermophilic family B DNA polymerases, KOD Dash, Pwo, and Vent(exo-), to form the corresponding PCR product, but not by the thermophilic family A DNA polymerases, Taq, Tth, and T7 thermosequenase. Modified DNA containing this analogue was prepared by PCR on a large scale with KOD Dash DNA polymerase and 5(methoxycarbonylmethyl)-2'-deoxyuridine 5'-triphosphate as a substrate. The methyl ester of the modified DNA was further allowed to react with tris(2-aminoethyl)amine or histamine by an ester-amide exchange reaction to form the corresponding derivatized DNA bearing a tris(2-aminoethyl)amine or histamine moiety. Hydrolysis of the methyl ester of the modified DNA gave a functionalized DNA bearing an anionic carboxyl group. The derivatized DNA could act as a template for the PCR with KOD Dash DNA polymerase and the natural 2'-deoxythymidine 5'-triphosphate or the modified thymidine analogue as a substrate. The postsynthetic derivatization of the modified DNA may expand the variety of structurally modified DNA produced by PCR. 相似文献
90.