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51.
Okamoto K Chimori M Iwanaga F Hattori T Yanase H 《Journal of Bioscience and Bioengineering》2002,94(2):182-185
A wild strain of brown-rot basidiomycete Piptoporus soloniensis produced a sweet flavor similar to tropical fruits in liquid cultures. The major and minor compounds were identified to be gamma-decalactone and gamma-octanolactone by gas chromatography-mass spectrometry analysis, respectively. The growth and production of gamma-decalactone by P. soloniensis in broth to which fatty acids had been added were investigated. The addition of 12-hydroxystearic acid and ricinoleic acid to the culture markedly enhanced the production of gamma-decalactone. On the other hand, addition of myristic acid, palmitic acid, stearic acid and oleic acid to the culture resulted in a higher production of gamma-octanolactone. The addition of hexanoic acid, octanoic acid, decanoic acid, lauric acid, linoleic acid and linolenic acid to the culture reduced the growth of P. soloniensis and production of gamma-decalactone and gamma-octanolactone. This strain accumulated oxalic acid in liquid culture and grew sufficiently under strongly acidic conditions. 相似文献
52.
Takuya Uehara Hideshi Naka Shigeru Matsuyama Le van Vang Tetsu Ando Hiroshi Honda 《Journal of chemical ecology》2013,39(11-12):1441-1447
Homologs of bombykal, (10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth, Dolbina tancrei. Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kováts retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of D. tancrei are (9E,11Z)-9,11-pentadecadienal and (9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species. 相似文献
53.
Characteristics of yeast growth and ethanol fermentation were examined in membrane bioreactor using a grape juice. After inoculation, batch fermentation was carried out for 24 h. When yeast growth reached the stationary phase, continuous fermentation was initiated. In continuous fermentation, a linear relationship was observed between cell concentration and dilution rate. In single-vessel membrane bioreactor, the cell concentrations of 18.7 g/l and 76.9 g/l (15 and 60 times higher than that of the batch fermentation, respectively) were observed at dilution rates of 0.1 h(-1) and 0.3 h(-1), respectively. The residual sugar concentration was higher than 10 g/l at the dilution rate of 0.1 h(-1), 0.2 h(-1) or 0.3 h(-1), therefore the single-vessel membrane bioreactor was not suitable for producing dry wine (sugar concentration: 4 g/l or less). In the double-vessel membrane bioreactor, it is most suitable to set the recycle ratio at 0.15 for keeping the sugar concentration below 4 g/l. The productivity of dry wine in the double-vessel membrane bioreactor was 28 times higher than that in the batch fermentation. 相似文献
54.
Katsunori Matsushita Takumi Okuda Dr. Shohei Mori Dr. Masamitsu Konno Dr. Hidetoshi Eguchi Dr. Ayumu Asai Dr. Jun Koseki Dr. Yoshifumi Iwagami Dr. Daisaku Yamada Dr. Hirofumi Akita Dr. Tadafumi Asaoka Dr. Takehiro Noda Dr. Koichi Kawamoto Dr. Kunihito Gotoh Dr. Shogo Kobayashi Dr. Yuuya Kasahara Dr. Kunihiko Morihiro Prof. Dr. Taroh Satoh Prof. Dr. Yuichiro Doki Prof. Dr. Masaki Mori Prof. Dr. Hideshi Ishii Prof. Dr. Satoshi Obika 《ChemMedChem》2019,14(15):1384-1391
The main concern in the use of anticancer chemotherapeutic drugs is host toxicity. Patients need to interrupt or change chemotherapy due to adverse effects. In this study, we aimed to decrease adverse events with gemcitabine (GEM) in the treatment of pancreatic ductal adenocarcinoma and focused on the difference of hydrogen peroxide levels in normal versus cancer cells. We designed and synthesized a novel boronate-ester-caged prodrug that is activated by the high H2O2 concentrations found in cancer cells to release GEM. An H2O2-activatable GEM (A-GEM) has higher selectivity for H2O2 over other reactive oxygen species (ROS) and cytotoxic effects corresponding to the H2O2 concentration in vitro. A xenograft model of immunodeficient mice indicated that the effect of A-GEM was not inferior to that of GEM when administered in vivo. In particular, myelosuppression was significantly decreased following A-GEM treatment compared with that following GEM treatment. 相似文献
55.
56.
In general, a computing system with high reliability can be achieved by redundancy and/or maintenance. The sophisticated maintenance techniques are more and more important since a computing system can be operated by applying remote maintenance. In this paper we discuss a multisystem with preventive maintenance, which is one of the fault-tolerant computing systems. Making the suitable assumptions, we construct a stochastic model of such a computing system for evaluating reliability/performance. Applying Markov renewal and queueing theories, we analytically obtain several reliability/performance measures. Calculating such measures numerically, we show the impacts of preventive maintenance on such a computing system. 相似文献
57.
Islam A Yamamoto M Sugie M Naka H Tabata J Arita Y Ando T 《Journal of chemical ecology》2007,33(9):1763-1773
In addition to 2,13- and 3,13-octadecadien-1-ols and their acetates, aldehyde analogs have been identified from lepidopteran
species in the family Sesiidae. To establish a reliable analytical method for determining the positions and configurations
of the two double bonds in natural pheromone components, all geometric isomers of the 2,13- and 3,13-octadecadienals were
synthesized by Dess-Martin oxidation of the corresponding alcohols with limited isomerization of the double bond at the 2-
or 3-position. GC-MS analysis of these aldehydes showed isomerization of (Z)-2-, (Z)-3-, and (E)-3-double bonds to an (E)-2-double bond, even with a cool on-column injection. In contrast, HPLC analysis with an ODS column was accomplished without
isomerization. The geometric isomers of each dienal eluted in the order ZZ → EZ → ZE → EE. The conjugated 2,13-dienals were detectable in nanogram amounts with a UV detector at 235 nm. Whereas the detection of 3,13-dienals
was difficult because of the lack of a chromophore, a highly sensitive analysis was achieved after derivatization with 2,4-dinitrophenylhydrazine.
LC-MS with atmospheric pressure chemical ionization showed a strong [M-1]- at m/z 443 for the derivatives. Based on these analytical data, a pheromone extract of a sesiid moth, Macroscelesia japona, was examined by HPLC and LC-MS, and it was confirmed that the octadecadienal tentatively identified by a previous GC-MS
analysis did indeed have the 2E,13Z configuration. Furthermore, field evaluation of four synthetic geometric isomers of the 2,13-dienal revealed specific attraction
to a lure with the (2E,13Z)-isomer as a main component. 相似文献
58.
Matsuoka K Yamamoto M Yamakawa R Muramatsu M Naka H Kondo Y Ando T 《Journal of chemical ecology》2008,34(11):1437-1445
Gas chromatography-mass spectrometry (GC-MS) and GC-electroantennographic detection (EAD) analyses of the sex pheromone extract from a wasp moth, Syntomoides imaon (Lepidoptera: Arctiidae: Syntominae), showed that virgin females produced (Z,Z,Z)-3,6,9-henicosatriene and (Z,Z,Z)-1,3,6,9-henicosatetraene with a trace amount of their C(20) analogs. Identification of the chemical structures was facilitated by comparison with authentic standards and the double-bond positions were confirmed by dimethyl disulfide derivatization of monoenes produced by a diimide reduction. In a field test in the Yonaguni-jima Islands, males of the diurnal species were captured in traps baited with a 1:2 mixture of the above-described synthetic C(21) polyenes. Lipids were extracted from the abdominal integument and its associated oenocytes and peripheral fat bodies. Following derivatization, fatty acid methyl esters (FAMEs) were fractionated by HPLC equipped with an ODS column, and methyl (Z,Z,Z)-11,14,17-icosatrienoate and (Z,Z,Z)-13,16,19-docosatrienoate were identified by GC-MS. These novel C(20) and C(22) acid moieties are longer-chain analogs of linolenic acid, (Z,Z,Z)-9,12,15-octadecatrienoic acid. They are presumed to be biosynthetic precursors of the S. imaon pheromone because the C(21) trienyl component might be formed by decarboxylation of the C(22) acid. On the other hand, the C(20) acid, but not the C(22) acid, was found in FAMEs of Ascotis selenaria cretacea (Lepidoptera: Geometridae), which secretes C(19) pheromone components, (Z,Z,Z)-3,6,9-nonadecatriene and the monoepoxy derivative, indicating that different systems of the chain elongation might play an important role in developing species-specific communication systems mediated with polyunsaturated hydrocarbons and/or epoxy derivatives, components of Type II lepidopteran sex pheromones. 相似文献
59.
In this paper the time‐dependent characteristics of surface‐averaged Nusselt number in a square enclosure with hot and cold side walls exposed to vertical vibrations were numerically examined. In the computation, the Prandtl number, the Rayleigh number, and the vibration Grashof number were held constant at 0.71, 104, and 106, respectively. The angular frequency of vibration was changed in the range between 10 and 7680. The results showed that the change in the characteristics of the surface‐averaged Nusselt number proposed by Fu and Shieh corresponded to the change in the shape of reconstructed attractor and that these regions could also be characterized by the three indices defined in phase space: average location of trajectory, the largest Lyapunov exponent, and the correlation dimension. Moreover, the time scale with which the autocorrelated coefficient of the surface‐averaged Nusselt number becomes 1/e was found to be a very important parameter for the time‐ and surface‐averaged Nusselt number. © 2000 Scripta Technica, Heat Trans Asian Res, 30(1): 11–21, 2001 相似文献
60.
Kiyoyuki Shimizu Noriaki Kounami Hiroyasu Wada Tetuya Shishido Hideshi Hattori 《Catalysis Letters》1998,54(3):153-158
The distributions of Brønsted and Lewis acid sites of different acid strengths on sulfated zirconia calcined at 450–650°C were measured by IR of adsorbed pyridine to elucidate the active sites for butane isomerization. The total numbers of Brønsted acid sites were largest when the catalyst was calcined at 500°C. The total numbers of Lewis acid sites increased with increasing calcination temperature to a maximum at 650°C. The catalytic activity in skeletal isomerization of butane correlated well with the number of Brønsted acid sites but not with the number of Lewis acid sites. The active sites were completely blocked by pyridine irreversibly absorbed at 350°C. We suggest that the strong Brønsted acid sites, which are able to retain pyridine against evacuation at 350°C, act as active sites for butane isomerization on sulfated zirconia. 相似文献