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751.
Maeda K Teramura K Takata T Hara M Saito N Toda K Inoue Y Kobayashi H Domen K 《The journal of physical chemistry. B》2005,109(43):20504-20510
The physical and photocatalytic properties of a novel solid solution between GaN and ZnO, (Ga(1-x)Zn(x))(N(1-x)O(x)), are investigated. Nitridation of a mixture of Ga(2)O(3) and ZnO at 1123 K for 5-30 h under NH(3) flow results in the formation of a (Ga(1-x)Zn(x))(N(1-x)O(x)) solid solution with x = 0.05-0.22. With increasing nitridation time, the zinc and oxygen concentrations decrease due to reduction of ZnO and volatilization of zinc, and the crystallinity and band gap energy of the product increase. The highest activity for overall water splitting is obtained for (Ga(1-x)Zn(x))(N(1-x)O(x)) with x = 0.12 after nitridation for 15 h. The crystallinity of the catalyst is also found to increase with increasing the ratio of ZnO to Ga(2)O(3) in the starting material, resulting in an increase in activity. 相似文献
752.
Watabe Y Kondo T Morita M Tanaka N Haginaka J Hosoya K 《Journal of chromatography. A》2004,1032(1-2):45-49
We have developed a simple HPLC method for the microanalysis of bisphenol A (BPA), which is often contained in environmental water and is known as an endocrine disrupter. HPLC coupled with electrochemical detection requires a simpler procedure of pretreatment compared to GC-MS. In this study, we analyzed BPA using molecularly imprinted polymer as an on-line pretreatment device. This polymer has molecular recognition sites and provides specific selectivity in extraction process. Due to this effect, the detection limit obtained with this HPLC was 0.36 ng/l. This method applied to environmental water and purified water samples containing 2-70 ng/l of BPA successfully. Furthermore, UV detection was performed in some actual analyses. 相似文献
753.
Takao M. Kojima Nobuo Kobayashi Yozaburo Kaneko 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1992,23(2):181-185
The formation of cluster ions when hydrogen molecular ions H 2 + and H 3 + are injected into a drift tube filled with helium gas at 4.4 K has been investigated. When H 2 + ions are injected, cluster ions HHe x + (x≦14) are produced. No production of H2He x + ions is observed. When H 3 + ions are injected, cluster ions HHe x + (x≦14) are produced as well as H3He x + (x≦13), and very small signals corresponding to H2He x + (3≦x≦10) are observed. Information on the stability of HHe x + and H3He x + is derived from the drift field dependence of the cluster size distributions. The cluster sizex=13 is found to be a magic number for HHe x + , and for H3He x + ,x=10 and 11. 相似文献
754.
Chien-Yuan Chen Eiichi Tamiya Kazuhiko Ishihara Yukio Kosugi Yuan-Chi Su Nobuo Nakabayashi Isao Karube 《Applied biochemistry and biotechnology》1992,36(3):211-226
A biocompatible needle-type glucose sensor with a 3-electrode configuration was constructed. A platinum-electroplated carbon stick was used as the working electrode, Ag/AgCl as the reference electrode, and a disposable hypodermic needle made of stainless steel as the counter electrode. A Nafion membrane, an immobilized glucose oxidase (GOD) membrane, and a biocompatible membrane with diffusion-limiting effect were coated successively onto the working electrode. The sensor showed a rapid response (< 120 s in batch operation), good reproducibility (RE < 3%), good stability (over 36 h in control serum), a wide dynamic range (5-600 mg/dL glucose), and superior biocompatibility. It was used to determine glucose in serum. The data obtained from the sensor showed good agreement with that from a clinical autoanalyzer (R > 0.95). 相似文献
755.
Chi C Tanaka R Okuda Y Ikota N Yamamoto H Urano S Ozawa T Anzai K 《Chemical & pharmaceutical bulletin》2005,53(11):1411-1415
To find efficient methods to evaluate oxidative stress in mouse skin caused by X-ray irradiation, several markers and methodologies were examined. Hairless mice were irradiated with 50 Gy X-rays and skin homogenates or skin strips were prepared. Lipid peroxidation was measured using the skin homogenate as the level of thiobarbituric acid reactive substances. The level of lipid peroxidation increased with time after irradiation and was twice that of the control at 78 h. ESR spectra of skin strips showed a clear signal for the ascorbyl radical, which increased with time after irradiation in a manner similar to that of lipid peroxidation. To measure levels of glutathione (GSH) and its oxidized forms (GSSG) simultaneously, two HPLC methods, sample derivatization with 1-fluoro-2,4-dinitrobenzene and detection with a UV detector (method A) and no derivatization and detection with an electrochemical detector (method B), were compared and the latter was found to be better. No significant change was observed within 24 h after irradiation in the levels of GSH and GSSG measured by method B. The GSH/GSSG ratio may be a less sensitive parameter for the evaluation of acute oxidative stress caused by X-ray irradiation in the skin. Monitoring the ascorbyl radical seems to be a good way to evaluate oxidative stress in skin in vivo. 相似文献
756.
Nickel ions react with 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine in aqueous solution at pH 6.8 to form a red 1:3 complex cation which can be extracted at pH 6.3 into 1,2-dichloroethane with ethyl tetrabromophenolphthalein anion as an ion association compound having an absorption maximum at 610 nm. The apparent molar absorptivity is 2.21 × 105 l mol?1 cm?1 and a linear calibration graph is obtained in the range 0–0.05 μg ml?1 (0?8.52 × 10?7 M) nickel in aqueous solution. The r.s.d, is 1.5%. This method can be applied to the determination of traces of nickel in steels and aluminium chips. 相似文献
757.
Nobuo Kushibiki Masahiro Irie Koichiro Hayashi 《Journal of polymer science. Part A, Polymer chemistry》1975,13(1):77-85
Initiation and propagation mechanisms of the spontaneous polymerization of the system nitroethylene–isobutyl vinyl ether were studied. An equimolar mixture of these two monomers gives white precipitates below room temperature, though they react explosively to give viscous products at higher temperature. The precipitate was found to be composed of a polynitroethylene and a cycloadduct of these two monomers. The isolated cycloadduct product is so reactive that it not only polymerizes itself spontaneously but also initiates the polymerization of nitroethylene. The polymerization of the cycloadduct was revealed to proceed without termination to produce an alternate copolymer of these two monomers. These results indicate that the explosive spontaneous polymerization of this system consists of three elementary reaction processes; (1) cycloaddition reaction between two monomers, (2) anionic polymerization of nitroethylene induced by the cycloadduct, and (3) the living ring-opening polymerization of the cyclo-adduct. 相似文献
758.
Studies on stable free radicals. XVI. Copolymerizationo of a stable N-oxyl biradical with p-xylylene
Takashi Fujita Takao Yoshioka Nobuo Soma 《Journal of polymer science. Part A, Polymer chemistry》1980,18(11):3253-3264
Six copolymers were obtained by the reaction of a sterically hindered N-oxyl biradical with pseudodiradical p-xylylene using the reactivity of an N-oxyl toward the carbon radical. The feed ratio of the N-oxyl biradical to α-chloro-p-xylene, which was used as the precursor of the pseudodiradical p-xylylene, governed the properties of the copolymers produced. The copolymers with a terminalN-oxyl group, were obtained when a 0.4-1.2 molar ratio of the N-oxyl biradical to α-chloro-p-xylene. The polymerization process was also discussed. 相似文献
759.
Yamada M Kato K Nomizu M Sakairi N Ohkawa K Yamamoto H Nishi N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(6):1407-1412
Large amounts of DNA-enriched materials, such as salmon milts and shellfish gonads, are discarded as industrial waste. We have been able to convert the discarded DNA to a useful material by preparing novel DNA films by UV irradiation. When DNA films were irradiated with UV light, the molecular weight of DNA was greatly increased. The reaction was inhibited by addition of the radical scavenger galvinoxyl suggesting that the DNA polymerization with UV irradiation proceeded by a radical reaction. Although this UV-irradiated DNA film was water-insoluble and resistant to hydrolysis by nuclease, the structure of the DNA film in water was similar to non-irradiated DNA and maintained B-form structure. In addition, the UV-irradiated DNA film could effectively accumulate and condense harmful DNA-intercalating compounds, such as ethidium bromide and acridine orange, from diluted aqueous solutions. The binding constant and exclusion number of ethidium bromide for UV-irradiated DNA were determined to be 6.8 +/- 0.3 x 10(4) M(-1) and 1.6 +/- 0.2, respectively; these values are consisted with reported results for non-irradiated DNA. The UV-irradiated DNA films have potential uses as a biomaterial filter for the removal of harmful DNA intercalating compounds. 相似文献
760.
New polymer ligands containing β-dimethylaminoalkylphosphines were prepared using chloromethylated polystyrene, and the ligands were used for nickel-catalyzed asymmetric cross-coupling of sec-alkyl Grignard reagents with vinyl bromide to yield coupling products of ~50% ee. 相似文献