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991.
ZnO crystals were synthesized from basic aqueous solutions including zincate ions stabilized with triethanolamine (N(C2H4OH)3, teaH3) by heating at 60°C. The influence of the basicity of the solutions on the morphology of the ZnO crystals was examined. The aqueous solutions were prepared using ZnSO4·7H2O, N(CH3)4OH (TMAOH), and teaH3 as a zinc source, a base, and a stabilizer, respectively, at a zinc concentration of 0.2 M at a teaH3 / Zn molar ratio of 4. Clear solutions were obtained at a molar ratio of TMAOH / Zn ≥ 3.0. When the clear solutions, in which glass or polyester substrates were placed, were heated at 60°C, agglomerates of ZnO crystals were deposited on the substrates in the TMAOH / Zn range from 3.0 to 3.6. With increasing the TMAOH / Zn ratio, the shape of the resulting ZnO crystals changed from a short asymmetric column with a hexagonal flat edge and a rounded one, through a rocket‐like shape formed by intergrowth, to a hexagonal rod. Although no films of ZnO were formed, ZnO crystals with different shapes were synthesized. When the glass substrates pre‐coated with a ZnO thin film by a sol‐gel method were used, highly oriented, dense ZnO films were formed. The films consisted of rod‐like crystals aligned normal to the substrate surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
992.
The large amount of waste derived from coupling reagents is a serious drawback of peptide synthesis from a green chemistry viewpoint. To overcome this issue, we report an electrochemical peptide synthesis in a biphasic system. Anodic oxidation of triphenylphosphine (Ph3P) generates a phosphine radical cation, which serves as the coupling reagent to activate carboxylic acids, and produces triphenylphosphine oxide (Ph3P O) as a stoichiometric byproduct. In combination with a soluble tag-assisted liquid-phase peptide synthesis, the selective recovery of desired peptides and Ph3P O was achieved. Given that methods to reduce Ph3P O to Ph3P have been reported, Ph3P O could be a recyclable byproduct unlike byproducts from typical coupling reagents. Moreover, a commercial peptide active pharmaceutical ingredient (API), leuprorelin, was successfully synthesized without the use of traditional coupling reagents.The large amount of waste derived from coupling reagents is a serious drawback of peptide synthesis from a green chemistry viewpoint. 相似文献
993.
Kenzo Inoue Hidehito Miyamoto Tomoyuki Itaya 《Journal of polymer science. Part A, Polymer chemistry》1997,35(9):1839-1847
Novel multiarmed polymers with ethylene oxide units, [( CH2CH2O)n : 7, n = 3; 8, n= 7.2; 9, n = 11.8, and 12, n = 11.8] were prepared from the reaction of polyethylene glycol monomethyl ethers with acid chlorides of hexakis(3,5-dicarboxyphenoxy)-( 6 ) and hexakis(4-carboxyphenoxy)cyclotriphosphazenes ( 11 ) and conductivities of their Li+ salt complexes were investigated. The glass transition temperatures of the salt-free polymers are in the temperature range −59 to −54°C, indicative of a high degree of reorientational mobility of the arms. When LiClO4 was added to the multiarmed polymers, the Tg values raised monotonically. The extent of Tg elevation was affected by the length of arms and the number of oxygen atoms around cyclotriphosphazene core and increased in the order 7 > 8 > 12 > 9 . The conductivities increased in the order 9 > 8 = 12 > 7 and the maximum conductivities of 4.0 × 10−5 S/cm at 30°C and 6.0 × 10−4 S/cm at 90°C have been achieved for the 9 -Li+ complex with Li+/O = 0.03. Interestingly, the conductivity of 9 -Li+ complexes at constant reduced temperatures increased in the whole concentrations of LiClO4 examined (Li+/O = 0.01–0.2), although the degree of increase in conductivity above Li+/O = 0.06 became small. From the behaviors of Tg and the conductivity of multiarmed polymer–LiClO4 complexes, it appears that the conductivity is governed by relative concentrations of inter- and intramolecular complexes in the polymer matrix. The influence of structural change of the comb-shaped to multiarmed polymers on the conductivity is described. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1839–1847, 1997 相似文献
994.
Keiichiro Sugimoto Midori Amako Hiroaki Takeuchi Kazuya Nakagawa Morio Yoshimura Yoshiaki Amakura Tomoyuki Fujita Shigeo Takenaka Hiroshi Inui 《Molecules (Basel, Switzerland)》2022,27(1)
Inhibition of fructose absorption may suppress adiposity and adiposity-related diseases caused by fructose ingestion. Eucalyptus leaf extract (ELE) inhibits intestinal fructose absorption (but not glucose absorption); however, its active compound has not yet been identified. Therefore, we evaluated the inhibitory activity of ELE obtained from Eucalyptus globulus using an intestinal fructose permeation assay with the human intestinal epithelial cell line Caco-2. The luminal sides of a cell monolayer model cultured on membrane filters were exposed to fructose with or without the ELE. Cellular fructose permeation was evaluated by measuring the fructose concentration in the medium on the basolateral side. ELE inhibited 65% of fructose absorption at a final concentration of 1 mg/mL. Oenothein B isolated from the ELE strongly inhibited fructose absorption; the inhibition rate was 63% at a final concentration of 5 μg/mL. Oenothein B did not affect glucose absorption. In contrast, the other major constituents (i.e., gallic acid and ellagic acid) showed little fructose-inhibitory activity. To our knowledge, this is the first report that oenothein B in ELE strongly inhibits fructose absorption in vitro. ELE containing oenothein B can prevent and ameliorate obesity and other diseases caused by dietary fructose consumption. 相似文献
995.
Kohei Tamao Masahiro Asahara Tomoyuki Saeki Akio Toshimitsu 《Journal of organometallic chemistry》2000,600(1-2):118-123
Some new aspects of intramolecularly amine-coordinated silylenes, ammonium silaylide, and amine-coordinated magnesium (chloro)silylenoids are summarized. The divalent silicon species bearing the 8-(dimethylamino)-1-naphthyl group, generated by the thermal degradation of a pseudo-pentacoordinated ethoxy- or fluoro-disilane, behaves as a nucleophilic ammonium silaylide as well as the amine-coordinated silylene, whose electrophilic character is weakened in comparison with that of free silylenes in some reactions in the presence of trapping agents such as 1,3-diene, diphenyl acetylene (in the absence or presence of water), and phenylacetylene, and in the absence of any trapping agent. The amine-coordinated silylenoid also behaves as an ambiphile, but the reaction courses are different from those observed with the amine-coordinated silylene and silaylide. A novel amino-group migration from naphthyl carbon to silicon has been observed in both species. 相似文献
996.
Takuya Kuwahara Keiichiro Yoshida Tomoyuki Kuroki Kenichi Hanamoto Kazutoshi Sato Masaaki Okubo 《Plasma Chemistry and Plasma Processing》2014,34(1):65-81
Regulations governing marine diesel engine NOx emissions have recently become more stringent. As it is difficult to fulfill these requirements by combustion improvements alone, effective aftertreatment technologies are needed to achieve efficient NOx reductions. In this study, we develop an effective NOx-reduction aftertreatment system for a marine diesel engine that employs combined nonthermal plasma (NTP) and adsorption. Compared with selective catalytic reduction, the proposed technology offers the advantages of not requiring a urea solution or harmful heavy-metal catalysts and low operating temperatures of less than 150 °C. The NOx reduction comprises repeated adsorption and desorption flow processes using NTP combined with NOx adsorbents made of MnOx–CuO. High concentrations of NOx are treated by NTP after NOx adsorption and desorption, and this aftertreatment system demonstrates excellent energy efficiencies of 161 g(NO2)/kWh, which fulfills the most recent International Maritime Organization emission NOx standards in the Tier II–III regulations for 2016 and requires only 4.3 % of the engine output power. 相似文献
997.
We consider a class of second order quasilinear differential equations with singular ninlinearities. Our main purpose is to investigate in detail the asymptotic behavior of their solutions defined on a positive half-line. The set of all possible positive solutions is classified into five types according to their asymptotic behavior near infinity, and sharp conditions are established for the existence of solutions belonging to each of the classified types. 相似文献
998.
999.
1000.
Synthesis of Poly(L‐lactide) with One Terminal D‐Glucose Residue and Wettability of Its Film Surface
To develop the new‐type poly(L ‐lactide)‐based biomedical material having a wettable surface, the synthesis of poly(L ‐lactide) with one terminal D ‐glucose residue was investigated. After the hydroxyl group at 1‐C of α‐tetrabenzyl glucose, α‐Glc(Bzl)4, was converted to the corresponding potassium alkoxide by using potassium tert‐butoxide, L ‐lactide (L ‐LA) was polymerized in the presence of α‐Glc(Bzl)4‐OK as an initiator in tetrahydrofuran at room temperature to prepare α‐Glc(Bzl)4‐polyLA. Subsequently, the removal of O‐protecting benzyl groups in the terminal α‐Glc(Bzl)4 residue was carried out by hydrogenolysis with Pd/C to obtain the objective D ‐glucose‐end‐capped polyLA, α‐Glc‐polyLA. The wettability of surface of the α‐Glc‐polyLA material is discussed using the difference of the dynamic contact angle between a α‐Glc‐polyLA/homopolyLA blend film and a film of the polyLA homopolymer. 相似文献