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91.
3‐Methacryloxypropylpolysilsesquioxane (MA‐PS) was prepared by acid‐ or base‐catalyzed hydrolytic polycondensation of 3‐methacryloxypropyltrimethoxysilane (MAS). MA‐PS coating film was prepared by dip‐coating on organic, metal and inorganic substrates, including poly(ethylene terephthalate), aluminum, stainless steel, and glass. The coating films on poly(ethylene terephthalate) and glass showed high adhesive strength. The hardness of coating films increased with increasing heat treatment temperature, whereas they decreased with increasing H2O/MAS molar ratio. The refractive index of coating films increased with increasing heat treatment temperature. In addition, flat and transparent free‐standing films (0.24–0.27 mm thickness) were prepared from MA‐PS that were crack‐free after heat treatment at 1000 °C. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
92.
93.
This study intends to determine the rational criteria (e.g., threshold value) for applying the weight variation test and to investigate the adequacy of the acceptance value for existing commercial products in Japan. The studied products were 489 lots (3 lots x 163 products) of compressed tablets (plain, film-coated, sugar-coated) and 42 lots (3 lots x 14 products) of hard capsules marketed in Japan. The individual drug content and the weight of 10 units in a lot were determined for each product and the acceptance values were calculated according to the Japanese Pharmacopoeia thirteenth edition (JP13) Content Uniformity Test (M=100.0, k=2.2). Product-specific intra-lot relative standard deviation of content (RSDD), weight (RSDW) and concentration (RSDC) were calculated by analysis of variance (ANOVA) using three lots of data per product. The RSDD and RSDC tended to increase with the decrease of the label strength for plain tablets, but not for film-coated and sugar-coated tablets, and hard capsules. A good correlation was found between RSDD and RSDC but not between RSDD and RSDW. These findings indicate that 1) it is difficult to rationally set the threshold level for weight variation, especially regarding the dosage forms except for plain tablets, 2) the application of weight variation tests should, in principle, be decided on the mixing homogeneity that is RSDC. 3) Most (99.6%) of the tablets and all the capsules investigated met the requirement of content uniformity test of JP13. Therefore the criteria of the JP13 content uniformity test are considered acceptable from the viewpoint of manufacturing capability. 相似文献
94.
95.
Yoshie Ishikawa Qi Feng Naoto Koshizaki 《Applied Physics A: Materials Science & Processing》2010,99(4):797-803
We studied the fabrication of B4C submicron particles by laser irradiation of boron nanoparticles dispersed in an organic solvent. The spherical shape of
the formed particles suggests that instantaneous melt formation and solidification by quenching are involved in the particle-forming
process. B4C particles gradually became larger with irradiation time at relatively low laser fluence (1.5 J cm−2 pulse−1) by repetitive melting and fusion of the particles, and the B4C yield increased with irradiation time to 90% for 600 min of irradiation. At higher laser fluences, the B4C yield decreased due to the explosive ablation of boron or B4C to form H3BO3, and thus only the larger B4C particles were observed. The dielectric constant of the organic solvent also affected the generated B4C particle size, probably due to the degree of particle aggregation. Thus, this technique can provide a new approach for fabricating
spherical submicron particles of ceramic materials, such as carbides, with simple and safe processes. 相似文献
96.
The composition of the dopant for the analysis of polycyclic aromatic hydrocarbons (PAHs) by liquid chromatography/dopant-assisted atmospheric-pressure photoionization/mass spectrometry under reversed-phase conditions was optimized to enhance the ionization efficiency for PAHs. The most suitable dopant was a toluene/anisole mixture (99.5:0.5, v/v) and it could improve limit of detections (LODs) to 0.79-168 ng mL(-1) (signal-to-noise (S/N)=3) for 16 common PAHs. The LODs are 3.8-40 times lower than those obtained with toluene alone and are comparable to those obtained using gas chromatography/mass spectrometry. 相似文献
97.
We shall show an exact time interval for the existence of local strong solutions to the Keller‐Segel system with the initial data u0 in Ln /2w (?n), the weak Ln /2‐space on ?n. If ‖u0‖ is sufficiently small, then our solution exists globally in time. Our motivation to construct solutions in Ln /2w (?n) stems from obtaining a self‐similar solution which does not belong to any usual Lp(?n). Furthermore, the characterization of local existence of solutions gives us an explicit blow‐up rate of ‖u (t)‖ for n /2 < p < ∞ as t → Tmax, where Tmax denotes the maximal existence time (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
98.
Preferential 5‐Methylcytosine Oxidation in the Linker Region of Reconstituted Positioned Nucleosomes by Tet1 Protein
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Seiichiro Kizaki Tingting Zou Dr. Yue Li Dr. Yong‐Woon Han Dr. Yuki Suzuki Prof. Dr. Yoshie Harada Prof. Dr. Hiroshi Sugiyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(46):16598-16601
Tet (ten–eleven translocation) family proteins oxidize 5‐methylcytosine (mC) to 5‐hydroxymethylcytosine (hmC), 5‐formylcytosine (fC), and 5‐carboxycytosine (caC), and are suggested to be involved in the active DNA demethylation pathway. In this study, we reconstituted positioned mononucleosomes using CpG‐methylated 382 bp DNA containing the Widom 601 sequence and recombinant histone octamer, and subjected the nucleosome to treatment with Tet1 protein. The sites of oxidized methylcytosine were identified by bisulfite sequencing. We found that, for the oxidation reaction, Tet1 protein prefers mCs located in the linker region of the nucleosome compared with those located in the core region. 相似文献
99.
T. Hashimoto Y. Aoyagi H. Kudo T. Sotobayashi 《Journal of Radioanalytical and Nuclear Chemistry》1985,90(2):415-438
Alpha-recoil ranges were calculated for fifteen interesting minerals, especially for naturally occurring alpha-emitters, on the basis of the simple LSS-theory. The ranges obtained from single decay process were represented as a comprehensive range expression in A units, as well as the physical ranges in g/cm2 units. Furthermore, the total mean ranges concerning overall alpha-decaying members within each natural decay series, including the extinct neptunium series, have also been evaluated and tabulated. These calculated ranges can contribute to the interpretation of the widespread disequilibrium states in respective decay series in nature as well as in laboratory experiments. 相似文献
100.
Sekido M Aoyagi K Nakamura H Kabuto C Yamamoto Y 《The Journal of organic chemistry》2001,66(21):7142-7147
The reaction of the activated olefins 1 with the allylic carbonate 2, having a hydroxy group at the terminus of the carbon chain, in the presence of catalytic amounts of Pd(2)dba(3).CHCl(3) and dppe in THF at room temperature gave the corresponding cycloaddition products, tetrahydrofuran derivatives 5, in good to very high yields. The diastereoselectivities (trans/cis ratios) of the products were in the range of ca. 60-70/40-30. The reaction of 1 with the hydroxy allylic carbonate 3 in the presence of catalytic amounts of Pd(2)dba(3).CHCl(3) and (o-tolyl)(3)P in THF at 50 degrees C afforded the corresponding cycloaddition products, tetrahydropyran derivatives 6, in good to high yields. The trans/cis ratios of the products were in the range of ca. 0-40/99-80. The reaction of 1a with the hydroxy allylic carbonate 4 needed higher reaction temperatures (approximately 100 degrees C) to give the cycloaddition product, the oxepane 7a, in 31% yield with low diastereoselectivity. Next, catalytic asymmetric syntheses of tetrahydrofuran and -pyran derivatives were carried out. With the Trost ligand 15, good to high ees were accomplished in the cycloaddition, although the diastereoselectivities were of low level. With the Hayashi ligand 16, good to high ees were also achieved in the cycloaddition. The absolute stereochemistries of the major enantiomers of 5l, 5m, and 6d were determined unambiguously by X-ray crystallographic analysis: trans-(2R,4R)-5l, cis-(2S,4R)-5l, 4R-5m, trans-(2S,4S)-6d, and cis-(2R,4S)-6d were major enantiomers. Based upon the absolute stereochemistries of the major enantiomers, the mechanism of catalytic asymmetric induction in the cycloaddition reaction is discussed. 相似文献