全文获取类型
收费全文 | 969篇 |
免费 | 28篇 |
国内免费 | 3篇 |
专业分类
化学 | 701篇 |
晶体学 | 9篇 |
力学 | 11篇 |
数学 | 64篇 |
物理学 | 215篇 |
出版年
2022年 | 4篇 |
2021年 | 7篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 25篇 |
2015年 | 22篇 |
2014年 | 25篇 |
2013年 | 45篇 |
2012年 | 57篇 |
2011年 | 74篇 |
2010年 | 33篇 |
2009年 | 43篇 |
2008年 | 81篇 |
2007年 | 77篇 |
2006年 | 42篇 |
2005年 | 47篇 |
2004年 | 48篇 |
2003年 | 60篇 |
2002年 | 54篇 |
2001年 | 20篇 |
2000年 | 25篇 |
1999年 | 10篇 |
1998年 | 10篇 |
1997年 | 12篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 16篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 2篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1976年 | 9篇 |
1975年 | 8篇 |
1974年 | 3篇 |
1973年 | 6篇 |
1969年 | 2篇 |
排序方式: 共有1000条查询结果,搜索用时 0 毫秒
101.
Kazuyuki Fukano Eiichi Kageyama 《Journal of polymer science. Part A, Polymer chemistry》1975,13(6):1309-1324
The radiation-induced polymerization of styrene adsorbed on silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to elucidate the effect of properties of inorganic substances on the polymerization. The rate of adsorbed state polymerization on these inorganic substances was very fast in comparison with that of bulk-state polymerization. The amount of unextractable polymer depends on the specific surface area and chemical compositions of these inorganic substances. Inorganic substances which contain aluminum as a component element are more likely to be grafted than those which consist of SiO2 alone. The molecular weight and molecular weight distribution of unextractable polymer and extractable polymer differ from one another in each inorganic substance. In case of silicic acid anhydride, unextractable polymer has smaller molecular weight than extractable polymer. These results suggest that unextractable polymer cannot be extracted due to chemical bonds with the inorganic surface. 相似文献
102.
Takashi Murashima Kazuyuki Hayata Jun Matsui Daisuke Miyoshi Takashi Yamada Naoki Sugimoto 《Tetrahedron letters》2007,48(48):8514-8517
The DNAs modified with tetraphenyl porphyrin at the center of 13mer oligonucleotide were synthesized using phosphoramidite chemistry and automated DNA synthesis. When the porphyrin modified oligonucleotide was annealed with its complementary strand, they formed a standard B-form duplex. The porphyrin moiety intercalated in the duplex, and moderately lowered the thermal stability. 相似文献
103.
Shimizu M Sakakura M Kanehira S Nishi M Shimotsuma Y Hirao K Miura K 《Optics letters》2011,36(11):2161-2163
We report on the formation mechanism of element distribution in glass under high-repetition-rate femtosecond laser irradiation. We simultaneously focused two beams of femtosecond laser pulses inside a glass and confirmed the formation of characteristically shaped element distributions. The results of the numerical simulation in which we considered concentration- and temperature-gradient-driven diffusions were in excellent qualitative agreement with the experimental results, indicating that the main driving force is the sharp temperature gradient. Since the composition of a glass affects its refractive index, absorption, and luminescence property, the results in this study provide a framework to fabricate a functional optical device such as optical circuits with a high-repetition-rate femtosecond laser. 相似文献
104.
Tooru Kitagawa Kohji Tashiro Kazuyuki Yabuki 《Journal of Polymer Science.Polymer Physics》2002,40(13):1281-1287
Fourier transform Raman spectra were measured for poly‐p‐phenylenebenzobisoxazole (PBO) fiber subjected to a tensile stress, and the Raman shift factor (the frequency shift caused by 1 GPa tensile stress) depended strongly on the sample‐preparation condition. To clarify the reasons of this dependency, a mechanical series parallel model was adopted that could successfully and quantitatively explain the observed Raman shift factors and gave a concreate heterogeneous stress distribution in the PBO fibers. As a result, a mechanical series model was reasonable for PBO fiber. Broadening of Raman bands, which was observed when the PBO fiber was tensioned, could also be interpreted on the basis of an idea of heterogeneous stress distribution. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1281–1287, 2002 相似文献
105.
Yoshito Hirata Shunsuke Horai Kazuyuki Aihara 《The European physical journal. Special topics》2008,164(1):13-22
We propose a method to reproduce distance matrices and original time series
from recurrence plots. The procedure is to (i)convert a recurrence plot
to a weighted graph and (ii)calculate a distance between each pair
of nodes on this weighted graph.
We demonstrate this method by reproducing the topological shape of
original time series.
We also propose two applications.
The first application is to obtain the maximal Lyapunov exponent
from a recurrence plot without reproducing the shapes
of original time series.
The second application is to reconstruct a common deterministic driving
force from observations of forced systems.
Thus, the method opens new fields in data analysis. 相似文献
106.
107.
Thermal properties of organoindium thiolates were investigated by means of thermogravimetric (TG) and differential thermal (DT) analysis. Dibutyl-indium propylthiolates (Bun2InSPrn, Bun2InSPri, Bui2InSPrn and Bui2InSPri) decomposed up to 280°C along with an exothermic DT peak and gave indium(I) sulfide (InS) powders. Although the arylthiolate Bun2InSPh also afforded InS powders, it decomposed at a slightly higher temperature. In contrast, the dithiolate and the dithiocarbamate complexes [BunIn(SPri)2 and In (S2CNBu2)3] gave indium(III) sulfide (In2S3) powders. 相似文献
108.
We discuss the universal version of the Schwinger terms of current algebra (we call it the universal Schwinger cocycle) forp=3 (herep denotes the class of the Schatten idealI
p
, which is related to the (D+1) space-time dimensions byp=(D+1)/2) in detail, and give a conjecture of the general form of the cocycle for anyp. We also discuss the infinite charge renormalizations, the highest weight vector and state vectors forp=3. Last, we give brief comments on the problems caused by the difficulties to construct the measure of infinite-dimensional Grassmann manifolds. 相似文献
109.
Takashi Yoshida Rong Lu Shuqin Han Kazuyuki Hattori Takahiro Katsuta Kei‐Ichi Takeda Kazutoshi Sugimoto Masamitsu Funaoka 《Journal of polymer science. Part A, Polymer chemistry》2009,47(3):824-832
For the synthesis of a new biologically functional polymer from a natural resource by an environment‐friendly method, the laccase‐catalyzed polymerization of a lignin‐based macromonomer, lignocatechol, was carried out for the first time in ethanol–phosphate buffer solvent system to give crosslinked polymers in good yields. Lignocatechol was prepared by the phase separation system of lignin and catechol in aqueous sulfuric acid. The copolymerization was also performed with urushiol to afford the corresponding copolymers in high yields. The polymerization mechanism was estimated by the IR and pyrolysis GC‐MS measurements, suggesting that the polymerization proceeded mainly at the catechol ring through a quinone radical intermediate. The thermal properties were measured by the DSC, TG, and TMA analyses, indicating that the polymers had high thermal stabilities because of the crosslinked structures. In addition, it was found that the resulting polymers had the affinity of bovine serum albumin (BSA) and glucoamylase. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 824–832, 2009 相似文献