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991.
Masahiro Imoto Hiroyuki Yoshimura Nobuki Sakaguchi Shoichi Kusumoto Tetsuo Shiba 《Tetrahedron letters》1985,26(12):1545-1548
The first total synthesis of E. coli lipid A () is described. The synthetic compound was identical with a natural specimen and exhibited the full endotoxic activity. It was thus conclusively proved by this chemical synthesis that lipid A is the active principle of bacterial endotoxin. 相似文献
992.
Hideo Kawamura Masahiro Manabe Kohhei Yuyama Hajime Katsu-ura Masaki Shiomi 《Journal of solution chemistry》1999,28(11):1239-1247
The gel-to-liquid-crystalline phase transition temperature T
m of dipalmitoylphosphatidylcholine (DPPC) liposome membrane was measured in the presence of homologous -phenylalkanols (phenol to 8-phenyl-1-octanol). The decrease in T
m induced by the alkanols allowed us, by applying the van't Hoff equation for freezing-point depression, to estimate two partition coefficients of each alkanol: gel membrane/bulk water K
x
g
and liquid-crystalline membrane/bulk water K
x
1
. Shorter alkyl chain alkanols were solubilized only in the liquid-crystalline membrane, i.e., K
x
g
=0, whereas longer-chain alkanols were solubilized not only in the liquid-crystalline membrane but also in the gel membrane. The former result suggests that the fraction of liquid-crystalline phase in the liposome membrane is 0.83 at T
m. From the latter result, the values of the free energy changes of transfer of the alkanol molecules from bulk water to liposome membrane were estimated to be – 3.46 kJ-mol–1 (liquid-crystalline membrane) and – 3.85 kJ-mol–1 (gel membrane) per CH2 group in the alkanol molecules. 相似文献
993.
The π→π* absorption bands of azulene show circular dichroism in the presence of (+)-nopinone. 相似文献
994.
From the twigs of Myrica cerifera L. (Myricaceae), a new oleanane triterpenic acid named myrica acid was isolated along with myricalactone and several other known constituents. The structure of the acid was determined as 3beta-hydroxy-1-oxoolean-11,13(18)-dien-28-oic acid on the basis of chemical and spectral evidence. 相似文献
995.
996.
Akitoshi Hayashi Takanori Konishi Kiyoharu Tadanaga Tsutomu Minami Masahiro Tatsumisago 《Research on Chemical Intermediates》2006,32(5):497-506
SnS-P2S5 and SnO-P2O5 amorphous materials were prepared by a mechanical milling technique. The SnO-P2O5 milled materials worked as a reversible electrode with higher capacity than SnO crystal in rechargeable lithium cells with
conventional liquid electrolytes. All-solid-state cells with a SnX-P2X5 (X = S and O) amorphous electrode and the Li2S-P2S5 glass-ceramic electrolyte were charged and discharged at room temperature. The sulfide electrodes exhibited better charge-discharge
performance than the oxide electrodes, suggesting that SnS-P2S5 electrodes are more compatible with Li2S-P2S5 sulfide solid electrolytes. All-solid state batteries 80SnS·20P2S5/LiCoO2 showed a charge-discharge plateau of about 3.4 V and high reversible capacity of over 400 mAh/g, even after 50 cycles. The
SnX (X = S and O)-based amorphous materials are promising negative electrode materials with high capacity for rechargeable
lithium batteries using not only liquid electrolytes but solid electrolytes. 相似文献
997.
Kent MS Yim H Sasaki DY Satija S Seo YS Majewski J 《Langmuir : the ACS journal of surfaces and colloids》2005,21(15):6815-6824
The structure and orientation of adsorbed myoglobin as directed by metal-histidine complexation at the liquid-film interface was studied as a function of time using neutron and X-ray reflectivity (NR and XR, respectively). In this system, adsorption is due to the interaction between iminodiacetate (IDA)-chelated divalent metal ions Ni(II) and Cu(II) and histidine moieties at the outer surface of the protein. Adsorption was examined under conditions of constant area per lipid molecule at an initial pressure of 40 mN/m. Adsorption occurred over a time period of about 15 h, allowing detailed characterization of the layer structure throughout the process. The layer thickness and the in-plane averaged segment volume fraction were obtained at roughly 40 min intervals by NR. The binding constant of histidine with Cu(II)-IDA is known to be about four times greater than that of histidine with Ni(II)-IDA. The difference in interaction energy led to significant differences in the structure of the adsorbed layer. For Cu(II)-IDA, the thickness of the adsorbed layer at low protein coverage was < or = 20 A and the thickness increased almost linearly with increasing coverage to 42 A. For Ni(II)-IDA, the thickness at low coverage was approximately 38 A and increased gradually with coverage to 47 A. The in-plane averaged segment volume fraction of the adsorbed layer independently confirmed a thinner layer at low coverage for Cu(II)-IDA. These structural differences at the early stages are discussed in terms of either different preferred orientations for isolated chains in the two cases or more extensive conformational changes upon adsorption in the case of Cu(II)-IDA. Subphase dilution experiments provided additional insight, indicating that the adsorbed layer was not in equilibrium with the bulk solution even at low coverages for both IDA-chelated metal ions. We conclude that the weight of the evidence favors the interpretation based on more extensive conformational changes upon adsorption to Cu(II)-IDA. 相似文献
998.
Kenji Takahashi Kiyoharu Tadanaga Atsunori Matsuda Akitoshi Hayashi Masahiro Tatsumisago 《Journal of Sol-Gel Science and Technology》2007,43(1):85-91
Polybenzylsilsesquioxane (BnSiO3/2) particles become a supercooled liquid through a heat treatment above the glass transition temperature (T
g) of the particles. Micropatterns of BnSiO3/2 thick films with high transparency were obtained by the electrophoretic deposition of the BnSiO3/2 particles on indium tin oxide (ITO)-coated substrates with a hydrophobic-hydrophilic-patterned surface and subsequent heating
above T
g of the particles. It was found that the control of electrophoretic deposition conditions, in which the amounts of the particles
deposited on the substrates were changed, led to two types of micropatterning processes of the BnSiO3/2 thick films. In the first process, the particles were selectively deposited on the hydrophilic areas after the electrophoretic
deposition. In the second process, the particles were deposited on the whole area of the ITO-coated substrate with hydrophobic-hydrophilic
patterns after the electrophoretic deposition. Due to the difference in wettability of BnSiO3/2 molten liquids between hydrophobic and hydrophilic surfaces, the molten liquids on the hydrophobic areas, which were obtained
by heating above T
g of the particles, migrated toward the hydrophilic areas. In both the processes, convex-shaped BnSiO3/2 micropatterns with high transparency were fabricated only on the hydrophilic areas after a heat treatment above T
g of the particles. 相似文献
999.
Heterogeneity among multihollow polymer particles prepared by the alkali/cooling method under partial neutralization conditions 总被引:1,自引:0,他引:1
Heterogeneity in the formation of multihollow structure among styrene-methacrylic acid copolymer particles, which were produced by emulsion copolymerization, by the alkali/cooling method under partial neutralization conditions with potassium hydroxide was investigated. There was a threshold acid content to form the multihollow structure. The heterogeneity among the multihollow particles was based on the heterogeneity of acid contents among the original particles. 相似文献
1000.
Masahiro Tsunooka Younsik Cha Makoto Tanaka Fumiya Konishi 《Journal of polymer science. Part A, Polymer chemistry》1984,22(3):739-747
Poly(styrene-co-4-thiocyanatoacetylstyrene) and poly(4-acetylstyrene-co-4-thiocyanatoacetyl-styrene) were prepared and their photochemical reactions were studied in the solid state. It was found that the thiocyanatoacetyl groups were easily rearranged with the corresponding isothiocyanatoacetyl groups by ultraviolet (UV) irradiation and that the resulting isothiocyanatoacetyl groups underwent intramolecular cyclization when treated with triethylamine or ammonia to yield oxazole-2-thione moieties. The irradiated polymer films could be dyed selectively with cationic dyes in an appropriate dye bath because of the formation of anionic species by keto-enol tautomerization of oxazole-2-thione moieties in an alkaline state. 相似文献