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71.
Mubashir Hassan Balasaheb D. Vanjare Kyou-Yeong Sim Hussain Raza Ki Hwan Lee Saba Shahzadi Andrzej Kloczkowski 《Molecules (Basel, Switzerland)》2022,27(5)
A series of nine novel 1,2,4-triazole based compounds were synthesized through a multistep reaction pathway and their structures were scrutinized by using spectral methods such as FTIR, LC-MS, 1H NMR, and 13C NMR. The synthesized derivatives were screened for inhibitory activity against the mushroom tyrosinase and we found that all the synthesized compounds demonstrated decent inhibitory activity against tyrosinase. However, among the series of compounds, N-(4-fluorophenyl)-2-(5-(2-fluorophenyl)-4-(4-fluorophenyl)-4H-1,2,4-triazol-3-ylthio) acetamide exhibited more prominent activity when accompanied with the standard drug kojic acid. Furthermore, the molecular docking studies identified the interaction profile of all synthesized derivatives at the active site of tyrosinase. Based on these results, N-(4-fluorophenyl)-2-(5-(2-fluorophenyl)-4-(4-fluorophenyl)-4H-1,2,4-triazol-3-ylthio) acetamide could be used as a novel scaffold to design some new drugs against melanogenesis. 相似文献
72.
Olha Dzydzan Iryna Brodyak Paulina Strugaa-Danak Angelika Strach Alicja Z. Kucharska Janina Gabrielska Natalia Sybirna 《Molecules (Basel, Switzerland)》2022,27(7)
Although extracts are broadly used in order to support the treatment of numerous diseases, only in a limited number of cases is the process of applying and establishing their mechanisms of action scientifically analyzed. Fruits of Cornelian cherry are an abundant source of iridoids, anthocyanins, flavonols and phenolic acids. The aim of the present study was to evaluate the in vitro bioactivity of red and yellow Cornelian cherry fruits’ extracts. The biological potential of extracts, in a broad sense, involved antioxidant activity in relation to phosphatidylcholine liposomes, inhibitory ability against α-glucosidase and acetylcholinesterase enzymes, as well as interactions with human serum albumin. Studies showed that both extracts were more effective in protecting liposome membranes against free radicals produced by AAPH in an aqueous environment due to the fact that they can be better eliminated by the hydrophilic components of the extracts than those produced by UVB radiation. Extracts exhibited inhibitory activity against acetylcholinesterase and α-glucosidase, wherein loganic acid extract showed noncompetitive inhibition of the enzyme. Moreover, extracts binded to albumin mainly through hydrogen bonds and van der Waals forces. Taken together, red and yellow cherry fruits’ extracts exhibit diverse biological properties and can be exploited as a source of natural therapeutic agents. 相似文献
73.
In this study we describe the activation with chloroformates of Trisacryl-GF-2000, a new synthetic gel support that is stable,
hydrophilic, and contains large amounts of hydroxyl groups available for activation.
Of all the reagents tested, the activation withN-hydroxysuccinimide-chloroformate andp-nitrophenylchloroformate in organic solvents provides the best activation yield and subsequent coupling. When Trisacryl was
activated in acetone with the chloroformates in the presence of 4-dimethylaminopyridine as base and catalyst, up to 30% of
the hydroxyl groups, (i.e., 1/repeating unit) could be activated. Amino-containing ligands and proteins could be coupled to
these carriers at pH 8 or higher. For better results in affinitychromatographic applications, spacers of ε-amino caproic acid
or diaminohexane were introduced. The efficacy of these columns was demonstrated by purification of enzymes, antibodies, and
antigens. The performance of these new columns were compared with that of Sepharose columns activated in various ways. In
every case, the properties of the Trisacryl support proved superior with particular reference to the purity of the product
obtained. 相似文献
74.
The thermodynamics of the conversion of aqueous glucose to fructose has been investigated using both heat conduction microcalorimetry
and high pressure liquid chromatography (HPLC). The reaction was carried out in both aqueous Tris/HCl buffer and in aqueous
phosphate buffer in the pH range 7–8 using the enzyme glucose isomerase and the cofactors CoCl2 and MgSO4. The temperature range over which this reaction was investigated was 298.15–358.15 K. We have found that the enthalpy of
reaction is independent of pH over the range investigated. A combined analysis of both the HPLC and microcalorimetric data
leads to the following results at 298 15 K:ΔG° = 349 ± 53 J mol-1, ΔH° = 2.78 ± 0.20 kJ mol-1, and ΔC
p
°
= 76 ± 30 J mol-1 K-1. The stated uncertainties are based upon an analysis of both the random and systematic errors inherent in the measurements.
Comparisons are made with literature data. The percent conversion of glucose to fructose has been calculated for the temperature
range 300–373.15 K. 相似文献
75.
本文主要概述了近年来核酸工具酶辅助的基于金属稳定同位素标记的电感耦合等离子体质谱(ICP-MS)检测方法在生物分析中的发展和应用,简要介绍了该方法在蛋白质、核酸及一些生物小分子检测中的应用。最后对核酸工具酶辅助的基于金属稳定同位素标记的电感耦合等离子体质谱(ICP-MS)检测方法的发展前景做了展望。 相似文献
76.
77.
A large amount of inedible plant material, generated as a result of plant growth in a Controlled Ecological Life Support System
(CELSS), should be pretreated and converted into forms that can be recycled on earth as well as in space. The main portion
of the inedible biomass is lignocellulosic material. Enzymatic hydrolysis of this cellulose would provide sugars for many
other uses by recycling carbon, hydrogen, oxygen, and nitrogen through formation of carbon dioxide, heat, and sugars, which
are potential foodstuffs. To obtain monosaccharides from cellulose, the protective effect of lignin should be removed. White-rot
fungi degrade lignin more extensively and rapidly than other microorganisms.Pleurotus ostreatus degrades lignin effectively, and produces edible and flavorful mushrooms that increase the quality and nutritional value
of the diet. This mushroom is also capable of metabolizing hemicellulose, thereby providing a food use of this pentose containing
polysaccharide. This study presents the current knowledge of physiology and biochemistry of primary and secondary metabolisms
of basidiomycetes, and degradation mechanism of lignin. A better understanding of the ligninolytic activity of white-rot fungi
will impact the CELSS Program by providing insights on how edible fungi might be used to recycle the inedible portions of
the crops. 相似文献
78.
The effects of five polyethylene glycol (PEG) compounds of different molecular weight on the thermal stability of penicillin
G acylase (PGA) obtained from a mutant ofEscherichia coli ATCC 11105 have been investigated. The molecular weights of PEG compounds were 400, 4000, 6000, 10,000, and 15,000. The thermal
inactivation mechanisms of both native and PEG-containing PGA were considered to obey first order inactivation kinetics during
prolonged heat treatments. Optimal concentrations of PEGs at molecular weights of 400,4000, 6000,10,000, and 15,000 were found
to be 250,150,150,100, and 50 mM, respectively. The greatest enhancement of thermostability was observed with PEG 4000 and
PEG 6000, as a nearly 20-fold increase above 50°C. PGA showed almost the same temperature activity profile and optimal temperature
values both in the presence and absence of PEG. The addition of PEGs did not cause any change in the optimal temperature value
of PGA, but the parametersV
m
,K
m
, the activation energy, and thek
cat
values of enzyme were markedly decreased because of the mixed inhibition by PEG compounds. The type of inhibition was found
to be hyperbolic uncompetitive. 相似文献
79.
J. Díaz-Ferrero M.C. Rodríguez-Larena L. Comellas B. Jiménez 《Trends in analytical chemistry : TRAC》1997,16(10):1865-573
The usual methods for determining polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB) are generally expensive and time consuming. This fact has favored the development of faster and cheaper techniques, based on immunoassays and bioassays. This paper reviews these bioanalytical methods and their analytical importance at the present moment. 相似文献
80.
Yongcheng Liu Xin Chen Jianghong Qian Haiying Liu Zhengzhong Shao Jiaqi Deng Tongyin Yu 《Applied biochemistry and biotechnology》1997,62(2-3):105-117
The structure and properties of the blend of regenerated silk fibroin (RSF) and poly(vinyl alcohol) (PVA) were investigated.
The two polymers in the blend are in the state of phase segregation. Infrared (IR) spectra indicate that the RSF in the blend
maintains its intrinsic properties, thus, ethanol treatment can transfer silk I structure of RSF to silk II structure. The
water absorption property and mechanical property of the blend are improved in comparison with those of RSF. The blend maintains
the major merit of RSF, that is, it can immobilize glucose oxidase on the basis of the conformational transition from silk
I structure to silk II structure. The properties of the immobilized enzyme are examined. Moreover, the second generation of
glucose sensor based on the immobilized enzyme is fabricated and it has a variety of advantages including easy maintenance
of enzyme, simplicity of construction, fast response time and high stability. 相似文献