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11.
以C2H5NS和In(NO3)3为前驱物,采用简单的液相法成功制备了In2S3纳米多级结构,C2H5NS作为硫源的同时也起到了模板剂的作用.研究结果表明,前驱物浓度对In2S3形貌控制起着重要作用.随着In(NO3)3/C2H5NS摩尔比从1∶1.5增加到1∶6,In2S3纳米花呈现了不同的形貌和尺寸.XRD谱图显示,In2S3纳米花晶体具有立方结构.SEM和TEM照片显示,制备的In2S3纳米结构呈多级花状结构,这种结构由纳米片堆积组装而成.通过第一性原理计算并结合实验结果对C2H5NS影响纳米片生长的机理进行了分析,结果表明C2H5NS在In2S3(001)晶面上的吸附可以有效降低晶面的表面能,起到稳定晶面的作用;纳米花的形成是在C2H5NS影响In2S3的晶面稳定性及其成核速率之间的一个协同效应.In2S3纳米晶的形貌可以通过调整反应溶液中的C2H5NS浓度来调节. 相似文献
12.
Polyimide nanocomposites having low-k and UV shielding properties have been developed using fluorine functionalized graphene oxide and bis(quinoline amine) based polyimide. The polyimide was synthesized using bis(quinoline amine) and pyromellitic dianhydride at appropriate experimental conditions, and its molecular structure was confirmed through various spectral analysis such as FTIR and NMR. The polyimide (PI) composites were prepared using bis(quinoline amine), pyromellitic dianhydride, and separately filled with 1, 5, 10 wt% of fluorinated graphene oxide (FGO) through in situ polymerization. The polymer composites were characterized using thermo gravimetric analysis (TGA), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). In addition, the water contact angle, dielectric behavior, and UV–Vis shielding behavior of FGO/PI composites were evaluated. The value of the water contact angle of the polyimide was increased with increment of FGO in the polyimide matrix. The highest water contact angle of polyimide composites observed 108° was obtained for 15 wt% FGO reinforced polyimide composite. The value of the dielectric constant for neat, 1, 5, and 15 wt% FGO reinforced polyimide composites was obtained as 4.5, 3.7, 2.6, and 2.0, respectively. It is also observed from by UV–Vis spectroscopy analysis that the FGO reinforced polyimide composites have good UV shielding behavior. 相似文献
13.
Ramesh Sundar Amalraj Nagarathinam Selvaraj Ganesh Kumar Veluswamy Rahul Pathirickal Ramanujan Raveendran Muthurajan Malathi Palaniyandi Ganesh Kumar Agrawal Randeep Rakwal Rasappa Viswanathan 《Electrophoresis》2010,31(12):1959-1974
Sugarcane is an important commercial crop cultivated for its stalks and sugar is a prized commodity essential in human nutrition. Proteomics of sugarcane is in its infancy, especially when dealing with the stalk tissues, where there is no study to date. A systematic proteome analysis of stalk tissue yet remains to be investigated in sugarcane, wherein the stalk tissue is well known for its rigidity, fibrous nature, and the presence of oxidative enzymes, phenolic compounds and extreme levels of carbohydrates, thus making the protein extraction complicated. Here, we evaluated five different protein extraction methods in sugarcane stalk tissues. These methods are as follows: direct extraction using lysis buffer (LB), TCA/acetone precipitation followed by solubilization in LB, LB containing thiourea (LBT), and LBT containing tris, and phenol extraction. Both quantitative and qualitative protein analyses were performed for each method. 2‐DE analysis of extracted total proteins revealed distinct differences in protein patterns among the methods, which might be due to their physicochemical limitations. Based on the 2‐D gel protein profiles, TCA/acetone precipitation‐LBT and phenol extraction methods showed good results. The phenol method showed a shift in pI values of proteins on 2‐D gel, which was mostly overcome by the use of 2‐D cleanup kit after protein extraction. Among all the methods tested, 2‐D cleanup‐phenol method was found to be the most suitable for producing high number of good‐quality spots and reproducibility. In total, 30 and 12 protein spots commonly present in LB, LBT and phenol methods, and LBT method were selected and subjected to eLD‐IT‐TOF‐MS/MS and nESI‐LC‐MS/MS analyses, respectively, and a reference map has been established for sugarcane stalk tissue proteome. A total of 36 nonredundant proteins were identified. This is a very first basic study on sugarcane stalk proteome analysis and will promote the unexplored areas of sugarcane proteome research. 相似文献
14.
Gurusamy Rajagopal Shanmugam Selvaraj Karuthamohamed Dhahagani 《Tetrahedron: Asymmetry》2010,21(18):2265-2270
Various ketones have undergone asymmetric trimethylsilylcyanation at room temperature with (CH3)3SiCN (TMSCN) in the presence of a chiral-supported Cu(salen) complex and Ph3PO as the catalyst. Aromatic, aliphatic, and heterocyclic ketones have been converted into the corresponding cyanohydrin trimethylsilyl ethers in 83?96% yields with 52?84% ee. Several factors concerning the reactivity and enantioselectivity have been discussed. A double activation where Cu(salen) plays the role of Lewis acid and Ph3PO acts as a Lewis base is reported. Poly(ethylene glycol) monomethyl ether (MeO-PEG) has been used as a soluble support while JandaJel (JJ) and Merrifield (MF) resins served as insoluble supports. Each polymer is linked to the salen catalyst through a glutarate spacer. The soluble catalysts were recovered by precipitation with a suitable solvent while the insoluble catalysts were simply filtered from the reaction mixture. The JandaJel-attached Cu(salen) catalyst could be used for five cycles with the retention of efficiency and the Merrifield-bound Cu(salen) catalyst was found to loose activity with each use. 相似文献
15.
In this paper an attempt is made to understand the existence of any relationship between the sunspot activity and Tamil Nadu
annual rainfall from the 100 years data (1901–2000). It is found that the linear correlation between sunspot activity and
Tamil Nadu annual rainfall is − 0.21 which is significant at 1% level. When the data is smoothed for eliminating small period
oscillations such as El-nino and quasi -Biennial oscillation it is found that for 10 point smoothed values the linear correlation
coefficient is − 0.75 and that for 20 point smoothed values is −0.86. A regression estimate is made for Tamil Nadu annual
rainfall using sunspot activity by a quadratic regression equation. The excess rainfall period during 1996 to 1998 and deficient
rainfall period during 2000 to 2003 can be explained from the sunspot activity. 相似文献
16.
17.
Cauliflower-like CdS microspheres composed of nanocrystals and their physicochemical properties 总被引:1,自引:0,他引:1
Rengaraj S Venkataraj S Jee SH Kim Y Tai CW Repo E Koistinen A Ferancova A Sillanpää M 《Langmuir : the ACS journal of surfaces and colloids》2011,27(1):352-358
Cauliflower-like cadmium sulfide (CdS) microspheres composed of nanocrystals have been successfully synthesized by a hydrothermal method using poly(ethylene glycol) (PEG) as the template coordination agent and characterized by a variety of methods. Our experiments confirmed that the size of the CdS microspheres could be easily modified by controlling the chain length of PEG. Powder X-ray diffraction and Raman spectroscopy measurements revealed the cubic structure of the CdS microspheres; morphological studies performed by HR-SEM and HR-TEM methods showed the cauliflower-like structure of the synthesized CdS microspheres. Each microsphere was identified to be created by the self-assembly of CdS nanocrystals and is attributed to the oriented aggregation of the CdS nanocrystals around a polymer-Cd(2+) complex spherical framework structure. X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) analysis confirmed the stoichiometries of the CdS microspheres. Diffuse reflectance spectrum (DRS) measurements showed that increasing the PEG chain length increased the band gap value of the CdS microspheres slightly, from 1.99 to 2.06 eV. The cauliflower-like CdS microspheres could be applied to photocatalytic degradation studies. 相似文献
18.
Munirasu S Karunakaran RG Rühe J Dhamodharan R 《Langmuir : the ACS journal of surfaces and colloids》2011,27(21):13284-13292
We demonstrate, for the first time, the synthesis of model poly(benzyl methacrylate) [P(BnMA)] brushes of very high thickness (>300 nm) on silicon wafer. P(BnMA) brush is also synthesized from the surface of silica nanoparticles, from a covalently anchored initiator monolayer, using ambient temperature ATRP. The kinetic studies and block copolymerization from the surface anchored P(BnMA)-Br macroinitiator showed that the polymerization was controlled in nature. AFM, ellipsometry, and water contact angle were used for the characterization of the polymer brush. The grafting density of the P(BnMA) brush, formed by immersion in a dilute monomer solution, was relatively less (~11% less) in comparison to that obtained by immersion in neat monomer under similar conditions. The P(BnMA)-Br macroinitiator brushes were used to synthesize P(BnMA-b-S) diblock copolymer brushes by the ATRP of styrene at 95 °C. The P(BnMA-b-S) brushes showed stimulus response to a selective solvent and various nanopatterns were observed according to the composition of the block copolymer. 相似文献
19.
Selvaraj Mohana Roopan F. Nawaz Khan Jong Sung Jin R. Senthil Kumar 《Research on Chemical Intermediates》2011,37(8):919-927
Montmorillonite K10 efficiently catalyzed a one pot–three component cyclocondensation of isatoic anhydride, NH4OAc and aromatic/heteroaromatic aldehydes under ambient conditions to produce the corresponding 2-substituted-2,3-dihydroquinazolin-4(1H)-ones
in good yields. The 2-(2-chloroquinolin-3-yl)-2,3-dihydroquinazolin-4(1H)-ones 3a–d were screened for their antitumor activity against Ehrlich Ascites Carcinoma tumor cells 相似文献
20.
Folliet N Roiland C Bégu S Aubert A Mineva T Goursot A Selvaraj K Duma L Tielens F Mauri F Laurent G Bonhomme C Gervais C Babonneau F Azaïs T 《Journal of the American Chemical Society》2011,133(42):16815-16827
In the context of nanomedicine, liposils (liposomes and silica) have a strong potential for drug storage and release schemes: such materials combine the intrinsic properties of liposome (encapsulation) and silica (increased rigidity, protective coating, pH degradability). In this work, an original approach combining solid state NMR, molecular dynamics, first principles geometry optimization, and NMR parameters calculation allows the building of a precise representation of the organic/inorganic interface in liposils. {(1)H-(29)Si}(1)H and {(1)H-(31)P}(1)H Double Cross-Polarization (CP) MAS NMR experiments were implemented in order to explore the proton chemical environments around the silica and the phospholipids, respectively. Using VASP (Vienna Ab Initio Simulation Package), DFT calculations including molecular dynamics, and geometry optimization lead to the determination of energetically favorable configurations of a DPPC (dipalmitoylphosphatidylcholine) headgroup adsorbed onto a hydroxylated silica surface that corresponds to a realistic model of an amorphous silica slab. These data combined with first principles NMR parameters calculations by GIPAW (Gauge Included Projected Augmented Wave) show that the phosphate moieties are not directly interacting with silanols. The stabilization of the interface is achieved through the presence of water molecules located in-between the head groups of the phospholipids and the silica surface forming an interfacial H-bonded water layer. A detailed study of the (31)P chemical shift anisotropy (CSA) parameters allows us to interpret the local dynamics of DPPC in liposils. Finally, the VASP/solid state NMR/GIPAW combined approach can be extended to a large variety of organic-inorganic hybrid interfaces. 相似文献