全文获取类型
收费全文 | 114篇 |
免费 | 1篇 |
专业分类
化学 | 73篇 |
晶体学 | 7篇 |
力学 | 4篇 |
数学 | 2篇 |
物理学 | 29篇 |
出版年
2023年 | 2篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 11篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1946年 | 1篇 |
排序方式: 共有115条查询结果,搜索用时 312 毫秒
61.
Jeeven S. Solanki U. N. Tripathi Arpan Bhardwaj Vinod K. Jena 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):2169-2178
The synthesis and structure of antimony(III) tripyrazolinates complexes with bidentate N,O, Schiff base pyrazoline ligands are reported. Four new coordination complexes incorporating antimony have been synthesized and characterized by spectroscopic methods (IR, 1 H NMR, 13 C NMR), molecular weight, and elemental analysis. Novel complexes of the type Sb(C 15 H 12 N 2 OX) 3 have been synthesized in dry benzene by the reaction of SbCl3 and the sodium salt of pyrazoline, NaC 15 H 12 N 2 OX, [where X = H (1), CH 3 (2), OCH 3 (3), and Cl (4)] in 1:3 molar ratio. The 3(2′ -hydroxyphenyl)-5-(4-substituted aryl) pyrazoline behaves as a bidentate ligand and coordinates to antimony through oxygen and nitrogen atoms, leading to distorted pentagonal bipyramidal structure. The antimicrobial properties of antimony are greatly enhanced when antimony is combined with this pyrazoline ligand. Compounds were screened against different bacteria (B. licheniformis and K. pneumonia) and fungi (Aspergillus niger and Penicillium notatum), and show potential activities. 相似文献
62.
Surbhi Choudhary Anjana Solanki Sumant Upadhyay Nirupama Singh Vibha R. Satsangi Rohit Shrivastav Sahab Dass 《Journal of Solid State Electrochemistry》2013,17(9):2531-2538
Bilayered thin films of CuO/SrTiO3 with varying thickness of CuO were deposited by sol–gel spin-coating technique on indium tin oxide substrate and used as photoelectrode in the photoelectrochemical cell for water splitting reaction. Maximum photocurrent density of 1.85 mA/cm2 at ?0.9 V/saturated calomel electrode was exhibited by 590-nm-thick CuO/SrTiO3 bilayered photoelectrode, which is approximately eight times higher than that for CuO and 30 times higher than that for SrTiO3. The bilayered system offered increased photocurrent density and enhanced photoconversion efficiency, attributed to improved conductivity, which ameliorate separation of the photo-generated carriers at the CuO/SrTiO3 interface and higher value of flatband potential. Details about synthesis and various characterisations involving X-ray diffraction and scanning electron microscopy have been discussed. An energy band diagram has been proposed to dwell upon the mechanism of charge carrier transfer across the interface. 相似文献
63.
Two new mesogenic homologous series, each containing 1,3,5-trisubstituted pyrazolone derivatives, 4-n-alkoxyphenyl and Schiff base–cinnamate central linkages, have been synthesised to give 4-[(5-hydroxy-3-methyl-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl) methyleneamino] phenyl 3-(4-n-alkoxyphenyl)acrylate [Series-A] and 4-[(5-hydroxy-3-methyl-1-p-tolyl-4,5-dihydro-1H-pyrazol-4-yl)methyleneamino] phenyl 3-(4-n-alkoxyphenyl)acrylate [Series-B] and their Cu(II) complexes have also been synthesised. These compounds were characterised by elemental analysis, Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR), carbon-13 NMR (13C NMR) and ultraviolet (UV)-visible and mass spectral studies. Their mesomorphic behaviour was studied by polarising optical microscope (POM) with a heating stage. POM data were compared with differential scanning calorimetry thermograms. In Series-A and -B, all compounds exhibit mesomorphism. Series-A compounds exhibit an enantiotropic nematic mesophase except propyl derivative, while a smectic A (SmA) mesophase is observed from the heptyl derivative and persists up to the last member of the homologous series. n-Heptyloxy derivative is monotropic for SmA phase. Series-B compounds also exhibit the enantiotropic nematic mesophase, while the SmA mesophase is observed from the heptyl derivative and persists up to the last member of the homologous series. n-Dodecyloxy derivative exhibits monotropic SmA and nematic mesophases. The mesomorphic properties of both series are compared with each other and the other structurally related compounds. The study reveals that cinnamate linkage containing liquid crystals have higher thermal stability compared to structurally related series containing chalcone linkage. In case of complex series, only one compound from each series gives nematic mesophase. 相似文献
64.
Sh. Baluja A. Solanki N. Kachhadia 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(5):742-746
The density, ultrasonic velocity and viscosity of cetrizine, loratidine and chlorpheniramine have been studied in methanol
and dimethyl formamide at 308.15 K. From the experimental data, various acoustical parameters have been evaluated which helps
in understanding the molecular interactions occurring in these solutions.
The text was submitted by the authors in English. 相似文献
65.
R.R. DoshiP.S. Solanki Uma KhacharD.G. Kuberkar P.S.R. KrishnaA. Banerjee P. Chaddah 《Physica B: Condensed Matter》2011,406(21):4031-4034
Effect of A-site disorder in half-doped La0.5Ca0.5MnO3 created by the substitution of Tb at La site is studied through temperature dependent neutron diffraction, resistivity, and magnetization on La0.375Tb0.125Ca0.5MnO3 (LTC) to identify the evolution of phases as a function of temperature and magnetic field. Contrary to the parent system, the paramagnetic (PM) to ferromagnetic (FM) transition is found to be of first order but becomes observable only in fields above 1 T. Absence of this transition in zero and low fields along with the observation of a very intriguing and irreversible M-H curve at low temperature raises the question about the ground state of the system. It is identified from the specially designed measurement protocol that the ground state of the system becomes FM, contrary to the parent LCMO. However, this remains masked because of the hindrance to the transformation kinetics of the PM-FM first order transition in low fields. Significantly, though the thermal hysteresis of the first-order transition decreases with the measurement field, collapse of such a behavior to a critical point is not observed in LTC, unlike earlier observations in some other manganites. 相似文献
66.
Nanoparticle-enhanced sensitivity of a nanogap-interdigitated electrode array impedimetric biosensor 总被引:1,自引:0,他引:1
Singh KV Bhura DK Nandamuri G Whited AM Evans D King J Solanki R 《Langmuir : the ACS journal of surfaces and colloids》2011,27(22):13931-13939
Interdigitated electrode (IDE) arrays with nanometer-scale gaps have been utilized to enhance the sensitivity of affinity-based detection. The geometry of nanogap IDEs was first optimized on the basis of simulations of the electric field and current density. It was determined that the gap (G) between the electrodes was the most important geometric parameter in determining the distribution and strength of the electric field and the current density compared to the width (W) and height (H) of the IDEs. Several devices were materialized and analyzed for their sensitivity to the electrochemical environment using faradic electrochemical impedance spectroscopy (EIS) as the detection technique. Nanogap optimized IDEs were then employed as biosensors for the label-free, affinity-based detection of antitissue transglutaminase antibodies (αtTG-Abs), a biomarker for the detection of autoimmune disorder celiac sprue, triggered by ingesting gluten. The label-free biosensor assay was found to be less sensitive compared to on-chip ELISA. Gold nanoparticles (GNPs) were then employed to improve the sensitivity of the nanogap IDE-based biosensor. With GNPs, the transducer sensitivity increased by 350% over that of label-free detection. The suitability of nanogap IDEs as biosensor transducers for EIS in label-free and GNP-labeled formats was established. The immunobiosensor assay detection sensitivity with the GNPs was found comparable to ELISA. 相似文献
67.
Abstract Single crystals of GeS have been grown by DVT and CVT techniques. The grown crystals have been characterised by XRD. The band gaps Eg have been determined from the optical absorption studies. The results of simultaneous thermoelectric power and resistivity measurements up to 8 GPa on single crystals of GeS grown using different techniques are reported here. The measurements show a decrease in a.c. resistivity with increase in frequency up to 66.6 kHz. This behavior can be attributed to the presence of defects and impurity atoms in the semiconductor, which can contribute to conduction by the hopping process. 相似文献
68.
A. K. Panchal D. K. Rai Meril Mathew C. S. Solanki 《Journal of nanoparticle research》2011,13(6):2469-2473
40 alternate a-Si/SiN
x
multilayer are incorporated as an absorber layer in a p–i–n solar cell. The device is fabricated using hot-wire chemical
vapor deposition (HWCVD) technique. The structure of the multilayer film is examined by high resolution transmission electron
microscopy (HR-TEM) which shows distinct formation of alternate a-Si and SiN
x
layers. The a-Si and SiN
x
layers have thickness of ~3.5 and 4 nm, respectively. The photoluminescence (PL) of multilayer film shows bandgap energy
of ~2.52 eV, is larger than that of the c-Si and a-Si. Dark and illuminated current–voltage (I–V) characterization of the ML films shows that these ML are photosensitive. In the present work, it is seen that the p–i–n
structure with i-layer as ML quantum well (QW) structures show photovoltaic effect with relatively high open-circuit voltage
(V
OC). The increment of bandgap energy in PL and high V
OC of the device is attributed to the quantum confinement effect (QCE). 相似文献
69.
G. K. Solanki D. N. Gujarathi M. P. Deshpande D. Lakshminarayana M. K. Agarwal 《Crystal Research and Technology》2008,43(2):179-185
The transport properties of ternary mixed WSxSe2‐x single crystals have been studied by measuring the thermo power, electrical conductivities and Hall parameters in a small temperature range 303‐423 K. The electrical conductivity was highest for selenium rich WSe2 and lowest for sulphur rich WS2 crystals. All the crystals showed semiconducting behaviour from the temperature dependence of ‘ρ’, ‘RH’ and ‘S’. The Hall coefficients showed that the samples are p‐type conducting. The temperature dependence of resistivity, Hall coefficients, carrier concentration showed that all of them are thermally activated. The values of activation energies, pre‐exponential factors and the scattering parameters have been determined. The dominant scattering mechanism for the charge carriers has been explained. The relation between the TEP and the concentration of charge carriers and electrical conductivity was studied. The effective masses of holes and the effective density of states have been determined. These parameters show an increase with increase in sulphur content. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
70.
Irshad Ahmad Mir Kamla Rawat Pratima R. Solanki H. B. Bohidar 《Journal of nanoparticle research》2017,19(7):260
This report demonstrates a quantum dot (QD)-based selective and fast sensor platform for detection of folic acid (FA). This electrochemical platform provides a good linear relation between the anodic and cathodic peak currents (i pa and i pc ) in the FA concentration range of 12 to 96 nM, and the minimum detection limit (MDL) achieved was 10 nM. As an extension, absorbance and fluorescence methods were also used for the detection of FA in solutions. Core-shell QDs provided better binding than core-only ZnSe quantum dots, and showed twofold increment in binding constant. A detailed comparative evaluation of the three methods (absorbance, fluorescence, and electrochemical) is presented vis-a-vis real samples. Therefore, in principle absorbance and fluorescence spectroscopy can also be used for detecting folic acid with high selectivity and sensitivity. The MDL can be extended to be 4–7 nM level by using fluorescence and absorbance spectroscopy. FA metabolism occurs in the intestine, where the pH conditions are basic. Hence, sensing of FA under physiological conditions is relevant, which was achieved in our case. Earlier methods have reported sensing under acidic or neutral pH conditions. Considering the importance of folic acid in physiology, the significance of the present study can be hardly stressed. 相似文献