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31.
The lowest excited nπ* triplet of 9.10-anthraquinone, 1.4-naphthoquinone and 1,4-benzoquinone were studied in glassy matrices at 77 K using a time-resolved ESR method. The D value of the triplet state of 9,10-anthraquinone varied from ?0.351 cm?1 in a polar solvent to ?0.318 cm?1 in a non-polar solvent. Both 1,4-naphthoquinone and 1,4-benzoquinone in polar solvents showed triplet state spectra with a D value of ?0.330 cm?1. A computer simulation revealed the existence of widely distributed zero-field splitting parameters in the glassy condition. These data are compared with an analysis of CIDEP results of para-quinones. 相似文献
32.
Abdulaziz K. Alsharidi Ashfaq A. Khan John J. Shepherd Andrew J. Stacey 《Mathematical Methods in the Applied Sciences》2020,43(9):5729-5743
We construct the slowly varying limiting state solutions to a nonlinear dynamical system for anaerobic digestion with Monod-based kinetics involving slowly varying model parameters arising from slow environmental variation. The advantage of these approximate solutions over numerical solutions is their applicability to a wide range of parameter values. We use these limiting state solutions to develop analytic approximations to the full nonlinear system by applying a multiscaling technique. The approximate solutions are shown to compare favorably with numerical solutions. 相似文献
33.
Boubakri L. Al-Ayed Abdullah S. Mansour L. Harrath A. A. Al-Tamimi J. Özdemir I. Yasar S. Hamdi N. 《Transition Metal Chemistry》2019,44(4):321-328
Transition Metal Chemistry - The carbonylative Suzuki cross-coupling of 2-bromopyridine with various boronic acids to prepare unsymmetrical arylpyridine ketones has been carried out using... 相似文献
34.
Zhili Peng Shanghao Li Xu Han Abdulrahman O. Al-Youbi Abdulaziz S. Bashammakh Mohammad S. El-Shahawi Roger M. Leblanc 《Analytica chimica acta》2016
Peptides and proteins have become very promising drug candidates in recent decades due to their unique properties. However, the application of these drugs has been limited by their high enzymatic susceptibility, low membrane permeability and poor bioavailability when administered orally. Considerable efforts have been made to design and develop drug delivery systems that could transport peptides and proteins to targeted area. Although it is of great importance to determine the composition after loading a drug to the carrier, the ability to do so is significantly limited by current analytical methods. In this letter, five important proteins, α1-antitrypsin, hemoglobin human, human serum albumin, human transferrin and r-globulin were chemically conjugated to two model drug carriers, namely carbon dots and polymer O-(2-carboxyethyl) polyethylene glycol. A simple yet convenient method based on circular dichroism spectroscopy was developed to determine the compositions of the various protein-carrier conjugates. 相似文献
35.
Adel Ouannas Iqbal M. Batiha Stelios Bekiros Jinping Liu Hadi Jahanshahi Ayman A. Aly Abdulaziz H. Alghtani 《Entropy (Basel, Switzerland)》2021,23(11)
The Selkov system, which is typically employed to model glycolysis phenomena, unveils some rich dynamics and some other complex formations in biochemical reactions. In the present work, the synchronization problem of the glycolysis reaction-diffusion model is handled and examined. In addition, a novel convenient control law is designed in a linear form and, on the other hand, the stability of the associated error system is demonstrated through utilizing a suitable Lyapunov function. To illustrate the applicability of the proposed schemes, several numerical simulations are performed in one- and two-spatial dimensions. 相似文献
36.
Huang Chengdai Cao Jinde Alofi Abdulaziz AI-Mazrooei Abdullah Elaiw Ahmed 《Nonlinear dynamics》2017,87(1):313-336
Nonlinear Dynamics - The issues of the stability and bifurcation for a delayed BAM network involving two neurons in the I-layer and arbitrary neurons in the J-layer are concerned in the present... 相似文献
37.
Heterogeneous Ziegler-Natta catalysts produce polyolefins that have broad distributions of molecular weight (MWD) and chemical composition (CCD). For such broad distributions, mathematical models are useful to quantify the information provided by polyolefin analytical techniques such as high-temperature gel permeation chromatography (GPC), temperature rising elution fractionation (TREF), and crystallization analysis fractionation (CRYSTAF). In this paper, we developed a mathematical model to deconvolute the MWD and CCD of polyolefins simultaneously, using Flory's most probable distribution and the cumulative CCD component of Stockmayer's distribution. We have applied this procedure to “model” polyolefin resins and to one industrial linear low-density polyethylene (LLDPE) resin. The proposed methodology is able to deconvolute theoretical distributions even when random noise is added to the MWDs and CCDs, and it can be used to calculate the minimum number of active site types on heterogeneous Ziegler-Natta catalysts. 相似文献
38.
39.
M.S.H. Chowdhury I. Hashim O. Abdulaziz 《Communications in Nonlinear Science & Numerical Simulation》2009,14(2):371-378
In this paper, the homotopy analysis method (HAM) is compared with the homotopy-perturbation method (HPM) and the Adomian decomposition method (ADM) to determine the temperature distribution of a straight rectangular fin with power-law temperature dependent surface heat flux. Comparisons of the results obtained by the HAM with that obtained by the ADM and HPM suggest that both the HPM and ADM are special case of the HAM. 相似文献
40.