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排序方式: 共有199条查询结果,搜索用时 15 毫秒
171.
172.
The remedy for infected chronic wounds such as diabetic foot ulcers is more complicated particularly in the case of patients with an inefficient immune system. Also, fighting against microbial infections in the wound site by available antibiotics may not be effective because of emerging antibiotic resistance properties among pathogenic bacteria and fungi. Recently, applications of micro‐ and nanoformulations of biomaterials have demonstrated improved therapeutic abilities for wound dressings. In this way, carboxymethyl, dialdehyde, and 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐oxidized celluloses are common biomaterials having outstanding physicochemical and therapeutic properties compared to unmodified cellulose. Therefore, in this review, recent progress in the field of wound healing and antimicrobial activities of these derivatives are presented and discussed. 相似文献
173.
Dr. Ali Masoudi Alavi Dr. Almuth Sax Prof. Dr. Dr. h.c. Peter Quirmbach 《ChemistryOpen》2020,9(5):631-636
Aluminum phosphates are known as inorganic hardening agents for the setting of alkali silicate solutions, but only few studies have been published on the setting mechanism of potassium water glass. The solution behavior of two aluminum metaphosphates in alkaline environments were investigated photometrically determining the dissolved aluminum content. The crystalline phase composition of the hardened potassium silicate systems was determined by X-ray diffraction. New insights into the setting mechanism were obtained concerning the structure of the aluminum metaphosphate and the SiO2/K2O ratio of three different potassium silicate solutions. With increasing pH value aluminum tetrametaphosphate reacts rapidly and forms crystalline potassium tetrametaphosphate dihydrate by an ion-exchange-reaction. In parallel, a depolymerization of the cyclic metaphosphate structure occurs leading to potassium dihydrogen phosphate as final fragmentation product. With aluminum hexametaphosphate no ion-exchange reaction product was observed. Only potassium dihydrogen phosphate could be found in higher quantities compared to the reaction with aluminum tetrametaphosphate. 相似文献
174.
Seyed Ghorban Hosseini Mohammad Ali Zarei Seyed Jafar Hosseini Toloti Hamid Kardan Mohammad Amin Alavi 《Journal of Thermal Analysis and Calorimetry》2018,131(2):925-935
In this research, ultrasound irradiation as a simple method was used to produce boron nanostructures. Reaction conditions such as boron concentration and sonication time show important roles in the size, morphology and growth process of the final products. The boron nanostructures (nanoparticles and nanorods) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, small-angle X-ray scattering and inductively coupled plasma atomic emission spectroscopy techniques. Primary evaluation of results showed that nanoparticles and nanorods of boron successfully have been prepared with 25–40 and 50–100 nm average particle size, respectively. These nanostructures (nanoparticles and nanorods) were studied as an additive for promoting the thermal decomposition of ammonium perchlorate (AP) particles. Thermochemical decomposition behaviors of treated samples were characterized by thermal gravimetric analysis and differential scanning calorimetry techniques. Also, the kinetic parameters of thermal decomposition processes of pure and treated samples were obtained by nonisothermal methods proposed by Kissinger and Ozawa. However, boron nanoparticles with the smallest average particle size (25–40 nm) have the most significant catalytic effect including the decrease in decomposition temperature of AP + B nanocomposite by 100 °C, increase in the heat of decomposition from 580 to 1354 J g?1 and decrease in activation energy from 207 to 110 kJ mol?1. 相似文献
175.
Fatemeh S. Alavi Rahim Ghadari Mansour Zahedi 《Journal of the Iranian Chemical Society》2017,14(1):19-35
In this study, the binding properties of a set of neurology drugs to human serum albumin (HSA) were studied by docking and molecular dynamic (MD) methods. Based on the RMSD values for the MD simulation processes, the drug–protein complexes are stable. Site II of the HSA shows the best affinity for the studied drugs. Different kinds of interactions, including hydrogen bonding, π-cation interactions, and π–π interactions, are observable between ligand and protein during the MD simulation process. The MMGBSA calculations were done to evaluate the binding energy of the ligands and protein. The calculated energies are in good agreement with the previously reported experimental results. In some cases, there is a direct relation between the calculated binding energy with the half-life of the drugs, as it was expected. 相似文献
176.
Mehdi Shafiee Ardestani Ali Jabbari Arabzadeh Zahra Heidari Amirreza Hosseinzadeh Hamidreza Ebrahimi Elham Hashemi Mona Mosayebnia Mohammad Shafiee-Alavidjeh Abbas Alavi Mohammad Hossein Babaei Arman Rahmim Seyed Esmaeil Sadat Ebrahimi Massoud Amanlou 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(2):447-455
DTPA is a very strong metal chelator widely utilized in radiopharmaceutical chemistry for conjugation of chemicals which do not have enough potency for direct metalo-labeling and also to manage toxic radioactive materials such as plutonium, americium, and curium. It is difficult to conjugate DTPA to an amine group in a singular direction and such reactions usually also coincidently produce a mixture of DTPA-bis-amides and DTPA-mono-amide resulting in considerable insufficiencies/difficulties in synthesis and especially yield/separation procedures. In this paper, novel methods for the exclusive synthesis of DTPA-mono-amide have been established which extensively reduce the difficulties otherwise encountered and increase the reaction’s yield considering the green chemistry approaches. This is expected to be of interest to radiopharmaceutical researchers interested in the DTPA (Radio)-metallic-conjugate. Overall, this paper provides a framework to achieve a higher degree of propriety from DTPA as a chelator to conjugate to the chemical compounds. 相似文献
177.
Order components of a finite group are introduced in Chen (J. Algebra 15 (1996) 184). We prove that PSL(3,q) can be uniquely determined by its order components where q is an odd prime power. A main consequence of our result is the validity of Thompson's conjecture for the groups under consideration. 相似文献
178.
Michaelides A Liu ZP Zhang CJ Alavi A King DA Hu P 《Journal of the American Chemical Society》2003,125(13):3704-3705
The activation energy to reaction is a key quantity that controls catalytic activity. Having used ab inito calculations to determine an extensive and broad ranging set of activation energies and enthalpy changes for surface-catalyzed reactions, we show that linear relationships exist between dissociation activation energies and enthalpy changes. Known in the literature as empirical Br?nsted-Evans-Polanyi (BEP) relationships, we identify and discuss the physical origin of their presence in heterogeneous catalysis. The key implication is that merely from knowledge of adsorption energies the barriers to catalytic elementary reaction steps can be estimated. 相似文献
179.
Syngas Production by Methane Reforming with Carbon Dioxide on Noble Metal Catalysts 总被引:2,自引:2,他引:2
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M. Rezaei S. M. Alavi S. Sahebdelfar Zi-Feng Yan 《天然气化学杂志》2006,15(4):327-334
A series of noble metal catalysts (Ru, Rh, Ir, Pt, and Pd) supported on alumina-stabilized magnesia (Spinel) were used to produce syngas by methane reforming with carbon dioxide. The synthesized catalysts were characterized using BET, TPR, TPO, TPH, and H2S chemisorption techniques. The activity results showed high activity and stability for the Ru and Rh catalysts. The TPO and TPH analyses indicated that the main reason for lower activity and stability of the Pd catalyst was the formation of the less reactive deposited carbon and sintering of the catalyst. 相似文献
180.