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排序方式: 共有160条查询结果,搜索用时 15 毫秒
71.
Amin Azizi Tushar Khosla Brian S. Mitchell Nasim Alem Noshir S. Pesika 《Particle & Particle Systems Characterization》2014,31(4):474-480
Large‐scale and tunable synthesis of FeCo/graphitic carbon (FeCo/GC) core–shell nanoparticles as a promising material for multipurpose biomedical applications is reported. The high‐quality graphitic structure of the carbon shells is demonstrated through high‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction (XRD), and Raman spectroscopy. A saturation magnetization of 80.2 emu g?1 is reached for the pure FeCo/GC core–shell nanoparticles. A decrease in the saturation magnetization of the samples is observed with an increase in their carbon content with different carbon morphologies evolved in the process. It is also shown how hybrid nanostructures, including mixtures of the FeCo/GC nanoparticles and multi‐walled carbon nanotubes (MWNTs) or carbon nanorods (CNRs), can be obtained only by manipulation of the carbon‐bearing gas flow rate. 相似文献
72.
Nasim Ghasemzadeh Tore W. Wilhelmsen Fred Nyberg Stellan Hjertn 《Electrophoresis》2010,31(16):2722-2729
Although protein biomarkers have a great potential as biomarkers for diagnosis of diseases, they are seldom used in hospitals. There are many reasons for this, for instance, the difficulties to (i) find a biomarker for which the concentration in body fluids clearly differs between patients and healthy subjects, (ii) attain purification of the biomarker close to 100%, which is required for production of conventional protein antibodies as well as artificial gel antibodies for selective capture of a biomarker, (iii) design a standard curve for rapid and accurate determination of the concentration of the biomarker in the body fluid because of adsorption of the biomarker onto vials, pipettes, etc., (iv) determine accurately the sample volume delivered by a pipette, (v) avoid polymerization of the biomarker upon storage and to decide whether it is in the form not only of monomers, but also of dimers, trimers, etc., in the native state, (vi) determine the degree of possible glycosylation and amidation of the biomarker and (vii) decide whether glycosylation and amidation positively or negatively affects the possibility to use the protein as a biomarker. In this article, we discuss in quantitative terms the difficulties (iii–vii) and how to overcome them, which also may help to overcome the difficulty (ii), which in turn minimizes difficulty (i). 相似文献
73.
Mansoureh Mansour Bahmani Alireza Heravi Moussavi Alireza Vakili Mohammad Reza Rezaie Hassan Reza Dehghan Elham Rezvan Nejad 《Journal of Radioanalytical and Nuclear Chemistry》2014,301(3):653-657
Milk is considered as the richest nutrition, being used by people. When drinking milk or water the radon gas will transfer from air to them rapidly. Since milk is majorly composed of water, probably radon existence in livestock consumable water could be the main cause of its presence in milk. Different portion of milk changed by radon gamma ray and consumption of radon included water or milk has its effects on the human body. For investigation the effect of radon in water or milk on human organs, this study has been done in two phases with MCNPX software. In the first phase, the dose rate of absorbed gamma ray by different portion of milk which is indoctrinated by 1 Bq/m3 of radon during a day is calculated. Moreover, the effects shown by milk and its components in radon gamma spectrum, which is demonstrator of milk absorption spectrum, are also surveyed. In the second phase as well, according to the human body phantom, the absorbed gamma dose caused by daily consumption of indoctrinated water or milk with 1 Bq/m3 radon is calculated. The production rate of free radicals in milk and its different components are derived according to escape data of MCNPX code. 相似文献
74.
Masoumeh Heydari Peyman Najafi Moghadam Amir Reza Fareghi Morteza Bahram Nasim Movagharnezhad 《先进技术聚合物》2015,26(3):250-254
Synthesis and characterization of polyaniline‐grafted poly(styrene‐alt‐maleic anhydride) (PANI‐g‐PSMA) was carried out to obtain conductive comb copolymers with highly improved processability. First, polyaniline (PANI) was prepared in nano‐scale by chemical synthesis under ultrasonic irradiation. Then the poly(styrene‐alt‐maleic anhydride) (PSMA) was synthesized by free radical polymerization. Moreover, the PANI was grafted on the PSMA backbone to prepare a comb‐like conductive copolymer for improving its processability as a new method. The products were characterized by Fourier transform infrared, ultraviolet–visible spectroscopy and X‐ray diffraction patterns. Morphology of the samples was also investigated by scanning electron microscopy images. Finally, the solubility and conductivity of the products were studied, and it resulted in high solubility of the products in water and other common organic solvents in comparison to the pure PANI. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
75.
Khosrow Zamani Nasim Hassan Rama Rashid Iqbal 《Journal of heterocyclic chemistry》2000,37(6):1651-1654
The condensation of homophthalic acid (1) with 3‐methoxybenzoyl chloride, followed by demethylation gave 3‐(3‐hydroxyphenyl)isocoumarin (3b). Reaction of (3b) with α‐tetraacetobromo glucose yielded tetraacetylhomalicine (3d), which was deacetylated to homalicine (3e). 相似文献
76.
KF/Al2O3 Mediated Multicomponent Reactions for the Efficient Synthesis of Highly Substituted Dihydropyridines 下载免费PDF全文
Suman Pal Md. Nasim Khan Lokman H. Choudhury 《Journal of heterocyclic chemistry》2014,51(Z1):E156-E162
KF/Al2O3 was found to be an efficient solid supported catalyst for the facile access of highly substituted dihydropyridine derivatives from the multicomponent reaction of aromatic aldehydes, amines, malononitrile, and alkylacetylenedicarboxylates. The notable advantages of this protocol are reusable catalyst, good yields, applicable to a wide range of substrates for the synthesis of pharmacologically interesting dihydropyridine derivatives. 相似文献
77.
Dr. Md. Nasim Khan Prof. Dr. Thomas Wirth 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(24):7059-7068
Triptycenes have been established as unique scaffolds because of their backbone π-structure with a propeller-like shape and saddle-like cavities. They are some of the key organic molecules that have been extensively studied in polymer chemistry, in supramolecular chemistry and in material science. Triptycenes become chiral molecules when substituents are unsymmetrically attached in at least two of their different aromatic rings. This Minireview highlights the chirality of triptycenes from basics to an advanced stage for the development of functional molecules. 相似文献
78.
We present the first report on task specific ionic liquid (TSIL) for direct electrochemical detection of heavy metal oxides including cadmium oxide, copper oxide and lead oxide at room temperature. This TSIL based electrochemical sensor demonstrated a high sensitivity and selectivity towards the online monitoring of these trace metal oxide particulates, along with short detection time, low cost and high accuracy. This novel sensor platform opens new pathways for in-situ monitoring of metal oxide particulates for environmental sensing and decontamination applications. 相似文献
79.
Hayedeh Bagheri Sadeghi Atefeh Tamaddon Hadi Afifinia Nasim Almasian Fatemeh Bozorgvar Somayeh Mollaei 《Electroanalysis》2011,23(10):2472-2478
A new chromium(III) PVC membrane sensor incorporating p‐tertiary‐butyl calix[4]arene as ionophore, potassium tetrakis as additive and dibutyl phthalate (DBP) as plasticizer was constructed. The electrode exhibited an excellent potentiometric response over a wide concentration range of 1.0×10?7–1.0×10?1 M with a Nernstian slope of 20±0.5 mV per decade. The detection limit was 5.0×10?8 M. The electrode showed a better performance over a pH range of 3.0–8.0, and had a short response time of about <15 s.The electrode was successfully applied to potentiometric titration of Cr (III) with EDTA and for direct determination of chromium(III) in waste water. 相似文献
80.
Mina Husseinzadeh Kashan Ali Husseinzadeh Kashan Nasim Nahavandi 《Computational Optimization and Applications》2013,55(2):481-513
Differential evolution (DE) is one of the most powerful stochastic search methods which was introduced originally for continuous optimization. In this sense, it is of low efficiency in dealing with discrete problems. In this paper we try to cover this deficiency through introducing a new version of DE algorithm, particularly designed for binary optimization. It is well-known that in its original form, DE maintains a differential mutation, a crossover and a selection operator for optimizing non-linear continuous functions. Therefore, developing the new binary version of DE algorithm, calls for introducing operators having the major characteristics of the original ones and being respondent to the structure of binary optimization problems. Using a measure of dissimilarity between binary vectors, we propose a differential mutation operator that works in continuous space while its consequence is used in the construction of the complete solution in binary space. This approach essentially enables us to utilize the structural knowledge of the problem through heuristic procedures, during the construction of the new solution. To verify effectiveness of our approach, we choose the uncapacitated facility location problem (UFLP)—one of the most frequently encountered binary optimization problems—and solve benchmark suites collected from OR-Library. Extensive computational experiments are carried out to find out the behavior of our algorithm under various setting of the control parameters and also to measure how well it competes with other state of the art binary optimization algorithms. Beside UFLP, we also investigate the suitably of our approach for optimizing numerical functions. We select a number of well-known functions on which we compare the performance of our approach with different binary optimization algorithms. Results testify that our approach is very efficient and can be regarded as a promising method for solving wide class of binary optimization problems. 相似文献