排序方式: 共有64条查询结果,搜索用时 15 毫秒
21.
HERAVI Majid M. POORMOHAMMAD Nargess BEHESHTIHA Yahia Sh. BAGHERNEJAD Bita MALAKOOTI Reihaneh 《中国化学》2009,27(5):968-970
3-Acyl-coumarins were obtained in high yields from ortho-hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of mesoporous molecular sieve MCM-41. 3-Acyl-coumarins were obtained in high yields from ortho-hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of mesoporous molecular sieve MCM-41. 相似文献
22.
Zhihao Guo Shahdi Malakooti Shaya SheikhCamelia Al-Najjar Matthew LehmanBehnam Malakooti 《Applied Mathematical Modelling》2011
In this paper we develop a novel energy aware routing approach for mobile ad hoc network (MANET) problems. The approach is based on using Optimized Link State Routing Protocol. Our Energy Aware OLSR labeled as OLSR_EA measures and predicts per-interval energy consumptions using the well-known Auto-Regressive Integrated Moving Average time series method. We develop a composite energy cost, by considering transmission power consumption and residual energy of each node, and use this composite energy index as the routing metric. Our extensive ns2 simulation experiments show that OLSR_EA substantially prolongs the network lifetime and saves total energy used in MANET. In our experiments we considered different scenarios considering a variety of traffic loads, node mobilities, homogeneous power consumption, and heterogeneous power consumption. Simulation results also confirm that OLSR_EA improves the traffic balance between nodes, and packet delivery ratio in higher node speed. We further develop characteristics of OLSR_EA in power-wise heterogeneous MANET to achieve efficient energy preserving performance. 相似文献
23.
Majid M. Heravi Mansoureh Daraie Farahnaz K. Behbahani Reihaneh Malakooti 《合成通讯》2013,43(8):1180-1186
Aromatic aldehydes were reacted in a one-pot reaction with enolizable ketones, acetonitrile, and acetyl chloride in the presence of Mn(bpdo)2Cl2/MCM-41 under reflux condition or at 80 °C to afford the corresponding β-acetamido ketones in good yields. 相似文献
24.
Supported Palladium Oxide Nanoparticles in SBA‐15 as a Heterogeneous Catalyst for the Aerobic Oxidation of Alcohols 下载免费PDF全文
Palladium nanoparticles were first synthesized through the thermal decomposition method and subsequently immobilized on ordered mesoporous silica material, SBA‐15, to afford PdO/SBA‐15 catalyst. The synthesized catalyst was characterized by X‐ray diffraction, nitrogen adsorption‐desorption measurement, transmission electron microscopy, and inductively coupled plasma atomic emission spectrometry. The catalytic activity was tested for the aerobic oxidation of alcohols. Easy recovery, high yeilds and relatively short reaction times were observed for the mentioned catalyst. 相似文献
25.
Benzoxazoles can be rapidly and efficiently synthesized from acyl chloride with 2-aminophenols in one simple step, which provided a practical and efficient method for high-throughput synthesis of this important class of heterocyclic compounds. 相似文献
26.
We investigate the vehicle routing with demand allocation problem where the decision-maker jointly optimizes the location of delivery sites, the assignment of customers to (preferably convenient) delivery sites, and the routing of vehicles operated from a central depot to serve customers at their designated sites. We propose an effective branch-and-price (B&P) algorithm that is demonstrated to greatly outperform the use of commercial branch-and-bound/cut solvers such as CPLEX. Central to the efficacy of the proposed B&P algorithm is the development of a specialized dynamic programming procedure that extends works on elementary shortest path problems with resource constraints in order to solve the more complex column generation pricing subproblem. Our computational study demonstrates the efficacy of the proposed approach using a set of 60 problem instances. Moreover, the proposed methodology has the merit of providing optimal solutions in run times that are significantly shorter than those reported for decomposition-based heuristics in the literature. 相似文献
27.
Mohammad Bagher Teimouri Reihaneh Bazhrang 《Monatshefte für Chemie / Chemical Monthly》2008,139(8):957-961
An efficient and clean green synthesis of highly substituted linear naphtho[2,3-b]-furan-4,9-dione derivatives, starting from 2-hydroxy-1,4-naphthoquinone, alkyl isocyanides and a variety of aldehydes, is
described. This new method provides the first example of an efficient regioselective synthetic method for the synthesis of
linear naphtho[2,3-b]-furan-4,9-dione ring systems by formation of three bonds. This [3 + 1 + 1] furannulation strategy affords furanonaphthoquinones
in moderate to high yields, using water as a cheap, non-toxic, environmentally friendly solvent, in a one-step reaction, without
the need of complicated work-up procedures.
Correspondence: Mohammad Bagher Teimouri, Petrochemical Department, Iran Polymer and Petrochemical Institute, P.O. Box 14965-115,
Tehran, Iran. 相似文献
28.
Hosseini M Shafei MN Safari V Taiarani Z Kafami Ladani M Sadeghian R 《Natural product research》2012,26(16):1544-1548
The effect of olibanum administered during lactation to methimazole-treated dams on the learning of offspring was evaluated. The animals were treated for 60 days from the first day of lactation period: group 1--tap water, group 2-0.03% methimazole and groups 3 and 4-0.03% methimazole with 0.25% or 0.125% olibanum, respectively. The serum thyroxin level in the offspring of group 2 was significantly lower than that of group 1. However, there was no difference compared to groups 3 and 4. In a Morris water maze, the distance and time latency to reach the platform in offspring of group 2 was significantly higher than groups 1, 3 and 4. In probe trial, the time spent in target quadrant (Q?) by offspring of group 2 was lower than groups 1,?3 and 4. It is suggested that impaired learning and memory in the offspring of hypothyroid rats may be prevented by olibanum. 相似文献
29.
Sound insulation of triple-layered panels consisting of two impervious layers with the middle layer being a Newtonian fluid is studied here both theoretically and experimentally. The progressive impedance model is used to predict the transmission loss (TL) provided by the panel in a normal incidence field. Corrections are then made to obtain the TL values of such panels in random incidence field. A modified B&K impedance tube was constructed for experimental evaluation. Results are presented for a Pyrex glass cylindrical tube containing motor oil, a ferromagnetic nanoparticles fluid (in the absence of a magnetic field) and air. Good agreement is obtained between the measured and analytical results for a wide range of frequencies. Also, a significant difference in TL values, particularly at low frequencies (f ? 4 kHz), is observed once the air is replaced by the fluid layer. 相似文献
30.
Physical–chemical hybrid transiency: A fully transient li‐ion battery based on insoluble active materials 下载免费PDF全文
Yuanfen Chen Reihaneh Jamshidi Kathryn White Simge Çınar Emma Gallegos Nastaran Hashemi Reza Montazami 《Journal of Polymer Science.Polymer Physics》2016,54(20):2021-2027
Transient Li‐ion batteries based on polymeric constituents are presented, exhibiting a twofold increase in the potential and approximately three orders of magnitude faster transiency rate compared to other transient systems reported in the literature. The battery takes advantage of a close variation of the active materials used in conventional Li‐ion batteries and can achieve and maintain a potential of >2.5 V. All materials are deposited form polymer‐based emulsions and the transiency is achieved through a hybrid approach of redispersion of insoluble, and dissolution of soluble components in approximately 30 min. The presented proof of concept has paramount potentials in military and hardware security applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2021–2027 相似文献