检索结果-南通市图书馆

Performance evaluation of a WDM/OCDM based hybrid optical switch utilizing efficient resource allocation

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2014年第5期12卷 5-10页

作者： Ahmed Nabih Zaki rashed Abd-Elnaser A. Mohammed Osama M.A. Dardeer Electronics and Electrical Communication Engineering Department Faculty of Electronic EngineeringMenofia University

A hybrid optical switch （HOS） with physical layer of wavelength division multiplexing and optical code division multiplexing （WDM/OCDM） scheme is proposed. An additional feature to the HOS than optical cross connect （OXC） is that the controller can process requests for both circuit establishment and burst scheduling. In our study, the measurement criteria of HOS are the blocking probability, probability of error, and probability of outage. To simplify the analysis, no distinction is made between a circuit in progress and a burst in progress. Moreover, a minimum fit （MinF） resource allocation strategy is applied in order to increase the bandwidth efficiency and control the multiplexing interference of the OCDM. A 2D Markov model for the HOS is presented using the MinF strategy. Numerical results reveal that the code parameters and the resource allocation strategy greatly affect the performance. Certain periority can be achieved by assigning shorter codes to high periority users and longer codes to low periority users. Also, the probability of error and outage are reduced bv aonling the MinF strategy.

关键词： WDM Performance evaluation of a WDM/OCDM based hybrid optical switch utilizing efficient resource allocation

Modeled Influence of East Asian Black Carbon on Inter-Decadal Shifts in East China Summer Rainfall

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2011年第6期4卷 349-355页

作者： rashed MAHMOOD LI Shuang-Lin Nansen-Zhu International Research Centre Institute ofA tmospheric Physics Chinese A cademy of Sciences Beijing 100029 China Graduate University of Chinese Academy of Sciences Beijing 100029 China

Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been *** shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley and prolonged drought in North *** other shift occurred in the early 1990s and featured increased rainfall in South *** role of black carbon(BC) aerosol in the first shift event is controversial,and it has not been documented for the second *** this study,the authors used Geophysical Fluid Dynamics Laboratory's(GFDL's) atmospheric general circulation model known as Atmosphere and Land Model(AM2.1) ,which has been shown to capture East Asian climate variability well,to investigate these issues by conducting sensitive experiments with or without historical BC in East Asia. The results suggest that the model reproduces the first shift well,including intensified rainfall in the Yangtze River and weakened monsoonal ***,the model captures only a fraction of the observed variations for the second shift ***,the role of BC in modulating the two shift events is different,and its impact is relatively less important for the early 1990s event.

关键词：年代际变化黑碳气溶胶夏季降水东亚中国东部力学实验室建模地球物理流体

Robinia pseudoacacia leaves improve soil physical and chemical properties

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2010年第4期2卷 266-271页

作者： Babar KHAN Abdukadir Ablimit rashed MAHMOOD Muhammad QASIM World Wide Fund for Nature Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences COMSATS Institute of Information Technology

The role of the leaves of Robinia pseudoacacia L., which is widely distributed in the arid lands, on improving soil physical and chemical properties was analyzed at various incubation periods. The incubated soils added with 0, 25, 50 and 75 g Robinia pseudoacacia leaves were tested after consecutive incubation intervals of 6, 8 and 10 months and the different soil parameters were measured. The results showed the increases in organic matter (OM), extractable K, cation exchange capacity (CEC), aggregate stability and water holding capacity, but the decreases in pH value and bulk density after 6 months’ incubation. The gradual decrease in change rates of soil properties indicated less microbial population and organic residual mineralization under acidic conditions, which were resulted from fast decomposition of leaves after the first 6 months incubation. The increases in soil organic matter content, extractable K, CEC, aggregate stability and water holding capacity and the decreases in soil pH and bulk density provide favorable conditions for crop’s growth.

关键词： soil physical and chemical properties Robinia pseudoacacia Gilgit-Baltistan

Impact of European Black Carbon on East Asian Summer Climate

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2013年第5期6卷 375-380页

作者： WAN Jiang-Hua rashed MAHMOOD LI Shuanglin Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Meteorology Commission on Science and Technology for Sustainable Development in the South Institute of Infor mation Technology

The remote response of the East Asian summer monsoon(EASM)to European black carbon(EUBC)aerosols was studied by using an ensemble of sensitivity experiments with the Geophysical Fluid Dynamics Laboratory(GFDL)atmospheric general circulation model(AGCM)Atmospheric Model version 2.1(AM2.1).The results show that EUBC causes an enhanced *** resulted enhanced southwesterly brings more moisture supply from the Bay of Bengal,which causes an increase in precipitation over the Yangtze River valley,northeastern China,the eastern part of the Yellow River valley,and the Tibetan *** examination suggests that EUBC induces enhanced tropospheric heating over most of the Eurasian Continent through a propagating wave train and horizontal air temperature *** phenomenon results in intensified thermal contrast between land and ocean,which accounts for the enhanced ***,reductions in EUBC emission in 1992 may have contributed to decadal weakening of the EASM in the early 1990s.

关键词：东亚夏季风夏季气候黑碳欧洲大气环流模式地球物理流体水分供应力学实验室

Tuning the metal filling fraction in metal-insulator-metal ultra-broadband perfect absorbers to maximize the absorption bandwidth

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2018年第3期6卷 168-176页

作者： AMIR GHOBADI HODJAT HAJIAN ALIREZA RAHIMI rashed BAYRAM BUTUN EKMEL OZBAY NANOTAM-Nanotechnology Research Center Bilkent University Department of Electrical and Electronics Engineering Bilkent University Department of Physics Bilkent University UNAM-Institute of Materials Science and Nanotechnology Bilkent University

In this paper, we propose a methodology to maximize the absorption bandwidth of a metal-insulator-metal(MIM) based absorber. The proposed structure is made of a Cr-Al_2O_3-Cr multilayer design. At the initial step,the optimum MIM planar design is fabricated and optically characterized. The results show absorption above 0.9 from 400 nm to 850 nm. Afterward, the transfer matrix method is used to find the optimal condition for the perfect light absorption in an ultra-broadband frequency range. This modeling approach predicts that changing the filling fraction of the top Cr layer can extend light absorption toward longer wavelengths. We experimentally proved that the use of proper top Cr thickness and annealing temperature leads to a nearly perfect light absorption from 400 nm to 1150 nm, which is much broader than that of a planar design. Therefore, while keeping the overall process lithography-free, the absorption functionality of the design can be significantly improved. The results presented here can serve as a beacon for future performance-enhanced multilayer designs where a simple fabrication step can boost the overall device response without changing its overall thickness and fabrication simplicity.

关键词： Tuning the metal filling fraction perfect absorbers maximize the absorption bandwidth MIM

Review on Partial Discharge Detection Techniques Related to High Voltage Power Equipment Using Different Sensors

在线全文

学校读者我要写书评

暂无评论

Photonic Sensors 2014年第4期4卷 325-337页

作者： MM YAACOB MA ALSAEDI JR rashed AM DAKHIL SF ATYAH Institute of High Voltage and High Current Faculty of Electrical Engineering Universiti Teknologi Malaysia Department of Electrical Engineering College of Engineering Misan University Iraq

当在高电压操作一台设备或一个功率系统时，与部分分泌物(PD ) 联系的问题能被追踪到象臭氧和氧化氩氮气体的形成那样的电磁的排放，声学的排放或化学反应。高电压设备和高电压安装主人与对在象力量变压器，煤气的绝缘的变电所(GIS ) ... 详细信息

当在高电压操作一台设备或一个功率系统时，与部分分泌物(PD ) 联系的问题能被追踪到象臭氧和氧化氩氮气体的形成那样的电磁的排放，声学的排放或化学反应。高电压设备和高电压安装主人与对在象力量变压器，煤气的绝缘的变电所(GIS ) ，和电报安装那样的设备监视 PD 的过程的条件的需要达成协议。这份报纸考察象电的察觉，化学察觉，声学的察觉，和光察觉那样的可得到的 PD 察觉方法(包含的高电压设备) 。每个方法的优点和劣势被探索了并且比较。评论建议光察觉技术为应用在精确性和适用性的考虑提供许多优点什么时候与另外的技术相比。

关键词：检测技术设备使用局部放电电力系统气体绝缘变电站传感器高电压设备高压

Certification of a Multicomponent Reference Material from Natural Gas Mixture by Gravimetry and Dual GC-FID/TCD System

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green and Sustainable Chemistry 2023年第4期13卷 269-290页

作者： Adel Bassuoni Shehata Abdulrahman rashed AlAskar Najjy Hamad AlYami Abdullah Suleiman AlOwaysi Chemistry Department National Measurement and Calibration Center (NMCC) Saudi Standards Metrology and Quality Organization (SASO) Riyadh Kingdom of Saudi Arabia

Natural gas (NG) is one of the most important sources of energy for industrial and domestic consumption in the present era because it is cheap and free from sulfur impurities. Therefore, accurate and precise measurement of its composition is of fundamental importance for trade reasons. To improve the quality of NG gas measurements, certified reference materials (CRMs) should be used for calibration of measuring equipment in order to ensure the traceability of the measurement results to the SI units. For the traceability purpose, a multicomponent natural gas mixture was prepared gravimetrically as a reference material according to ISO 6142 from pure helium, hydrogen, n-pentane, i-pentane, n-butane, i-butane, propane, ethane, hexane, methane and nitrogen. The preparation was done in two dilution steps in 5 L aluminum cylinders. The calculated mole fractions and associated uncertainties of natural gas components were verified by a dual GC-FID/TCD system in accordance with ISO 6143 calibrated by a series of primary gas mixtures (CRMs) produced by an NMI. The results obtained by gravimetry and by GC measurements have been checked for compatibility as required by ISO 6142 and were found in very good agreement. Details of the preparation and calculation of the mole fractions and uncertainties of all gas components are explained in this article.

关键词： Pure Gases Gravimetry Reference Material Stability GC Verification Uncertainty

Polyurethane coated with polyvinylpyrrolidones via triazole links for enhanced surface fouling resistance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biosurface and Biotribology 2021年第4期7卷 219-227页

作者： Xin Wen rashed Almousa Sungsoo Na Gregory GAnderson Dong Xie Department of Biomedical Engineering Purdue School of Engineering and TechnologyIndianapolisIndianaUSA Department of Medical Equipment Technology College of Applied Medical ScienceMajmaah UniversityRiyadhSaudi Arabia Department of Biology Purdue School of ScienceIUPUIIndianapolisIndianaUSA

Surfaces with hydrophilic and antimicrobial properties are very attractive for cardio-vascular device-associated *** aim of this study was to prepare and coat a hydrophilic polymer containing a functional group capable of forming triazole functionality onto the surface of polyurethane(PU).The modified surfaces were assessed with cell adhesion,bacterial adhesion and bacterial *** fibroblast cells(NIH-3T3)and three bacterial species were used for *** results showed that the modified surface not only exhibited a significant reduction in cell adhesion with a 25%-59%decrease to mouse fibroblast but also showed a sig-nificant reduction in bacterial attachment with 26%-67%,24%-61%and 23%-57%decrease to Staphylococcus aureus,Escherichia coli and Pseudomonas aeruginosa,respectively,as compared with original ***,the polymer-modified surface exhibited a significant antibacterial function by inhibiting bacterial growth with reduction of 49%-84%,44%-79%and 53%-79%to ***,*** and ***-ginosa,respectively,as compared with original *** results indicate that covalent polymer attachment enhanced the antibacterial and antifouling properties of the PU surface.

关键词： bacterial adhesion and inhibition cell adhesion polymer coating polyurethane

Coal rib response during bench mining: A case study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2018年第1期28卷 107-113页

作者： Morgan M.Sears John Rusnak Mark Van Dyke Gamal rashed Khaled Mohamed Michael Sloan Ground Control Branch NIOSH Pittsburgh Mining Research Division

In 2016, room-and-pillar mining provided nearly 40% of underground coal production in the United *** the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in *** coal *** of these 12 fatalities(75%) have occurred in room-andpillar *** objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 *** paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated numerical model of the observed rib response, and application of this calibrated model to a second site.

关键词： Deep cover Bench mining Thick seam Retreat mining Rib response Rib support