检索结果-南通市图书馆

Generation of Q-Switched Mode-Locked Erbium-Doped Fiber Laser Operating in Dark Regime

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2016年第3期33卷 32-35页

作者： Zian Cheak Tiu Arman Zarei Harith Ahmad Sulaiman Wadi harun Photonics Research Center University of Malaya Department of Electrical Engineering Faculty of EngineeringUniversity of Malaya

We demonstrate a stable Q-switched mode-locked erbium-doped fiber laser （EDFL） operating in dark regime based on the nonlinear polarization rotation technique. The EDFL produces a pulse train where the Q-switching envelope is formed by multiple dark pulses. The repetition rate of the Q-switched envelope can be increased from 0.96kHz to 3.26kHz, whereas the pulse width reduces from 211 #s to 86#s. The highest pulse of 479nJ is obtained at the pump power of 55 mW. It is also observed that the dark pulses inside the Q-switching envelope consist of two parts： square and trailing dark pulses. The shortest pulse width of the dark square pulse is obtained at 40.5μs when the pump power is fixed at 145mW. The repetition rate of trailing dark pulses can be increased from 27.62kHz to 50kHz as the pump power increases from 55mW to 145mW.

关键词： of on is as Generation of Q-Switched Mode-Locked Erbium-Doped Fiber Laser Operating in Dark Regime in

Some Electromagnetic Transition Properties of Odd-A Europium Isotopes

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2010年第4期53卷 711-715页

作者： harun Resit YAZAR Ihsan ULUER Volkan NALOGLU Sinan YAsAR Nevsehir University Faculty of Art & Science Kirikkale University Faculty of Art & Science

In this work, we analyze the positive parity of states of odd-A Eu isotopes within the framework of interacting boson fermion model （IBFM-1）. The result of an IBFM-1 multilevel calculation with the 3s1/2, 2d3/2, 2d5/2, and 1g7/2 single panicle orbits is reported for the positive parity states of the odd-A Eu isotopes. A/so, an IBM-1 calculation is presented for the low-lying states in the even-even 152-154Sm core nucleus. The energy levels and B（E2） transition probabilities are calculated and compared with the experimental data. It is found that the calculated positive parity low spin state energy spectra of the odd-A Eu isotopes agree quite well with the experimental data.

关键词： interacting boson model interacting boson fermion model low spin states

温度、炭纤维和硅土粉对轻量混凝土力学性能的影响

在线全文

学校读者我要写书评

暂无评论

新型炭材料 2008年第4期23卷 339-344页

作者： harun TANYILDIZI Department of Construction Education Firat University Elazig TURKEY

研究了温度、炭纤维和硅土粉含量对轻量混凝土力学性能的影响。制备了含硅土粉(质量分数0%和10%)及炭纤维(质量分数0%,0.5%,1%,和2%)的混合物,测定了高温(400℃,600℃和800℃)暴烤后轻量混凝土的压缩强度和弯曲强度。采用三个控制因素(... 详细信息

研究了温度、炭纤维和硅土粉含量对轻量混凝土力学性能的影响。制备了含硅土粉(质量分数0%和10%)及炭纤维(质量分数0%,0.5%,1%,和2%)的混合物,测定了高温(400℃,600℃和800℃)暴烤后轻量混凝土的压缩强度和弯曲强度。采用三个控制因素(硅土粉含量、炭纤维含量及处理温度),应用Taguchi法确定最佳条件并减少实验次数,采用方差(Anova)法确定主要实验参数与轻量混凝土力学性能的基准。结果表明:轻量混凝土力学性能最实效的参数是加热程度,而抗拉强度与抗弯强度的最佳参数各不相同。

关键词：轻量混凝土炭纤维力学性能变异(Anova)分析 Taguchi法

Enhancement of Gain in L-Band Bismuth-Based Erbium-Doped Fibre Amplifier Using an Un-pumped EDF and Midway Isolator

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2004年第12期21卷 2452-2453页

作者： W.Y.Chong S.W.harun H.Ahmad PhotonicsLaboratory DepartmentofPhysicsUniversityofMalaya50603KualaLumpur FacultyofEngineering MultimediaUniversityJalanMultimedia63100CyberjayaSelangorMalaysia

A hybrid L-band erbium-doped fibre amplifier (EDFA) with enhanced gain characteristic is demonstrated without a significant noise figure penalty. It uses a backward C-band amplified stimulated emission from both the ends of a bismuth-based EDFA system to pump an unpumped erbium-doped fibre (EDF) for gain enhancing. The maximum gain enhancement of 4.0dB is obtained at wavelength 1604nm with EDF length of 20m. The gain spectrum is reasonably flat in this amplifier compared with the amplifier without an EDF. The gain varies from 27.4dB to 30.2dB at wavelength region 1564--1608nm with incorporation of 20m EDF. Noise figure also varies from 6.0 to 7.7dB at this wavelength region.

关键词： Condensed matter: electrical magnetic and optical Optics quantum optics and lasers

Do phytotoxic allelochemicals remain in ashes after burning Chrysanthemoides monilifera subsp. monilifera(boneseed)?

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

Journal of Environmental Sciences 2016年第6期28卷 109-119页

作者： Md.Abdullah Yousuf Al harun Joshua Johnson Randall W.Robinson Institute for Sustainability and Innovation College of Engineering and ScienceVictoria University

Australia is facing challenges in controlling Chrysanthemoides monilifera subsp. monilifera（boneseed）. However, burning has achieved some success in this regard. We aimed to investigate the comparative phytotoxicity of boneseed dried powder and ashes（burnt at 450℃ and250℃）. Phenolic compounds in powder and ashes were measured using Folin–Ciocalteu assay and HPLC. The phytotoxicity of boneseed powder and ash extracts was assessed through germination bioassay on Lactuca sativa and the phytotoxicity of litter and ashes was evaluated using field soil, both in growth chamber. Burning of boneseed reduced total phenolics in ashes of boneseed organs by 99% and 100% both at high and low temperatures. The four phenolic compounds that were detected in boneseed were either absent or at negligible levels in the ashes,with inversely related to temperature. Both boneseed ash extracts and litter ash-mediated soil significantly reduced phytotoxicity displaying increased germination, biometric and biochemical parameters of test species compared with unburnt powder extracts and litter powder-mediated soil respectively, with greater reduction of phytotoxicity found for ashes produced at the lower temperature. Interestingly, the ash extracts and litter ash-mediated soil were found to stimulate some of those parameters of the test species compared to control. There was no excessive reactive oxygen species（ROS） produced in test species exposed to ash extracts compared with unburnt powder extracts. These findings suggest that burning of boneseed is an appropriate method of weed control and that this approach will reduce phytotoxicity of this species on native plants.

关键词： Boneseed Burning Phenolic compounds HPLC Phytotoxicity ROS

Saturation states of carbonate minerals in a freshwater-seawater mixing zone of small tropical island’s aquifer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of Geochemistry 2010年第3期29卷 278-286页

作者： Ahmad Zaharin Aris Sarva Mangala Praveena Mohd harun Abdullah Department of Environmental Sciences Faculty of Environmental StudiesUniversiti Putra Malaysia Environmental Science Programme School of Science and TechnologyUniversiti Malaysia Sabah

Groundwater is a crucial resource on the Manukan Island as it is the only source of freshwater available on the island. The aquifer has deteriorated to a high degree, during the last decade. Nine domestic wells were sampled from March 2006 to January 2007 to probe the hydrochemical components that influence the water quality. Geochemical data on dissolved major constituents in groundwater samples from the Manukan Island revealed the main processes responsible for their geochemical evolution. The results using statistical analyses, graphical method and numerical model output (PHREEQC) showed that the groundwater was chemically highly enriched in Na and Cl, indicative of seawater intrusion into the aquifer as also supported from the Na-Cl signature on the Piper diagram. From the PHREEQC simulation model, calcite, dolomite and aragonite solubility showed positive values of the saturation indices (SI), indicating supersaturation which led to mineral precipitation condition of water by these minerals.

关键词：海水入侵含水层碳酸盐矿物淡水饱和态混合区水化学成分水地球化学

Mode-Locked Erbium-Doped Fiber Laser Using Vanadium Oxide as Saturable Absorber

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第4期35卷 46-48页

作者： A.Nady M.F.Baharom A.A.Latiff S.W.harun Physics Department Faculty of Science Beni Suef University Photonics Engineering Laboratory Department of Electrical Engineering University of Malaya Center for Telecommunication Research & Innovation Universiti Teknikal Malaysia Melaka

A mode-locked erbium doped fiber laser（EDFL） is demonstrated using the vanadium oxide（V2O5） material as a saturable absorber（SA）. The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber ferule in the laser cavity. It shows 7% modulation depth with 71 MW/cm2 saturation intensity. By incorporating the SA inside the EDFL cavity with managed intra-cavity dispersion, ultrashort soliton pulses are successfully generated with a full width at half maximum of 3.14 ps. The laser operated at central wavelength of 1559.25 nm and repetition frequency of 1 MHz.

关键词： EDF SA Mode-Locked Erbium-Doped Fiber Laser Using Vanadium Oxide as Saturable Absorber

Elemental Assessments in Paddy Soil for Geographical Traceability of Rice from Peninsular Malaysia

在线全文

学校读者我要写书评

暂无评论

Rice science 2023年第5期30卷 486-498页

作者： Nazaratul Ashifa Abdullah SALIM Norlida Mat DAUD Julieta GRIBOFF Abdul Rahim harun Department of Food Sciences Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia43600 BangiSelangorMalaysia Malaysian Nuclear Agency 43000 KajangSelangorMalaysia Innovation Centre for Confectionery Technology Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia43600 BangiSelangorMalaysia National Council for Scientific and Technical Research/Centre for Research in Clinical Biochemistry Immunology/Clinical Biochemistry Department Faculty of Chemical ScienceNational University of Córdoba/Ciudad UniversitariaMedina Allende esq.Haya de la Torre s/n5000 CórdobaArgentina

This investigation aimed to establish the geographical traceability of Malaysian rice by assessing the elemental composition in paddy ***-element determination in combination with a chemometric approach was applied to evaluate the elemental concentrations of paddy soil from granaries cultivated with the same rice variety and to assess the relationship between elements in the soil and rice(SAR) system.A total of 29 elements(aluminum,arsenic,barium,bromine,calcium,chlorine,cobalt,chromium,cesium,europium,iron,gallium,hafnium,potassium,lanthanum,lutetium,magnesium,manganese,sodium,rubidium,antimony,scandium,samarium,thorium,titanium,uranium,vanadium,ytterbium and zinc) were successfully determined in paddy soil from Kedah,Selangor and Langkawi by neutron activation analysis.A significant difference(P < 0.05) between 18 elements in the soil samples was *** chemometric approaches of principal component and linear discriminant analyses demonstrated clear discrimination and highly corrected classification(100%) of the soil samples.A high classification(98.1%) was also achieved by assessing 10 elements(aluminum,arsenic,bromine,chlorine,potassium,magnesium,manganese,sodium,rubidium and zinc),which similarly applied to rice geographical origin *** elements in SAR were also observed for differences in the pattern of correlation and bioaccumulation factor between the ***,the generalized Procrustes analysis showed a 98% consensus between SAR and clear differences between the studied *** canonical correlation analysis demonstrated a significant correlation between the chemical profile of SAR(r~2 = 0.88,P < 0.001).Therefore,the current work model provides a reliable assessment to establish rice provenance.

关键词： soil rice multi-element correlation geographical origin

Sequential generation of self-starting diverse operations in all-fiber laser based on thulium-doped fiber saturable absorber

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第6期31卷 87-90页

作者： Pei Zhang Kaharudin Dimyati Bilal Nizamani Mustafa M.Najm S.W.harun School of Electrical and Information Engineering Huaihua UniversityHuaihua 418008China Key Laboratory of Intelligent Control Technology for Wuling-Mountain Ecological Agriculture in Hunan Province Huaihua UniversityHuaihua 418008China Department of Electrical Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Faculty of Advanced Technology and Multidiscipline Airlangga UniversitySurabaya 60115Indonesia Institute of Computer Science and Digital Innovation UCSI UniversityKuala LumpurMalaysia

Self-starting Q-switching,Q-switched mode-locking and mode-locking operation modes are achieved sequentially in an all-fiber erbium-doped fiber laser with thulium-doped fiber saturable absorber for the first *** central wavelengths of Q-switching,Q-switched mode-locking and mode-locking operation modes are 1569.7 nm,1570.9 nm,and 1572 nm,*** mode-locking operation of the proposed fiber laser generates stable dark soliton with a repetition rate of 0.99 MHz and signal-to-noise ratio of 65 *** results validate the capability of generating soliton pulse by doped fiber saturable ***,the proposed fiber laser is beneficial to the applications of optical communication and signal processing system.

关键词： all-fiber laser Q-switched mode-locking dark soliton fiber saturable absorber