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Experimental evaluation of a“u”type earth-to-air heat exch.nger planned for narrow installation space in warm climatic conditions

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Energy and Built Environment 2024年第5期5卷 772-786页

作者： Ricardo Molina-Rodea Jorge Alejandro Wong-Loya Hugo Pocasangre-ch.vez Jennifer Reyna-Guillén Institute of Renewable Energies National Autonomous University of MexicoTemixcoMorelosMexico

The thermal performance of a“u”type earth-to-air heat exch.nger is presented in this experimental *** device has a serial-connected vertical *** wells where tubes were installed have a depth of fewer than 3 m and are separated every 1.5 m,using an installation area of *** experimentation was carried out in March.in Morelos,Mexico when the environmental temperature reach.s 35℃ during the *** performance of the device was measured and compared to the requirements of an office for cooling purposes within a university campus to reproduce the space restrictions found in urbanized *** using a small land surface,it is feasible for urbanized *** air temperature inside the“u”type earth-to-air heat exch.nger,the surrounding soil temperature,the airspeed,and the power consumed by the fan were *** air temperature and the fan’s power consumption data were obtained by modify.ng the airspeed in four constant values,from 1.3 m/s to 6.6 m/*** show that the device evaluated in this work has adequate thermal performance for cooling purposes compared to the requirements of an office.A decrease in air temperature was recorded in a range of 5.1℃ to 9.4℃.Over 70%of the total temperature difference was reach.d in the first well,where the average soil thermal disturbance at 5 cm was 2.8℃.The device ach.eved a maximum COP of 12.8 and a maximum effectiveness of 88.4%.With these results,it is concluded that the system is suitable for cooling purposes in areas with space *** work is novel since the dimensions available for installation in urbanized areas are considered and compared with the thermal requirements of an *** addition to the fact that there are no published works with vertical heat exch.ngers connected in series.

关键词： Low temperature geothermal energy Thermal performance Vertical heat exch.ngers Space restrictions in urbanized areas Geothermal direct uses

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Effect of drainage on CO_2, ch.4, and n_2O fluxes from aquaculture ponds during winter in a subtropical estuary of ch.na

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Journal of Environmental Sciences 2018年第3期30卷 72-82页

作者： Ping y.ng Derrick y.F Lai Jia F.Huang ch.an Tong Sch.ol of Geographical Sciences Fujian Normal University Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education of ch.na Fujian Normal University Department of Geography and Resource Management and Centre for Environmental Policy and Resource ManagementThe Chinese University of Hong Kong

Aquaculture ponds are dominant features of the landscape in the coastal zone of ***,aquaculture ponds are drained during the non-culture period in ***,the effects of such.drainage on the production and flux of greenhouse gases（GHGs）from aquaculture ponds are largely *** the present study,field-based research.was performed to compare the GHG fluxes between one drained pond（DP,with a water depth of 0.05 m）and one undrained pond（uDP,with a water depth of 1.16 m）during one winter in the Min River estuary of southeast *** the entire study period,the mean CO2flux in the DP was（0.75±0.12）mmol/（m^2·hr）,which.was significantly higher than that in the uDP of（-0.49±0.09）mmol/（m^2·hr）（p0.01）.This indicates that drainage drastically transforms aquaculture ponds from a net sink to a net source of CO2in *** ch.and n2O emissions were significantly higher in the DP compared to those in the uDP（ch.=（0.66±0.31）vs.（0.07±0.06）mmol/（m^2·hr）and n2O=（19.54±2.08）vs.（0.01±0.04）μmol/（m^2·hr））（p〈0.01）,suggesting that drainage would also significantly enhance ch.and n2O *** in environmental variables（including sediment temperature,p H,salinity,redox status,and water depth）contributed significantly to the enhanced GHG emissions following pond ***,analysis of the sustained-flux global warming and cooling potentials indicated that the combined global warming potentials of the GHG fluxes were significantly higher in the DP than in the uDP（p〈0.01）,with values of739.18 and 26.46 mg CO2-eq/（m^2·hr）,*** findings suggested that drainage of aquaculture ponds can increase the emissions of potent GHGs from the coastal zone of ch.na to the atmosphere during winter,further aggravating the problem of global warming.

关键词： Aquaculture pond Drainage management Greenhouse gas flux Global warming Min River estuary

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Spectroscopic investigations and luminescence spectra of Sm3+ doped soda lime silicate glasses

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Journal of Rare Earths 2009年第5期27卷 773-780页

作者： y.K. Sharma S.S.L. Surana R.K. Singh Department of Physics Govt. Post Graduate College Rudrapur 263153 (U S Nagar) India Department of Physics J. N. V. University Jodhpur-342001 India Department of Physics Govt. Post Graduate College Rudrapur 263153 (U S Nagar) India

Sm3+ doped soda lime silicate glasses co-doped with As2O3 were prepared and ch.racterised by measuring their absorption spectra in uV-VIS/nIR regions and luminescence spectra in the visible region. Judd-Ofelt intensity parameters, Ωλ, were evaluated from the measured intensities of the various absorption bands. Ωλ parameters of these glasses were compared with the Ωλ parameters of other reported Sm3+ glasses to study the bonding environment surrounding the Sm3+ in the present glasses. Presence of [AsO4]3– tetrahedra in the second coordination sphere around the central Sm3+ ion made these glasses less covalent as compared to other oxide glasses but the ratio Ω4/Ω6 of the 1.83 indicated them to be fairly stable. With the help of Ωλ parameters and luminescence data for various emission lines, radiative properties for different emission lines were calculated. The values of radiative properties indicated that 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions responsible for orange luminescence might be used in the development of materials for LED's and other optical devices in the visible region.

关键词： rare earth glasses Judd-Ofelt theory absorption spectroscopy luminescence

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关中旱地绿肥发展前途的初步探讨

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土壤学报 1963年第4期 395-404页

作者：张学上陕西省土壤肥料研究所

我国绿肥多分布于高温多湿的长江流域,陕西绿肥亦多集中于秦岭以南。半干旱的关中地区是否有发展绿肥的可能性?在农业工作者中认识极不一致,有进一步研究的必要。关中年降雨量在500—700毫米之间,夏闲期(6—9月)正值高温多雨季节,对绿... 详细信息

我国绿肥多分布于高温多湿的长江流域,陕西绿肥亦多集中于秦岭以南。半干旱的关中地区是否有发展绿肥的可能性?在农业工作者中认识极不一致,有进一步研究的必要。关中年降雨量在500—700毫米之间,夏闲期(6—9月)正值高温多雨季节,对绿肥的生长、翻压和分解十分有利。但由于降雨量在地区上的分布不均,且年雨量变化大,特别是春旱较严重,对旱地绿肥播种、生长、翻压却又带来了一定的风险。从关中豆科绿肥的种类来衡量,夏播绿肥,如绿豆、黑豆、小豆等,和夏末秋初播种的毛苕,其播种、生长及翻压期均在雨季或雨季后的湿润气候条件下,栽培成功的可能性最大。草木樨系春季套播于麦田,与主要作物还有着较复杂的关系,且生长期长,经春、夏、秋三个季节,而春旱是播种、出苗和保苗的主要威胁。解决草木樨出苗和保苗的主要措施是,冬季播种或早春解冻初期播下,借助于解冻水分把苗出好。早春不但土壤湿度高,且小麦荫蔽不大,有利于出苗和根系的发育。只要根系发育良好,草木樨耐旱力强,保苗问题可以获得解决。7、8、9月为关中雨季,也是草木樨生长和翻压有利的季节。只要掌握在7月底到8月上旬进行翻压,对绿肥的分解及土壤蓄墒均无不良影响,在一般正常气候的条件下,关中旱地发展草木樨绿肥的可能性是存在的。从关中降雨、气温及作物布局来考虑,秦岭以北、渭河以南和省西平原区,年雨量在600—700毫米之间,且分布较均匀,为多种绿肥发展的有利地区。省西北山沼山丘陵区及渭北高原区降雨量在600毫米左右,但气候冷凉,适于发展夏播短期绿肥及毛苕绿肥。省中、省东旱塬区,年雨量为500毫米左右,夏秋雨季常错前推后,变化较大,夏播绿肥及草木樨的栽培均有较大的风险,但总雨量能满足毛苕的需要,发展棉田绿肥毛苕有较大的希望。

关键词：绿肥旱地耕地小麦麦类作物草木樨豆科牧草翻压回茬麦发展前途

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肝纤维化的无创评价：拉伸指数扩散加权模型与其他扩散加权MRI模型和瞬间弹性成像的比较

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国际医学放射学杂志 2021年第5期 608-609页

作者： J.H.Park n.Seo y.E.ch.ng S.u.Kim y.n.Park J.y.ch.i 谭邦国

摘要目的比较拉伸指数模型与其他扩散加权成像(DWI)模型和瞬间弹性成像(TE)的诊断性能,并评价混杂因素对肝纤维化分期的影响。方法该回顾性研究连续纳入了

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Exploiting Quantum Confinement for Future Solar Cell Application

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Journal of Energy and Power Engineering 2010年第1期4卷 26-34页

作者： M.y. Sulaiman u.C. Ahamefula K. Sopian Z. Ibarahim M.A. Alghoul M.y. Othman n. Amin Solar Energy Research.Institute Universiti Kebangsaan Malaysia Bangi Selangor 43600 Malaysia

Present solar cells are expensive making photovoitaic electricity only attractive whenever there is government incentive. This paper highlights the cost of photovoltaic classified according to first, second and third generations. The first and second generations make up the current photovoltaic. The reasons for the efficiency limitation of the first and second generation photovoltaic are given. nanoparticles such.as quantum dots have confinement properties that can be exploited to improve solar cell efficiency and help reduce the cost. Quantum effect that support hot electron collection and multiple exciton generation through impact ionization are discussed. These form the basis of the future generation quantum dot solar cell.

关键词： Photovoltaic electricity photovoltaic generations efficiency quantum dot solar cell quantum yield multiple exciton generation impact ionization.

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First large scale application of novel Si stripixel detector in real large experiment: Si VTX in PHEnIX upgrade at RHIC

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中国有色金属学会会刊：英文版 2006年第B01期16卷 141-145页

作者： LI Zheng H. EnyO y. GOTO J. TOJO y. AKIBA R. nOuICER A. L. DESHPAnDE K. BOyLE V. CIAnCIOLO RIKEn BnL Research.Center and BnL Instrumentation Division Upton NY 11973-5000 USA RIKEn Wako Saitama 351-0198 Japan BnL Chemistry Department Upton NY 11973-5000 USA Stony Brook university Department of Physics and Astronomy Stony Brook NY 11794 USA Oak Ridge national Laboratory Oak Ridge TN 37831 USA

2D position sensitive, single-sided Si stripixel detector was selected as the one of the two main components of the Si vertex tracker (Si SVX) in the upgraded PHEnIX detector at RHIC (relativistic heavy ion collider) in Brookhaven national Laboratory (BnL). This is the first large scale application of the novel Si stripixel detector in a real large experiment after many years of research.and development at BnL. The first and second prototype fabrication runs of the SVX stripixel detectors were carried out successfully in BnL’s Si detector development and processing Lab. The processing of these stripixel detectors is similar to that for the standard single-sided strip detectors: one-sided processing, single implant for the pixel (strip) electrodes, etc. The only additional processing step is the double metal process, a tech.ology that is simple and well matured by many Si detector processing industries and labs, including BnL. The laser and beam tests on those prototype detectors show the 2D position sensitivity and good position resolution in both X and u coordinates (about 25 μm for 80 μm pitch.. For the mass production of 400 sensors needed for the Si SVX, the processing tech.ology has been successfully transferred to the industrial: Hamamatsu Photonics (HPK). HPK has produced a pre-production run of stripixel sensors with the full PHEnIX SVX specification on 150 mm diameter wafers. The laser tests on these pre-production wafers show good signal to noise ratio (about 20∶1).

关键词：相对论性重离子碰撞 PHEnIX探测器天顶跟踪器硅顶点探测器硅条探测器应用

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RELIABILITy AnALySIS FOR An AERO EnGInE TuRBInE DISK unDER LOW CyCLE FATIGuE COnDITIOn

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 514-520页

作者： C.L.Liu Z.Z.Lü y.L.Xu Sch.ol of Aviation Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Aviation Northwestern Polytechnical University Xi'an 710072 ChinaChina Aviation Research Institute 608 Zhuzhou 412002 China

Reliability analysis methods based on the linear damage accumulation law (LDAL) and load-life interference model are studied in this paper. According to the equal probability rule, the equivalent loads are derived, and the reliability analysis method based on load-life interference model and recurrence formula is constructed. In conjunction with finite element analysis (FEA) program, the reliability of an aero engine turbine disk under low cycle fatigue (LCF) condition has been analyzed. The results show the turbine disk is safety and the above reliability analysis methods are feasible.

关键词： low cycle fatigue life reliability analysis load-life interference model recurrence method aero engine turbine disk

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THE PERTuRBATIOn METHOD APPLIED TO SOLVE ELASTODynAMIC PROBLEMS: WEDGE PROBLEM

THE PERTURBATION METHOD APPLIED TO SOLVE ELASTODYNAMIC PROBL...

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理论与应用地球物理研讨会

作者： yu-ch.ung Teng Femarco, Inc. new york, n y 10025, u S A

＜正＞ The root-mean-square perturbation method for solving wave scattering and diffraction introduced by Thau and Pao has been further developed to include the higher order terms. The method is particularly suited for solving, for example, the classic problem of wave propagation in wedged medium. As an illustration, the formal solutions to the problem of SH-wave propagation in a wedged half-space are obtained. Future numerical evaluation of the solutions is in order.

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渐变低温对不同规格菲律宾蛤仔斑马蛤酶活性的影响

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大连海洋大学学报 2018年第2期33卷 217-222页

作者：李杰孙溪蔓张鹏袁洪梅王晔闫喜武杨凤大连海洋大学水产与生命学院辽宁大连116023 辽宁省贝类良种繁育工程技术研究中心辽宁大连116023

斑马蛤是菲律宾蛤仔Ruditapes philippinarum的一个新品种,具有抗逆性强的特点,为探明其耐低温能力和机制,在实验室条件下模拟冬季低温环境,以8.2℃为对照,每3天降1℃,进行渐变低温(5.4、2.2、0.2℃)对3种规格(壳长8、13、17 mm)斑马蛤... 详细信息

斑马蛤是菲律宾蛤仔Ruditapes philippinarum的一个新品种,具有抗逆性强的特点,为探明其耐低温能力和机制,在实验室条件下模拟冬季低温环境,以8.2℃为对照,每3天降1℃,进行渐变低温(5.4、2.2、0.2℃)对3种规格(壳长8、13、17 mm)斑马蛤幼贝消化酶(淀粉酶AMS、脂肪酶LPS和胃蛋白酶)及抗氧化酶(超氧化物歧化酶SOD和过氧化氢酶CAT)酶活性的影响试验。结果表明:试验期间各组斑马蛤幼贝死亡率均小于3%;低温对淀粉酶呈诱导作用,并且对小规格幼贝(壳长8 mm)的诱导作用更明显,各温度下未检测到脂肪酶和胃蛋白酶;低温对SOD表现为诱导-抑制(8 mm和13 mm蛤仔)或诱导-抑制-诱导(17 mm蛤仔)的变化规律,总体上呈诱导作用,水温降至0.2℃时,随着规格的增大SOD酶活性升高;低温对CAT呈抑制作用(17 mm蛤仔)或抑制-诱导作用(8 mm和13 mm蛤仔),总体呈抑制作用,且较小规格幼贝(壳长8 mm,5.4℃)比较大规格(壳长13 mm和17 mm,2.2℃)起始抑制的温度高,水温降至0.2℃时,随着规格的增大CAT酶活性下降;与CAT相比,幼贝以SOD为主来抵御低温带来的氧化损伤。本研究结果可为斑马蛤耐低温机制及中国北方大规模生产推广提供参考。

关键词：斑马蛤低温消化酶抗氧化酶

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