简介:Thisletterpresentsalowcostsolutionforwavelengthdivisionmultiplexedorthogonalfrequencydivisionmultiplexedpassiveopticalnetwork(WDM-OFDM-PON)withwidelytunableopticalfilterandlinearsmallform-factorpluggable(SFP)module.With9-nmtunablerangefrom1551to1560nm,thetunablefiltercansupportupto10-channel100-GHzspacingWDMPONsystem.Alinearavalanchephotodiode(APD)basedSFP+moduleisdesignedforopticalOFDMsignaldemodulation,whichcanprovidebetterreceiverperformancecomparedwithlimitingAPDmodule.Experimentalresultsshowthat~34dBpowerbudgetcanbeachievedin4×5-GbpsWDM-OFDM-PONsystem,whichcansatisfythetransmissionrequirementsofnextgenerationPONsystem.
简介:AbstractBackground:Continuing progress in the global pediatric human immunodeficiency virus (HIV) response depends on timely identification and care of infants with HIV. As countries scale-out improvements to HIV early infant diagnosis (EID), economic evaluations are needed to inform program design and implementation. This scoping review aimed to summarize the available evidence and discuss practical implications of cost and cost-effectiveness analyses of HIV EID.Methods:We systematically searched bibliographic databases (Embase, MEDLINE and EconLit) and grey literature for economic analyses of HIV EID in low- and middle-income countries published between January 2008 and June 2021. We extracted data on unit costs, cost savings, and incremental cost-effectiveness ratios as well as outcomes related to health and the HIV EID care process and summarized results in narrative and tabular formats. We converted unit costs to 2021 USD for easier comparison of costs across studies.Results:After title and abstract screening of 1278 records and full-text review of 99 records, we included 29 studies: 17 cost analyses and 12 model-based cost-effectiveness analyses. Unit costs were 21.46-51.80 USD for point-of-care EID tests and 16.21-42.73 USD for laboratory-based EID tests. All cost-effectiveness analyses stated at least one of the interventions evaluated to be cost-effective. Most studies reported costs of EID testing strategies; however, few studies assessed the same intervention or reported costs in the same way, making comparison of costs across studies challenging. Limited data availability of context-appropriate costs and outcomes of children with HIV as well as structural heterogeneity of cost-effectiveness modelling studies limits generalizability of economic analyses of HIV EID.Conclusions:The available cost and cost-effectiveness evidence for EID of HIV, while not directly comparable across studies, covers a broad range of interventions and suggests most interventions designed to improve EID are cost-effective or cost-saving. Further studies capturing costs and benefits of EID services as they are delivered in real-world settings are needed.
简介:和开发的迪拜唯一的率,在统一阿拉伯人酋长(UAE)的本地设计和构造惯例保证特殊注意到侧面的抵抗力量的系统(LFRS)的选择。这研究为高大楼为LFRS的选择建议四个不同可行答案并且确定地震性能和费用上的这些选择的影响。考虑的系统是:钢特殊抵抗时刻的框架(SMRF),具体SMRF,钢双系统(有特殊的钢盘子的SMRF砍墙,SPSW),并且具体双系统(有特殊水泥的SMRF砍墙,SCSW)。LFRS选择被地震安装以及采用的设计和构造惯例在迪拜驾驶。具体设计选择是,这被发现一致地不比他们的钢对应物昂贵。钢双系统被期望基于它的相对更小的interstory飘移有最少的损坏。然而,这比较喜欢的表演以更高起始的构造成本来。相反地,钢SMRF系统被期望有大多数损坏并且由于它的过多的灵活性联系了修理费用。二种具体选择被期望除了他们的更小的起始的构造费用有相对中等的损坏和修理费用。
简介:Industrialgrademulti-walledcarbonnanotubes(IG-MWCNTs)arealow-costsubstituteforcommerciallypurifiedmulti-walledcarbonnanotubes(P-MWCNTs).Inthiswork,IG-MWCNTswerefunctionalizedwithtetraethylenepentamine(TEPA)forCO2capture.TheTEPAimpregnatedIG-MWCNTswerecharacterizedwithvariousexperimentalmethodsincludingN2adsorption/desorptionisotherms,elementalanalysis,X-raydiffraction,Fouriertransforminfraredspectroscopyandthermogravimetricanalysis.BoththeadsorptionisothermsofIGMWCNTs-nandtheisostericheatsofdifferentadsorptioncapacitieswereobtainedfromexperiments.TEPAimpregnatedIG-MWCNTswerealsoshowntohavehighCO2adsorptioncapacitycomparabletothatofTEPAimpregnatedP-MWCNTs.TheadsorptioncapacityofIG-MWCNTsbasedadsorbentswasintherangeof2.145to3.088mmol/g,dependingonadsorptiontemperatures.Havingtheadvantagesoflow-costandhighadsorptioncapacity,TEPAimpregnatedIG-MWCNTsseemtobeapromisingadsorbentforCO2capturefromfluegas.
简介:与谈论气候的世界,变化,美国(美国),中国和印度宣布了他们的碳排放减小目标。这三个国家完成他们的目标,重要问题产生例如将是完成那些目标的年度排放减小努力的,它将花费多少并且什么将是经济效果。这份报纸把中国和印度的碳紧张减小目标放进和美国的绝对排放减小目标一样的非线性的模型到最佳的排放控制策略和联系总数为在一年2020完成那些目标花费了的份量上学习,并且估计并且比较三个国家的最小化的全部的费用到达他们的目标。我们总数花费了让美国完成它的排放减小目标的结果表演以绝对数量比中国和印度的那些大。以到GDP的全部的费用的比例,然而,中国和印度比率比美国的显著地大,显示为象中国和印度那样的发展中的国家,排放减小目标的成就需要相对更大的努力。
简介:Reducingthemanufacturingcostofsolarcellsisnecessarytotheirindustrialproduction.Electrodepositingisaneffective,non-vacuummethodwhichisverysuitableforcuttingthemanufacturingcostofthinfilmsaswellasdevelopingitslarge-scaleindustrialproduction.Inthisstudy,about1-μm-thickCu(In,Ga)Se_2(CIGS)precursorswereelectrodepositedonMo/glasssubstratesinaqueoussolutionutilizingathree-electrodepotentiostaticsystem.Triethanolaminewasusedascomplexingagent,andallparametersofelectrodepositionwerepreciselycontrolled.Afterthat,theelectrodepositedprecursorswereselenizedinaSeatmospherewithdifferentheatingramprates(60and600℃·min~(-1)).High-qualityCIGSfilmswereobtained,andtheircharacteristicswereinvestigatedbyX-rayfluorescence,scanningelectronmicroscopy,energydispersivespectroscopy,X-raydiffraction,Ramanspectraandnear-infrared-visible(NIR-Vis)spectra.Theresultsrevealthattherearemanydifferencesbetweenthepropertiesofthefilmsunderdifferentheatingrates.Finally,CIGSsolarcellswerefabricatedusingafastandaslowheatingrate.Themaximumefficienciesachievedforthefilmsselenizedat60and600℃-min~(-1)are3.15%and0.71%,respectively.
简介:A100-Gb/shigh-speedopticaltransmitterisproposedandexperimentallydemonstrated.Basedonfrequency-quadruplingtechnique,twosub-channelswithafixed50-GHzspacingareobtainedfromonelasersource.Usingreturn-to-zerodifferentialquadraturephase-shiftkeying(RZ-DQPSK)modulationformatandpolarizationmultiplexing(PolMux),onlylow-speedelectronicdevicesof12.5GHzareneededforthe100-Gb/stransmitter.Thiseliminatestheneedofultrahigh-speedoptoelectronicdevicesandthusgreatlyreducesthecost.Theexperimentalresultsshowthatthistransmittercanachievegoodperfor-manceindispersiontoleranceofa25-kmsinglemodefiber(SMF).
简介:Background:Replacementoffossilfuelbasedenergywithbiochar-basedbioenergyproductioncanhelpreducegreenhousegasemissionswhilemitigatingtheadverseimpactsofclimatechangeandglobalwarming.However,theproductionofbiochar-basedbioenergydependsonasustainablesupplyofbiomass.Although,NorthwesternOntariohasarichandsustainablesupplyofwoodybiomass,acomprehensivelifecyclecostandeconomicassessmentofbiochar-basedbioenergyproductiontechnologyhasnotbeendonesofarintheregion.Methods:Inthispaper,weconductedathoroughlifecyclecostassessment(LCCA)ofbiochar-basedbioenergyproductionanditslandapplicationunderfourdifferentscenarios:1)biocharproductionwithlowfeedstockavailability;2)biocharproductionwithhighfeedstockavailability;3)biocharproductionwithlowfeedstockavailabilityanditslandapplication;and4)biocharproductionwithhighfeedstockavailabilityanditslandapplication-usingSimaPro~,EIOLCA~softwareandspreadsheetmodeling.BasedontheLCCAresults,wefurtherconductedaneconomicassessmentforthebreak-evenandviabilityofthistechnologyovertheprojectperiod.Results:Itwasfoundthattheeconomicviabilityofbiochar-basedbioenergyproductionsystemwithinthelifecycleanalysissystemboundarybasedonstudyassumptionsisdirectlydependentoncostsofpyrolysis,feedstockprocessing(drying,grindingandpelletization)andcollectiononsiteandthevalueoftotalcarbonoffsetprovidedbythesystem.SensitivityanalysisoftransportationdistanceanddifferentvaluesofCoffsetshowedthatthesystemisprofitableincaseofhighbiomassavailabilitywithin200kmandwhenthecostofcarbonsequestrationexceedsCAD$60pertonneofequivalentcarbon(CO_2e).Conclusions:Biochar-basedbioenergysystemiseconomicallyviablewhenlifecyclecostsandenvironmentalassumptionsareaccountedfor.Thisstudyprovidesamediumscaleslow-pyrolysisplantscenarioandwerecommendsimilarexperimentswithlarge-scale
简介:
简介:学术为本创建名校中国艺术研究院研究生院(原名研究生部)成立1978年,是国务院首批公布的博士、硕士学位授予单位,
简介:摘要目的测量公立三级综合医院成本效率及其构成要素,分析其成本效率的影响因素。方法采用数据包络分析法的COST、CCR、BCC模型,分别测量我国3个省份141所样本医院的成本效率、配置效率、技术效率、纯技术效率和规模效率值。对数据进行描述性分析和多元线性回归分析。结果2018年样本医院成本效率值为0.632,配置效率值为0.929,技术效率值为0.675,纯技术效率值为0.732,规模效率值为0.917。10所(7.09%)样本医院处于规模报酬不变状态,41所(29.08%)样本医院处于规模报酬递减状态,90所(63.83%)样本医院处于规模报酬递增状态。地区人均GDP以及医院的床位使用率、平均住院日、每门急诊人次平均收费水平等,对样本医院成本效率值的影响具有显著性。结论技术效率是影响成本效率的主要原因,纯技术效率是提升技术效率的关键因素,不断提升医院内部管理水平是提高技术效率的主要和必要途径。内部因素对成本效率影响较大。降低平均住院日、提高床位使用率、降低每门急诊人次平均收费水平等,有利于提高医院成本效率。
简介:AbstractBackground:When utilizing the retrosigmoid approach (RA), accurately identifying the transverse and sigmoid sinus transition (TSST) is a key procedure for neurosurgeons, especially in developing countries restricted by the lack of expensive devices, such as the neural navigation system and the three-dimensional volumetric image-rendered system. Before operations, a computed tomography scan is a common and cost-effective method of checking patients who suffer lesions located at the cerebellopontine angle. Therefore, we present a technique using only high-resolution computed tomography to identify the transverse and sigmoid sinus transition.Methods:This retrospective study included 35 patients who underwent retrosigmoid approach operations to resect an acoustic neurinoma with the assistance of our technique. In brief, our technique contains 4 steps: (1) All patients’ 1-mm, consecutive, high-resolution computed tomographic images that clearly displayed landmarks, such as the inion, lambdoid suture, occipitomastoid suture, and the mastoid emissary foramen, were investigated initially. (2) We selected two particular slices (A and B) among all of these high-resolution computed tomographic images in which scanning planes were parallel with the line drawn from the root of the zygoma to the inion (LZI). Slice A contained both the root of the zygoma and the inion simultaneously, and slice B displayed the mastoid emissary foramen. (3) Four points (α, β, γ, δ) were arranged on slices A and B, and point α was located at the inner surface of the skull, which represents the posterior part of the sulci of the sigmoid sinus. Point β was located at the outer surface of the skull, and the line connecting them was perpendicular to the bone. Similarly, on slice B, we labeled point γ as the point that represents the posterior part of the sulci of the sigmoid sinus at the inner surface and point δ as the point located at the outer surface of the skull, and the line connecting them was also perpendicular to the bone. The distances between point β and the lambdoid suture/occipitomastoid suture and between point δ and the mastoid emissary foramen were calculated for slices A and B, respectively. (4) During the operation, a line indicating the LZI was drawn on the bone with ink when the superficial soft tissue was pushed away, and this line would cross the lambdoid suture/occipitomastoid suture. With both the crosspoint and the distance obtained from the high-resolution CT images, we could locate point β. We also used the same method to locate point δ after revealing the mastoid emissary foramen. The line connecting point β and point δ indicated the posterior border of the sigmoid sinus, and the intersection between the line and LZI indicated the inferior knee of the transverse and sigmoid sinus transition (TSST).Results:All 35 patients underwent the RA craniectomies that were safely assisted by our technique, and neither the sigmoid sinus nor the transverse sinus was lacerated during the operations.Conclusion:Our cost-effective technique is reliable and convenient for identifying the transverse and sigmoid sinus transition (TSST) which could be widely performed to guarantee the safety of RA craniectomy.