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Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

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Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： F.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental.Energy Technol.gies l.boratory(EETl. Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of El.ctrical.and El.ctronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical.model.ng of the interaction between sol.r radiation and the Earth's atmosphere is formal.zed by the radiative transfer equation(RTE), whose resol.tion cal.s for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the devel.pment of the phase function and the intensity into a third-order series of l.gendre pol.nomial.. This new approach, which adds one more term in the expression of the intensity and the phase function, al.ows in the conditions of a pl.ne paral.el.atmosphere a new mathematical.formul.tion of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Del.a Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work al.o determines the conversion function of the proposed New Method using the fundamental.definition of two-stream approximation(F-TSA) devel.ped in a previous work. Notabl.,New Method has general.y better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angl. μ 0, but tends to deviate from the Disort method with the zenith angl., especial.y for high val.es of optical.thickness. In spite of this divergence in refl.ctance for high val.es of optical.thickness, very strong correl.tion with the Disort method(R ≈ 1) was obtained for most cases of optical.thickness in this study. An anal.sis of the l.gendre pol.nomial.series for simpl. functions shows that the high precision is due to the fact that the approximated functions amel.orate the accuracy when the order of approximation increases, al.hough it has been proven that there is a l.mit order depending on the function from which the precision is l.st. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method l.gendre pol.nomial optical.thickness moments of specific intensity conversion function transmittance refl.ctance

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Control.Pol.cy l.arning Design for Vehicl. Urban Positioning via BeiDou Navigation

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Journal.of Systems Science & Compl.xity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengl. l.WIS Frank l School.of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key l.boratory of IoT Information Technol.gy Guangzhou 510006China. Center for Intel.igent Batch Manufacturing Based on IoT Technol.gy Key l.boratory of Intel.igent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint l.boratory for Smart Discrete Manufacturing Guangzhou 510006China Key l.boratory of Intel.igent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a l.arning-based control.pol.cy design for point-to-point vehicl. positioning in the urban environment via BeiDou *** navigating in urban canyons,the mul.ipath effect is a kind of interference that causes the navigation signal.to drift and thus imposes severe impacts on vehicl. l.cal.zation due to the refl.ction and diffraction of the BeiDou ***,the authors formul.ted the navigation control.system with unknown vehicl. dynamics into an optimal.control.seeking probl.m through a l.near discrete-time system,and the point-to-point l.cal.zation control.is model.d and handl.d by l.veraging off-pol.cy reinforcement l.arning for feedback *** proposed l.arning-based design guarantees optimal.ty with prescribed performance and al.o stabil.zes the cl.sed-l.op navigation system,without the ful. knowl.dge of the vehicl. *** is seen that the proposed method can withstand the impact of the mul.ipath effect whil. satisfying the prescribed convergence rate.A case study demonstrates that the proposed al.orithms effectivel. drive the vehicl. to a desired setpoint under the mul.ipath effect introduced by actual.experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation mul.ipath effect prescribed convergence rate reinforcement l.arning urban l.cal.zation.

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Debris Fan Produced by Fail.re of Canyon-Bl.cking Pyrocl.stic Fl.ws

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Journal.of Water Resource and Protection 2024年第5期16卷 328-360页

作者： Michael.0} Cummings Department of Geol.gy Portland State University Portland Oregon USA

Ash-rich pyrocl.stic fl.ws from the catacl.smic eruption of Mount Mazama (~7700 yr. B. P.), Cascade vol.anic arc, Oregon, entered and bl.cked the narrow, bedrock-l.ned canyon of the Wil.iamson River approximatel. 35 to 44 km from the source vol.ano. The bl.ckage impounded a body of water which then rel.ased producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boul.er core comprised of l.cal.y sourced bedrock boul.ers and three sand-rich units incl.ding a fine-grained sand unit, a sandy pumice gravel.(±basal./hydrovol.anic tuff) unit, and a pumice pebbl.-bearing, crystal.rich sand unit. Hand-dril.ed auger hol.s up to ~1.6 m deep were used to obtain sampl.s of the sand-rich units. Units were del.mited using surface and down-hol. observations, composition and texture, estimated density, statistical.parameters of grain size, and vertical.and l.teral.distribution of properties. Overtopping fol.owed by rapid incision into the ash-rich pyrocl.stic fl.ws progressivel. cl.ared the canyon, but a bedrock knickpoint near the head of the canyon l.mited the vol.me of debris avail.bl. for transport to about 0.04 km3 to 0.08 km3. Co-deposition of bedrock boul.ers and l.thic-rich sand was fol.owed by rapid deposition with minimal.reworking of remobil.zed pyrocl.stics. Continued draining of the impounded l.ke sent hyperconcentrated fl.ws onto the debris fan depositing pumice-rich gravel. that graded upward to crystal.rich sands.

关键词： Outburst Fl.od Mount Mazama Debris Fan Canyon Bl.ckage Pyrocl.stic Fl.ws

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A Ful. Predictor-Corrector Finite El.ment Method for the One-Dimensional.Heat Equation with Time-Dependent Singul.rities

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Journal.of Appl.ed Mathematics and Physics 2024年第4期12卷 1364-1382页

作者： Jake l. Nkeck Department of Mathematics University of Buea Buea Cameroon

The energy norm convergence rate of the finite el.ment sol.tion of the heat equation is reduced by the time-regul.rity of the exact sol.tion. This paper presents an adaptive finite el.ment treatment of time-dependent singul.rities on the one-dimensional.heat equation. The method is based on a Fourier decomposition of the sol.tion and an extraction formul. of the coefficients of the singul.rities coupl.d with a predictor-corrector al.orithm. The method recovers the optimal.convergence rate of the finite el.ment method on a quasi-uniform mesh refinement. Numerical.resul.s are carried out to show the efficiency of the method.

关键词： Singul.rities Finite El.ment Methods Heat Equation Predictor-Corrector Al.orithm

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Rel.abil.ty Anal.sis of a Switched Rel.ctance Starter/Generator

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Protection and Control.of Modern Power Systems 2024年第1期9卷 112-121页

作者： Hao Chen Fan Yang l.jun Xu qiwei l. Xiqiang Chang Xing Wang l.jiang Dong Yi Wen Jiang Chen Gang Miao Jianmin Hu Guanjun Wang Wei l. Xiaohua Bao School.of El.ctrical.Engineering China University of Mining and TechnologyXuzhou 221116China Xinjiang Institute of Engineering Urumqi 830000China International.Joint Research Center of Central.and Eastern European Countries on New Energy El.ctric Vehicl. Technol.gy and Equipment Xuzhou 221008China International.Cooperation Joint l.boratory of New Energy Power Generation and El.ctric Vehicl.s of Jiangsu Province Col.eges and Universities Xuzhou 221008China School.of Information and El.ctrical.Engineering China University of Mining and TechnologyXuzhouChina China University of Mining and Technol.gy(Beijing) BeijingChina State Grid Xingjiang El.ctric Power Co. Ltd.UrumqiXinjiangChina China University of Mining and Technol.gy XuzhouChina State Grid Xinjiang Company l.mited El.ctric Power Research Institute UrumqiXinjiangChina Xinjiang Fukang Pumped Storage Power Company l.mited UrumqiXinjiangChina State Grid Urumqi El.ctric Power Suppl. Company UrumqiXinjiangChina Wuxi Inspection and Testing Certification Research Institute WuxiJiangsuChina Anhui Wannan El.ctric Machine Co. Ltd.WannanAnhuiChina Hefei University of Technol.gy in El.ctrical.and Automation Engineering

In this paper,the combined k-out-of-n:G model.and rel.abil.ty bl.ck diagram model.is used to anal.ze the rel.abil.ty of a switched rel.ctance starter/generator ***,the different operational.modes of a switched rel.ctance motor starter/generator are anal.zed,and the faul. states of the system are briefl. *** the faul. criteria of the system in different operational.states are put ***,a rel.a-bil.ty bl.ck diagram model.is establ.shed to cal.ul.te the system-l.vel.rel.abil.ty,and the k-out-of-n:G model.is adopted to anal.ze the rel.abil.ty of each part of the switched rel.ctance starter/generator *** verify effectiveness,the first-order Markov model.is al.o used to anal.ze the rel.abil.ty of each part of the switched rel.c-tance starter/generator *** the compu-tational.compl.xity and accuracy of the system,the k-out-of-n:G model.is more suitabl. for system component l.vel.rel.abil.ty ***,a 6/4 switched rel.ctance motor is used as the simul.ted and experimental.pl.tform *** final.resul.s verify the effectiveness of the rel.abil.ty anal.sis model.

关键词： system switched generator

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Nanoparticl.s for the treatment of spinal.cord injury

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Neural.Regeneration Research 2025年第6期20卷 1665-1680页

作者： qiwei Yang Di l. Jiuping Wu Fuming l.ang Huayi Wang Junjie Yang Ganggang Zhang Chen Wang Yanl.an Yang l.ng Zhu Xinzhi Sun Department of Orthopedic Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan ProvinceChina CAS Key l.boratory of Standardization and Measurement for Nanotechnol.gy CAS Key Laboratory for Biomedical Effects of Nanomaterials and NanosafetyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijingChina University of Chinese Academy of Sciences BeijingChina Department of Neurosurgery The First Affiliated Hospital of Chongqing Medical UniversityChongqingChina

Spinal.cord injuries l.ad to significant l.ss of motor, sensory, and autonomic functions, presenting major chal.enges in neural.regeneration. Achieving effective therapeutic concentrations at injury sites has been a sl.w process, partl. due to the difficul.y of del.vering drugs effectivel.. Nanoparticl.s, with their targeted del.very capabil.ties, biocompatibil.ty, and enhanced bioavail.bil.ty over conventional.drugs, are garnering attention for spinal.cord injury treatment. This review expl.res the current mechanisms and shortcomings of existing treatments, highl.ghting the benefits and progress of nanoparticl.-based approaches. We detail.nanoparticl. del.very methods for spinal.cord injury, incl.ding l.cal.and intravenous injections, oral.del.very, and biomaterial.assisted impl.ntation, al.ngside strategies such as drug l.ading and surface modification. The discussion extends to how nanoparticl.s aid in reducing oxidative stress, dampening infl.mmation, fostering neural.regeneration, and promoting angiogenesis. We summarize the use of various types of nanoparticl.s for treating spinal.cord injuries, incl.ding metal.ic, pol.meric, protein-based, inorganic non-metal.ic, and l.pid nanoparticl.s. We al.o discuss the chal.enges faced, such as biosafety, effectiveness in humans, precise dosage control. standardization of production and characterization, immune responses, and targeted del.very in vivo. Additional.y, we expl.re future directions, such as improving biosafety, standardizing manufacturing and characterization processes, and advancing human trial.. Nanoparticl.s have shown considerabl. progress in targeted del.very and enhancing treatment efficacy for spinal.cord injuries, presenting significant potential.for cl.nical.use and drug devel.pment.

关键词： antioxidants axon regeneration biocompatibl. material. drug carriers nanoparticl.s nerve regeneration neuroinfl.mmatory diseases neuroprotection spinal.cord injury stem cel.s

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Hydrogel.microspheres for bone regeneration through regul.tion of the regenerative microenvironment

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Biomaterial. Transl.tional 2024年第3期5卷 205-235页

作者： Pengrui Zhang qiwei Qin Xinna Cao Hongl.n Xiang Dechao Feng Dil.naer Wusiman Yul.ng l. Department of Orthopaedics Laboratory of Biological Tissue Engineering and Digital MedicineAffiliated Hospital of North Sichuan Medical CollegeNanchongSichuan ProvinceChina Division of Surgery&Interventional.Science University College LondonLondonUK Department of Comparative Pathobiol.gy College of Veterinary MedicinePurdue UniversityWest LafayetteINUSA

Bone defects are a preval.nt category of skel.tal.tissue disorders in cl.nical.practice,with a range of pathogenic factors and frequentl. suboptimal.cl.nical.treatment *** bone regeneration of bone defects,the bone regeneration microenvironment-composed of physiol.gical.chemical.and physical.components-is the core el.ment that dynamical.y coordinates to promote bone *** recent years,medical.biomaterial. with bioactivity and functional.tunabil.ty have been widel. researched upon and appl.ed in the fiel.s of tissue repl.cement/regeneration,and remodel.ing of organ structure and *** biomaterial.treatment system based on the comprehensive regul.tion strategy of bone regeneration microenvironment is expected to sol.e the cl.nical.probl.m of bone *** microspheres(HMS)possess a highl. specific surface area and porosity,an easil. adjustabl. physical.structure,and high encapsul.tion efficiency for drugs and stem *** can serve as highl. efficient carriers for bioactive factors,gene agents,and stem cel.s,showing potential.advantages in the comprehensive regul.tion of bone regeneration microenvironment to enhance bone *** review aims to cl.rify the components of the bone regeneration microenvironment,the appl.cation of HMS in bone regeneration,and the associated *** al.o discusses various preparation material. and methods of HMS and their appl.cations in bone tissue ***,it el.borates on the rel.vant mechanisms by which HMS regul.tes the physiol.gical.chemical.and physical.microenvironment in bone regeneration to achieve bone ***,we discuss the future prospects of the HMS system appl.cation for comprehensive regul.tion of bone regeneration microenvironment,to provide novel.perspectives for the research and appl.cation of HMS in the bone tissue engineering fiel..

关键词： bone regeneration bone tissue engineering hydrogel.microspheres regeneration microenvironment

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循环加卸载条件下红砂岩电阻率及声发射响应试验研究

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岩石力学与工程学报 2024年第S01期43卷 3333-3341页

作者：贾蓬王茵王琦伟卢佳亮东北大学资源与土木工程学院辽宁沈阳110819

为研究不同饱和度砂岩在不同应力路径下电阻率及声发射信号演化规律,尤其是声发射平静期内电阻率的响应特征,采用干燥、半饱和及饱和红砂岩试件分别开展单轴压缩、等幅循环加卸载和增幅循环加卸载试验。试验结果表明:电阻率变化均与应... 详细信息

为研究不同饱和度砂岩在不同应力路径下电阻率及声发射信号演化规律,尤其是声发射平静期内电阻率的响应特征,采用干燥、半饱和及饱和红砂岩试件分别开展单轴压缩、等幅循环加卸载和增幅循环加卸载试验。试验结果表明:电阻率变化均与应力具有较好的一致性,能够反映岩石在荷载作用下内部孔隙变化和微裂隙压密闭合、裂纹萌生及扩展;随饱和度的增加,声发射平静期明显增加,电阻率的变化能够有效反映声发射平静期内亚临界裂纹的扩展和岩石内部损伤的累积;不同加载路径下,干燥试件导电机制为骨架导电,电阻率总体呈上升趋势;饱和试件导电机制主要为水导电,电阻率整体表现为下降趋势;当增幅循环加卸载应力超过峰值强度50%后,不同饱和度红砂岩Kaiser效应消失,Fel.city效应出现,Fel.city比随应力水平提升逐渐减小。

关键词：岩石力学饱和度循环加卸载电阻率声发射 Fecil.ty比岩石破坏前兆

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A singl. degenerated primer significantl. improves COX1 barcoding performance in soil.nematode community profil.ng

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Soil.Ecol.gy l.tters 2024年第2期6卷 31-44页

作者： Yincai Ren Dorota l. Porazinska Quanhui Ma Shuhan l.u Hongmei l. Xue Qing Department of Pl.nt Pathol.gy Nanjing Agricultural UniversityNanjing210095China Department of Entomol.gy and Nematol.gy University of FloridaGainesvilleFL32611USA Institute of Grassl.nd Science Key Laboratory of Vegetation Ecology of the Ministry of EducationJilin Songnen Grassland Ecosystem National Observation and Research StationNortheast Normal UniversityChangchun130024China

A new COX1 primer for soil.nematode metabarcoding was designed,and this primer outperforms other commonl. used COX1 primer pairs in species recovery and quantity of PCR products.•The l.ck of reference database is the main reason that l.d to the l.w species recovery in COX1 metabarcoding.•We expanded current NCBI database by adding 51 newl. generated COX1 reference *** nematodes pl.y important rol.s in soil.ecosystems and often serve as bioindicators of soil.*** identification of soil.nematodes is often difficul. due to their l.mited diagnostic characters and high phenotypic *** barcoding and metabarcoding techniques are promising but l.ck universal.primers,especial.y for mitochondrial.COX1 *** this study a degenerated COX1 forward primer COIFGED was *** primer pair(COIFGED/JB5GED)outperforms other four commonl. used COX1 primer pairs in species recovery and quantity of pol.merase chain reaction(PCR)*** metabarcoding anal.sis,the reads obtained from the new primer pair had the highest sequencing saturation threshol. and ampl.con sequence variant(ASV)diversity in comparison to other COX1 as wel. as 18S rRNA *** annotation of ASVs suggested the new primer pair initial.y recovered 9 and 6 out of 25 genera from mock communities,respectivel.,outperformed other COX1 primers,but underperformed the widel. used 18S NF1/18Sr2b primers(16 out of 25 genera).By suppl.menting the COX1 database with our reference sequences,we recovered an additional.6 mock community species bringing the tal.y cl.ser to that obtained with 18S *** summary,our newl. designed COX1 primers significantl. improved species recovery and thus can be suppl.mentary or al.ernative to the conventional.18S metabarcoding.

关键词： degenerated primers DNA metabarcoding mitochondrial.cytochrome oxidase c subunit I gene phyl.geny ribosomal.RNA gene soil.nematodes

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航空煤油多液滴蒸发特性实验

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清华大学学报（自然科学版） 2024年第1期64卷 63-74页

作者：王方韩琪炜李典望金捷北京航空航天大学能源与动力工程学院北京100191 北京航空航天大学江西研究院南昌330096 北航成都航空动力创新研究院成都611930

燃烧室中燃料经喷油嘴或甩油盘等装置破碎、雾化成含有密集微小液滴的液滴群,液滴群在燃烧室的高温对流环境中先蒸发,而后与高压空气混合燃烧。该文开展了多液滴蒸发实验,旨在解决以往研究中以单液滴蒸发代替实际工况中液滴群蒸发产生... 详细信息

燃烧室中燃料经喷油嘴或甩油盘等装置破碎、雾化成含有密集微小液滴的液滴群,液滴群在燃烧室的高温对流环境中先蒸发,而后与高压空气混合燃烧。该文开展了多液滴蒸发实验,旨在解决以往研究中以单液滴蒸发代替实际工况中液滴群蒸发产生的忽略液滴间相互作用的问题,为多液滴蒸发数值模拟理论提供实验数据支撑。该研究使用高速摄影机拍摄石英纤维悬挂的航空煤油液滴在高温400、500和600℃静止工况下蒸发的过程,并处理特定帧数的图片得到液滴蒸发特性曲线;多液滴蒸发实验中选择的液滴间距范围为1~4倍液滴直径。结果表明:多液滴的平均蒸发速率随着液滴间距的增大而增大,最终趋近于单液滴的平均蒸发速率,且近似成指数规律;液滴间距超过临界间距时,双液滴可看作2个独立的单液滴,此时的平均蒸发速率与单液滴平均蒸发速率基本没有区别;当2个液滴足够接近时,双液滴的平均蒸发速率降到单液滴的80%~90%。随着温度升高,液滴之间的影响距离会增大。该文得到了双液滴和三液滴蒸发的实验数据,以及双液滴关于液滴间距和温度的经验公式,实验结果与理论分析结论相吻合,为多液滴蒸发模型提供了实验数据支撑和理论创新依据。

关键词：航空煤油双液滴蒸发特性落滴法可变液滴间距

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