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Optimal Timing of Business Conversion for Solvency Improvement

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 744-757页

作者： Peng LI ming ZHOU School of Finance Nanjing University of Finance and EconomicsNanjing 210023China Center for Applied Statistics and School of Statistics Renmin University of ChinaBeijing 100872China

In this paper,we study the optimal timing to convert the risk of business for an insurance company in order to improve its *** cash flow of company evolves according to a jump-diffusion *** conversion option offers the company an opportunity to transfer the jump risk business *** exchange for this option,the company needs to pay both fixed and proportional transaction *** proportional cost can also be seen as the profit loading of the jump risk *** formulated this problem as an optimal stopping *** solving this stopping problem,we find that the optimal timing of business conversion mainly depends on the profit loading of the jump risk business.A larger profit loading would make the conversion option *** fixed cost,however,only delays the optimal timing of business *** the end,numerical results are provided to illustrate the impacts of transaction costs and environmental parameters to the optimal strategies.

关键词： optimal stopping jump-diffusion process conversion option

The Contribution of United States Aircraft Reconnaissance Data to the China Meteorological Administration Tropical Cyclone Intensity Data:An Evaluation of Homogeneity

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Advances in Atmospheric Sciences 2024年第4期41卷 639-654页

作者： ming YING Xiaoqin LU Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030China

This paper investigates the homogeneity of United States aircraft reconnaissance data and the impact of these data on the homogeneity of the tropical cyclone(TC)best track data for the seasons 1949-1987 generated by the China Meteorological Administration(CMA).The evaluation of the reconnaissance data shows that the minimum central sea level pressure(MCP)data are relatively homogeneous,whereas the maximum sustained wind(MSW)data show both overestimations and spurious abrupt *** comparisons suggest that both the reconnaissance MCP and MSW were well incorporated into the CMA TC best track *** no spurious abrupt changes were evident in the reconnaissance-related best track MCP data,two spurious changepoints were identified in the remainder of the best-track MCP ***,the influence of the reconnaissance MSWs seems to extend to the best track MSWs unrelated to reconnaissance,which might reflect the optimistic confidence in making higher estimates due to the overestimated extreme wind“observations”.In addition,the overestimation of either the reconnaissance MSWs or the best track MSWs was greater during the early decades compared to later decades,which reflects the important influence of reconnaissance data on the CMA TC best track *** wind-pressure relationship(WPR)used in the CMA TC best track dataset is also evaluated and is found to overestimate the MSW,which may lead to inhomogeneity within the dataset between the aircraft reconnaissance era and the satellite era.

关键词： tropical cyclone intensity homogeneity best track aircraft reconnaissance

Fluorescent carbon dots synthesized in solid phase and air for application in LEDs

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Nano Research 2024年第9期17卷 8495-8503页

作者： Wei-Jie Zheng Zhao-Nan Sun Yi-ming Wang Huan-ming Xiong Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200438China

Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent ***,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothermal reactions,leading to intractable problems such as toxic and flammable solvents,complex and inseparable by-products,and dangerously high pressures and ***-phase synthesis of CDs in air is an effective solution to overcome the above issues,but solid reactions always result in uncontrolled growth and agglomeration of *** this study,some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air,which also play as dispersants to hinder CDs *** the meantime,some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources,ground with the optimized catalyst,and then heated together in *** production yields are affected by the reaction time and reactant ratio,while the graphitization degrees of the CDs are determined by the reaction *** IG/ID value of their Raman spectra increases from 0.59 to 0.85,and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280℃.The as-prepared CDs show emission peaks ranging from 366 to 606 nm,with the photoluminescence(PL)quantum yield up to 53%.Their emission color variation mainly results from different carbon sources,which can be ascribed to the differences in the element composition,functional groups,and graphitic nitrogen content of these *** dispersing CDs of different concentrations into polyvinyl alcohol(PVA)and combining them with blue LEDs,cold,standard,and warm white light emitting devices(WLEDs)are prepared,with a color rendering index(CRI)up to *** the as-prepared CDs have antioxidant ability at high temperature,the as-prepared WLEDs have long lifespans,remaining the effective white luminescence after 72 h continuous work.

关键词： carbon dot solid-phase synthesis white LED photoluminescence inorganic salt catalysis

Hydrogen bond producers in powerful protic ionic liquids for enhancing dissolution of natural cellulose

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SusMat 2024年第5期4卷 189-201页

作者： Shi-Peng Chen Dan-Yang Zhao jin-Long Zhu jing Wang Gan-Ji Zhong Hua-Dong Huang Zhong-ming Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengduChina

The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and ***,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of *** optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of *** experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to ***,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea *** concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.

关键词： cellulose dissolution hydrogen bond producers protic ionic liquids

Multiscale control of MnO_(2) growth via[WO_(6)]-perturbed[MnO_(6)]assembly toward a favorable balance between capacitance and rate performance

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Rare Metals 2024年第4期43卷 1658-1671页

作者： jin-Kang Liu Tian-Shuo Yang Zhi-Bin Ren Adekunle-Adedapo Obisanya Xin-Yi Tan Yan-Di Rao Jun-Shuang Zhou Fa-ming Gao Jian-Ren Wang Hebei Key Laboratory of Applied Chemistry Yanshan UniversityQinhuangdao066004China

Although pseudocapacitive manganese dioxide(MnO_(2))integrates the high-power merit of carbonaceous materials with the high-energy merit of battery-type materials,it still has a long way to go in achieving a more satisfactory balance of higher energy and power density,and in decoupling the relationship of structural characteristics with energy storage *** realize such goals,a bottom-up[WO_(6)]-perturbed[MnO_(6)]assembly strategy has been developed here due to their similar structure,yet mismatched lattice *** facile protocol is capable of finely controlling the morphology and crystal structure of MnO_(2)by adjusting its internal[WO_(6)]***,the as-prepared W_xMnO_(2)is treated as an ideal platform to scrutinize the correlations of the structure with the energy storage *** operando Raman spectra and finite element analysis have fully demonstrated the superiority of the locally ordered defects-enriched structure of W_(0.02)-MnO_(2),which could reach a favorable balance between the ion diffusion equilibrium time and the number of active *** a result,the W_(0.02)-MnO_(2)is able to deliver a high capacitance of 292 F·g^(-1)at a current density of 1 A·g^(-1)and a remarkable rate performance with a 60%capacity retention at a current density of 50 A·g^(-1).The further unveiled structure-performance relationship provides a guideline for the design of better pseudocapacitive energy storage devices.

关键词： Supercapacitors Pseudocapacitive materials MnO_(2) Tungsten doping Crystal structure regulation

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

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Acta Mechanica Solida Sinica 2024年第3期37卷 385-395页

作者： Zhiqiang Fan Zhihe jin School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering University of MaineOronoME04469USA

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the“wellbore skin zone”,play a pivotal role in determining flow dynamics and the resulting formation *** models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir *** paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic *** solutions are derived using the Laplace transform method,addressing both positive and negative skin *** results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a *** results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.

关键词： Poroelastic Graded permeability Analytical solution Wellbore Skin zone

enOsCas12f1-mediated exon skipping for Duchenne muscular dystrophy therapy in humanized mouse model

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Journal of Genetics and Genomics 2024年第2期51卷 256-259页

作者： ming jin Jiajia Lin Yu Zhang Qingquan Xiao Xiangfeng Kong Xiumei Zhang Zhurui Shao Yin Wang Yuyang Yu jinjing Li Wan-jin Chen Guoling Li Hui Yang Ning Wang Department of Neurology and Institute of Neurology of First Affiliated Hospital Institute of NeuroscienceFujian Key Laboratory of Molecular NeurologyFujian Medical UniversityFuzhouFujian 350004China HUIDAGENE Therapeutics Co. Ltd.Shanghai 200131China Institute of Neuroscience State Key Laboratory of NeuroscienceKey Laboratory of Primate NeurobiologyCAS Center for Excellence in Brain Science and Intelligence TechnologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghai 200031China

Duchenne muscular dystrophy(DMD)is a severe neuromuscular disorder caused by mutations in the dystrophin gene,which encodes the essential protein *** genetic condition,affecting approximately 1 in 5000 male births worldwide(Birnkrant et al.,2018),is characterized by progressive muscle weakness and wasting,leading to premature death in the second or third decade of life(Farini et al.,2016).The absence of dystrophin protein causes instability in the sarcolemma,which predisposes individuals to myonecrosis and activation of inflammatory signaling ***,there is currently no effective cure for DMD,and glucocorticoid steroids are commonly used in clinical settings to delay symptom development(Merlini et al.,2003).

关键词： dystrophy Duchenne

Advanced Algorithm for Parameters Estimation of Negative Binomial Distribution with High Dimensional Sparse Group Structure

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Journal of Systems Science & Complexity 2024年第5期37卷 2173-2195页

作者： LI Meiqi jin Baisuo School of Management University of Science and Technology of China

Negative binomial regression is a powerful technique for modeling count data, particularly when dealing with overdispersion. However, estimating the parameters for large-dimensional sparse models is challenging due to the complexity of optimizing the mean and dispersion parameter of the negative binomial distribution. To address this issue, the authors propose a novel approach that employs two iterations of the majorize-minimize(MM) algorithm, one for estimating the dispersion parameter and the other for estimating the mean parameters. These approaches improve the convergence speed and stability of the algorithm. The authors also use group penalty for variable selection, which enhances the accuracy and efficiency of the algorithm. The proposed method provides an explicit solution,simplifies the iteration process, and maintains good stability while ensuring algorithm ***, the authors apply the proposed algorithm to the zero-inflated model and demonstrate its promising predictive performance on specific data sets. The research has important implications for count data modeling and analysis in various fields, such as data mining, machine learning, and bioinformatics.

关键词： Group structure majorize-minimize (MM) negative binomial

Design and synthesis of polyoxovanadate-based framework for efficient dye degradation

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Tungsten 2024年第2期6卷 447-453页

作者： Qing Lan Su-Juan jin Zheng Wang Xu-Yang Li Yan Xiong Zhuo-Cheng Wang Shan-Shan Liu Zhi-ming Zhang Qiang Zhao Engineering Technology Research Center of Henan Province for Solar Catalysis School of Chemical and Pharmaceutical EngineeringNanyang Normal UniversityNanyang 473061China Institute of New Energy Materials&Low Carbon Technology Tianjin University of TechnologyTianjin 300384China

A new polyoxovanadate-based framework material[Cu(en)_(2)]_(4)V_(18)O_(42)(H_(2)O)·6H_(2)O(1)was designed and synthesized by hydrothermal reaction of NaVO_(3),Cu(NO_(3))_(2)·6H_(2)O and 1,2-diaminoethane(en)via carefully adjusting the pH value of the reaction *** structure of the title compound has been determined by single-crystal X-ray diff raction analysis,thermogravimetric analysis,infrared spectra and elemental *** structural analysis demonstrate the three-dimensional(3D)framework structure of compound 1,which was composed of the[V_(18)O_(42)(H_(2)O)]_(8)−({V_(18)O_(42)(H_(2)O)})anions linked by the Cu^(2+)*** 1 represents the fi rst 3D framework based on{V_(18)O_(42)(H_(2)O)}polyoxoanions and copper ***-driven degradation of residual organic pollutants in industrial wastewater is still a major problem for human *** experiments reveal that compound 1 possesses of excellent photocatalytic activity for the degradation of methylene blue and rhodamine B.

关键词： Polyoxovanadate Framework Polyoxovanadate-based framework Photocatalytic Organic pollutants