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Defined Contribution Pension Planning with the Return of Premiums Clauses and HARA Preference in Stochastic Environments

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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 396-423页

作者： Hao chang Xing-jiang CHEN School of Mathematical Sciences Tiangong UniversityTianjin 300387China Department of Mathematical Sciences School of EngineeringComputer and Mathematical SciencesAuckland University of TechnologyAucklandNew Zealand

This paper studies a defined contribution(DC)pension fund investment problem with return of premiums clauses in a stochastic interest rate and stochastic volatility environment.In practice,most of pension plans were subject to the return of premiums clauses to protect the rights of pension members who died before retirement.In the mathematical modeling,we assume that a part of pension members could withdraw their premiums if they died before retirement and surviving members could equally share the difference between accumulated contributions and returned premiums.We suppose that the financial market consists of a risk-free asset,a stock,and a zero-coupon bond.The interest rate is driven by a stochastic affine interest rate model and the stock price follows the Heston’s stochastic volatility model with stochastic interest rates.Different fund managers have different risk preferences,and the hyperbolic absolute risk aversion(HARA)utility function is a general one including a power utility,an exponential utility,and a logarithm utility as special cases.We are concerned with an optimal portfolio to maximize the expected utility of terminal wealth by choosing the HARA utility function in the analysis.By using the principle of dynamic programming and Legendre transform-dual theory,we obtain explicit solutions of optimal strategies.Some special cases are also derived in detail.Finally,a numerical simulation is provided to illustrate our results.

关键词： defined contribution pension plan return of premiums clauses stochastic interest rate HARA preference Legendre transform-dual theory stochastic optimal control

Methods and Practices for Institutional Benchmarking based on Research Impact and Competitiveness: A Case Study of ShanghaiTech University

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Journal of Data and Information Science 2019年第3期4卷 55-72页

作者： Jiang Chang Jianhua Liu Library and information services ShanghaiTech University Shanghai 201210 China Beijing Wanfang Data Ltd. Beijing 100038 China

Purpose: To develop and test a mission-oriented and multi-dimensional benchmarking method for a small scale university aiming for internationally first-class basic research.Design/methodology/approach: An individualized evidence-based assessment scheme was employed to benchmark ShanghaiTech University against selected top research institutions,focusing on research impact and competitiveness at the institutional and disciplinary levels.Topic maps opposing ShanghaiTech and corresponding top institutions were produced for the main research disciplines of ShanghaiTech. This provides opportunities for further exploration of strengths and weakness. Findings: This study establishes a preliminary framework for assessing the mission of the university. It further provides assessment principles, assessment questions, and indicators.Analytical methods and data sources were tested and proved to be applicable and efficient.Research limitations: To better fit the selective research focuses of this university, its schema of research disciplines needs to be re-organized and benchmarking targets should include disciplinary top institutions and not necessarily those universities leading overall rankings.Current reliance on research articles and certain databases may neglect important research output types.Practical implications: This study provides a working framework and practical methods for mission-oriented, individual, and multi-dimensional benchmarking that ShanghaiTech decided to use for periodical assessments. It also offers a working reference for other institutions to adapt. Further needs are identified so that ShanghaiTech can tackle them for future benchmarking.Originality/value: This is an effort to develop a mission-oriented, individually designed,systematically structured, and multi-dimensional assessment methodology which differs from often used composite indices.

关键词： Differentiating evaluation Mission-driven assessment Evidence-based assessment Benchmarking Research performance

Intraspecific variation in microhabitat selection in reintroduced Chinese giant salamanders

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Current Zoology 2023年第2期69卷 121-127页

作者： Chunlin Zhao Jianyi Feng Zijian Sun Wei Zhu Jiang Chang Wenbo Fan Jianping jiang Bisong Yue Tian Zhao Key Laboratory of Bio-resources and Eco-environment(Ministry of Education) College of Life SciencesSichuan UniversityChengdu 610064China CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

Reintroduction of captive-bred Chinese giant salamanders is a primary approach for restoring wild populations.Despite previous studies have investigated the habitat preferences of reintroduced Chinese giant salamanders,the intraspecific variation in their habitat selection has been neglected.In the present study,30 captive-bred Chinese giant salamanders belonging to 3 groups(i.e.,10 males,10 females,and 10 juveniles)were released into a montane stream to explore whether intraspecific variation in habitat selection occurred in this species using radiotelemetry.Our results indicated that linear home range and daily movement of males were significantly higher than those of females and juveniles.Male sedentariness was significantly lower than that of females and juveniles.No significant differences were detected between females and juveniles in these measures.Importantly,we found that males preferred microhabitats with low water conductivity and deep water depth.Females preferred microhabitats with high water conductivity,low dissolved oxygen and ammonium-nitrogen,and slow current velocity,while juveniles occupied microhabitats with low ammonium-nitrogen.In addition,males and juveniles exhibited higher niche breadth than females.Niche overlap was high between adults and juveniles but low between males and females.Our study revealed the presence of spatial segregation in reintroduced Chinese giant salamanders.Males,females,and juveniles exhibited variation in microhabitat selection.These results provide important information for use when planning strategies for conservation of Chinese giant salamanders.

关键词： intraspecific variability microhabitatvariables niche reintroduction spatial segregation

BER Performance Analysis of Asynchronous NOMA with Arbitrary Phase Offset

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China Communications 2022年第11期19卷 195-208页

作者： chang Liu Sheng Wu Chunxiao jiang Hongwen Yang School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Tsinghua Space Center Tsinghua UniversityBeijing 100084China

An asynchronous transmission scenario for non-orthogonal multiple access(NOMA)user signals with arbitrary phase offset is investigated in this paper.To improve the system performance in the user power-balanced conditions,we adopt a synthetic detection method at the receiver,i.e.,the jointly optimal maximal likelihood detection aided triangular successive interference cancellation(JO ML-TSIC)method.Analytical bit error rate(BER)solutions are obtained for a two-user case with the optimal,intentional onehalf symbol period time delay implemented between the user signals.Furthermore,closed-form BER solutions for the case using the triangular successive interference cancellation(TSIC)detection method are also derived for comparisons.Numerical results show that the JO ML-TSIC receiver for the asynchronous system outperforms the TSIC receiver as well as the synchronous successive interference cancellation(SIC)receiver in all the conditions concerned.The results also show that the superiority of the JO ML-TSIC receiver is strengthened when the signals experience flat Rayleigh fading channels compared to the TSIC and the synchronous SIC receivers.

关键词： non-orthogonal multiple access(NOMA) asynchronous transmission jointly optimal(JO)maximum likelihood(ML)detection successive interference cancellation(SIC) bit error rate(BER)

Elevating kinetics of passivated Fe anodes with NH_(4)Cl regulator:Toward low-cost,long-cyclic and green cathode-free Fe-ion aqueous batteries

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Nano Research 2022年第4期15卷 3187-3194页

作者： Shibo Chai Jianhui Zhu Jian jiang chang Ming Li School of Physical Science and Technology Southwest UniversityNo.2 Tiansheng RoadBeiBei DistrictChongqing 400715China School of Materials and Energy and Chongqing Key Lab for Advanced Materials and Clean Energies of TechnologiesSouthwest UniversityNo.2 Tiansheng RoadBeiBei DistrictChongqing 400715China Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province Key Laboratory of Functional Materials and Photoelectrochemistry of HaikouCollege of Chemistry and Chemical EngineeringHainan Normal UniversityHaikou 571158China

The environment benignity and battery cost are major concerns for grid-scale energy storage applications.The emerging dendrite-free Fe-ion aqueous batteries are promising due to the rich natural abundance,low cost and non-toxicity for Fe resources.However,serious passivation reactions on Fe anodes and poor long-term cyclability for matched cathodes still stand in the way for their practical usage.To settle above constraints,we herein use NH_(4)Cl as the electrolyte regulator to elevate the reaction kinetics of passivated Fe anodes,and also propose a special cathode-free design to prolong the cells lifetime over 1,000 cycles.The added NH_(4)Cl can erode/break inert passivation layers and strengthen the ion conductivity of electrolytes,facilitating the reversible Fe plating/stripping and Fe^(2+)shuttling.The highly puffed nano carbon foams function as current collectors and actives anchoring hosts,enabling expedite Fe^(2+)adsorption/desorption,FeII/FeIII redox conversions and FeIII deposition.The configured rocking-chair Fe-ion cells have good environmental benignity and decent energy-storage behaviors,including high reactivity/reversibility,outstanding cyclic stability and far enhanced operation longevity.Such economical,long-cyclic and green cathode-free Fe-ion batteries may hold great potential in near-future energy-storage power stations.

关键词： elevated kinetics passivated Fe anodes NH_(4)Cl regulator cathode-free design Fe-ion batteries

Synthesis of highly active Cu(Ⅰ)-Y(Ⅲ)-Y zeolite and its selective adsorption desulfurization performance in presence of xylene isomers

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Petroleum Science 2021年第1期18卷 295-306页

作者： Bo-Long jiang Nan jiang You-Xin chang Innovation Institute for Sustainable Maritime Architecture Research and Technology Qingdao University of TechnologyQingdao 266000China Chongqing changshou Sino French Water Co.Ltd. Chongqing 404100China

A bimetal-exchanged NaY zeolite(Cu(Ⅰ)-Y(Ⅲ)-Y)with a desirable adsorptive desulfurization(ADS)performance was prepared and characterized by means of X-ray diffraction,specific surface area measurements,X-ray fluorescence spectrometer,X-ray photoelectron spectroscopy,thermal gravity analysis and Fourier transform infrared spectroscopy.The effect of Y(Ⅲ)ions on ADS in the presence of the xylenes was investigated.Results indicated that the ADS performance of Y(Ⅲ)-Y is higher than that of most reported CeY.The Y(Ⅲ)-based Cu(Ⅰ)-Y(Ⅲ)-Y demonstrated the higher breakthrough loading than those of reported Ce(Ⅲ)/Ce(Ⅳ)-based transition metal Y zeolites,showing that Y(Ⅲ)ions play a promoting role in improving the ADS selectivity.For Cu(Ⅰ)-Y(Ⅲ)-Y,a new strong S-M interaction(S stands for sulfur,while M stands for metal)active site was formed,which might be caused by the synergistic effect between Cu(Ⅰ)and Y(Ⅲ).The Cu(Ⅰ)-Y(Ⅲ)-Y,which combined the advantages of Cu(I)-Y and Y(Ⅲ)-Y,is a kind of promising adsorbent.The breakthrough loading decreased in the order of Cu(Ⅰ)-Y(Ⅲ)-Y>Y(Ⅲ)-Y>Cu(Ⅰ)-Y,and the effect of xylene isomers on the sulfur removal was in the order of ortho-xylene>meta-xylene>para-xylene,which exhibited the same trend with the bond order of xylenes.

关键词： Desulfurization Yttrium Copper Y zeolite Competitive adsorption Xylenes

Improved de-interleaving algorithm of radar pulses based on dual fuzzy vigilance ART

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Journal of Systems Engineering and Electronics 2020年第2期31卷 303-311页

作者： jiang Wen FU Xiongjun chang Jiayun School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

As a core part of the electronic warfare(EW) system,de-interleaving is used to separate interleaved radar signals. The de-interleaving algorithm based on the fuzzy adaptive resonance theory(fuzzy ART) is plagued by the problems of premature saturation and performance improving dilemma. This study proposes a dual fuzzy vigilance ART(DFV-ART) algorithm to address these problems and make the following improvements. Firstly, a correction method is introduced to prevent the network from prematurely saturating;then, the fuzzy vigilance models(FVM) are constructed to replace the conventional vigilance parameter, reducing the error probability in the overlapping region;finally, a dual vigilance mechanism is introduced to solve the performance improving dilemma. Simulation results show that the proposed algorithm could improve the clustering accuracy(quantization error dropped60%) and the de-interleaving performance(clustering quality increased by 10%) while suppressing the excessive proliferation of categories.

关键词： fuzzy adaptive resonance theory(fuzzy ART) deinterleaving dual vigilance mechanism

Additive manufacturing of metallic glasses and high-entropy alloys:Significance,unsettled issues,and future directions

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Journal of Materials Science & Technology 2023年第9期140卷 79-120页

作者： Haishun Liu Dengfeng Yang Qi jiang Yangyang jiang Weiming Yang Lin Liu Lai-chang Zhang School of Materials Sciences and Physics China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for Geomechanics and Deep Underground Engineering School of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China School of Engineering Edith Cowan University270 Joondalup DriveJoondalupPerthWA 6027Australia

As two kinds of well-known prominent high-performance alloys,metallic glasses(MGs)and high-entropy alloys(HEAs)have attracted increasing attention.Most of them contain multiple alloying components,demonstrate intriguing microstructures,and exhibit excellent properties;however,their unique performances are closely dependent on the fabrication process,although they are limited due to the need for rapid solidification during fabrication.On the other hand,additive manufacturing(AM)can be used to fabricate complex parts via rapid solidification,thus saving materials.These advantages provide AM with a great possibility to produce MG and HEA materials with tunable microstructures therefore properties,and corresponding parts with complex geometries,large dimensions,and more functions.This paper provides a comprehensive and systematic overview of the manufacturing and properties of MGs and HEAs using AM techniques.The correlation between MGs and HEAs with conventional manufacturing meth-ods and the difficulties encountered are retrospectively discussed.Afterward,this review specifically focuses on the recent research advances in MGs and HEAs fabricated using AM technologies.Then,various properties of the AM-fabricated MGs and HEAs are discussed.Finally,the remaining issues and potential solutions,challenges,and future directions on the AM of MGs and HEAs are also presented.

关键词： Additive manufacturing Powder bed fusion Metallic glasses High-entropy alloys Research status

Multifunctional mesoporous bioactive glass/upconversion nanoparticle nanocomposites with strong red emission to monitor drug delivery and stimulate osteogenic differentiation of stem cells

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Nano Research 2016年第4期9卷 1193-1208页

作者： Fangfang Wang Dong Zhai Chengtie Wu Jiang Chang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai200050 China

For the therapy and regeneration of bone defects resulting from malignant bone tumors, it is necessary to develop multifunctional biomaterials that are able to deliver therapeutic drugs, monitor drug release, and stimulate bone formation. Herein, a multifunctional mesoporous bioactive glass （MBG）/upconversion nanoparticle （UCNP） nanocomposite [UCNPs@SiO2@mSiO2-XCa （X = 0, 5, 10, 15, and 20）] with the ability to deliver anti-cancer drugs, monitor drug release, and stimulate osteogenic differentiation of bone marrow stromal cells （BMSCs） was successfully prepared using a layer-by-layer strategy. The nanocomposite spheres possess a core--sheU structure composed of UCNPs and a mesoporous SiO2/Ca layer with a uniform size distribution of 100 nm. The incorporation of Ca into the nanocomposites induced phase transformation from a pure hexagonal phase to a cubic phase, and facilitated the occurrence of red emission, which significantly improved fluorescence penetration for deep tissue imaging. In addition, since the red emission strongly overlaps with the maximum absorbance of the anti-cancer drug zinc phthalocyanine （ZnPc）, red luminescence could be strongly quenched by ZnPc. Consequently, drug release could be quantified by monitoring changes in fluorescence intensity. Furthermore, the incorporation of Ca into MBG/UCNP nanocomposites remarkably improved bioactivity, i.e., it stimulated apatite mineralization in simulated body fluids and enhanced cell proliferation and bone-related gene expression in BMSCs for the concentration range of 200-500 ~g/mL. Our results suggest that the prepared MBG/UCNP nanocomposites are useful for the therapy and regeneration of bone defects resulting from malignant bone tumors owing to their distinct multifunctionality, including strong red emission and functions in drug-delivery monitoring and osteostimulation.

关键词： multifunctionalnanocomposites,upconversion,osteoblastic activity,drug release monitoring,bone tumors