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How to Construct a Lower Risk FOF Based on Correlation Network? The Method of Principal Component Risk Parity Asset Allocation

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Journal of Systems Science & Complexity 2024年第3期37卷 1052-1079页

作者： BAI Wei zhang Junting LIU Haifei LIU Kai School of Management and Engineering Nanjing UniversityNanjing 210093China Postdoctoral Workstation of Bank of Jiangsu Co. LtdNanjing 210006China College of Finance Nanjing Agricultural UniversityNanjing 210095China University of Prince edward Island 550 University AveCharlottetownPE C1A4P3Canada

In order to build a low-risk Fund of Funds(FOF), from the perspective of correlation, the principal component factor is used to improve the traditional risk parity model. Principal component analysis is used to decompose the underlying assets and generate unrelated principal component factors,and then the authors can construct a principal component risk parity portfolio. The proposed empirical results based on China’s mutual fund market show that the performance of principal component risk parity portfolio(PCRPP) is better than that of equal weight portfolio(EWP) and traditional risk parity portfolio(RPP). That is to say, not only the PCRPP in this paper has much lower risk than EWP and RPP, but also slightly better than EWP and RPP in terms of average return. Moreover, the study of dividing the underlying assets shows that the PCRPP in this paper is not sensitive to the underlying assets. The PCRPP in this paper is better than EWP and RPP for both the better performing funds and the worse performing funds. In addition, the empirical results on dynamic portfolio adjustments show that it is not appropriate to adjust asset allocation too frequently when the expected rate of return is calculated using the arithmetic mean.

关键词： Fund of funds(FOF) mutual funds portfolio risk principal component analysis risk parity portfolio

Optimization Control of Multi-Mode Coupling All-Wheel Drive System for Hybrid Vehicle

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 340-355页

作者： Lipeng zhang zijian Wang Liandong Wang Changan Ren School of Vehicle and Energy Yanshan UniversityQinhuangdao 066004China

The all-wheel drive(AWD)hybrid system is a research focus on high-performance new energy vehicles that can meet the demands of dynamic performance and passing *** optimization of the power and economy of hybrid vehicles becomes an issue.A unique multi-mode coupling(MMC)AWD hybrid system is presented to realize the distributed and centralized driving of the front and rear axles to achieve vectored distribution and full utilization of the system power between the axles of *** on the parameters of the benchmarking model of a hybrid vehicle,the best model-predictive control-based energy management strategy is ***,the drive system model was built after the analysis of the MMC-AWD’s drive ***,three fundamental strategies were established to address power distribution adjustment and battery SOC maintenance when the SOC changed,which was followed by the design of a road driving force ***,the energy consumption rate in the average time domain was processed before designing the minimum fuel consumption controller based on the equivalent fuel consumption ***,the advantage of the MMC-AWD was confirmed by comparison with the dynamic performance and economy of the BYD Song PLUS *** findings indicate that,in comparison to the comparative hybrid system at road adhesion coefficients of 0.8 and 0.6,the MMC-AWD’s capacity to accelerate increases by 5.26%and 7.92%,*** the road adhesion coefficient is 0.8,0.6,and 0.4,the maximum climbing ability increases by 14.22%,12.88%,and 4.55%,*** a result,the dynamic performance is greatly enhanced,and the fuel savings rate per 100 km of mileage reaches 12.06%,which is also very *** proposed control strategies for the new hybrid AWD vehicle can optimize the power and economy simultaneously.

关键词： Hybrid vehicle All-wheel drive Multi-mode coupling Energy management Model predictive control

Structure-Preserving Recurrent Neural Networks for a Class of Birkhoffian Systems

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Journal of Systems Science & Complexity 2024年第2期37卷 441-462页

作者： XIAO Shanshan CHEN Mengyi zhang Ruili TANG Yifa LSEC ICMSECAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China

In this paper,the authors propose a neural network architecture designed specifically for a class of Birkhoffian systems—The Newtonian *** proposed model utilizes recurrent neural networks(RNNs)and is based on a mathematical framework that ensures the preservation of the Birkhoffian *** authors demonstrate the effectiveness of the proposed model on a variety of problems for which preserving the Birkhoffian structure is important,including the linear damped oscillator,the Van der Pol equation,and a high-dimensional *** with the unstructured baseline models,the Newtonian neural network(NNN)is more data efficient,and exhibits superior generalization ability.

关键词： Birkhoffian system k(z,t)-symplectic neural networks recurrent neural network

CrisprStitch:Fast evaluation of the efficiency of CRISPR editing systems

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Plant Communications 2024年第3期5卷 13-16页

作者： Yangshuo Han Guanqing Liu Yuechao Wu Yu Bao Yong zhang Tao zhang Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education Agricultural College of Yangzhou UniversityYangzhou 225009China Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/Jiangsu Key Laboratory of Crop Genetics and Physiology Yangzhou UniversityYangzhou 225009China Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation Integrative Science Center of Germplasm Creation in Western China(Chongqing)Science CitySchool of Life SciencesSouthwest UniversityChongqing 400715China

Dear Editor,Targeted genome-editing technology using designed nucleases has been rapidly advancing and catalyzing significant breakthroughs in the life ***-designed CRISPR editing experiments can be efficiently evaluated through nextgeneration sequencing(NGS).Nevertheless,NGS data analysis currently lacks a user-friendly pipeline capable of automatically calculating mutations and evaluating editing efficiency in bulk,as well as providing a more comprehensive visualization of results.

关键词： breakthrough editing efficiency

Enhanced photocatalytic performance of Bi_(2)O_(2)CO_(3)/Bi_(4)O_(5)Br_(2)/reduced graphene oxide z-schemehe terojunction via a one-pot room-temperature synthesis

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Journal of Environmental Sciences 2024年第4期138卷 418-427页

作者： Xiaoge Wu Lei Yan Rongrong Qin Qikai zhang Wei Yang Xiaozhi Wang Yongcai zhang Min Luo Jianhua Hou College of Environmental Science and Engineering Yangzhou UniversityYangzhouJiangsu 225009China Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization Nanjing 210095China Beijing Xinfeng Aerospace Equipment Co. Ltd.Beijing 100854China Beijing System Design Institute of Electro-Mechanic Engineering Beijing 100005China College of Chemistry and Chemical Engineering Ningxia UniversityYinchuanNingxia 750021China

Bi_(2)O_(2)CO_(3)(BOC)/Bi_(4)O_5Br_(2)(BOB)/reduced graphene oxide(rGO)z-scheme heterojunction with promising photocatalytic properties was synthesized via a facile one-pot room-temperature ***-thin nanosheets of BOC and BOB were grown in situ on r *** formed 2D/2D direct z-scheme heterojunction of BOC/BOB with oxygen vacancies(OVs)effectively leads to lower negative electron reduction potential of BOB as well as higher positive hole oxidation potential of BOC,showing improved reduction/oxidation ***,rGO is an acceptor of the electrons from the conduction band of *** dual roles significantly improve the transfer performance of photo-induced charge carriers and accelerate their *** layered nanosheet structure,rich OVs,high specific surface area,and increased utilization efficiency of visible light,the multiple synergistic effects of BOC/BOB/rGO can achieve effective generation and separation of the electron-holes,thereby generating more·O_(2)^(-)and h^(+).The photocatalytic reduction efficiency of CO_(2)to CO(12.91μmol/(g·hr))is three times higher than that of BOC(4.18μmol/(g·hr)).Moreover,it also achieved almost 100%removal of Rhodamine B and cyanobacterial cells within 2 hours.

关键词： Bi_(2)O_(2)CO_(3) Bi_(4)O_(5)Br_(2) Reduced graphene oxide z-scheme heterojunction Photocatalysis CO_(2)reduction

Significantly Improved High-Temperature Energy Storage Performance of BOPP Films by Coating Nanoscale Inorganic Layer

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Energy & Environmental Materials 2024年第2期7卷 30-38页

作者： Tiandong zhang Hainan Yu Young Hoon Jung Changhai zhang Yu Feng Qingguo Chen Keon Jae Lee Qingguo Chi School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbin 150080China Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 350701Korea

Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high *** this study,growing an inorganic nanoscale coating layer onto the BOPP film's surface is proposed to suppress electrical conduction loss at high temperature,as well as increase its upper operating *** kinds of inorganic coating layers that have different energy band structure and dielectric property are grown onto the both surface of BOPP films,*** effect of inorganic coating layer on the high-temperature energy storage performance has been systematically *** favorable coating layer materials and appropriate thickness enable the BOPP films to have a significant improvement in high-temperature energy storage ***,when the aluminum nitride(AIN)acts as a coating layer,the AIN-BOPP-AIN sandwich-structured films possess a discharged energy density of 1.5 J cm^(-3)with an efficiency of 90%at 125℃,accompanying an outstandingly cyclic *** the discharged energy density and operation temperature are significantly enhanced,indicating that this efficient and facile method provides an important reference to improve the high-temperature energy storage performance of polymer-based dielectric films.

关键词： coating layer energy storage interfacial barrier polymer films

Species recognition and the divergences in the chemical and ultrasonic signals between two coexisting Rattus species

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Current zoology 2024年第4期70卷 531-538页

作者： Wei-Chao Wang zhi-Ming Li Yi Chen Jin-Hua zhang Jian-Xu zhang Yao-Hua zhang The State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China CAs Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijingChina

The ability to recognize and differentiate between conspecifics and heterospecifics as well as their signals is critical for the coexistence of closely related *** the genus Rattus,species are morphologically similar and multiple species often ***,we investigated the interspecific recognition and signal differentiation of two sympatric rat species,the brown rat(Rattus norvegicus,RN)and the Asian house rat(Rattus tanezumi,RT).In a two-way choice test,both RN and RT females showed a preference for conspecific male rats to heterospecific *** females showed a significant preference for accessible urine of males of same species to those of other species,but not for the inaccessi-ble *** the other hand,there were significant differences in the structural characteristics of the ultrasonic vocalization emitted by males of these two rat *** dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE)and isoelectric focusing electrophoresis unveiled that major urinary proteins(MUPs)in voided urine were more highly expressed in RN males versus RT *** interspecific dif-ferences of urinary volatile compounds were also *** conclusion,female rats had the ability to distinguish between males of either species.

关键词： Asian house rats brown rats closely related species pheromones ultrasonic vocalization.

Multifunctional MOF@COF Nanoparticles Mediated Perovskite Films Management Toward Sustainable Perovskite Solar Cells

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Nano-Micro Letters 2024年第9期16卷 195-208页

作者： Yayu Dong Jian zhang Hongyu zhang Wei Wang Boyuan Hu Debin Xia Kaifeng Lin Lin Geng Yulin Yang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001HeilongjiangPeople’s Republic of China School of Materials Science and Engineering East China Jiaotong UniversityNanchang 330013JiangxiPeople’s Republic of China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangPeople’s Republic of China

Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking and aggregation ***,metal-organic framework(MOF-808)is selected as an ideal platform for the in situ homogeneous growth of a COF to construct a core-shell MOF@COF nanoparticle,which could effectively inhibit COF stacking and *** synergistic intrinsic mechanisms induced by the MOF@COF nanoparticles for reinforcing intrinsic stability and mitigating lead leakage in PSCs have been *** complementary utilization ofπ-conjugated skeletons and nanopores could optimize the crystallization of large-grained perovskite films and eliminate *** resulting PSCs achieve an impressive power conversion efficiency of 23.61%with superior open circuit voltage(1.20 V)and maintained approximately 90%of the original power conversion efficiency after 2000 h(30-50%RH and 25-30℃).Benefiting from the synergistic effects of the in situ chemical fixation and adsorption abilities of the MOF@COF nanoparticles,the amount of lead leakage from unpackaged PSCs soaked in water(<5 ppm)satisfies the laboratory assessment required for the Resource Conservation and Recovery Act Regulation.

关键词： Perovskite solar cells Covalent organic frameworks Metal-organic frameworks Lead leakage Stability

Composition characterization and transformation mechanism of dissolved organic phosphorus in wastewater treatment using 31P NMR spectroscopy

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Frontiers of Environmental Science & Engineering 2024年第3期18卷 103-113页

作者： Yuting zhang Wei Shang SoonThiam Khu Xingcan zheng Yongli Sun Pengfeng Li Miao Gu Wen-an zhang Huanmei Ma National Engineering Research Center For Urban Water&Wastewater North China Municipal Engineering Design&Research Institute Co.Ltd.Tianjin 300381China School of Environment Science&Engineering Tianjin UniversityTianjin 300350China

The migration and transformation of phosphorus components in wastewater treatment plants(WWTPs)play a crucial role in the convergence and circulation of ***,the composition and variation of dissolved organic phosphorus(DOP)in WWTPs were unclear because of its complex nature,hindering its efficient *** this study,the DOP species and their transformation during the treatment process in WWTP were comprehensively ***,two enrichment methods were assessed for their effectiveness at facilitating wastewater analysis:lyophilization and aluminum salt *** salt precipitation was found to be better because its application allowed 31P nuclear magnetic resonance(31P NMR)spectroscopy to identify more species in the secondary effluent:orthophosphate(Ortho-P)(81.1%–89.3%of the dissolved total phosphorus),pyrophosphates(Pyro-P)(0%–2.3%),orthophosphate monoesters(Mono-P)(7.0%–10.77%),orthophosphate diesters(Di-P)(1.0%–2.96%),and phosphonate(Phos-P)(1.7%–5.16%).Furthermore,the variation and transformation mechanism of phosphorus,particularly those of DOP,during the entire sewage-treatment process were *** the treatment steps,biological treatment combined tertiary treatment achieved better DOP removal ***,biological treatment mainly removed Mono-P and Di-P with removal efficiencies of 33.3%and 41.7%compared with the effluent of the grit ***-P has higher bioavailability and is more easily converted and utilized by microorganisms than ***,Phos-P,with low bioavailability,was hardly utilized by microorganisms,which showed only 18.4%removal efficiency in biological *** tertiary treatment,coagulation process exhibited higher removal ability of Ortho-P(69.1%)and partial removal efficiencies of DOP,resulting in an increase in the DOP proportion in *** addition,Phos-P could not be effectively removed through the biological treatment and was only partially reduced via the adsorption pro

关键词： Municipal wastewater Dissolved organic phosphorus Composition Transformation 31P nuclear magnetic resonance