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Lightweight,Strong and High Heat-Resistant Poly(lactide acid)Foams via Microcellular Injection Molding with Self-Assembly Nucleating Agent

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Chinese Journal of Polymer Science 2024年第6期42卷 739-750页

作者： Xiao-Hu Bing wen-Yu ma Ming-Hui Wu Peng Gao Xiao Zhou Hai-Bin Luo Long Wang wen-Ge Zheng School of materials Science and Engineering Shanghai UniversityShanghai200444China Ningbo Key Lab of Polymer materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China

Poly(lactide acid)(PLA)foams have shown considerable promise as eco-friendly alternatives to nondegradable plastic foams,such as polystyrene(PS)***,PLA foam typically suffers from low heat-resistance and poor cellular structure stemming from its inherent slow crystallization rate and low melt *** this study,a high-performance PLA foam with well-defined cell morphology,exceptional strength and enhanced heat-resistance was successfully fabricated via a core-back microcellular injection molding(MIM)*** scanning calorimetry(DSC)results revealed that the added hydrazine-based nucleating agent(HNA)significantly increased the crystallization temperature and accelerated the crystallization process of ***,the addition of a 1.5 wt%of HNA led to a significant reduction in PLA’s cell size,from 43.5µm to 2.87µm,and a remarkable increase in cell density,from 1.08×10^(7)cells/cm^(3)to 2.15×10^(10)cells/cm^(3).This enhancement resulted in a final crystallinity of approximately 55.7%for the PLA blend foam,a marked improvement compared to the pure PLA ***,at 1.5 wt%HNA concentration,the tensile strength and tensile toughness of PLA blend foams demonstrated remarkable improvements of 136%and 463%,***,the Vicat softening temperature of PLA blend foam increased significantly to 134.8°C,whereas the pure PLA foam exhibited only about 59.7℃.These findings underscore the potential for the preparation of lightweight injection-molded PLA foam with enhanced toughness and heat-resistance,which offers a viable approach for the production of high-performance PLA foams suitable for large-scale applications.

关键词： Poly(lactide acid) Nucleating agent Microcellular injection molding Heat-resistance Toughness

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Experimental demonstration of a quantum downstream access network in continuous variable quantum key distribution with a local local oscillator

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Photonics Research 2024年第6期12卷 1262-1273页

作者： DENGKE qi XIANGYU WANG ZHENGHUA LI JIAYU ma ZIYANG CHEN YUEMING LU SONG YU State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Trustworthy Distributed Computing and Service(MoE) Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronicsand Center for Quantum Information TechnologyPeking UniversityBeijing 100871China

Quantum networks provide opportunities and challenges across a range of intellectual and technical frontiers,including quantum computation,communication,and *** traditional communication networks,quantum networks utilize quantum bits rather than classical bits to store and transmit *** key distribution(QKD)relying on the principles of quantum mechanics is a key component in quantum networks and enables two parties to produce a shared random secret key,thereby ensuring the security of data *** this work,we propose a cost-effective quantum downstream access network structure in which each user can get their corresponding key information through terminal *** on this structure,we demonstrate the first four-end-users quantum downstream access network in continuous variable QKD with a local local *** contrast to point-to-point continuous variable QKD,the network architecture reevaluates the security of each user and accounts for it accordingly,and each user has a lower tolerance for excess noise as the overall network expands with more ***,the feasibility of the experiment is based on the analysis of the theoretical model,noise analysis,and multiple techniques such as the particle filter and adaptive equalization algorithm used to suppress excess *** results show that each user can get a low level of excess noise and can achieve secret key rates of 546 kbps,535 kbps,522.5 kbps,and 512.5 kbps under a transmission distance of 10 km,respectively,with the finite-size block of 1×10~*** not only verifies the good performance but also provides the foundation for the future multi-user quantum downstream access networks.

关键词： quantum oscillator local

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Research progress in failure mechanisms and electrolyte modification of high-voltage nickel-rich layered oxide-based lithium metal batteries

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Infomat 2024年第2期6卷 57-75页

作者： Jiandong Liu Xinhong Hu Shihan qi Yurong Ren Yong Li Jianmin ma School of Chemistry Tiangong UniversityTianjinthe People's Republic of China School of Physics and Electronics Hunan UniversityChangshathe People's Republic of China School of materials Science and Engineering Jiangsu Collaborative Innovation Center of Photovoltaic Science and EngineeringChangzhou UniversityChangzhouthe People's Republic of China State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power SourcesShanghaithe People's Republic of China

High-voltage nickel(Ni)-rich layered oxide-based lithium metal batteries(LMBs)exhibit a great potential in advanced batteries due to the ultra-high energy ***,it is still necessary to deal with the challenges in poor cyclic and thermal stability before realizing practical application where cycling life is *** many improved strategies,mechanical and chemical stability for the electrode electrolyte interface plays a key role in addressing these ***,extensive effort has been made to address the challenges of electrode-electrolyte *** this progress,the failure mechanism of Ni-rich cathode,lithium metal anode and electrolytes are reviewed,and the latest breakthrough in stabilizing electrode-electrolyte interface is also ***,the challenges and future research directions of Ni-rich LMBs are put forward.

关键词： electrode-electrolyte interface electrolyte modification failure mechanisms high voltage lithium metal anode nickel-rich layered oxide cathode

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Efficient and fair PPO-based integrated scheduling method for multiple tasks of SATech-01 satellite

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Chinese Journal of Aeronautics 2024年第2期37卷 417-430页

作者： qi SHI Lu LI Ziruo FANG Xingzi BI Huaqiu LIU Xiaofeng ZHANG wen CHEN Jinpei YU Shanghai Satellite Network Research Institute CO. LTDShanghai 201210China Innovation Academy for Microsatellites of Chinese Academy of Sciences Shanghai 201306China University of Chinese Academy of Sciences Beijing 100039China

SATech-01 is an experimental satellite for space science exploration and on-orbit demonstration of advanced *** satellite is equipped with 16 experimental payloads and supports multiple working modes to meet the observation requirements of various *** to the limitation of platform power supply and data storage systems,proposing reasonable mission planning schemes to improve scientific revenue of the payloads becomes a critical *** this article,we formulate the integrated task scheduling of SATech-01 as a multi-objective optimization problem and propose a novel Fair Integrated Scheduling with Proximal Policy Optimization(FIS-PPO)algorithm to solve *** use multiple decision heads to generate decisions for each task and design the action mask to ensure the schedule meeting the platform *** results show that FIS-PPO could push the capability of the platform to the limit and improve the overall observation efficiency by 31.5%compared to rule-based plans currently ***,fairness is considered in the reward design and our method achieves much better performance in terms of equal task *** of its low computational complexity,our task scheduling algorithm has the potential to be directly deployed on board for real-time task scheduling in future space projects.

关键词： Satellite observatories SATech-01 Multi-modes platform Scheduling algorithms Reinforcement learning Proximal Policy Optimization(PPO)

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Nursing effect of narrative nursing intervention on postoperative patients with severe lung cancer

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World Journal of Clinical Cases 2024年第1期12卷 76-85页

作者： Bin wen Ying Liu Xiao-Xia Min An-qi Wang Department of Intensive Care Tongren Hospital of Wuhan University and Wuhan Third HospitalOptics Valley BranchWuhan 430074Hubei ProvinceChina The First Department of Thoracic Oncology Hubei Cancer Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430079Hubei ProvinceChina Department of Emergency Medicine Taizhou First People's HospitalTaizhou 318020Zhejiang ProvinceChina

BACKGROUND Lung cancer is a common disease with high mortality,and psychological support is very important in the diagnosis and treatment of postoperative patients with cancer *** To explore the application effect of the narrative nursing method in postoperative lung cancer patients in the intensive care *** A total of 120 patients diagnosed with lung cancer and experiencing cancer-related pain were randomly allocated into two groups:an observation group and a control group,each consisting of 60 *** control group was given routine analgesic and psychological care,while the research group applied the five-step narrative nursing method based on routine care,comparing the visual analogue scale scores,sleep status,anxiety and depression status,and quality of life of the two groups of patients before and after the *** The pain scores,anxiety scores,and depression scores of the study group were lower than those of the control group after the intervention using the narrative nursing method,and the difference was statistically significant(P<0.05).CONCLUSION Using narrative nursing methods to intervene in patients with lung cancer combined with cancerous pain can help patients to correctly recognize their disease,adjust their mentality,establish confidence,alleviate patients'subjective pain feelings,and improve their adverse emotions.

关键词： Narrative care Lung cancer Care unit Pain Quality of life

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Technical innovation in the “Beishan No. 1” hard rock tunnel boring machine for high-gradient spiral tunnels

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Frontiers of Engineering management 2024年第1期11卷 175-179页

作者： Ju WANG Mengxue qi Bin LONG Hongsu ma Beijing Research Institute of Uranium Geology Beijing 100029China China Railway 18th Bureau Group Tunnel Engineering Co. Ltd.Chongqing 400700China China Railway Construction Heavy Industry Co. Ltd.Changsha 410100China

1 Project overview The“Beishan No.1”,the world’s first-ever hard rock Tunnel Boring machine(TBM)tailored for high-gradient spiral tunnels,constitutes a pivotal element within the Beishan Underground Research Laboratory(URL)initiative in *** URL,the first URL for geological disposal of high level radioactive waste(HLW)in China,is a national key construction project listed in the“13th Five-Year Plan”.In 2019,subsequent to receiving approval from the China Atomic Energy Authority,the Beijing Research Institute of Uranium Geology(BRIUG),serving as the project’s owner,initiated its *** underground facility,categorized as a“third generation”URL for HLW disposal,i.e.,area-specific URL,was located in Beishan,Jiuquan City,Gansu Province,China,following more than three decades of rigorous research on site selection.

关键词： tunnel boring machine extremely hard rock continuous small-radius curves high gradient equipment technology innovation

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Intrinsically asymmetric atomic character regulates piezoelectricity in two-dimensional materials

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Frontiers of physics 2024年第3期19卷 153-162页

作者： Yun-qin Li qi-wen He Dai-Song Tang Xiao Shang Xiao-Chun Wang School of Physics Science and Information Technology Liaocheng UniversityLiaocheng 252000China Key Laboratory of Polar materials and Devices Ministry of EducationDepartment of ElectronicsEast China Normal UniversityShanghai 200241China Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China

Decreasing of layer thickness causes the decrease of polarization until it disappears due to the existence of depolarization ***,the search for strong piezoelectric materials is highly desirable for multifunctional ultra-thin piezoelectric ***,we propose a common strategy for achieving strong piezoelectric materials through the electronic asymmetry induced by the intrinsically asymmetric atomic character of different chalcogen ***,in the tetrahedral lattice structures,for example,M4X3Y3(M=Pd/Ni,X/Y=S,Se or Te,X≠Y)monolayers are proved to display excellent out-of-plane ***4Se3Te3 possesses the largest piezoelectric coefficient d33 of 61.57 pm/V,which is much larger than that of most 2D *** the electronic asymmetry further increases the out-of-plane piezoelectricity of Janus M4X3Y3 ***,the out-of-plane piezoelectricity is positively correlated with the ratio of electronegativity difference(Red)and the electric dipole moment(P).This work provides alternative materials for energy harvesting nano-devices or self-energized wearable devices,and supplies a valuable guideline for predicting 2D materials with strong out-of-plane piezoelectricity.

关键词： piezoelectricity intrinsically asymmetric atomic character ratio of electronegativity difference electric dipole moment first-principles calculations

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Low-viscosity oligoether esters(OEEs)as high-efficiency lubricating oils:Insight on their structure‒lubricity relationship

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Friction 2024年第6期12卷 1133-1153页

作者： Hanwen WANG Ying WANG Ping wen Lin ma Mingjin FAN Rui DONG Chunhua ZHANG Shaanxi Key Laboratory of Phytochemistry College of Chemistry&Chemical EngineeringBaoji University of Arts and SciencesBaoji 721013China Key Laboratory of Shaanxi Province for Development and Application of New Transportation Energy Chang’an UniversityXi’an 710064China

Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic *** esters(OEEs),as a low-viscosity ester base oil,have characteristics such as simple synthesis and excellent lubrication effect;however,the application of OEEs in tribology field has rarely been *** objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure‒property relationship(QSPR)through a combination of experiment and statistical *** showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of *** to branched-chain OEEs,straight-chain OEEs exhibited reduced wear,which was mainly due to the thicker adsorption film formed by the straight-chain ***,carbon films were detected on lightly worn surfaces,indicating that OEEs underwent oxidation during the friction *** on the results of principal component analysis(PCA)and partial least squares(PLS),it could be found that the predictive models of viscosity‒temperature performance,thermal stability performance,coefficient of friction(COF),and wear volume(WV)performed well and *** them,COF and WV can be best predicted with an R^(2) of about 0.90.

关键词： oligoether esters(OEEs) low-viscosity ester friction wear quantitative structure-property relationship(QSPR)

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Mechanism of a dual-phase Ti-Nb alloy exhibiting near-linear elastic deformation

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Rare Metals 2024年第5期43卷 2282-2289页

作者： Yan Guo Wang Ding wen ma Shun Guo Hao-Dong Meng Nian-Yao Xu School of Automotive Engineering Changzhou Institute of TechnologyChangzhou 213032China School of materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Youke Publishing Co. LtdChina Grinm Group Co.LtdBeijing 100088China

In this work,the underlying mechanism responsible for the near-linear elastic deformation behavior of a dual-phase Ti-Nb alloy consisting of β and α'' phase with large recoverable strain was systematically *** on in situ synchrotron X-ray diffraction(SXRD)analyses,it was found that besides intrinsic elastic deformation,a slight reversible β-α'' stress-induced martensitic(SIM)transformation,which proceeded in a consecutive mode under the retarding effect of micro-defects,took place during the near-linear elastic *** unloading,a small amount of residual macroscopic strain remained in the specimen due to the incomplete reverse α''→β transformation on *** high near-linear elastic deformability of the cold drawing(CD)Ti-Nb alloy has been revealed to be attributed to the coupling actions of intrinsic elasticity as well as the consecutive and reversible β-α'' SIM *** research may contribute to a new avenue for the design and development of novel dual-phase Ti-based alloys with desirable elastic deformability.

关键词： Titanium alloys Dual-phase Near-linear elastic deformation martensitictransformation

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High-Precision Doppler Frequency Estimation Based Positioning Using OTFS Modulations by Red and Blue Frequency Shift Discriminator

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China Communications 2024年第2期21卷 17-31页

作者： Shaojing Wang Xiaomei Tang Jing Lei Chunjiang ma Chao wen Guangfu Sun School of Electronic Science National University of Defense TechnologyChangsha 410073China

Orthogonal Time Frequency and Space(OTFS) modulation is expected to provide high-speed and ultra-reliable communications for emerging mobile applications, including low-orbit satellite communications. Using the Doppler frequency for positioning is a promising research direction on communication and navigation integration. To tackle the high Doppler frequency and low signal-to-noise ratio(SNR) in satellite communication, this paper proposes a Red and Blue Frequency Shift Discriminator(RBFSD) based on the pseudo-noise(PN) *** paper derives that the cross-correlation function on the Doppler domain exhibits the characteristic of a Sinc function. Therefore, it applies modulation onto the Delay-Doppler domain using PN sequence and adjusts Doppler frequency estimation by red-shifting or blue-shifting. Simulation results show that the performance of Doppler frequency estimation is close to the Cramér-Rao Lower Bound when the SNR is greater than -15dB. The proposed algorithm is about 1/D times less complex than the existing PN pilot sequence algorithm, where D is the resolution of the fractional Doppler.

关键词： channel estimation communication and navigation integration Orthogonal Time Frequency and Space pseudo-noise sequence red-blue frequency shift discriminator

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