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Nano research 2024年第7期17卷 6527-6533页

作者： Oul Cho Sujin Park Hogeun Chang Jiwhan Kim Jaekwon Kim Sungwoo Kim Taehyung Kim Jeonghun Kwak Department of Electrical and Computer Engineering Inter-university Semiconductor Research Centerand Soft Foundry InstituteSeoul National UniversitySeoul 08826Republic of Korea Material research center Samsung Advanced Institute of TechnologySuwonGyeonggi-do 16419Republic of Korea

ZnTeSe quantum dots(QDs),recognized as promising eco-friendly blue electroluminescent emitters,remain under-explored in light-emitting diode(LED)***,to elucidate the operation and degradation mechanisms of ZnTeSe blue QD-LEDs,stacked ZnTeSe QD layers with discernable luminescence are designed by varying Te doping concentrations,and the recombination zones(RZs)of the blue QD-LEDs are *** RZs are identified near the hole-transport layer(HTL),confirmed by angular-dependent electroluminescence measurements and optical *** addition,in order to investigate carrier dynamics in the process of recombination,the transient electroluminescence(tr-EL)signals of the dichromatic QD-LEDs are *** a result,it is inferred that the RZ initially formed near the electron-transport layer(ETL)due to the high injection barriers of ***,due to the fast electron mobility,the RZ shifts toward the HTL as the operating current *** the device lifetime tests,the RZ remains stationary while the photoluminescence(PL)corresponding to the RZ undergoes a substantial decrease,indicating that the degradation is accelerated by the concentrated *** this study contributes to a deeper understanding of the operational mechanisms of ZnTeSe blue QD-LEDs.

关键词： quantum dots light-emitting diodes degradation recombination zones carrier dynamics

Recent Advances in Asymmetric Structural Composites for Excellent Electromagnetic Interference Shielding: A Review

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Chinese Journal of Polymer Science 2024年第6期42卷 693-710页

作者： Ying Zhou Bai Xue Lan Xie Chang-Mei Wu Qiang Zheng Department of Polymer Materials and Engineering College of Materials and Metallurgy Guizhou University national Engineering research center for Compounding and Modification of Polymer Materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane Processes State Key Laboratory of Public Big Data Guizhou University Department of Polymer Science and Engineering Zhejiang University

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness(EMI SE) via designing the hierarchical structures for electromagnetic interference(EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the “absorption-reflection-reabsorption” shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation(5G) technology.

关键词： Asymmetric structure Microano functional filler Polymer composite Electromagnetic interference shielding

Effects of processing parameters on fabrication defects,microstructure and mechanical properties of additive manufactured Mg–Nd–Zn–Zr alloy by selective laser melting process

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Journal of Magnesium and Alloys 2024年第6期12卷 2249-2266页

作者： Wenyu Xu Penghuai Fu Nanqing Wang Lei Yang Liming Peng Juan Chen Wenjiang Ding national Engineering research center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite School of Materials Science and EngineeringShanghai Jiao Tong University800 Dongchuan RoadShanghai 200240China Shanghai Light Alloy Net Forming national Engineering research center Co. LtdShanghai 201615China

Mg–3Nd–0.2Zn–0.4Zr(NZ30K,wt.%)alloy is a new kind of high-performance metallic *** combination of the NZ30K Magnesium(Mg)alloy and selective laser melting(SLM)process seems to be an ideal solution to produce porous Mg degradable ***,the microstructure evolution and mechanical properties of the SLMed NZ30K Mg alloy were not yet studied ***,the fabrication defects,microstructure,and mechanical properties of the SLMed NZ30K alloy under different processing parameters were *** results show that there are two types of fabrication defects in the SLMed NZ30K alloy,gas pores and unfused *** the increase of the laser energy density,the porosity sharply decreases to the minimum first and then slightly *** minimum porosity is 0.49±0.18%.While the microstructure varies from the large grains with lamellar structure inside under low laser energy density,to the large grains with lamellar structure inside&the equiaxed grains&the columnar grains under middle laser energy density,and further to the fine equiaxed grains&the columnar grains under high laser energy *** lamellar structure in the large grain is a newly observed microstructure for the NZ30K Mg *** laser energy density leads to finer grains,which enhance all the yield strength(YS),ultimate tensile strength(UTS)and elongation,and the best comprehensive mechanical properties obtained are YS of 266±2.1 MPa,UTS of 296±5.2 MPa,with an elongation of 4.9±0.68%.The SLMed NZ30K Mg alloy with a bimodal-grained structure consisting of fine equiaxed grains and coarser columnar grains has better elongation and a yield drop phenomenon.

关键词： Selective laser melting Mg alloy Processing parameter Lamellar structure Bimodal-grained structure

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Achieving full mutualism with massive passive devices for multiuser MIMO symbiotic radio

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Science China(Information Sciences) 2024年第9期67卷 196-212页

作者： Jingran XU Zhuoyin DAI Yong ZENG Shi JIN Tao JIANG national Mobile Communications research Laboratory Southeast University Purple Mountain Laboratories research center of 6G Mobile Communications School of Cyber Science and Engineering and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

Symbiotic radio(SR) is one of the attractive communication technologies to facilitate largescale Internet of Things(IoT) connections with enhanced energy and spectrum efficiency, where passive backscatter devices(BDs) modulate their information over the radio frequency(RF) signals emitted by the active primary transmitters(PTs). Meanwhile, the primary transmission can be strengthened with the additional multipaths created by BDs. To capitalize to a greater extent on the mutualism relationship between the two types of communication, this paper studies multiple-input multiple-output(MIMO) SR communication systems including multiple PTs and massive BDs. We derive the achievable rate expressions of each PT and BD, as well as the sum rate expressions of primary and secondary communication, *** asymptotic analysis is given to derive the active and passive communication rates with a large number of BDs. Furthermore, for the general case with a finite number of BDs, we study the precoding optimization problem to maximize the sum rate of primary communication, while ensuring that the sum rate of secondary communication and the individual rate for each PT and BD in the prescribed active and passive user sets satisfy the specified thresholds. Simulation results are presented to verify the analytical studies.

关键词： multiuser MIMO SR backscattering massive backscatter devices asymptotic analysis active and passive communication

Understanding adversarial attacks on observations in deep reinforcement learning

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Science China(Information Sciences) 2024年第5期67卷 69-83页

作者： You QIAOBEN Chengyang YING Xinning ZHOU Hang SU Jun ZHU Bo ZHANG Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology Tsinghua-Bosch Joint Center for Machine Learning Institute for Artificial Intelligence Tsinghua University Peng Cheng Laboratory

Deep reinforcement learning models are vulnerable to adversarial attacks that can decrease the cumulative expected reward of a victim by manipulating its observations. Despite the efficiency of previous optimization-based methods for generating adversarial noise in supervised learning, such methods might not achieve the lowest cumulative reward since they do not generally explore the environmental ***, a framework is provided to better understand the existing methods by reformulating the problem of adversarial attacks on reinforcement learning in the function space. The reformulation approach adopted herein generates an optimal adversary in the function space of targeted attacks, repelling them via a generic two-stage framework. In the first stage, a deceptive policy is trained by hacking the environment and discovering a set of trajectories routing to the lowest reward or the worst-case performance. Next, the adversary misleads the victim to imitate the deceptive policy by perturbing the observations. Compared to existing approaches, it is theoretically shown that our adversary is strong under an appropriate noise level. Extensive experiments demonstrate the superiority of the proposed method in terms of efficiency and effectiveness, achieving state-of-the-art performance in both Atari and MuJoCo environments.

关键词： deep learning reinforcement learning adversarial robustness adversarial attack

Review of the detasseling techniques for maize(Zea mays L.)hybrid seed production

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 1-11页

作者： Ruirui Zhang Jiaxuan Yang Liping Chen Chenchen Ding Longlong Li Linhuan Zhang national research center of Intelligent Equipment for Agriculture Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China national center of International research on Agricultural Aerial Application Technology Beijing 100097China research center of Intelligent Equipment Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China

Maize(Zea mays L.)is a critical staple crop globally,integral to human consumption,food security,and agricultural product *** quality and purity of maize seeds,essential for hybrid seed production,are contingent upon effective *** study investigates the evolution of detasseling technologies and their application in Chinese maize hybrid seed production,with a comparative analysis against the United States.A comprehensive examination of the development and utilization of detasseling technology in Chinese maize hybrid seed production was undertaken,with a specific focus on key *** from the United States were included for comparative *** analysis encompassed various detasseling methods,including manual,semi-mechanized,and cytoplasmic male sterility,as well as more recent innovations such as detasseling machines,and the emerging field of intelligent detasseling driven by unmanned aerial vehicles(UAVs),computer vision,and mechanical *** detasseling methods were predominantly employed by *** the challenges of inflexible and occasionally overlooked,applying detasseling machines is efficient and *** present,China’s detasseling operations in hybrid maize seed production are mainly carried out by manual work,which is labor-intensive and *** order to address this issue,China is dedicated to developing intelligent detasseling *** study emphasizes the critical role of detasseling in hybrid maize seed *** United States has embraced mechanized *** application and development of manual and mechanized detasseling were applied later than those in the United States,but latest intelligent detasseling technologies first appeared in *** detasseling is expected to be the future direction,ensuring the quality and efficiency of hybrid maize seed production,with implications for global food security.

关键词： detasseling technique detasseling machine UAVs intelligent agriculture maize hybrid seed production

Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing Ma Bo Wang Xiaodi Li Shuo Wang Wen Wang Yongzhen Peng national Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen ***,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater *** this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of *** using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 *** long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,*** eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase *** in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and ***,16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial ***,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification Mainstream wastewater

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Two-Dimensional Metallophthalocyanine Nanomaterials for Electrocatalytic Energy Conversion

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Energy & Environmental Materials 2024年第4期7卷 364-385页

作者： Xinqi Wang Shaohui Sun Jiahao Yao Hao Wan Renzhi Ma Wei Ma School of Chemical Engineering and Zhongyuan Critical Metals Laboratory Zhengzhou University research center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS)

Crowing energy demand drives the rapid development of clean and reliable energy *** the past years,the exploration of novel materials with considerable efficiency and durability has drawn attention in the area of elec... 详细信息

关键词： conjugated nanostructure electrocatalysis 2D metallophthalocyanines

Black Phosphorus for Photonic Integrated Circuits

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research 2024年第2期2023卷 339-353页

作者： Mingxin Zhang Lele Yang Xiaoxuan Wu Junjia Wang national research center for Optical Sensors/communications Integrated Networks School of Electronic Science and EngineeringSoutheast University2 SipailouNanjing 210096China

Black phosphorus gives several advantages and complementarities over other two-dimensional *** has drawn extensive interest owing to its relatively high carrier mobility,wide tunable bandgap,and in-plane anisotropy in recent *** manuscript briefly reviews the structure and physical properties of black phosphorus and targets on black phosphorus for photonic integrated *** of the applications are discussed including photodetection,optical modulation,light emission,and polarization *** recent progresses,associated challenges,and future potentials are covered.

关键词： polarization tunable phosphorus

Chemotactic nanomotor for multimodal combined therapy of glioblastoma

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Science China Chemistry 2024年第4期67卷 1277-1288页

作者： Ting Li Lin Chen Yunxin Xue Xiangyu Xiao Wenjun Dai Kaiyuan Tan Tiantian Chen Yingfang Tao Chun Mao Jian Shen Mimi Wan national and Local Joint Engineering research center of Biomedical Functional Materials School of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China

Glioblastoma(GBM) is the most aggressive malignant brain tumor. Due to the infiltration and heterogeneity of GBM, the obstruction of the blood-brain barrier(BBB) and the unique immunosuppressive mechanism, it is hard to achieve significant effects of GBM treatment. Here, a kind of chemotactic nanomotor that loaded with glucose oxidase(GOx) and carboxylated cisplatin(Pt(IV)) prodrug on the L-arginine-derived polymer is proposed. The nanomotors are driven by catalysis of glucose decomposition and the positive chemotaxis towards the GBM microenvironment where inducible nitric oxide synthase and reactive oxygen species are highly expressed. This facilitates the BBB crossing and GBM targeting of the nanomotors. In addition, the released nitric oxide(NO) during propulsion as well as the loaded GOx and Pt(IV) can exert combined NO/starvation/chemotherapy. Meanwhile, it is able to induce and enhance the immune response through multiple pathways, thus better coping with the complexities of GBM treatment.

关键词： chemotaxis combined therapy glioblastoma nanomotors

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