检索结果-南通市图书馆

Full-parameter omnidirectional transformation optical devices

National Science Review 2024年第3期11卷 92-99页

作者： Yuan Gao Yu Luo Jingjing Zhang Zhengjie Huang Bin Zheng hongsheng chen Dexin Ye Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and InstrumentationZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang University School of Electrical and Electronic Engineering Nanyang Technological University CNRS-InternationalNTU-Thales Research Alliance Nanyang Technological University Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University International Joint Innovation Center The Electromagnetics Academy at Zhejiang University Zhejiang University Key Laboratory of Advanced Micro/Nano Electronic Devices&Smart Systems of Zhejiang Jinhua Institute of Zhejiang UniversityZhejiang University Shaoxing Institute of Zhejiang University Zhejiang University

Transformation optics(TO) provides an unprecedented technique to control electromagnetic(EM) waves by engineering the constitutive parameters of the surrounding medium through a proper spatial transformation. In general, ideal transformation optical devices require simultaneous electric and magnetic responses along all three dimensions. To ease the practical implementation, previous studies usually made use of reduced parameters or other simplified approaches, which inevitably introduce extra reflection or unwanted phase shift. Up to today, experimental realizations of full-parameter transformation optical devices in free space are still quite limited. Here, a general design strategy is proposed to solve this problem.As a specific example, a full-parameter spatial-compression TO medium with constitutive parameters taking the diagonal form diag(a, a, 1/a) for the TM wave incidence was designed and realized experimentally. Such spatial-compression TO media were then applied to the implementation of an ideal omnidirectional invisibility cloak capable of concealing a large-scale object over a wide range of illumination angles. Both the simulation and experiment confirm that the cloak allows for nearly unity transmission of EM waves in the forward direction without introducing extra scattering or phase shift. This work constitutes an important stepping stone for future practical implementation of arbitrary full-parameter omnidirectional transformation optical devices.

关键词： transformation optical devices omnidirectional impedance matching full-parameter invisibility cloak

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Autonomous aeroamphibious invisibility cloak with stochastic-evolution learning

引用

Advanced Photonics 2024年第1期6卷 64-72页

作者： Chao Qian Yuetian Jia Zhedong Wang Jieting chen Pujing Lin Xiaoyue Zhu Erping Li hongsheng chen Zhejiang University ZJU-UIUC InstituteInterdisciplinary Center for Quantum InformationState Key Laboratory of Extreme Photonics and InstrumentationHangzhouChina Zhejiang University ZJU-Hangzhou Global Science and Technology Innovation CenterKey Laboratory of Advanced Micro/Nano Electronic Devices and Smart Systems of ZhejiangHangzhouChina Zhejiang University Jinhua Institute of Zhejiang UniversityJinhuaChina

Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential threats.Decades ago,the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks,which have been mainly demonstrated in ground and waveguide modalities.However,an omnidirectional flying cloak has not been achieved,primarily due to the challenges associated with dynamic synthesis of metasurface dispersion.We demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception,decision,and execution modules,capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external stimuli.The physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency domains.To intelligently control the spatiotemporal metasurfaces,we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic inference.In a fully self-driving experiment,we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes-sea,land,and air-with a similarity rate of up to 95%.Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.

关键词： intelligent metasurfaces optical materials and structures deep learning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design and fabrication of Nd-Fe-B magnet with excellent thermal stability

引用

Journal of Rare Earths 2024年第5期42卷 980-986,I0006页

作者： Rui Han Shengzhi Dong Dong Li Dongmin Zhang hongsheng chen Jiyuan Xu George CHadjipanayis Zhuolin Li Ying Zhang Wei Li Division of Functional Materials Research Central Iron and Steel Research InstituteBeijing100081China Department of Physics and Astronomy Sharp Lab University of DelawareNewarkDE19716USA Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing100190China

A novel Nd-Fe-B type permanent magnet with excellent thermal stability was designed by Co replacing Fe in the main phase and the grain boundary phase.The remanence and coercivity temperature coefficient reach 0.058%/℃and 0.465%/℃in the te mperature range from 25 to 100℃,which are much lower than those of commercial Nd-Fe-B magnet.An enhanced Curie temperature is obtained for the novel magnet due to the Co substitution,which significantly improves the operating temperature.The microstructure result reveals that an amorphous phase exists in the intergranular grains which is probably responsible for the deterioration of intrinsic coercivity.This work can provide a reference for the design and optimization of components of sintered Nd-Fe-B magnets with excellent thermal stability.

关键词： Thermal stability Remanence temperature coefficient Operating temperature Atomic substitution Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flow Loss Mechanism in a Supercritical Carbon Dioxide Centrifugal Compressor at Low Flow Rate Conditions

引用

Journal of Thermal Science 2024年第1期33卷 114-125页

作者： YANG Zimu JIANG hongsheng ZHUGE Weilin CAI Ruikai YANG Mingyang chen Haoxiang QIAN Yuping ZHANG Yangjun State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

With the advantages of high efficiency and compact structure,supercritical carbon dioxide(sC02)Brayton cycles have bright prospects for development in energy conversion field.As one of the core components of the power cycle,the centrifugal compressor tends to operate near the critical point(304.13 K,7.3773 MPa).Normally,the compressor efficiency increases as the inlet temperature decreases.When the inlet temperature is close to the critical point,the density increases sharply as the temperature decreases,which results in quickly decreasing of volume flow rate and efficiency reducing.The flow loss mechanism of the sCO_(2) compressor operating at low flow rate is studied in this paper.Computational fluid dynamics(CFD) simulations for sCO_(2)compressor were carried out at various inlet temperatures and various mass flow rates.When the sCO_(2)compressor operates at low volume flow rate,the flow loss is generated mainly on the suction side near the trailing edge of the blade.The flow loss is related to the counterclockwise vortexes generated on the suction side of the main blade.The vortexes are caused by the flow separation in the downstream region of the impeller passage,which is different from air compressors operating at low flow rates.The reason for this flow separation is that the effect of Coriolis force is especially severe for the sCO_(2) fluid,compared to the viscous force and inertial force.At lower flow rates,with the stronger effect of Coriolis force,the direction of relative flow velocity deviates from the direction of radius,resulting in its lower radial component.The lower radial relative flow velocity leads to severe flow separation on the suction side near the trailing edge of the main blade.

关键词： supercritical CO_(2) centrifugal compressor flow loss mechanism Coriolis force

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

RNA ac^(4)C modification in cancer biology:from regulatory mechanisms to clinical applications

引用

Science China(Life Sciences) 2024年第4期67卷 832-835页

作者： Lijun Tao Yunqing Lu Zhuojia chen Lichen Ge Junming He Jianxin Peng hongsheng Wang School of Pharmaceutical Sciences Sun Yat-sen UniversityGuangzhou 510006China Sun Yat-sen University Cancer Center State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhou 510060China Department of Hepatobiliary Surgery Guangdong Province Traditional Chinese Medical HospitalGuangzhou 510120China

RNA modifications are increasingly recognized for their significance in diverse physiological and pathological processes,with over 170 types of chemical modifications having been discovered since the1960s.Among these modifications,N4-acetylcytidine(ac^(4)C)is the first acetylated modification identified on eukaryotic RNAs,previously reported in transfer RNA(t RNA)and ribosomal RNA(rRNA)。

关键词： clinical (4) modification

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Potassium transporter OsHAK9 regulates seed germination under salt stress by preventing gibberellin degradation through mediating OsGA2ox7 in rice

引用

Journal of Integrative Plant Biology 2024年第4期66卷 731-748页

作者： Peng Zeng Ting Xie Jiaxin Shen Taokai Liang Lu Yin Kexin Liu Ying He Mingming chen Haijuan Tang Sunlu chen Sergey Shabala hongsheng Zhang Jinping cheng National Key Laboratory of Crop Genetics&Germplasm Enhancement and Utilization Jiangsu Collaborative Innovation Center for Modern Crop ProductionHainan Yazhou Bay Seed LabJiangsu Province Engineering Research Center of Seed Industry Science and TechnologyNanjing Agricultural UniversityNanjing 210095China International Research Center for Environmental Membrane Biology Foshan UniversityFoshan 528000China School of Biological Sciences University of Western AustraliaCrawley WA 6009Australia

Soil salinity has a major impact on rice seed germination,severely limiting rice production.Herein,a rice germination defective mutant under salt stress(gdss)was identified by using chemical mutagenesis.The GDSS gene was detected via MutMap and shown to encode potassium transporter OsHAK9.Phenotypic analysis of complementation and mutant lines demonstrated that OsHAK9 was an essential regulator responsible for seed germination under salt stress.OsHAK9 is highly expressed in germinating seed embryos.Ion contents and non-invasive micro-test technology results showed that OsHAK9 restricted K^(+)efflux in salt-exposed germinating seeds for the balance of K^(+)/Na^(+).Disruption of OsHAK9 significantly reduced gibberellin 4(GA4)levels,and the germination defective phenotype of oshak9a was partly rescued by exogenous GA_(3)treatment under salt stress.RNA sequencing(RNA-seq)and real-time quantitative polymerase chain reaction analysis demonstrated that the disruption of OsHAK9 improved the GA-deactivated gene OsGA2ox7 expression in germinating seeds under salt stress,and the expression of OsGA2ox7 was significantly inhibited by salt stress.Null mutants of OsGA2ox7 created using clustered,regularly interspaced,short palindromic repeat(CRISPR)/CRISPR-associated nuclease 9 approach displayed a dramatically increased seed germination ability under salt stress.Overall,our results highlight that OsHAK9 regulates seed germination performance under salt stress involving preventing GA degradation by mediating OsGA2ox7,which provides a novel clue about the relationship between GA and OsHAKs in rice.

关键词： GDSS gibberellins potassium transporter rice salt tolerance seed germination

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Penetration into a granular bed in the presence of upward gas flows

引用

Particuology 2023年第11期82卷 1-12页

作者： hongsheng chen Li Xia chenrui Li Zengyong Zheng College of Materials Science and Engineering Chongqing UniversityChongqing400044China

We present a numerical study on the penetration of spherical projectiles into a granular bed in the presence of upward gas flows.Due to the presence of interstitial fluid,the force chains between particles in the granular bed are weakened significantly,and this distinguishes the penetration behavior from that in the absence of fluid.An interesting phenomenon,namely granular jet,is observed during the penetration,and the mechanism for its formation and growth is attributed to the merging of granular vortices generated by the interaction between the intruder and primary particles.Moreover,both the final penetration depth and the maximum diameter of the crater are found to follow a power-law dependence with the impact velocity,and the maximum height reached by the granular jet tends to increase linearly as the impact velocity increases,agreeing well with the experimental results reported in the literature.

关键词： Penetration Granular bed Granular jet CFD-DEM

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microstructure evolution and corrosion resistance of AZ31 magnesium alloy tube by stagger spinning

引用

International Journal of Minerals,Metallurgy and Materials 2022年第7期29卷 1361-1372页

作者： Fanlin Zheng hongsheng chen Yuanqi Zhang Wenxian Wang Huihui Nie College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-Based Materials Taiyuan 030024China College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China

This study fabricates an AZ31 magnesium alloy tube by spinning technology-power stagger forward spinning.The microstructure evolution of the tube is investigated by combining electron backscatter diffraction and transmission electron microscopy analysis,and the corrosion resistance is measured by an electrochemical corrosion test.Results show that the grains are obviously more uniform and finer along the wall thickness’s direction of the AZ31 alloy tube after the third spinning pass.The number of twins ascends first and then descends,while the varying trend of low-angle grain boundaries(LAGBs)is opposite to that of the twins as the spinning pass increases.With the increase of the total spinning deformation,the deformation texture initially increases and the c-axis of the{0001}crystal plane gradually rotates to the axial direction of the tube;the deformation texture then decreases and the orientation of grains becomes more random.The main mechanism of grain refinement is dynamic recrystallization by the twin-induced way and bowing out of the nucleation at grain boundaries during the first and second pass.However,the dominant mechanism of the refined grain is the high-temperature dynamic recovery in the third pass,and the microstructure mainly consists of substructured grains.After the spinning deformation,the corrosion resistance of the AZ31 alloy tube decreases due to the combined effect of twins and high density-dislocations.

关键词： AZ31 magnesium alloy power stagger forward spinning microstructure evolution corrosion resistance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Superscattering of water waves

引用

National Science Review 2023年第7期10卷 91-97页

作者： Zijian Qin Chao Qian Lian Shen Xiaoping Wang Ido Kaminer hongsheng chen Huaping Wang Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province Institute of Marine Electronics Engineering Ocean College Zhejiang University ZJU-Hangzhou Global Science and Technology Innovation Center Key Lab.of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Zhejiang University ZJU-UIUC Institute Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation Zhejiang University Jinhua Institute of Zhejiang University Zhejiang University Department of Electrical Engineering Technion-Israel Institute of Technology

Inspired by the concept of superscattering in optics,we for the first time theoretically predict and experimentally demonstrate the superscattering phenomenon in water waves.The subwavelength superscatterer is constructed by multi-layered concentric cylinders with an inhomogeneous depth profile.The superscatterer breaks the long-held single-channel scattering limit by several times and thus significantly enhances the total scattering strength.The underlying mechanism originates from the near degeneracy of the resonances of multiple channels.We fabricate the superscatterer prototype and experimentally measure the near-field patterns,which are consistent with theoretical prediction and numerical simulation.Our study opens a new avenue to strengthen water-wave scattering and deepen the understanding in water waves,which can be useful for ocean energy harvesting and harbor protection.

关键词： superscattering water wave metamaterials

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

N6-methyladenosine facilitates mitochondrial fusion of colorectal cancer cells via induction of GSH synthesis and stabilization of OPA1 mRNA

引用

National Science Review 2024年第3期11卷 72-91页

作者： Jiawang Zhou Haisheng Zhang Ke Zhong Lijun Tao Yu Lin Guoyou Xie Yonghuang Tan You Wu Yunqing Lu Zhuojia chen Jiexin Li Xin Deng Qin Peng Zigang Li hongsheng Wang Guangdong Provincial Key Laboratory of New Drug Design and Evaluation School of Pharmaceutical Sciences Sun Yat-sen University Sun Yat-sen University Cancer Center State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine Department of Biomedical Sciences City University of Hong Kong Institute of Systems and Physical Biology Shenzhen Bay Laboratory

Mitochondria undergo fission and fusion that are critical for cell survival and cancer development, while the regulatory factors for mitochondrial dynamics remain elusive. Herein we found that RNA m6A accelerated mitochondria fusion of colorectal cancer（CRC） cells. Metabolomics analysis and function studies indicated that m6A triggered the generation of glutathione（GSH） via the upregulation of RRM2B——a p53-inducible ribonucleotide reductase subunit with anti-reactive oxygen species potential. This in turn resulted in the mitochondria fusion of CRC cells. Mechanistically, m6A methylation of A1240 at 3 UTR of RRM2B increased its m RNA stability via binding with IGF2BP2. Similarly, m6A methylation of A2212 at the coding sequence（CDS） of OPA1——an essential GTPase protein for mitochondrial inner membrane fusion——also increased m RNA stability and triggered mitochondria fusion. Targeting m6A through the methyltransferase inhibitor STM2457 or the dm6ACRISPR system significantly suppressed mitochondria fusion. In vivo and clinical data confirmed the positive roles of the m6A/mitochondrial dynamics in tumor growth and CRC progression. Collectively, m6A promoted mitochondria fusion via induction of GSH synthesis and OPA1 expression, which facilitated cancer cell growth and CRC development.

关键词： m6A mitochondrial fusion glutathione OPA1 colorectal cancer

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：