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Rare Metals 2024年第10期43卷 5152-5163页

作者： dong-Wei Ma Jing-Sheng Lu xiang-Xin Cao Yan-Wei cheng Gang Wang Zi-Qian Zhang Bo-cheng chen Ning Lin Qing chen College of Pharmacy Guangxi Scientific Research Center of Traditional Chinese MedicineGuangxi University of Chinese Medicine Guangxi Zhuang Yao Medicine Center of Engineering and Technology

The rational design of a specific co-drug delivery platform that can address the unavoidable resistance, toxic side effects and low targeting efficiency of traditional cancer treatments is of great ***, Zn-based MOF-zeolitic imidazole framework-90(ZIF-90) was selected as the drug delivery carrier, with the cancer therapeutic drug mercaptopurine(6-MP) and glucose oxidase(GOD) as the drug models, hyaluronic acid(HA) was used for protection and targeted delivery, which designed and fabricated an intelligent drug delivery platform(6-MP@ZIF-90@GOD@HA). This platform aims to reduce the toxic side effects of 6-MP and enhance its efficacy while improving the targeting ability of GOD,thereby further enhancing the treatment outcome. Notably,results from both in vitro and in vivo experiments demonstrate that the targeted synergistic chemo/reactive oxygen species(ROS)-mediated/starvation therapy inhibited the cancer cell growth while reducing the chemotherapy toxicity, which provides new possibilities for the development of more precise and effective treatment strategies.

关键词： Cancer treatment Combination therapy Drug delivery Metal-organic framework Reduced toxicity

Reduction of unactivated alkyl chlorides enabled by light-induced single electron transfer

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Science China Chemistry 2024年第2期67卷 471-481页

作者： Lei Dai Zhao-Fei Zhang xiang-Yu chen School of Chemical Sciences University of the Chinese Academy of SciencesBeijing100049China Institute of Chemistry Chinese Academy of SciencesBeijing100190China Binzhou Institute of Technology Weiqiao-UCAS Science and Technology ParkBinzhou256606China

Alkyl chlorides are abundant and easily accessible starting ***,due to the high reduction potentials associated with unactivated alkyl chlorides,achieving their single electron reduction remains a persistent *** challenge has spurred the exploration of efficient activation methods to overcome this *** recent years,photocatalysis has emerged as a mild and potent tool for the single electron reduction of unactivated alkyl chlorides,opening up new possibilities in this *** the rapid advancements in this area,a comprehensive review that provides a conceptual understanding of this emerging field,with a specific focus on reaction design and catalytic mechanisms,would be timely and highly ***,we present an overview of various synthetic techniques for photoinduced single electron reduction of unactivated alkyl ***,we also discuss the limitations of the present methods and future directions that lie ahead in this field.

关键词： photocatalysis unactivated alkyl chlorides single electron transfer radical reactions

Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400℃

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Journal of Materials Science & Technology 2024年第5期172卷 71-82页

作者： xiang Su Yuan Lei Yang chen Hongjie Qu Zhixiang Qi Gong Zheng Xu Liu Henggao xiang Guang chen National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China School of Aviation and Mechanical Engineering Changzhou Institute of TechnologyChangzhou 213032China

Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy ***,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening ***,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3Ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum *** enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one *** significant segregation of Ni,Ce,and Zr elements at the interfaces helps improve the thermal stability of the T *** thermostable T phase effectively strengthens the matrix by in-hibiting dislocation ***,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high *** finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications.

关键词： Aluminum alloys Precipitation Thermally reinforcement phase Re-aging treatment High-temperature strength

Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： Gui-quan Wang Zhuo Xu Zhong-li Liu xiang chen Yan-xiang Li School of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake *** this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical *** graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of *** peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction *** morphology of thermal cracks and 3D profiles of the worn surfaces were also *** is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue *** of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal *** the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

I_(2)-DMSO-Mediated Multicomponent [2+1+1+1] Annulation Reaction via Ethyl Nitroacetate C-NO_(2), Bond Cleavage as a C1 Synthon: A Route to Multisubstituted 6-Pyrrolidinones Derivatives with a Quaternary Center

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Chinese Journal of Chemistry 2024年第17期42卷 2029-2034页

作者： Zhi-cheng Yu Xi Shen You Zhou xiang-Long chen Li-Sheng Wang Yan-dong Wu An-Xin Wu National Key Laboratory of Green Pesticide International Joint Research Centerfor Intelligent BiosensorTechnologyand HealthCollegeof ChemistryCentral ChinaNormal UniversityWuhanHubei 430079China

A[2+1+1+1]cyclization reaction has been developed for the synthesis of multisubstituted 6-pyrrolidinones from commercially available aryl methyl ketones,primary amines,and ethyl *** this I_(2)-DMSO-meditated process,the C-NO_(2) bond of ethyl nitroacetate is cleaved,affording a C1 synthon,and the formation of two C-C and two C-N bonds and a quaternary carbon center are constructed in one *** method has good substrate compatibility and permits the late-stage modification of pharmaceutical compounds.

关键词： Cyclization Multisubstituted 6-pyrrolidinones I_(2)-DMSO C1 building blocks Quaternary carbon center Late-stage modification Cracking

Low-noise and low-power pixel sensor chip for gas pixel detectors

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Nuclear Science and Techniques 2024年第3期35卷 142-152页

作者： Zhuo Zhou Shi-Qiang Zhou dong Wang xiang-Ming Sun Chao-Song Gao Peng-Zhen Zhu Wei-Ping Ren Jun Liu Mu-Xian Li chen Lian Chun-Lai dong PLAC Key Laboratory of Quark and Lepton Physics(MOE)Central China Normal UniversityWuhan 430079China

Topmetal-M2 is a large-area pixel sensor chip fabricated using the GSMC 130 nm CMOS process in *** pixel array of Topmetal-M2 consists of pixels of 400 rows×512 columns with a pixel pitch of 45μm×45μ*** array is divided into 16 subarrays,with pixels of 400 rows×32 columns per *** pixel incorporates two charge sensors:a diode sensor and a Topmetal *** in-pixel circuit primarily consists of a charge-sensitive amplifier for energy measurements,a discriminator with a peak-holding circuit,and a time-to-amplitude converter for time-of-arrival *** pixel of Topmetal-M2 has a charge input range of~0-3 k e-,a voltage output range of~0-180 mV,and a charge-voltage conversion gain of~59.56μV∕e-.The average equivalent noise charge of Topmetal-M2,which includes the readout electronic system noise,is~43.45 e-.In the scanning mode,the time resolution of Topmetal-M2 is 1 LSB=1.25μs,and the precision is^()7.41μ*** an operating voltage of 1.5 V,Topmetal-M2 has a power consumption of~49 mW∕cm~*** this article,we provide a comprehensive overview of the chip architecture,pixel working principles,and functional behavior of ***,we present the results of preliminary tests conducted on Topmetal-M2,namely,alpha-particle and soft X-ray tests.

关键词： Charge collection Gas detectors Semiconductor detectors X-ray detectors

Practical cloud storage auditing using serverless computing

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Science China(Information Sciences) 2024年第3期67卷 33-47页

作者： Fei chen Jianquan CAI Tao xiang Xiaofeng LIAO College of Computer Science and Software Engineering Shenzhen University College of Computer Science Chongqing University

Cloud storage auditing research is dedicated to solving the data integrity problem of outsourced storage on the cloud. In recent years, researchers have proposed various cloud storage auditing schemes using different techniques. While these studies are elegant in theory, they assume an ideal cloud storage model;that is, they assume that the cloud provides the storage and compute interfaces as required by the proposed schemes. However, this does not hold for mainstream cloud storage systems because these systems only provide read and write interfaces but not the compute interface. To bridge this gap, this work proposes a serverless computing-based cloud storage auditing system for existing mainstream cloud object storage. The proposed system leverages existing cloud storage auditing schemes as a basic building block and makes two adaptations. One is that we use the read interface of cloud object storage to support block data requests in a traditional cloud storage auditing scheme. Another is that we employ the serverless computing paradigm to support block data computation as traditionally required. Leveraging the characteristics of serverless computing, the proposed system realizes economical, pay-as-you-go cloud storage auditing. The proposed system also supports mainstream cloud storage upper layer applications(e.g., file preview) by not modifying the data formats when embedding authentication tags for later auditing. We prototyped and open-sourced the proposed system to a mainstream cloud service, i.e., Tencent Cloud. Experimental results show that the proposed system is efficient and promising for practical use. For 40 GB of data, auditing takes approximately 98 s using serverless computation. The economic cost is 120.48 CNY per year, of which serverless computing only accounts for 46%. In contrast, no existing studies reported cloud storage auditing results for real-world cloud services.

关键词： cloud storage auditing serverless computing object storage usability

Filtering and regret network for spacecraft component segmentation based on gray images and depth maps

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Chinese Journal of Aeronautics 2024年第7期37卷 439-449页

作者： xiang LIU Hongyuan WANG Zijian WANG Xinlong chen Weichun chen Zhengyou XIE Institute of Aeronautics Harbin Institute of TechnologyHarbin 150001China Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100080China

Identifying and segmenting spacecraft components is vital in many on-orbit space missions,such as on-orbit maintenance and component *** depth maps with visual images has been proven effective in improving segmentation ***,existing methods ignore the noise and fallacy in collected depth maps,which interfere with the network to extract representative features,decreasing the final segmentation *** this end,this paper proposes a Filtering and Regret Network(FRNet)for spacecraft component *** FRNet incorporates filtering and regret mechanisms to suppress the abnormal depth response in shallow layers and selectively reuses the filtered cues in deep layers,avoiding the detrimental effects of low-quality depth information while preserving the semantic context inherent in depth ***,a two-stage feature fusion module is proposed,which involves information interaction and *** module effectively explores the feature correlation and unifies the multimodal features into a comprehensive ***,a large-scale spacecraft component recognition dataset is constructed for training and evaluating spacecraft component segmentation *** results demonstrate that the FRNet achieves a state-of-the-art performance with a mean Intersection Over Union(mIOU)of 84.13%and an average inference time of 133.2 ms when tested on an NVIDIA RTX 2080 SUPER GPU.

关键词： Spacecraft component recognition Multi-modal feature fusion Satellite dataset Intelligent systems Deep learning

Actin-depolymerizing factors 8 and 11 promote root hair elongation at high pH

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Plant Communications 2024年第3期5卷 232-247页

作者： dong Qian Tian Li chen Zheng Yue Niu Yingzhi Niu chengying Li Muxuan Wang Yang Yang Lizhe An Yun xiang Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations School of Life SciencesLanzhou UniversityLanzhou 730000China These authors contributed equally to this article

A root hair is a polarly elongated single-celled structure that derives from a root epidermal cell and func-tions in uptake of water and nutrients from the surrounding *** reports have demon-strated that short periods of high pH inhibit root hair extension;but the effects of long-term high-pH treat-ment on root hair growth are still ***,we report that the duration of root hair elongation is signicantly prolonged with increasing external pH,which counteracts the effect of decreasing root hair elongation rate and ultimately produces longer root hairs,whereas loss of actin-depolymerizing factor 8 and 11(ADF8/11)function causes shortening of root hair length at high pH(pH 7.4).Accumulation of ADF8/11 at the tips of root hairs is inhibited by high pH,and increasing environmental pH affects the actinlament(F-actin)meshwork at the root hair *** high pH,the tip-focused F-actin meshwork is absent in root hairs of the adf8/11 mutant,actinlaments are disordered at the adf8/11 root hair tips,and actin turn-over is *** and recycling vesicles do not aggregate in the apical region of adf8/11 root hairs at high ***,our results suggest that,under long-term exposure to high extracellular pH,ADF8/11 may establish and maintain the tip-focused F-actin meshwork to regulate polar trafcking of secretory/recycling vesicles at the root hair tips,thereby promoting root hair elongation.

关键词： pH ADF actin Rab GTPase vesicle root hair

Effects of layer interactions on instantaneous stability of finite Stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： chen ZHAO Zhenli chen C.T.MUTASA dong LI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

The stability analysis of a finite Stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite Stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. The oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. The effects of the Stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. The growth rates of two most unstable modes when δ 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the Stokes-layer interactions are strong. We also find that the stability of the Stokes layer is closely related to the inflectional points of the base-flow velocity profile. The effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. The energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. The effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite Stokes layer instantaneous stability Stokes-layer interaction asynchronous oscillation