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稳定同位素技术在食品检验中的应用研究进展

中国食品卫生杂志 2023年第3期35卷 487-490页

作者：赵悦金莹吕宁王萍翟丽娜青岛海关技术中心青岛海关风险防控分局山东青岛266000

近年来,稳定同位素技术在产品质量安全控制和真实性鉴别方面被广泛应用。本文综述了该技术近年来在各类食品真伪鉴别和食品安全溯源中的研究进展,并对其应用前景进行展望,旨在推动稳定同位素技术在我国的应用步伐,以期为管理部门的监管... 详细信息

近年来,稳定同位素技术在产品质量安全控制和真实性鉴别方面被广泛应用。本文综述了该技术近年来在各类食品真伪鉴别和食品安全溯源中的研究进展,并对其应用前景进行展望,旨在推动稳定同位素技术在我国的应用步伐,以期为管理部门的监管提供参考。

关键词：稳定同位素技术质量安全检测溯源掺杂使假

Effect of fore/aft-loaded rotor on compressor stability under inlet circumferential distortion

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Chinese Journal of Aeronautics 2024年第5期37卷 199-213页

作者： Dakun SUN Benhao GU Fangfei ning Dengke XU Xiaofeng SUN School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-engine Beihang UniversityBeijing 102206China

A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stability under circumferentially distorted inlet *** inlet total pressure distribution downstream of the distortion screen is measured in experiments and employed for simulations which are implemented via time-space spectral *** stall inception prediction results via the stability model indicate that the compressor with aft-loaded rotor not only performs better in terms of stability under uniform inlet,but also maintains a larger stability margin under circumferentially distorted *** experiments for compressors with fore-loaded and aft-loaded rotor are respectively carried *** results validate the reliability of numerical simulations and the predicted conclusion that the aft-loaded rotor is beneficial for compressor ***,the ability of the developed theoretical model for compressor stability prediction under circumferential distortions is *** addition,dynamic pressure signals at rotor tip measured in experiments illustrate that the circumferential distortion has little effect on the compressor stall pattern.

关键词： Axial compressor stability Inlet distortion Blade loading Small perturbation Time-space spectral method

重症肺炎患者血清APC和相关炎症因子对病情及预后评估价值探讨

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社区医学杂志 2023年第3期21卷 129-135页

作者：张焱吕宁南阳市康复医院呼吸科河南南阳473000

目的观察重症肺炎患者血清活化蛋白C(APC)及相关炎症因子表达并分析其对病情及预后的评估价值。方法选取2020-05-30-2022-05-30南阳市康复医院收治的120例(纳入123例患者,其中2例失访,1例入住ICU 48 h内死亡,120例进入本研究)重症肺炎... 详细信息

目的观察重症肺炎患者血清活化蛋白C(APC)及相关炎症因子表达并分析其对病情及预后的评估价值。方法选取2020-05-30-2022-05-30南阳市康复医院收治的120例(纳入123例患者,其中2例失访,1例入住ICU 48 h内死亡,120例进入本研究)重症肺炎患者为研究对象,入院24 h内采用急性生理学与慢性健康状况评分Ⅱ(APACHEⅡ)系统评估病情,检测入院时血清APC及相关炎症因子[肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-6、IL-10]水平;采用Pearson相关性分析各指标与APACHEⅡ评分之间的关系。根据患者28 d内的预后结局分为生存组(n=82)与死亡组(n=38);比较2组患者入住重症监护室(ICU)1、2和3 d的血清APC、TNF-α、IL-6、IL-10水平的变化情况,绘制受试者工作特征(ROC)曲线分析各指标对患者28 d预后的预测价值。结果入院时重症肺炎患者血清APC为(31.62±4.51)pmol/L,TNF-α为(57.66±9.62)ng/L,IL-6为(85.63±8.75)pg/mL,IL-10为(65.16±7.38)ng/L;入院24 h内APACHEⅡ评分为(24.70±3.94)分,采用Pearson相关性分析发现,血清APC与APACHEⅡ评分呈负相关,r=-0.460,P<0.001;血清TNF-α、IL-6、IL-10与APACHEⅡ评分均呈正相关,r值分别为0.407、0.390和0.272,均P<0.001。与入住ICU 1 d相比,死亡组血清APC水平整体呈下降趋势,TNF-α、IL-6、IL-10水平整体呈升高趋势,均P<0.05;生存组血清APC水平整体呈升高趋势,TNF-α、IL-6、IL-10水平整体呈下降趋势,均P<0.05。Cox回归分析显示,血清APC(HR=0.893,95%CI为0.822~0.970)、TNF-α(HR=1.045,95%CI为1.012~1.080)、IL-6(HR=1.042,95%CI为1.004~1.082)、IL-10(HR=1.040,95%CI为1.016~1.064)是重症肺炎患者28 d内病死的危险因素,P<0.05;ROC曲线显示,入住ICU 1 d时血清APC、TNF-α、IL-6、IL-10单独及联合预测重症肺炎患者预后的曲线下面积(AUC)分别为0.710、0.717、0.721、0.790、0.892,均有一定的预测价值,但整体预测价值不高。结论重症肺炎患者血清APC低表达,TNF-α、IL-6、IL-10过表达,与病情程度及预后存在关联性,且各指标可作为评估重症肺炎患者病情和预测预后的辅助性指标。

关键词：重症肺炎活化蛋白C 肿瘤坏死因子-α 白细胞介素-6 白细胞介素-10

Effects of heat treatment on microstructures and properties of a heterostructured alloy with dissimilar components fabricated by WAAM

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Rare Metals 2024年第9期43卷 4441-4461页

作者： Ming-Cai Pan Jun-Qiang Xu Yong Peng ning-ning Liang Si Lan Qi Zhou Ke-Hong Wang School of Materials Science and Engineering Nanjing University of Science and Technology Key Laboratory of Controlled Arc Intelligent Additive Manufacturing Technology

Heat treatment significantly influences homogeneous material microstructures and mechanical properties, which can be improved by an optimal heat treatment process. However, heat treatment application to heterogeneous materials presents significant challenges due to compositional and microstructural heterogeneities. Herein,a laminated heterostructured alloy comprising alternating316L stainless steel（SS） and 18Ni300 maraging steel（MS）layers fabricated using wire and arc additive manufacturing was investigated. A solution treatment was applied at900 °C for 0.5 h. Subsequently, the solution-treated and asfabricated（AF） samples were aged at 500 °C for 4 h; these samples were denoted SA and AT, respectively. The AT phase compositions and orientations were similar to those of AF. The SA 316L SS layer resembled that of AF, but the SA 18Ni300 MS layers exhibited a reduced austenite phase fraction and refined grain size, attributable to solid-state transformation. In the AT sample, aging induced the formation of nanoscale acicular ω phase and ellipsoidal Ni3Ti,Fe2Mo, and X precipitates in the 18Ni300 MS ***, the SA precipitates contained acicular Fe Ni2and ellipsoidal ω, Ni3Ti, and X precipitates, and their fractions were lower than those in AT precipitates. The18Ni300 MS layer microhardness in the heat-treated samples increased due to nanoprecipitation, but the 316L SS layer microhardness resembled that of AF. The AT and SA ultimate tensile strengths increased to（1360 ± 50） and（1473 ± 41） MPa, respectively, attributable to precipitation strengthening. The SA 316L SS layer exhibited a high stress-induced martensite fraction, enhancing the ductility of heated samples.

关键词： Heat treatment Laminated heterostructured alloy Mechanical property Microstructure Wire and arc additive manufacturing

Empirical model of concrete block fragment behavior under explosion loads

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Science China Technological Sciences 2024年第8期67卷 2515-2529页

作者： YANG Shuai ning JianGuo REN HuiLan XU XiangZhao State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of Technology

Concrete structures undergo integral fragmentation under explosion loads. The fragmentation degree and particle-size distribution of concrete blocks under explosion loads must be considered during mining to ensure safety. In this study, the impulse is calculated based on the relationship between overpressure and time, and the impact energy of the explosion wave is obtained based on blast theory. Subsequently, the Mohr-Coulomb shear strength fracture criterion is introduced to determine the ultimate shear stress of the concrete materials, and an empirical model that can effectively calculate the energy consumption of concrete blocks under explosion loads is established. Furthermore, concrete fragments with different particle sizes under explosion scenarios are quantitatively predicted with the principle of energy conservation. Finally, explosion tests with different top standoff distances are conducted, and the concrete fragments after the explosion tests are recovered, sieved, weighed, and counted to obtain experimental data. The effectiveness of the fragment empirical model is verified by comparing the model calculation results with the experimental data. The proposed model can be used as a reference for civil blasting, protective engineering design, and explosion-damage assessment.

关键词： concrete structures explosion loads fragment behavior empirical model

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Online Monitoring Method for Junction Temperature of SiC MOSFETs based on Temperature Sensitive Electrical Parameter

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1799-1807页

作者： Han Cao Puqi ning Yunhao Huang Xuhui Wen Wuhan Second Ship Design and Research Institute Wuhan 430205China Key Laboratory of Power Electronics and Electric Drive Institute of Electrical EngineeringChinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081China

Compared to Si devices,the junction temperature of SiC devices is more critical due to the reliability concern introduced by immature packaging technology applied to new *** paper proposes a practical SiC MOSFET junction temperature monitoring method based on the on-state voltage$\\boldsymbol{V}_{\\mathbf{ds}(\\mathbf{on})}$*** Section II of the paper,the temperature sensitivity of the on-state voltage$\\boldsymbol{V}_{\\mathbf{ds}(\\mathbf{on})}$is *** hardware of the measurement system is set up in Section III,which consists of an On-state Voltage Measurement Circuit(OVMC),the sampling and isolation ***,a calibration method based on the self-heating of the SiC MOSFET chip is presented in Section *** the final Section,the junction temperature is monitored synchronously according to the calibration *** proposed method is applied to a Buck converter and verified by both an Infrared Radiation(IR)camera and a Finite Element Analysis(FEA)tool.

关键词： Junction temperature Silicon Carbide(SiC)MOSFET TSEP

Multi-Smart Meter Data Encryption Scheme Basedon Distributed Differential Privacy

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Big Data Mining and Analytics 2024年第1期7卷 131-141页

作者： Renwu Yan Yang Zheng ning Yu Cen Liang School of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou 350118China Department of Computing Sciences at The College at Brockport State University of New YorkNew YorkNY 14420USA

Under the general trend of the rapid development of smart grids,data security and privacy are facing serious challenges;protecting the privacy data of single users under the premise of obtaining user-aggregated data has attracted widespread *** this study,we propose an encryption scheme on the basis of differential privacy for the problem of user privacy leakage when aggregating data from multiple smart ***,we use an improved homomorphic encryption method to realize the encryption aggregation of users’***,we propose a double-blind noise addition protocol to generate distributed noise through interaction between users and a cloud platform to prevent semi-honest participants from stealing data by colluding with one ***,the simulation results show that the proposed scheme can encrypt the transmission of multi-intelligent meter data under the premise of satisfying the differential privacy *** if an attacker has enough background knowledge,the security of the electricity information of one another can be ensured.

关键词： smart grid homomorphic encryption data aggregation differential privacy cloud computing

Reduced Macrophage Uptake of Nanoparticles through Surface Modification of Polypeptides with Valine Residues

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Chinese Journal of Chemistry 2024年第11期42卷 1209-1216页

作者： ning Li Shanshan Xiao Xiaoxiong Jin Ziyuan Song Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhouJiangsu215123 China

The structural and surface properties of nanomedicines play an important role in determining their biological fate. Surface chemistry of nanomedicines is one of the key parameters, where researchers used various strategies such as PEGylation to avoid the undesired clearance of nanoparticles (NPs) for enhanced targeting effect. Nevertheless, the fine-tuning of surface chemistry through polymer functionalization remains largely unexplored. In this concise report, we find that the incorporation of only 10 mol% valine residues into the surface-anchored poly(L-glutamic acid) significantly lowered the macrophage uptake of NPs. The introduction of other hydrophobic amino acid residues, however, increased the NPs internalization instead. The chirality and the side-chain structure of valine played an important role in the unexpected uptake behavior. We believe this work highlights the impact of slight changes of the surface-anchored polymer structure on the behavior of NPs, drawing people's attention to the careful design of surface chemistry to optimize the nanomedicine design.

关键词： Nanoparticles Copolymers Structure-activity relationships Surface chemistry Polypeptide Macrophage uptake

CToMP: a cycle-task-oriented memory protection scheme for unmanned systems

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Science China(Information Sciences) 2024年第6期67卷 399-417页

作者： Chengyan MA ning XI Di LU Yebo FENG Jianfeng MA School of Cyber Engineering Xidian University School of Computer Science and Technology Xidian University Department of Computer and Information Science University of Oregon

Memory corruption attacks(MCAs) refer to malicious behaviors of system intruders that modify the contents of a memory location to disrupt the normal operation of computing systems, causing leakage of sensitive data or perturbations to ongoing processes. Unlike general-purpose systems, unmanned systems cannot deploy complete security protection schemes, due to their limitations in size, cost and *** in unmanned systems are particularly difficult to defend against. Furthermore, MCAs have diverse and unpredictable attack interfaces in unmanned systems, severely impacting digital and physical sectors. In this paper, we first generalize, model and taxonomize MCAs found in unmanned systems currently, laying the foundation for designing a portable and general defense approach. According to different attack mechanisms,we found that MCAs are mainly categorized into two types — return2libc and return2shellcode. To tackle return2libc attacks, we model the erratic operation of unmanned systems with cycles and then propose a cycle-task-oriented memory protection(CToMP) approach to protect control flows from tampering. To defend against return2shellcode attacks, we introduce a secure process stack with a randomized memory address by leveraging the memory pool to prevent Shellcode from being executed. Moreover, we discuss the mechanism by which CTo MP resists the return-oriented programming(ROP) attack, a novel variant of return2libc attacks. Finally, we implement CTo MP on CUAV V5+ with Ardupilot and Crazyflie. The evaluation and security analysis results demonstrate that the proposed approach CTo MP is resilient to various MCAs in unmanned systems with low footprints and system overhead.

关键词： unmanned system memory corruption attack memory protection system security randomized memory address

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