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Stage identification and process optimization for fast drilling EDM of film cooling holes using KBSI method

Advances in Manufacturing 2023年第3期11卷 477-491页

作者： Jian Wang Xue-Cheng Xi ya-ou zhang Fu-Chun Zhao Wan-Sheng Zhao State Key Laboratory of Mechanical System and Vibration Shanghai 200240People's Republic of China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240People's Republic of China

Fast drilling electrical discharge machining(EDM)is widely used in the manufacture of film cooling holes of turbine blades.However,due to the various hole orientations and severe electrode wear,it is relatively intricate to accurately and timely identify the critical moments such as breakout,hole completion in the drilling process,and adjust the machining strategy properly.Existing breakout detection and hole completion determination methods are not suitable for the high-efficiency and fully automatic production of film cooling holes,for they almost all depend on preset thresholds or training data and become less appropriate when machining condition changes.As the breakout and hole completion detection problems can be abstracted to an online stage identification problem,in this paper,a kurtosis-based stage identification(KBSI)method,which uses a novel normalized kurtosis to denote the recent changing trends of gap voltage signals,is developed for online stage identification.The identification accuracy and generalization ability of the KBSI method have been verified in various machining conditions.To improve the overall machining efficiency,the influence of servo control parameters on machining efficiency of each machining stage was analyzed experimentally,and a new stage-wise adaptive control strategy was then proposed to dynamically adjust the servo control parameters according to the online identification results.The performance of the new strategy is evaluated by drilling film cooling holes at different hole orientations.Experimental results show that with the new control strategy,machining efficiency and the machining quality can be significantly improved.

关键词： Fast drilling electrical discharge machining(EDM) Film cooling holes Breakout detection Hole completion determination Stage identification Process optimization

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Effect of WeiJia on carbon tetrachloride induced chronic liver injury

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World Journal of Gastroenterology 2006年第12期12卷 1912-1917页

作者： Pik-Yuen Cheung Qizhang Gan-Rong Bai Chi-Chun Fong Lin Shi Yue-Feng Shi Meng-Suyang DepartmentofBiology ya-ou zhang Marie Chia-Mi Lin Bernard Chan Jay Chun Hsiang-Fu Kung Department of Biology and Chemistry City University of Hong Kong 83 Tat Chee AvenuKowloonHong Kong SARChina Life Science Division Tsinghua University Graduate School at ShenzhenTsinghua CampusUniversity TownShenzhenChina Institute of Molecular Biology The University of Hong KongPokfulamHong KongSARChina Life Tec Enterprise Limited CentralHong KongSARChina The Centre for Emerging Infectious Diseases Faculty of MedicineThe Chinese University of Hong KongShatinN.T.Hong Kong SARChina

瞄准：为了在长期的肝损伤使用上学习 WeiJia 的效果，四氯化碳(CCl (4 )) 劝诱了肝损伤动物模型。方法: 称 180-220g 的 Wistar 老鼠随机被划分成三个组：正常控制组(组 A ) ，导致的肝损伤控制组织的 CCl (4 )( 组 B ) 和有 WeiJia ... 详细信息

瞄准：为了在长期的肝损伤使用上学习 WeiJia 的效果，四氯化碳(CCl (4 )) 劝诱了肝损伤动物模型。方法: 称 180-220g 的 Wistar 老鼠随机被划分成三个组：正常控制组(组 A ) ，导致的肝损伤控制组织的 CCl (4 )( 组 B ) 和有 WeiJia 处理的正式就职组织的 CCl (4 )( 组 C ) 。每个组由 14 只老鼠组成了。肝损坏和纤维变性被皮下注射在 3 mL/kg 体重在齐墩果油与 40% CCl (4 ) 导致两次为为组 B 和 C 老鼠的八个星期的一个星期而齐墩果油被用于组 A 老鼠。从第三个星期开始，组 C 老鼠也在 1.25 microg/kg 体重的剂量收到了 WeiJia 的每日的腹膜内注射。动物在第五个星期被牺牲(4 男性， 3 女性) ，并且第八个星期(4 男性， 3 女性) 分别地。纤维变性的度被测量并且为肝纤维变性和功能包括透明质酸的血清学的标记(哈) ，类型 IV 骨胶原(CIV ) ， gamma-glutamyl 转移酶(gamma-GT ) ，丙氨酸 aminotransferase (中高音) 和 aspartate aminotransferase (著名计算机生产厂商) 被决定。α平滑肌肌动朊(alpha-SMA ) 和原子抗原(PCNA ) 免疫组织化学也是的增殖的房间表现了。结果：当时， CCl (4 ) 正式就职在组 B 和组 C 老鼠导致了肝的损坏和纤维变性的开发与组 A 相比老鼠。在组 C 老鼠的 WeiJia 的处理能与组 B 老鼠相比显著地减少纤维变性条件。效果能在三星期处理以后被观察并且在八星期处理以后是更明显的。浆液哈，在八星期为组 C 老鼠的处理以后的 CIV ，中高音，著名计算机生产厂商和 gamma-GT 层次是 58+/-22 microg/L ( P0.05 )分别地，从导致的肝损伤控制组织的 CCl ( 4 )(组 B )类似于正常控制组(组 A )，却显著地不同。PCNA 的增加和在 alpha-SMA 表示水平的减少也被观察。结论：WeiJia 能改进肝功能和可能通过星形的房间活动的抑制的还原剂肝纤维变性。

关键词：慢性肝损伤四氯化碳感应反应病理机制

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Alleviating the anisotropic microstructural change and boosting the lithium ions diffusion by grain orientation regulation for Ni-rich cathode materials

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Journal of Energy Chemistry 2024年第1期88卷 213-222,I0005页

作者： Xinyou He Shilin Su Bao zhang Zhiming Xiao Zibo zhang Xing ou Engineering Research Center of the Ministry of Education for Advanced Battery Materials School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083HunanChina Zhejiang Power New Energy Co.Ltd Zhuji 311899ZhejiangChina

Generally,layered Ni-rich cathode materials exhibit the morphology of polycrystalline secondary sphere composed of numerous primary particles.While the arrangement of primary particles plays a very important role in the properties of Ni-rich cathodes.The disordered particle arrangement is harmful to the cyclic performance and structural stability,yet the fundamental understanding of disordered structure on the structural degradation behavior is unclarified.Herein,we have designed three kinds of LiNi_(0.83)Co_(0.06)Mn_(0.11)O_(2) cathode materials with different primary particle orientations by regulating the precursor coprecipitation process.Combining finite element simulation and in-situ characterization,the Li^(+)transport and structure evolution behaviors of different materials are unraveled.Specifically,the smooth Li^(+)diffusion minimizes the reaction heterogeneity,homogenizes the phase transition within grains,and mitigates the anisotropic microstructural change,thereby modulating the crack evolution behavior.Meanwhile,the optimized structure evolution ensures radial tight junctions of the primary particles,enabling enhanced Li^(+)diffusion during dynamic processes.Closed-loop bidirectional enhancement mechanism becomes critical for grain orientation regulation to stabilize the cyclic performance.This precursor engineering with particle orientation regulation provides the useful guidance for the structural design and feature enhancement of Ni-rich layered cathodes.

关键词： Ni-rich cathode Grain orientation regulation Anisotropic microstructural change Precursor engineering Li~+-ions diffusion

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Sex-biased adaptation shapes uniparental gene pools in Tibetans

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Science China(Life Sciences) 2024年第3期67卷 611-613页

作者： Min-Sheng Peng ya-Ping zhang State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunming 650201China KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases Kunming Institute of ZoologyChinese Academy of SciencesKunming 650201China Kunming College of Life Science University of Chinese Academy of SciencesKunming 650204China State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan School of Life SciencesYunnan UniversityKunming 650091China

During the past two decades, a series of archaeological and genetic investigations substantially improve our perception of the hominin settlement of the Tibetan Plateau(zhang et al., 2022). In addition to the identifi... 详细信息

关键词： Tibetan Plateau altitude

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Re-examination of statistical relationships between dietary fats and other risk factors,and cardiovascular disease,based on two crucial datasets

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Quantitative Biology 2024年第1期12卷 117-127页

作者： Jiarui ou Le zhang Xiaoli Ru College of Computer Science Sichuan UniversityChengduChina Department of Gynecology and Obstetrics Beijing Chao-Yang HospitalCapital Medical UniversityBeijingChina

Cardiovascular disease(CVD)is the major cause of death in many regions around the world,and several of its risk factors might be linked to diets.To improve public health and the understanding of this topic,we look at the recent Minnesota Coronary Experiment(MCE)analysis that used t-test and Cox model to evaluate CVD risks.However,these parametric methods might suffer from three problems:small sample size,right-censored bias,and lack of long-term evidence.To overcome the first of these challenges,we utilize a nonparametric permutation test to examine the relationship between dietary fats and serum total cholesterol.To address the second problem,we use a resampling-based rank test to examine whether the serum total cholesterol level affects CVD deaths.For the third issue,we use some extra-Framingham Heart Study(FHS)data with an A/B test to look for meta-relationship between diets,risk factors,and CVD risks.We show that,firstly,the link between low saturated fat diets and reduction in serum total cholesterol is strong.Secondly,reducing serum total cholesterol does not robustly have an impact on CVD hazards in the diet group.Lastly,the A/B test result suggests a more complicated relationship regarding abnormal diastolic blood pressure ranges caused by diets and how these might affect the associative link between the cholesterol level and heart disease risks.This study not only helps us to deeply analyze the MCE data but also,in combination with the long-term FHS data,reveals possible complex relationships behind diets,risk factors,and heart disease.

关键词： A/B test bioinformatics cardiovascular disease nonparametric statistics

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Height and body mass index trajectories from 1975 to 2015 and prevalence of stunting,underweight and obesity in 2016 among children in Chinese cities:findings from five rounds of a national survey

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World Journal of Pediatrics 2024年第4期20卷 404-412页

作者： Xin‑Nan Zong Hui Li ya‑Qin zhang Department of Growth and Development Capital Institute of PediatricsBeijing 100020China

Background A more comprehensive assessment of growth and nutrition in children is required in China due to rapid socioeconomic processes.We aimed to investigate height and body mass index(BMI)trajectories from 1975 to 2015 and the prevalence of stunting and obesity in 2016 among children in Chinese cities.Methods A total of 904,263 children from birth to 6.9 years were collected from a series of nationally representative surveys in China.Height and BMI trajectories and prevalence of stunting,underweight,overweight and obesity were assessed.Results The average height level of Chinese urban children under 7 years presented a positive secular trend from 1975 to 2015;however,a slowing tendency occurred in 2005‒2015.An apparent increase was observed at the 5th,50th and 95th percentiles of BMI in urban children aged 3 years and older,with a more prominent increase at the 95th percentile.The total prevalence of stunting and underweight under 7 years was 1.4%and 2.0%,respectively.The total prevalence of overweight and obesity under 7 years was 12.6%and 4.3%,respectively,with 12.7%and 4.9%for boys,12.6%and 3.6%for girls,12.1%and 4.0%in urban areas and 13.1%and 4.5%in suburban rural areas.Conclusions The average height level of Chinese urban children has reached World Health Organization child growth standards since 2005 and presented a slowing tendency in secular trend in 2005‒2015.More attention and efforts and public health interventions should be urgently made to combat overweight and obesity among preschool children.

关键词： Body mass index Children Height Obesity Stunting

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Recent landscape and trends for industry-sponsored pediatric clinical trials in China from 2013 to 2022

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儿科学研究(英文) 2024年第1期8卷 12-20页

作者： Liu Chang Liu Yi ou Ling Qi Yuenan zhang Jianmin Drug Clinical Trial Institution Children’s Hospital Capital Institute of Pediatrics Beijing China

Importance: Pediatric medication is a challenging issue globally. Promoting trials of medications for children and implementing measures to encourage innovation for addressing unmet medical and health needs are important.Objective: To explore the recent landscape of pediatric clinical trials of new investigational drugs conducted by pharmaceutical enterprises in China from 2013 to 2022 to provide insight into pediatric drug development in the pharmaceutical industry and regulatory policy formulation.Methods: We performed a cross-sectional observational investigation of pediatric clinical trials registered from January 1, 2013, to December 31, 2022, on the Registration and Information Disclosure Platform for Drug Clinical Trials, the official registration platform established in 2013 for trials of new investigational drugs initiated by biopharmaceutical enterprises. Trials that included pediatric participants (under 18 years old) were retrieved, and their relevant characteristics were extracted and analyzed.Results: In total, 895 pediatric clinical trials were collected, accounting for 5.1% of the total registered clinical trials initiated prior to January 1, 2023. The overall average annual growth rate for the number of pediatric clinical trials was 12% (P ounted for the highest proportion (49.1%, 439). Of the 895 trials included, 736 (82.2%) were domestic trials, and 159 (17.8%) were international multicenter trials. In terms of tested drugs, investigations of biological products accounted for the largest proportion of trials (67.4%, 603). Among pediatric clinical trials, studies of vaccines accounted for the largest proportion of trials (41.0%, 367), followed by trials for rare diseases (17.2%, 154). Furthermore, geographical distribution analysis revealed that the largest and smallest numbers of trials were conducted in North China (35.7%, 320) and Northeast China (0.8%, 7), respectively.Interpretation: The growth trends for industry-sponsored clinical trials involving children il

关键词： Geographic distribution Pediatric clinical trials Pediatric medication Rare disease

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Examining the Spatiotemporal Dynamics and Determinants of Land Urbanization in Prefecture-level Cities,China

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Chinese Geographical Science 2024年第1期34卷 19-33页

作者： yaNG Zhen ZHU Huxiao zhang Xinlin ou Xiangjun School of Geography Geomatics and Planning&Urban-rural Integration Development Research InstituteJiangsu Normal UniversityXuzhou221116China

Examining the spatiotemporal dynamics and determinants of land urbanization is critical for promoting healthy urban development and the rational use of land resources.Based on the dataset consisting of land use change data and selected factors in 2010 and2020,this study used visual analysis to reveal the spatiotemporal dynamics of land urbanization across prefecture-level cities in China.Meanwhile,the driving forces underlying land urbanization were examined by using geographical detector technique.Following are the findings:1)we find that there exist notable spatial variances in land urbanization across prefecture-level cities.Currently,the differentiation in land urbanization between the northern and southern cities is more pronounced than that between the coastal and inland cities,or between the eastern and western cities.Prefecture-level cities located in central and western China have experienced the most rapid growth in land urbanization.Conversely,the growth rate in northeastern China is the lowest,while the velocity in eastern China remains relatively stable.By using spatial autocorrelation analysis,this study reveals that the land urbanization level in prefecture-level cities has significant spatial agglomeration.2)We further find that land urbanization in China is influenced by factors related to urban land supply and demand,and urban population growth,economic growth,land financial and political incentive have greater impact on land urbanization than other factors.3)We also find that the impacts of determinants on China’s land urbanization vary over time,the explanatory power of economic development increased,while the explanatory power of state forces declined.We argue that integrating the supply and demand factors of land urbanization can provide a more comprehensive understanding of the driving mechanisms underlying land urbanization in China and other transitional countries,and help decision-makers in these countries formulate more detailed and specific land urbanization policies.

关键词： land urbanization spatial pattern influencing factor geographical detector China

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Luminescence and magnetic properties of bifunctional nanoparticles composited by nitrogen-doped graphene quantum dots and gadolinium

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Journal of Rare Earths 2024年第4期42卷 716-723页

作者： Wanli zhang Hao Zhou Meigui ou Donghao Sun Chunlin yang College of Materials and Metallurgy University of GuizhouGuiyang550025China National Local Co-construction Engineering Laboratory for High Performance Metal Structure Material and Manufacture Technology Guiyang550025 China College of Chemistry and Materials Engineering Guiyang UniversityGuiyang550003China

In this paper,nitrogen-doped graphene quantum dots(N-GQDs)were combined with gadolinium ions(Gd^(3+))by a surface modification to obtain magneto-optical dual-functional N-GQDs/Gd^(3+)nanoparticles.The morphology of obtained composite was characterized by field emission scanning electron microscopy and transmission electron microscopy.Luminescence and magnetic properties were measured by a fluorescence spectrophotometer and a vibrating sample magnetometer,respectively.Results indicate that well-dispersed spherical N-GQDs/Gd^(3+)nanoparticles have an average diameter of 7 nm.N-doping significantly increases the luminesce nce of particles with an optimal luminescence intensity at 20℃and pH=9.X-ray photoelectron spectroscopy results indicate that the N-doping introduces pyrrolic N as an electron donor,enhancing fluorescence by increasing the surface electron cloud density of N-GQDs.In addition,density functional theory calculation results reveal that N-doping reduces the band gap of NGQDs/Gd^(3+),enabling electronic transitions to higher energy levels and generating more activation sites,thereby enhancing luminescence.Compared to N-GQDs/Gd^(3+)prepared at 20℃,the saturated magnetization of particles prepared at 40℃is 0.85 emu/g,indicating a better magnetic response.The above results suggest that bifunctional nanomaterials N-GQDs/Gd^(3+)with excellent optical properties and magnetism can be better used for fluorescence and magnetic resonance imaging.

关键词： Nitrogen-doped graphenequantum dots Gadolinium Luminescence Magnetism Rare earths

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Development of a convolutional neural network based geomechanical upscaling technique for heterogeneous geological reservoir

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2111-2125页

作者： Zhiwei Ma Xiaoyan ou Bo zhang Earth and Environmental Sciences Division Los Alamos National LaboratoryLos AlamosUSA Civil and Environmental Engineering University of AlbertaEdmontonCanada

Geomechanical assessment using coupled reservoir-geomechanical simulation is becoming increasingly important for analyzing the potential geomechanical risks in subsurface geological developments.However,a robust and efficient geomechanical upscaling technique for heterogeneous geological reservoirs is lacking to advance the applications of three-dimensional(3D)reservoir-scale geomechanical simulation considering detailed geological heterogeneities.Here,we develop convolutional neural network(CNN)proxies that reproduce the anisotropic nonlinear geomechanical response caused by lithological heterogeneity,and compute upscaled geomechanical properties from CNN proxies.The CNN proxies are trained using a large dataset of randomly generated spatially correlated sand-shale realizations as inputs and simulation results of their macroscopic geomechanical response as outputs.The trained CNN models can provide the upscaled shear strength(R^(2)>0.949),stress-strain behavior(R^(2)>0.925),and volumetric strain changes(R^(2)>0.958)that highly agree with the numerical simulation results while saving over two orders of magnitude of computational time.This is a major advantage in computing the upscaled geomechanical properties directly from geological realizations without the need to perform local numerical simulations to obtain the geomechanical response.The proposed CNN proxybased upscaling technique has the ability to(1)bridge the gap between the fine-scale geocellular models considering geological uncertainties and computationally efficient geomechanical models used to assess the geomechanical risks of large-scale subsurface development,and(2)improve the efficiency of numerical upscaling techniques that rely on local numerical simulations,leading to significantly increased computational time for uncertainty quantification using numerous geological realizations.

关键词： Upscaling Lithological heterogeneity Convolutional neural network(CNN) Anisotropic shear strength Nonlinear stressestrain behavior

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