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Automated regression test method for scientific computing libraries:Illustration with SPHinXsys

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Journal of Hydrodynamics 2024年第3期36卷 466-478页

作者： Bo zhang chi zhang Xiangyu Hu TUM School of Engineering and Design Technical University of MunichMunichGermany

Scientific computing libraries,whether in-house or open-source,have witnessed enormous progress in both engineering and scientific ***,it is important to ensure that modifications to the source code,prompted by bug fixing or new feature development,do not compromise the accuracy and functionality that have been already validated and *** paper introduces a method for establishing and implementing an automatic regression test environment,using the open-source multi-physics library SPHinXsys as an illustrative ***,a reference database for each benchmark test is generated from observed data across multiple *** comprehensive database encapsulates the maximum variation range of metrics for different strategies,including the time-averaged,ensemble-averaged,and dynamic time warping *** accounts for uncertainties arising from parallel computing,particle relaxation,physical instabilities,and ***,new results obtained after source code modifications undergo testing based on a curve-similarity comparison against the reference *** the source code is updated,the regression test is automatically executed for all test cases,providing a comprehensive assessment of the validity of the current *** regression test environment has been successfully implemented in all dynamic test cases within SPHinXsys,including fluid dynamics,solid mechanics,fluid-structure interaction,thermal and mass diffusion,reaction-diffusion,and their multi-physics couplings,and demonstrates robust capabilities in testing different *** is noted that while the current test environment is built and implemented for a particular scientific computing library,its underlying principles are generic and can be easily adapted for use with other libraries,achieving equal effectiveness.

关键词： Scientific computing open-source library verification and validation regression test automatic test environment curve similarity comparison smoothed particle hydrodynamics

Understanding the formation mechanism of subsurface damage in potassium dihydrogen phosphate crystals during ultraprecision fly cutting

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Advances in Manufacturing 2019年第3期7卷 270-277页

作者： Yong zhang Ning Hou Liang-chi zhang School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001People's Republic of China School of Mechatronics Engineering Shenyang Aerospace UniversityShenyang 110136People's Republic of China Laboratory for Precision and Nano Processing Technologies School of Mechanical and Manufacturing EngineeringThe University of New South WalesSydneyNSW 2052Australia

Potassium dihydrogen phosphate(KDP)crystals play an important role in high-energy laser systems,but the laser damage threshold(LDT)of KDP components is lower than *** LDT is significantly influenced by subsurface damage produced in KDP ***,it is very challenging to detect the subsurface damage caused by processing because a KDP is soft,brittle,and sensitive to the external environment(e.g.,humidity,temperature and applied stress).Conventional characterization methods such as transmission electron microscopy are ineffective for this *** paper proposes a nondestructive detection method called grazing incidence X-ray diffraction(GIXD)to investigate the formation of subsurface damage during ultra-precision fly cutting of KDP *** crystal planes,namely(200),(112),(312),(211),(220),(202),(301),(213),(310)and(303),were detected in the processed subsurface with the aid of GIXD,which provided very different results for KDP crystal *** results mean that single KDP crystals change into a lattice misalignment structure(LMS)due to mechanical stress in the *** crystal planes match the slip systems of the KDP crystals,implying that dislocations nucleate and propagate along slip systems to result in the formation of the LMS under shear and compression *** discovery of the LMS in the subsurface provides a new insight into the nature of the laser-induced damage of KDP crystals.

关键词： Potassium dihydrogen phosphate(KDP)crystals Subsurface damage Lattice misalignment structure Slip systems

PALES: Optimizing Secure Data Deletion in SSDs via Page Group and Reprogram Speedup

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chinese Journal of Electronics 2022年第1期31卷 40-51页

作者： NIE Shiqiang WU Weiguo zhang chi zhang Chen Department of Computer Science and Technology Xi'an Jiaotong University

As solid-state drives(SSD) have been widely adopted, secure data deletion becomes an essential component for ensuring user privacy, preventing sensitive data leakage. Due to the erase-before-write property,erasure operation and scrub operation substituting for overwriting technologies are proposed to meet the requirements. However, both methods bring the severe page-copying issue, declining read/write performance, and shortening the lifetime of SSD. In this paper, this issue is alleviated by reserving pages at the page allocation stage to mitigate program disturbance and increasing program step voltage during reprogramming operation to reduce the reprogram latency. The proposed scheme is evaluated by a series of experiments; the results show that the proposed scheme could achieve significant deletion time reduction and alleviate page-copying overhead.

关键词： reprogramming operation storage management solid-state drives SSD flash memories page group page-copying overhead erase-before-write property secure data deletion PALES data privacy erasure operation page allocation stage user privacy security of data program step voltage sensitive data leakage reprogram speedup

Advancements in transfer printing techniques for flexible electronics:adjusting interfaces and promoting versatility

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International Journal of Extreme Manufacturing 2024年第5期6卷 95-117页

作者： Zijian Chen chi zhang Zijian Zheng School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong Special Administrative Region of ChinaPeople’s Republic of China Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHong Kong Special Administrative Region of ChinaPeople’s Republic of China State Key Laboratory for Ultra-Precision Machining Technology The Hong Kong Polytechnic UniversityHong Kong Special Administrative Region of ChinaPeople’s Republic of China Research Institute for Intelligent Wearable Systems The Hong Kong Polytechnic UniversityHong Kong Special Administrative Region of ChinaPeople’s Republic of China Research Institute for Smart Energy The Hong Kong Polytechnic UniversityHong Kong Special Administrative Region of ChinaPeople’s Republic of China

The burgeoning interest in flexible electronics necessitates the creation of patterning technology specifically tailored for flexible substrates and complex surface *** a variety of patterning techniques,transfer printing emerges as one of the most efficient,cost-effective,and scalable *** boasts the ability for high-throughput fabrication of 0–3D micro-and nano-structures on flexible substrates,working in tandem with traditional lithography *** review highlights the critical issue of transfer printing:the flawless transfer of devices during the pick-up and printing *** encapsulate recent advancements in numerous transfer printing techniques,with a particular emphasis on strategies to control adhesion forces at the substrate/device/stamp *** strategies are employed to meet the requirements of competing fractures for successful pick-up and print *** mechanism,advantages,disadvantages,and typical applications of each transfer printing technique will be thoroughly *** conclusion section provides design guidelines and probes potential directions for future advancements.

关键词： transfer printing flexible electronics adhesion interfacial adjujstments

Elucidation of Regional Mechanical Properties of Brain Tissues Based on Cell Density

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Journal of Bionic Engineering 2021年第3期18卷 611-622页

作者： chi zhang Long Qian Hongwei Zhao School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130025China

Research on the mechanical properties of brain tissue has received extensive ***,most of the current studies have been conducted at the phenomenological *** this study,the indentation method was used to explore the difference in local mechanical properties among different regions of the porcine cerebral ***,hematoxylin-eosin and immunofluorescence staining methods were used to determine the correlation between the cellular density at different test points and mechanical properties of the porcine cerebral *** frontal lobe exhibited the strongest *** temporal lobe displayed the lowest sensitivity to changes in the indentation speed,and the occipital lobe exhibited the highest shear ***,the shear modulus of different areas of the cerebral cortex was negatively correlated with the total number of local cells per unit area and positively correlated with the number of neuronal cell bodies per unit *** of the mechanical properties of the local brain tissue can provide basic data for the establishment of a finite element model of the brain and mechanical referential information for the implantation position of brain chips.

关键词： cerebral cortex mechanical properties staining correlation cellular density

Carbon Deposition on the Venturi of a Gas Turbine Combustor Using Ethanol-Kerosene Blends

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Journal of Thermal Science 2022年第6期31卷 2216-2224页

作者： WANG Xiaofeng LIN Yuzhen zhang chi Department of Aircraft Airworthiness Certification Civil Aviation Management Institute of ChinaBeijing 100102China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Research Institute of Aero-EngineBeihang UniversityBeihang UniversityBeijing100191China

This paper reports an investigation of carbon deposition on the venturi component of a gas turbine combustor fueled with ethanol/kerosene fuel blends. china RP-3 kerosene and its ethanol blends(10%, 30%, and 50% ethanol by weight) were used in a gas turbine model combustor. Each combustion test of carbon deposition was conducted at 0.3 MPa for an hour. Measuring carbon deposition became difficult because of the special structure of venturi which is a component of swirl cup air atomization nozzle. An image processing method called planar reconstruction, was developed to evaluate the amount of carbon deposition semi-quantitatively. To study the morphology and structure of the deposition for different test fuels, a Scanning Electron Microscope(SEM) was employed to visualize the detailed structures of carbon deposition. Results show that with the increasing addition of ethanol, the amount of carbon deposition decreases, and the morphology of carbon changes significantly. For pure kerosene case, small spherules and flake graphite were closely interwoven on venturi surface. For other fuel blends, small spherules were not observed, and flake graphite neatly stacked and lined on the venturi surface. These results indicate that the mechanism of carbon deposition can vary significantly, due to the change of fuel’s molecular structures;the current study shows that the morphology and structure of carbon deposition of kerosene were altered remarkably by the ethanol addition.

关键词： ethanol kerosene carbon deposition venturi combustor

Ta_(3)N_(5)–LaTaON_(2) heterojunction with matched interfaces to accelerate charge separation for efficient photocatalytic water oxidation

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Journal of Materials Science & Technology 2023年第23期154卷 241-250页

作者： Guoan Lin chi zhang Xiaoxiang Xu Clinical and Central Lab Putuo People's Hospital Tongji University Shanghai 200060 China Shanghai Key Lab of Chemical Assessment and Sustainability School of Chemical Science and Engineering Tongji University Shanghai 200092 China

Charge separation is generally considered as the most critical step to achieve efficient photocatalytic reactions. Although charge separation can be promoted by a semiconductor heterojunction, its efficacy is inherently restrained by the mismatched atomic arrangements across the heterojunction interfaces. Here, Ta3N5–LaTaON2 heterojunction with matched interfaces has been fabricated by one-step ammonolysis treatment of KLaTa2O7. The match interfaces are formed by nearly perfect adhesion of Ta3N5 (010) and LaTaON2 (101¯) facets whose interatomic distance is similar. Compared with conventional heterojunction, the so-formed Ta3N5–LaTaON2 heterojunction are extremely efficient in accelerating charge separation which in turn enables a high photocatalytic activity. An apparent quantum efficiency as high as 11.6% at 420 ± 20 nm has been reached by Ta_(3)N_(5)–LaTaON_(2) heterojunction, which is almost three times higher than Ta_(3)N_(5)-LaTaON_(2) mixtures. These results signify the importance of matched heterojunction interfaces for charge separation and provide a paradigm in the design of efficient heterojunction-based semiconductor photocatalysts.

关键词： Semiconductor heterojunction LaTaON_(2) Ta_(3)N_(5) Photocatalyst Water oxidation

Reversible RNA Modification N^1-methyladenosine(m^1A) in mRNA and tRNA

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Genomics, Proteomics & Bioinformatics 2018年第3期16卷 155-161页

作者： chi zhang Guifang Jia Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry and Molecular EngineeringPeking University

More than 100 modifications have been found in RNA. Analogous to epigenetic DNA methylation, epitranscriptomic modifications can be written, read, and erased by a complex network of proteins. Apart from Na-methyladenosine （m6A）, N1-methyladenosine （mXA） has been found as a reversible modification in tRNA and mRNA. mlA occurs at positions 9, 14, and 58 of tRNA, with m1A58 being critical for tRNA stability. Other than the hundreds of m1A sites in mRNA and long non-coding RNA transcripts, transcriptome-wide mapping of m1A also identifies 〉 20 m1A sites in mitochondrial genes, m1A in the coding region of mitochondrial transcripts can inhibit the translation of the corresponding proteins. In this review, we summarize the current understanding of mlA in mRNA and tRNA, covering high-throughput sequencing methods developed for m1A methylome, m1A-related enzymes （writers and erasers）, as well as its functions in mRNA and tRNA.

关键词： Epitranscriptome RNA modification N1-methyladenosine (m1A) m1A writer m1A eraser

Improvement of Surface Ridging Resistance of an Ultra-purified Ferritic Stainless Steel by Optimizing Hot Rolling Condition

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Acta Metallurgica Sinica(English Letters) 2016年第6期29卷 561-567页

作者： chi zhang Li-Wen zhang Zhen-Yu Liu School of Materials Science and Engineering Dalian University of Technology State Key Lab of Rolling Technologies and Automation Northeastern University

The effects of the finisher entry temperatures（FETs） on the surface ridging behavior for an ultra-purified21%Cr ferritic stainless steel have been investigated. The results indicate that decreasing the FET facilitates the formation of in-grain shear bands in the hot rolled slab. The in-grain shear bands supplied recrystallization nucleation sites in grains during subsequent annealing through coalescence of subgrains, which is beneficial to refine the microstructures and intensify the {111}//ND textures. This effect will evolve to the final cold rolled and annealed sheet. The micro-texture analysis indicates that the formation of grain colony in the final sheet is weakened by decreasing the FET. Then, the surface ridging resistance of FSS is enhanced due to the optimizing of micro-texture distribution.

关键词： Ferritic steels Surface ridging Micro-texture Electron backscattered diffraction(EBSD)