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A general method for instantaneous undeformed chip thickness calculation in five-axis milling based on Boolean operations

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2021年第7-8期116卷 2325-2334页

作者： Li, Guochao liu, Yunlong Zhao, Donghao Dai, Lei Zhou, Honggen Jing, xuwen Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212003 Jiangsu Peoples R China Jiangsu Univ Sci & Technol Jiangsu Prov Key Lab Adv Mfg Marine Mech Equipmen Zhenjiang 212003 Jiangsu Peoples R China

Instantaneous undeformed chip thickness (IUCT) plays a critical role in optimizing and monitoring of five-axis milling processes, as it determines machining precision and tool life by affecting cutting forces. Analytical and numerical methods have been widely used for IUCT calculation. However, these methods have some deficiencies, such as solving the unsolvable transcendental equations, modeling the complex cutting edge trajectory, and poor adaptability for five-axis milling. Therefore, a Boolean method which consists of subtraction and intersection operations is developed. First, the blank for the current cutting edge is obtained by the Boolean subtraction operation between the workpiece and the swept volume that produced by the front cutting edges. Second, the Boolean intersection operation is executed between the blank and the auxiliary edge entity (AEE) that corresponding to the tool edge. Then, the IUCT of each cutting edge or each cutting point can be deduced based on the Boolean result with the known blank geometry, tool geometry, tool path, and machining parameters. The method is verified by milling force experiments. It is an efficient, accurate, and general method because it does not need to establish complex mathematical or numerical models. The calculated IUCT will promote the optimizing and monitoring of five-axis milling processes.

关键词： Chip thickness Boolean operation Five-axis milling Milling force

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Micro-compound tissue grafting for repairing linear scars

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Chinese Journal of Plastic and Reconstructive Surgery 2021年第4期3卷 202-203页

作者： xuwen Tang Yang liu Dongyun Yang Yong Zhang Department of Chongqing Kewei Scar Medical Institute/Dongshang Medical Aesthetic Clinic Chongqing 400010China

This study explored the clinical application and therapeutic effect of micro-compound tissue grafting(MCTG)for linear *** February 2019,one patient received MCTG treatment and the recovery at 20 months postoperative was *** patient was completely satisfied with the *** MCTG technique is simple and reliable and can significantly improve scar *** technique may be an effective method for treating linear scars,but it requires further validation in large samples.

关键词： Linear scar Micro-compound tissue grafting Excision and suture

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Removal of viscous and clogging suspended solids in the wastewater from acrylonitrile-butadiene-styrene resin production by a new dissolved air release device

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PROCESS SAFETY AND ENVIRONMENTAL PROTECTION 2021年 148卷 524-535页

作者： Zhang, Xiaohang Zhang, Xuewei liu, Yanping Zhang, Qing Yang, Shipeng He, xuwen Chinese Acad Sci Ctr Agr Resources Res Inst Genet & Dev Biol Key Lab Agr Water Resources 286 Huaizhong Rd Shijiazhuang 050021 Hebei Peoples R China China Univ Min & Technol Beijing Sch Chem & Environm Engn Xueyuan Rd Beijing 100083 Peoples R China Handan Municipal Publ Util Investment Grp Co Ltd Dept Engn & Technol 58 Guoyuan Rd Handan City 056000 Hebei Peoples R China Tsinghua Univ State Key Joint Lab Environm Simulat & Pollut Con 30 Shuangqing Rd Beijing 100084 Peoples R China

The suspended solids in the acrylonitrile-butadiene-styrene(ABS) wastewater are in the form of viscouslatex, which strengthens the blocking phenomenon of the release device, increases the suspended solids in the return water and reduces the removal effect of the air flotation apparatus. Therefore, we designed a new release device. To achieve the goal of controlling the bubbles in the target diameter and enlarge the hole size as much as possible to reduce blockage, we studied the relationship between the geometry structure and performance of the new, which could be describeed by fixed polynomials. The best demulsification effect could be obtained by the hybrid of the polyferric sulfate and FO4440SSH, and the highest removal rate was 92.51 %. After a long-running in the ABS sewage treatment plant of the petrochemical industry, the removal rate of the new could maintain at a high level(>90 %), and the removal effect was stable. Compared with other release devices that reported in the literatures, the new one had advantages significant in both removal efficiency and operation cost. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Acrylonitrile-butadiene-styrene wastewater Dissolved air flotation The volume of gas release The flow rate Demulsification

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Probing the Interfacial Forces and Surface Interaction Mechanisms in Petroleum Production Processes

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Engineering 2022年第11期18卷 49-61页

作者： Diling Yang xuwen Peng Qiongyao Peng Tao Wang Chenyu Qiao Ziqian Zhao Lu Gong Yueliang liu Hao Zhang Hongbo Zeng Department of Chemical and Materials Engineering University of AlbertaEdmontonAB T6G 1H9Canada College of Petroleum Engineering China University of PetroleumBeijing 102249China

Despite the advances that have been made in renewable energy over the past decade,crude oil or petroleum remains one of the most important energy resources to the *** production presents many challenging issues,such as the destabilization of complex oil-water emulsions,fouling phenomena on pipelines and other facilities,and water *** problems are influenced by the molecular forces at the oil/water/solid/gas interfaces involved in relevant ***,we present an overview of recent advances on probing the interfacial forces in several petroleum production processes(e.g.,bitumen extraction,emulsion stabilization and destabilization,fouling and antifouling phenomena,and water treatment)by applying nanomechanical measurement technologies such as a surface forces apparatus(SFA)and an atomic force microscope(AFM).The interaction forces between bitumen and mineral solids or air bubbles in the surrounding fluid media determine the bitumen liberation and flotation efficiency in oil sands *** stability of complex oil/water emulsions is governed by the forces between emulsion drops and particularly between interface-active species(e.g.,asphaltenes).Various oil components(e.g.,asphaltenes)and emulsion drops interact with different substrate surfaces(e.g.,pipelines or membranes),influencing fouling phenomena,oil-water separation,and wastewater *** these intermolecular and interfacial forces has advanced the mechanistic understanding of these interfacial interactions,facilitating the development of advanced materials and technologies to solve relevant challenging issues and improve petroleum production *** challenges and suggestions on future research directions in the field are also presented.

关键词： Intermolecular and surface forces Interface Emulsion Colloids Fouling and antifouling Water treatment

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Ultrathin and Wavy PdB Alloy Nanowires with Controlled Surface Defects for Enhanced Ethanol Oxidation Electrocatalysis

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ACS APPLIED MATERIALS & INTERFACES 2021年第15期13卷 17599-17607页

作者： Wang, Yaru Lv, Hao Sun, Lizhi Guo, xuwen Xu, Dongdong liu, Ben Nanjing Normal Univ Jiangsu Collaborat Innovat Ctr Biomed Funct Mat Sch Chem & Mat Sci Jiangsu Key Lab New Power Batteries Nanjing 210023 Peoples R China Sichuan Univ Coll Chem Chengdu 610064 Peoples R China

Engineering crystalline structures/defects and elemental compositions is synthetically critical to optimize surface features of noble metal nanocrystals and thus improve their catalytic performances in various reactions. In this manuscript, we report a facile one-step aqueous synthesis of one-dimensional (1D) noble metal-metalloid alloy nanowires (NWs) with an ultrathin and wavy morphology, controlled crystalline defects, and binary PdB compositions as a highly efficient catalyst toward the electrochemical ethanol oxidation reaction (EOR). We show that the utilization of hexadecylpyridinium chloride as functional surfactant is of great importance to confine in-the-columnar epitaxial nucleation of anisotropic ultrathin PdB NWs, while the attachment growth precisely controls their surface crystalline defects with a wavy morphology. Meanwhile, this strategy is synthetically universal and can be readily extended to engineer an ultrathin wavy morphology and crystalline defect of ternary PdMB (M = Cu and Pt) alloy NWs. Owing to multiple structural and compositional merits, resultant PdB alloy NWs synergistically expose more electrocatalytically active sites and also kinetically accelerate the removal of CO-related poisons, remarkably improving electrocatalytic EOR activity and stability compared to their counterpart catalysts. Besides, wavy PdB alloy NWs are also electrochemically more active for electrocatalytic oxidation of other alcohols (methanol, glycerol, and glucose). The findings reported here thus shed a bright light on rational design of the high-performance metal alloy catalysts for their potential applications in fine chemical synthesis, fuel cells, and beyond.

关键词： nanowires crystalline defects metal-metalloid catalysis ethanol oxidation reaction

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Treatment of Keloids in A Child with Surgery Alone:Clinical Application of the LBD Suturing Technique

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Chinese Journal of Plastic and Reconstructive Surgery 2021年第1期3卷 46-50页

作者： Yong ZHANG xuwen TANG Yang liu Dongyun YANG Department of Chongqing Kewei Scar Medical Institute/Dongshang Medical Aesthetic Clinic Chongqing 400038China

Keloids are fibroproliferative disorders that can result from cutaneous injuries to the reticular *** rates as high as 100%have been reported following surgical excision ***,a variety of post-surgical techniques have been employed to prevent keloid recurrence,including the use of *** numerous studies have shown that post-excisional X-rays,electron beams,lasers,and brachytherapy can reduce the rate of keloid recurrence,numerous inconsistencies,including a wide range of definitions for keloid recurrence,render it difficult to compare the *** treatment of severe keloids in children is much more challenging,and there have been few previous *** is generally believed that children with keloids should be treated with nonsurgical treatment such as hormone injections and *** severe keloids,these methods require a long treatment period,and their efficacy is not ***,the side effects of the treatment can affect children’s *** keloid scars are not effectively treated,they will often seriously affect the physical and mental health of *** purpose of this review is to discuss case studies of children with severe keloids who were only treated with surgery and their postoperative *** this case,the deep-embedded circular mattress suture technique(LBD,the looped,broad,and deep buried suturing technique)was used in the scar *** 18 months of follow-up,the surgical scar was evaluated using the Vancouver Scar Scale(VSS).The scar was stable and did not *** child was *** case shows that it is completely feasible to treat severe keloids with surgery alone,as long as the tension is reduced during the operation to prevent surgical scar hyperplasia.

关键词： Keloid Child Scar resection Surgery LBD suturing technique Recurrence

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Looped,Broad,and Deep Buried Suturing Technique for Wound Closure

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Chinese Journal of Plastic and Reconstructive Surgery 2021年第2期3卷 85-88页

作者： xuwen TANG Yong ZHANG liu YANG Dongyun YANG Department of Chongqing Kewei Scar Medical Institute/Dongshang Medical Aesthetic Clinic Chongqing 400038China

This study explores the clinical application of the circular wide and deep(looped,broad,and deep buried,LBD)suture technique for scar resection and examines its clinical effectiveness for scar *** June 2017 to March 2019,a total of 68 patients with scars were sutured using LBD technique,and recovery was achieved 24 months *** all 68 patients,postoperative scars were slightly evident in two cases of cervical scar,one case of leg scar,and one case of chest *** addition,the remaining 62 patients were completely satisfied with the *** LBD suturing technique could provide sustained and stable tension-reducing effects postoperatively and significantly improve scar formation in *** method is most applicable to incisions with ***,it should be more widely used for clinical scar treatment.

关键词： Suture technology Looped,broad,and deep buried suturing technique Scar resection Cosmetic technology

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The relationship between geometry and hemodynamics of the stenotic carotid artery based on computational fluid dynamics

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CLINICAL NEUROLOGY AND NEUROSURGERY 2023年第1期231卷 107860-107860页

作者： liu, Yongsheng Jiang, Guinan Wang, xuwen An, Xiangbo Wang, Feng Dalian Med Univ Dept Pathol Affiliated Hosp 1 Dalian Peoples R China 222 Zhongshan Rd Dalian Peoples R China

Objective: The purpose of this work was to investigate the relationship between the geometric factors and the hemodynamics of the stenotic carotid ***: We retrospectively reviewed data of patients with carotid stenosis (40%-95%). The Navier-Stokes equations were solved using ANSYS CFX 18.0. Correlation analysis was based on Spearman's test. Geometric variables (p < 0.1 in the univariate analysis) were entered into the logistical regression. A receiver-operating characteristics analysis was used to detect hemodynamically significant lesions. Results: 81 patients (96 arteries) were evaluated. The logistic regression analysis revealed that the translesional pressure ratio was significantly correlated with the stenosis degree (OR = 1.147, p < 0.001) and the angle between internal carotid artery and external carotid artery (angle ?) (OR = 0.933, p = 0.01). The translesional wall shear stress ratio was significantly correlated with stenosis degree (OR = 1.094, p < 0.001), lesion length (OR = 0.873, p = 0.01), lumen area of internal carotid artery (OR = 0.867, p = 0.002), and lumen area of common carotid artery (OR = 1.058, p = 0.01). For predicting low translesional pressure ratio, the AUC was 0.71 (p < 0.001) for angle ?, and was 0.87 (p < 0.001) for stenosis degree. For predicting high translesional wall shear stress ratio, the AUC was 0.62 (p = 0.04) for lumen area of internal carotid artery, and was 0.77 (p < 0.001) for stenosis ***: Apart from stenosis degree, other geometric characteristics of lesions may also have an influence on hemodynamics of the stenotic carotid artery.

关键词： Carotid artery Computational fluid dynamics Geometry Hemodynamics Stenosis

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A Mixed-Ligand Strategy to Modulate P3HT Regioregularity forHigh-Efficiency Solar Cells

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MACROMOLECULES 2022年第8期55卷 3078-3086页

作者： liu, Yang Xian, Kaihu Zhang, xuwen Gao, Mengyuan Shi, Yibo Zhou, Kangkang Deng, Yunfeng Hou, Jianhui Geng, Yanhou Ye, Long Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Mol Optoelect Sci Tianjin 300350 Peoples R China Chinese Acad Sci Inst Chem Beijing Natl Lab Mol Sci State Key Lab Polymer Phys & ChemCAS Res Educ Ct Beijing 100190 Peoples R China Joint Sch Natl Univ Singapore & Tianjin Univ Fuzhou 350207 Peoples R China

Sustainable synthesis of polythiophenes (e.g.,P3HT) is highly desired for the development of low-cost organicsolar cells. Regulating the regioregularity of P3HT is a promisingway to boost its performance. Yet, few eco-friendly methods canprepare P3HT with tunable regioregularity. Herein, we put forwarda facile strategy tofinely modulate the regioregularity of P3HTfrom 90% to 98% by tuning the molar ratio of two ligands in directarylation polycondensation. Moreover, the ligand effect onregioregularity is well elucidated with DFT calculations, and theregioregularity effect of P3HT in non-fullerene solar cells isclarified for thefirst time. Our calorimetric, microscopic, and scattering results show that regioregularity strongly impacts thepolymer crystallinity and phase separation, and device performance of the blendfilms. The P3HT batch with a regioregularity of 95%yields an unprecedented power conversion efficiency of 10.82%. Importantly, this realizationfirmly provides optimism for cheapmaterials such as polythiophenes, which are made via eco-friendly polycondensation for the application of solar cells and beyond.

关键词： Crystallinity Organic polymers Photovoltaics Power conversion efficiency Solar cells

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Heavy Metal Distribution and Microbial Diversity of the Surrounding Soil and Tailings of Two Cu Mines in China

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WATER AIR AND SOIL POLLUTION 2023年第4期234卷 241-241页

作者： Xia, Yu liu, Jing Chang, Jie Li, Weijia Xia, Kaiyu liu, Zilong liu, Yizhen He, xuwen China Univ Min & Technol Beijing Sch Chem & Environm Engn Beijing 100083 Peoples R China China Natl Gold Grp Co Ltd Beijing 100011 Peoples R China

Mining activities can cause heavy metal pollution which affects soil microbial diversity. Current understanding on the impact of Cu mines especially that of bioavailable heavy metals on microbial communities is still limited. This study investigated heavy metal distribution and microbial diversity of the surrounding soil and tailings of two Cu mines from Tibet (JM) and Zhejiang (JD), China. Cu, Pb, Zn, and Cr concentrations in the soil around JM were 107.33 +/- 75.48, 29.21 +/- 19.66, 73.89 +/- 28.79, and 17.88 +/- 4.91 mg center dot kg(-1), respectively, and those of JD were 40.59 +/- 21.86, 27.00 +/- 19.40, 95.45 +/- 54.36, and 30.87 +/- 11.55 mg center dot kg(-1), respectively. For each mine, the sites closer to the mining area displayed higher PINemerow values and acid extractable contents of Cu (Cu-_AE), Zn (Zn-_AE), and Pb (Pb-_AE). The tailings samples showed lower microbial diversity and higher abundances of heavy metal-resistant organisms including the ones from the phyla Firmicutes and Bacteroidetes and the genera Bacteroides, Lactobacillus, and Staphylococcus than the surrounding soil samples. Canonical corresponding analysis (CCA) revealed that water content, altitude, electrical conductivity (EC), total concentration of Zn (Zn-_total), Cu-_AE, Zn-_AE, and Pb-_AE, and pH value were effective environmental factors shaping the structure of all the investigated communities. Acid extractable contents of Pb and Zn rather than their total concentrations were significantly correlated to JM surrounding soil microbial structure. Microbial structure differentiations of the surrounding soil of JM and JD were largely attributed to stochastic processes, suggested by the beta nearest taxon index (beta NTI).

关键词： Acid extractable fraction Cu mine Effective factors Heavy metal Microbial communities

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