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Effect of reduction pretreatment process on evolution of micro-porosity in 42CrMo billet

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Journal of Iron and Steel Research International 2021年第4期28卷 413-423页

作者： Zhen Ning Wei Yu Hong-qiang Liu Qing-wu cai Collaborative Innovation Centre of Steel Technology University of Science and Technology BeijingBeijing 100083China HBIS Group Co. Ltd.Shijiazhuang 050000HebeiChina

Reduction pretreatment(RP)process,which is implemented after the billet is completely solidified,is an alternative process to further improve billet *** element method and experiment were used to investigate the effect of the RP process on the internal quality of 42CrMo *** ultrasonic testing technology was used to study the influence of the RP process on the *** a three-dimensional finite element model,the mechanism of the RP process on the porosity closure was *** experimental results show that the RP process eliminates the macro-porosities of the billet *** number of micro-porosities in the billets is effectively reduced,and the increase in deformation contributes to the reduction in *** with isothermal rolling,the RP process leads to a larger equivalent strain and hydrostatic integration in the billet center because of the temperature gradient,and the effect of the temperature gradient is greater with the increase in *** closure effect of micro-porosity is related not only to the stress state,but also to the distribution of *** increase in three-dimensional compressive stress is beneficial to the porosity *** the micro-porosities distributed densely,excessive stress could induce micro-porosity coalescence,which has the risk of inducing cracks.

关键词： Reduction pretreatment Temperature gradient Large deformation Micro-porosity Ultrasonic testing

Shaped charge penetration into high-and ultrahigh-strength Steel-Fiber reactive powder concrete targets

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Defence Technology（防务技术） 2020年第1期16卷 217-224页

作者： qiang-qiang Xiao Zheng-xiang Huang Xudong Zu Xin Jia Qi-feng Zhu Wei cai School of Mechanical Engineering Nanjing University of Science and TechnologyXiaolingwei 200Nanjing210094China China South Industries Group Corporation Chongqing400039China

Experiments on shaped charge penetration into high and ultrahigh strength steel-fiber reactive powder concrete(RPC) targets were performed in this *** show that the variation of penetration depth and crater diameter with concrete strength is different from that of shaped charge penetration into normal strength concrete(NSC).The crater diameter of RPC is smaller than that of NSC penetrated by the shaped *** jet particles are strongly disturbed and hardly reach the crater bottom because they pass through the narrow channel formed by jet penetration into the *** effects of radial drift velocity and gap effects of jet particles for a shaped charge penetration into RFC target are ***,a theoretical model is presented to describe the penetration of shaped charge into RPC *** the concrete strength increases,the penetration resistance increases and the entrance crater diameter *** the drift velocity and narrow crater channel,the low-velocity jet particles can hardly reach the crater bottom to increase the penetration ***,the narrow channel has a stronger interference to the jet particles with increasing concrete strength;hence,the gap effects must be *** drift velocity and gap effects,which are the same as penetration resistance,also have significant effects during the process of shaped charge penetration into ultrahigh-strength concrete,The crater profiles are calculated through a theoretical model,and the results are in good agreement with the experiments.

关键词： Shaped charge Reactive powder concrete target Penetration Radial drift velocity Gap effects

Design and construction of a multi-sensor position monitoring system applied to key components of synchrotron sources

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Nuclear Science and Techniques 2016年第6期27卷 79-85页

作者： Wei Wang Zheng Tang Xiao-ye He qiang Zhang University of Science and Technology of China Hefei 230029China

High-accuracy position monitoring of key components is required for modern synchrotron sources,such as free-electron lasers and diffraction-limited storage *** various position monitoring sensors have been adopted to monitor the displacement of key components in each direction in real time,these monitoring systems are usually based on their own coordinate *** from such systems are meaningful when evaluating and examining the data from each positioning monitoring system in a unified coordinate *** paper presents the design and construction of a multi-sensor position monitoring system(MPMS).A hydrostatic levelling system,a wire position sensor(WPS) and a tiltmeter are fixed to a stainless steel plate that has been calibrated by a coordinate-measurement *** plates form the *** system must compensate for the sag of the stretched wires so that the WPSs create a straight *** method of the coordinate transformation from the sensor coordinate system to the MPMS coordinate system was thoroughly *** experimental MPMS that includes five plates was setup in a 20-m tunnel,and a validation study to verify fully the feasibility of the MPMS was performed.

关键词：实时监测系统位置传感器自由电子激光器坐标系统坐标变换方法关键部件不锈钢板同步加速器

Risk scoring system and predictor for clinically relevant pancreatic fistula after pancreaticoduodenectomy

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World Journal of Gastroenterology 2015年第19期21卷 5926-5933页

作者： Ji-ye Chen Jian Feng Xian-qiang Wang Shou-Wang cai Jia-Hong Dong Yong-Liang Chen Hospital and Institute of Hepatobiliary Surgery Chinese PLA General Hospital Chinese PLA Postgraduate Medical School

AIM: To establish a scoring system to predict clinicallyrelevant postoperative pancreatic fistula(CR-POPF)after pancreaticoduodenectomy(PD).METHODS: The clinical records of 921 consecutive patients who underwent PD between 2008 and 2013 were reviewed retrospectively. Postoperative pancreatic fistula(POPF) was defined and classified by the international study group of pancreatic fistula(ISGPF).We used a logistic regression model to determine the independent risk factors of CR-POPF and developed a scoring system based on the regression coefficient of the logistic regression model. The optimal cut-off value to divide the risk strata was determined by the Youden index. The patients were divided into two groups(low risk and high risk). The independent sample t test was used to detect differences in the means of drain amylase on postoperative day(POD) 1, 2 and 3. The optimal cut-off level of the drain amylase to distinguish CR-POPF from non-clinical POPF in the two risk strata groups was determined using the receiver operating characteristic(ROC) ***: Grade A POPF occurred in 106(11.5%)patients, grade B occurred in 57(6.2%) patients,and grade C occurred in 32(3.5%) patients. A predictive scoring system for CR-POPF(0-6 points) was constructed using the following four factors: 1 point for each body mass index ≥ 28 [odds ratio(OR) = 3.86;95% confidence interval(CI): 1.92-7.75, P = 0.00],soft gland texture(OR = 4.50; 95%CI, 2.53-7.98, P =0.00), and the difference between the blood loss and transfusion in operation ≥ 800 mL(OR = 3.45; 95%CI,1.92-7.75, P = 0.00); and from 0 points for a 5 mm or greater duct diameter to 3 points for a less than 2 mm duct(OR = 8.97; 95%CI: 3.70-21.77, P = 0.00). The ROC curve showed that the area under the curve of this score was 0.812. A score of 3 points was suggested to be the best cut-off value(Youden index = 0.485). In the low risk group, a drain amylase level ≥ 3600 U/L on POD3 could distinguish CR-POPF from non-clinicalPOPF(the

关键词： Pancreatic fistula Pancreaticoduodenectomy Postoperative complication Risk factor Logistic model

Ethoxylation of Phenols Catalyzed by Metal-Free Lewis Pairs:Living/Controlled Polymerization in a Slow-lnitiation Mode

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Chinese Journal of Chemistry 2021年第9期39卷 2579-2587页

作者： qiang Zhang Yubo Zhou ye Chen Junpeng Zhao Faculty of Materials Science and Engineering South China University of TechnologyGuangzhouGuangdong 510640China Key Laboratory of Luminescence from Molecular Aggregates of Guangdong Province South China University of TechnologyGuangzhouGuangdong 510640China

Phenols,in stead of con venti onal alcoholic compounds,are used to in itiate ring-openi ng polymerizati on(ROP)of ethyle neoxide and propyle ne oxide in bulk at room temperature in cooperati on with the recently prevaili ng bicompone nt metal-free catalyst comprising an organobase and *** and DFT calculation results both point out that due to the lower nucleophilicity of the initiating(phe no late)species than the propagating(alcoholate)species,chai n initiat ion is distinctly slower tha n propagation and the difference becomes eve n larger as the acidity of the phe nolic in itiator ***,we 11-defi ned polyethers with expected molar mass,low dispersity,and high end-group fidelity are afforded substa ntiating that the ROP is living/c on trolled in spite of the slow *** of product composition indicates that the reaction on alcoholates(i.e.,propagation)is effectively inhib-ited by the unreacted phenols during the initiation step because of the adequately large acidity differenee,which is key to the success of the slow-initiation living/controlled *** acidity difference betwee n phe nol and alcohol also facilitates the fulfill-ment of highly selective phenolysis of epoxides,a"1+1"type addition reaction between phenol and epoxide(in excess)rather than the"1+n"type ROP reaction,by use of a milder organobase and decreased Lewis acid/base ratio.

关键词： Ring-opening polymerization Organocatalysis Lewis bases Ethoxylation Phenol

基于SCIATRAN的临近空间氧气光谱敏感性分析

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光谱学与光谱分析 2025年第1期45卷 170-178页

作者：叶松胡双寒熊伟李树王新强王方原汪杰君桂林电子科技大学光电工程学院广西桂林541004 中国科学院安徽光学精密机械研究所中国科学院通用光学定标与表征技术重点实验室安徽合肥230031 广西光电信息处理重点实验室广西桂林541004

临近空间大气温度场的研究具有重要的科学意义,根据全时相大气温度示踪物辐射机制与分布特征研究表明,氧气作为大气的主要成分之一,广泛分布于临近空间且辐射强度明显,所以氧气探测是研究临近空间温度变化的重要基础。临近空间氧气探测... 详细信息

临近空间大气温度场的研究具有重要的科学意义,根据全时相大气温度示踪物辐射机制与分布特征研究表明,氧气作为大气的主要成分之一,广泛分布于临近空间且辐射强度明显,所以氧气探测是研究临近空间温度变化的重要基础。临近空间氧气探测主要是依据太阳辐射的短波红外部分被大气层氧气分子吸收得到的吸收谱线,该谱线携带着氧气含量等重要信息。利用探测器得到的氧气光谱进行高精度反演可以得到温度等信息。探测过程中的太阳天顶角、方位角、临边切高及气溶胶参数等因素对氧气影响不同,基于SCIATRAN模型分析氧气对不同参数的敏感性。通过对探测方式和环境因素引起的辐射亮度变化来分析计算氧气对其敏感性。结果表明:氧气的辐射亮度在天顶角为60°以下是随天顶角增大而增大的,但在超过60°后变化随之相反,一天内的太阳天顶角对于氧气的辐射亮度影响不超过0.01 W/m^(2)/nm/sr,且差值不超过7%;氧气辐亮度随方位角增大而减小;氧气辐射亮度随切线高增加而减小,且减小幅度逐渐下降;气溶胶类型对氧气辐射亮度的影响差值比例在10%以内;气溶胶季节对氧气辐射亮度影响是春夏季节要大于秋冬季节;不同气溶胶类型下的气溶胶光学厚度倍数对氧气辐射亮度影响的差值比例均在30%以内,且农村与海洋型气溶胶下光学厚度倍数与辐射亮度成正比,城市型气溶胶下与之相反。仿真数据的结果与实测数据结果对比分析验证了SCIATRAN模型仿真数据的有效性和可行性。该研究为临近空间的氧气探测提供了科学依据,为临近空间的反演等相关研究领域提供参考。

关键词：临近空间氧气辐射传输敏感性

Outcomes of per oral endoscopic pyloromyotomy in gastroparesis worldwide

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World Journal of Gastroenterology 2019年第8期25卷 909-922页

作者： Parit Mekaroonkamol Rushikesh Shah qiang cai Division of Digestive Diseases Emory University School of Medicine

Per oral endoscopic pyloromyotomy(POP),also known as gastric per-oral endoscopic myotomy(GPOEM),is a novel procedure with promising potential for the treatment of *** more data emerge and the procedure is becoming more recognized in clinical practice,its safety and efficacy need to be carefully *** patient selection for favorable clinical success prediction after GPOEM also needs additional *** review aims to systemically summarize the existing data on clinical outcomes of *** responses to the procedure,its adverse effects,procedural techniques,and predictive factors of clinical success are also discussed.

关键词： Gastroparesis Per oral endoscopic pyloromyotomy Gastric per-oral endoscopic myotomy Pyloromyotomy Outcomes

Chinese expert consensus on neoadjuvant and conversion therapies for hepatocellular carcinoma

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World Journal of Gastroenterology 2021年第47期27卷 8069-8080页

作者： Hai-Tao Zhao Jian-qiang cai Department of Hepatobiliary Surgery Peking Union Medical College HospitalBeijing 100021China Department of Hepatobiliary Surgery Cancer Hospital Chinese Academy of Medical SciencesBeijing 100021China

The low resection and high recurrence rates in hepatocellular carcinoma(HCC)are the major challenges to improving *** and conversion therapies are underlying strategies to overcome these *** date,no guideline or consensus has been published on the neoadjuvant and conversion therapies in *** studies showed that neoadjuvant therapy for resectable HCC and conversion therapy for unresectable HCC are safe,feasible,and *** and conversion therapies have the following advantages in treating HCC:R0 resection with sufficient volume of future liver remnant,relatively simple operation,and wide ***,it was necessary to conduct a widely accepted consensus among the experts in China who have extensive expertise and experience in treating HCC using neoadjuvant and conversion therapies,which is important to standardize the application of neoadjuvant and conversion therapies for the management of *** strategies of neoadjuvant therapy include the selection of the eligible patients,therapy regimen,cycles,effect evaluations,and multidisciplinary *** management of patients with insufficient volume of future liver remnant and patients who cannot achieve R0 resection is the key to the strategies of conversion ***,we present the resultant evidence-and experience-based consensus to guide the application of neoadjuvant and conversion therapies in clinical practice.

关键词： Consensus Hepatocellular carcinoma Neoadjuvant therapy Conversion therapy

Transforming liquid flow fuel cells to controllable reactors for highlyefficient oxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid at low temperature

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Journal of Energy Chemistry 2024年第3期90卷 621-631,I0014页

作者： ye qiang Xi Liu Denghao Ouyang Zhao Jiang Xuebing Zhao Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084China Institute of Applied Chemistry Department of Chemical EngineeringTsinghua UniversityBeijing 100084China School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an 710049ShaanxiChina

Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still ***,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild *** LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to *** reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of *** a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism.

关键词： 5-Hydroxymethylfurfural 2 5-Furandicarboxylic acid Electrodeposition Electron transport chain Liquid flow fuel cell