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Quantitative effects of phase transition on solute partition coefficient,inclusion precipitation, and microsegregation for high-sulfur steel solidification

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Journal of Materials Science & Technology 2019年第10期35卷 2383-2395页

作者： Lintao Gui Mujun Long Shixin Wu Zhihua Dong Dengfu Chen Yunwei Huang Huamei Duan Levente Vitos State Key Laboratory of Coal Mine Disaster Dynamics and Control College of Materials Science and EngineeringChongqing UniversityChongqing400044China Department of Materials Science and Engineering KTH Royal Institute of TechnologyStockholm10044Sweden Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing400044China

Segregation and inclusion precipitation are the common behaviours of steel solidification, which are resulted from the redistribution and diffusion of the solute elements at the solid-liquid interface. The effect of the phase transition of high-sulfur free-cutting steel is quantified in the present work for the solute partition coefficient(ki), inclusion precipitation, and microsegregation by establishing a coupling model of microsegregation and inclusion precipitation, wherein the quantified dependencies of ki in terms of temperature, phase and carbon(C) content were applied. Results showed that the solidification temperature range and phase transition of high-sulfur steel that under different solidification paths and C contents were quite different, leading to differences in ki and eventually in microsegregation. kC,kP, and kS were mainly affected by phase composition and kSi was primarily by temperature, while kMn depended on both phase composition and temperature during solidification. Increasing the C content within the interval 0.07-0.48 wt%, the ‘proportion of the δ phase maintained temperature region during solidification’(Pδ), kave Pand kave S(kiave, the average value of the ki across the whole stages of solidification)decreased monotonically, whereas kave Cincreased linearly. The peritectic reaction impacted on the phase composition and ki, leading to the change in microsegregation. Such effect of the peritectic reaction was more significant at the last stage of solidification. When the Pδ was between 75% and 100%(corresponding to 0.07-0.16 wt% C), the solidification path resulted in a greater effect on the microsegregation of solutes C, P, and S because of the peritectic reaction. The microsegregation of solutes Mn and S were comprehensively influenced by kMn, kS and Mn S precipitation as well. The studies would help reveal the solute redistribution at the solid-liquid interface, and improve the segregation of high-sulfur steel by controlling the solidification and precipitation in practice.

关键词： Phase transition Microsegregation Solute partition coefficient Inclusion precipitation High-sulfur steel

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Influences of fisheries management measures on biological characteristics of threadfin bream(Nemipterus virgatus)in the Beibu Gulf,South China Sea

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Acta Oceanologica Sinica 2022年第3期41卷 24-33页

作者： Kui Zhang Ping Geng Jiajun Li Youwei Xu Muhsan Ali Kalhoro Mingshuai Sun dengfu Shi Zuozhi chen South China Sea Fisheries Research Institute Chinese Academy of Fishery SciencesGuangzhou 510300China Key Laboratory for Sustainable Utilization of Open-sea Fishery Ministry of Agriculture and Rural AffairsGuangzhou 510300China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Faculty of Marine Sciences Lasbela University of AgricultureWater and Marine SciencesUthal 90150Pakistan

Long-term variations in population structure,growth,mortality,length at median sexual maturity,and exploitation rate of threadfin bream(Nemipterus virgatus)are reported based on bottom trawl survey data collected during 1960-2012 in the Beibu Gulf,South China Sea.Laboratory-based analyses were conducted on 16791 individuals collected quarterly in eight different sampling years.Average body length,estimated asymptotic length,and percentage of large individuals have decreased significantly with the growth of marine catch and fishing power,indicating individual miniaturization of this fish species.Estimated exploitation rates indicate that the N.virgatus stock in the Beibu Gulf was moderately exploited in 1960 and 1962 and overexploited after 1992.This stock was taking a good turn in status in 2012,with the lowest exploitation rate since 1992 and ceased downward trend in length indexes.These results suggest that management measures to reduce fishing pressure may have a positive influence on the biological characteristics of this commercial fish species.Biological characteristics of most commercial fish species have phenotypic plasticity and might change over years in response to fisheries management.Therefore,attentions should be paid on variations in fish biological characteristics,when evaluating the effectiveness of current measures to control the total catch for all fisheries.

关键词： growth mortality length at median sexual maturity fishing pressure phenotypic plasticity

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A new method for calculating the activity of stable compound from binary phase diagram

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Rare Metals 2006年第5期25卷 448-451页

作者： chen dengfu DONG Lingyan BAI chenguang LIU Qingcai WANG Chuanjun College of Materials Science and Engineering Chongqing University Chongqing 400030 China

A new method to calculate the activity of a stable compound in a binary phase diagram was presented and discussed. According to the formula for calculating activity from the binary phase diagram, the equilibrium constant can be calculated through the mass action principle after the activities of two pure components were computed respectively. Based on that, the activity of a stable compound can be easily obtained at last. The activity of the stable compound InSb is calculated in the In-Sb binary system by using this method. The result is well consistent with another calculation value.

关键词： physic-chemistry of metallurgy phase diagram mass action principle stable compound activity

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Preparation and characterization of porous titanium using space-holder technique

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Rare Metals 2009年第4期28卷 338-342页

作者： NIU Wenjuan BAI chenguang QIU Guibao WANG Qiang WEN Liangying chen dengfu DONG Lingyan College of Materials Science and Engineering Chongqing University Chongqing 400044 China

Titanium-based porous materials can be used in structural applications and medical implants because of their excellent mechanical properties at elevated temperatures, good corrosion resistance and wonderful biocompatibility. However, most of the methods used to produce the porous metal can only give limited porosity and uncontrollable pore morphologies. In the present study, a newly developed method of powder metallurgy using the space-holder technique was used to fabricate porous titanium with controllable porosity. The morphological features and mechanical properties of the products were fully investigated. The results show that the porosity is in the range of 55%-75%, and the mean pore size, with an average sphericity of -0.72, is 600 μm. The plateau stresses vary between 10 MPa and 35 MPa. As predicted by the Gibson-Ashby model, the plateau stress decreases with increasing porosity.

关键词： powder metallurgy porous titanium space-holder pore morphology mechanical properties

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基于生活史特征的数据有限条件下渔业资源评估方法比较

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中国水产科学 2020年第1期27卷 12-24页

作者：史登福张魁陈作志中国水产科学研究院南海水产研究所农业农村部外海渔业开发重点实验室上海海洋大学海洋科学学院

渔业资源评估是开展渔业资源管理,维系渔业可持续发展的基础工作。传统的渔业资源评估方法需要统计产量、资源丰度指数甚至年龄结构等大量数据,由于调查经费和数据的缺乏,全球仅1%的鱼种进行过系统性的资源评估。近年来,在数据有限(data... 详细信息

渔业资源评估是开展渔业资源管理,维系渔业可持续发展的基础工作。传统的渔业资源评估方法需要统计产量、资源丰度指数甚至年龄结构等大量数据,由于调查经费和数据的缺乏,全球仅1%的鱼种进行过系统性的资源评估。近年来,在数据有限(data-limited)条件下如何开展资源评估已日益成为学术界的关注热点。本文将基于生活史特征的评估方法分为仅需要生活史参数,需要产量数据和生活史参数,需要产量数据、生活史参数及体长或年龄数据等3大类,分别从方法、数据要求、输出结果及局限性进行了系统回顾分析,提供了关于生活史特征参数的常见估算方法,并就其中两种模型对北大西洋大青鲨(Prionace glauca)的可持续渔获量进行了初步评估与比较。最后,对数据缺乏模型的使用及模型在中国近海渔业资源评估中的运用提出了建议。

关键词：渔业资源评估模型数据缺乏生活史特征北大西洋大青鲨渔业

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Clinicopathological features of hypoxia-inducible factor-1α and vascular endothelial growth factor expression in patients with lung cancer

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Oncology and Translational Medicine 2016年第6期2卷 261-267页

作者： Xuli Yang Li Wang Wenli Sai Yin Cai Juanjuan Gu Xin chen dengfu Yao Research Center of Clinical Medicine The Affiliated Hospital of Nantong University Center of Medical Informatics Medical School of Nantong University Department of Oncology The Affiliated Hospital of Nantong University School of Life Science Nantong University

Objective The aim of the study was to investigate the clinicopathological characteristics of hypoxiainducible factor-1α(HIF-1α) and vascular endothelial growth factor(VEGF) expression in patients with lung cancer.Methods Cancerous and noncancerous tissues were collected post-operation from 115 patients with lung cancers by the self-control method. Total RNA was extracted from the lung tissues. The status of tissue HIF-1α expression and intercellular distribution was observed by immunochemistry using a tissue microarray. The expression levels of circulating HIF-1α and VEGF were detected by enzyme-linked immunosorbent assay(ELISA).Results The expression of serum HIF-1α [(138.3 ± 28.8) μg/L] in the group of patients with lung cancer was significantly higher(P < 0.01) than that in the group of patients with pneumonia [(58.8 ± 14.5) μg/L] and the control group of patients ((24.1 ± 3.3) μg/L)There was a strong positive correlation of serum HIF-1α levels(r = 0.937, P < 0.01) with serum VEGF levels. The specific concentration of total RNA [(1.52 ± 1.14) μg/mg wet lung tissues] in the cancerous tissues was significantly higher(t = 8.494, P < 0.001) than that in the noncancerous tissues ((0.58 ± 0.33) μg/mg)The clinicopathological features of HIF-1α expression in lung cancer tissues revealed a significant relationship between positive HIF-1α expression and patient sex(χ~2 = 4.494, P = 0.034), tumor size(χ~2 = 4.679, P = 0.031), differentiation degree(χ~2= 8.846, P = 0.012), and presence of lymphatic node metastasis(χ~2= 6.604, P = 0.037).Conclusion Abnormal HIF-1α expression in lung cancer is closely related with nucleic acid metabolism and angiogenesis, and it may be helpful in the diagnosis and identification of lung cancer.

关键词： lung cancer hypoxia-inducible factor-1α(HIF-1α) nucleic acid metabolism enzyme-linked immunosorbent assay(ELISA) diagnosis

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Abnormal expression of VEGF and its gene transcription status as diagnostic indicators in patients with non-small cell lung cancer

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Oncology and Translational Medicine 2015年第5期1卷 201-207页

作者： Yun Shi Yang Shi Xuli Yang Jianrong chen Qi Qian dengfu Yao Guangzhou Wu Research Center of Clinical Medicine Affiliated Hospital of Nantong University Department of Cardiothoracic Surgery The Affiliated Yancheng Hospital of Nantong University Department of Respiration Medicine The 1st People's Hospital of Nantong City

Objective Angiogenesis is known to be essential for the survival,growth,invasion,and metastasis of lung cancer cells. Vascular endothelial growth factor(VEGF) is an important factor regulating angiogenesis of non-small cell lung cancer(NSCLC); however,its pathologic features and significance are unclear. In this study,the tissue VEGF expression levels and its gene transcriptional status,as well as circulating VEGF levels,were investigated in patients with lung disease. Methods VEGF protein and m RNA expression levels in 38 lung tissue samples were analyzed by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR),respectively. Circulating VEGF levels were detected quantitatively by an enzyme linked immuno-sorbent assay. Results The level of VEGF expression was significantly higher in lung cancer tissue than in the corresponding paracancerous or non-cancerous tissues. The average level of VEGF-positive staining was 76% in tissue samples from NSCLC patients; the levels were 89% in tissue samples from stage III patients and 92% in stage IV patients. High VEGF expression was also evident in cases with lymph node metastasis(84%),distant metastasis(90%),and lower differentiation degree(89%). VEGF m RNA in cancerous tissues was represented predominantly by the VEGF121 and VEGF165 isoforms. Circulating VEGF levels were significantly higher in NSCLC patients [(840 ± 324) pg/m L] than in patients with benign lung diseases [(308 ± 96) pg/m L] or in healthy individuals serving as controls [(252 ± 108) pg/m L]. Conclusion The over-expression of lung VEGF and its gene transcription status should be useful molecular indicators for NSCLC diagnosis.

关键词：肿瘤学临床诊断癌症患者化疗

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板坯连铸机二次冷却均匀性的分析与优化

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炼钢 2021年第1期37卷 57-62,72页

作者：黎建全龙木军陈登福周明佳攀钢集团攀枝花钢钒有限公司提钒炼钢厂四川攀枝花617062 重庆大学材料科学与工程学院重庆400044

针对某厂连铸板坯裂纹频繁出现的问题,结合连铸机的喷嘴布置特点,在测试分析铸机喷嘴的喷淋冷却特性的基础上,以Q235G钢为对象,考虑板坯宽度方向二冷水流密度分布状态,采用数值仿真方法模拟计算了200 mm×1350 mm连铸坯的凝固壳生长形... 详细信息

针对某厂连铸板坯裂纹频繁出现的问题,结合连铸机的喷嘴布置特点,在测试分析铸机喷嘴的喷淋冷却特性的基础上,以Q235G钢为对象,考虑板坯宽度方向二冷水流密度分布状态,采用数值仿真方法模拟计算了200 mm×1350 mm连铸坯的凝固壳生长形貌及铸坯表面内弧温度分布。研究表明:板坯铸机二冷前期足辊段与零段原喷嘴布置及水流密度分布不合理,提出了调整喷嘴靶距改善板坯宽度方向冷却强度分布均匀性的解决方案,实现了凝固坯壳的均匀生长和温度的均匀分布,有效减少了铸坯裂纹。

关键词：板坯二次冷却喷嘴布置温度场

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电镀废水化学法综合处理及回用工程设计

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电镀与精饰 2019年第5期41卷 33-37页

作者：陈俊峰刘金玲邓超黄德福桂林航天电子有限公司广西桂林541002

本文通过分析企业废水来源和废水含量,应用化学法处理含铬、含镍、含氰等多类型废水,利用膜分离技术进行回水再利用,设计建立了废水处理中心系统。该系统由pH和ORP控制仪控制各处理单元自动加药,过程稳定可控,结果可数据化且可实时传递... 详细信息

本文通过分析企业废水来源和废水含量,应用化学法处理含铬、含镍、含氰等多类型废水,利用膜分离技术进行回水再利用,设计建立了废水处理中心系统。该系统由pH和ORP控制仪控制各处理单元自动加药,过程稳定可控,结果可数据化且可实时传递至环保管理部门,达到清洁生产Ⅱ级要求,实现了企业节能减排的目的。

关键词：电镀废水化学法处理膜分离技术水回用节能减排

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一种基于标准样品浓度稀释的在线氚监测仪校准装置

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核电子学与探测技术 2024年第2期44卷 208-213页

作者：方登富韦应靖王明亮李胤陈双强段嘉宇中国辐射防护研究院辐射安全与防护山西省重点实验室中核集团辐射防护技术重点实验室太原030006 清华大学北京100084

为解决在线氚监测仪的现场校准问题,开展了在线氚监测仪现场校准方法研究,主要包括现场校准装置的机械构造、工作原理、校准装置量值的确定,以及需要开展的校准项目。利用该现场校准装置和氚活度浓度标准装置,对同一台在线氚监测仪进行... 详细信息

为解决在线氚监测仪的现场校准问题,开展了在线氚监测仪现场校准方法研究,主要包括现场校准装置的机械构造、工作原理、校准装置量值的确定,以及需要开展的校准项目。利用该现场校准装置和氚活度浓度标准装置,对同一台在线氚监测仪进行了校准比较,结果表明两者的校准因子分别为1.07和1.05,相对偏差约为2%,该现场校准装置具备量值传递的能力,可满足现场校准要求。此外,该校准装置具有便携性、可操作性和可拆分的特点,可保证现场校准不受场所作业空间的限制,适合在现场进行校准实验,可解决国内在线氚监测仪设备无法溯源的问题。

关键词：在线式氚监测仪现场校准量值传递

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