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A deoxidation thermodynamic model for 304 stainless steel considering multiple-components coupled reactions

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Journal of Iron and Steel Research International 2024年第1期31卷 74-91页

作者： Yan Yan guang-hao shang Li-ping Zhang Shao-ying Li Han-jie Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Henan Jinhui Stainless Steel Industry Group Co. Ltd.Xuchang461500HenanChina Changge Jinhui Recycling Metal R&D Co. Ltd.Xuchang461500HenanChina

A thermodynamic model for predicting the equilibrium oxygens of 304 stainless steel was developed based on the theory of slag-steel equilibrium,the law of mass conservation,and the ion and molecule coexistence *** the developed model,the Fe-Cr-Mn-Si-Al-S-O-melts reaction system and CaO-MgO-CaF_(2)-FeO-MnO-Al_(2)O_(3)-SiO_(2)-Cr2O_(3)slags were *** oxygen contents calculated by the model are in good agreement with experimental results and reference *** equilibrium oxygen contents in 304 stainless steel mainly decrease with increasing binary basicity(w(CaO)/w(SiO_(2)),where w(i)is the mass percentage of component i)and decreasing *** binary basicity at 2.0 while maintaining temperatures lower than 1823 K will keep the oxygen contents in the 304 stainless steel lower than 15×10^(-6).The equilibrium oxygen contents may also be decreased with increasing content of MgO in slags,which is more significant at lower binary ***,a small amount of FeO,MnO,and Al_(2)O_(3)(about 0-2.5 wt.%)in slags has little effect on equilibrium oxygen ***,it is found that the[C]-[O]reaction may occur during refining process but will not significantly affect the equilibrium oxygen contents.

关键词： Complex deoxidation Thermodynamic model Ion and molecule coexistence theory 304 stainless steel Slag-steel reaction

Revealing effect of Al content on oxidation of novel Co-Cr-Nb-W carbide-strengthened superalloy

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Rare Metals 2024年第9期43卷 4521-4534页

作者： Chen Ling shang-ping Li Jie Hou He-Li Luo Central Iron&Steel Research Institute Beijing 100081China Beijing GAONA Materials&Technology Co. Ltd.Beijing 100081China

The high-temperature oxidation behavior of novel Co-Cr-Nb-W carbide-strengthened wear-resistance alloys with different Al contents(1wt%,2wt%and 3wt%)at 950,1000 and 1050℃was thoroughly investigated by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy and field emission electron probe *** porous property of NbC in-situ oxidation products(Nb_(2)O_(5),Co Nb_(2)O_(6)and Co_(4)Nb_(2)O_(9))induces a multi-layered oxide scale with micropores and ***-Cr-Nb-W alloy with 1 wt%Al undergoes catastrophic oxidation and spalling above 1000℃.The outward transportation of Cr and Co is effectively restrained by a continuous Al_(2)O_(3)scale formed around NbC in-situ oxidation region when Al content reaches 3 wt%.The β-Co Al in Co-Cr-Nb-W alloy with 3 wt%Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with Cr,thereby preventing the formation of Cr-depletion area and improving the self-healing ability of the oxide film.A slight change in Al content has a remarkable influence on the cooperative effect of Al and Cr and multiplies the antioxidant capacity of Co-Cr-Nb-W alloy above 1000℃.

关键词： High-temperature oxidation behavior Oxidation kinetics Superalloy Wear-resistant alloy Microstructure

Recent development of three-dimension printed graphene oxide and MXene-based energy storage devices

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Tungsten 2024年第1期6卷 196-211页

作者： Liang-Hao Yu Xin Tao shang-Ru Feng Jin-Tao Liu Lin-Lin Zhang guang-Zhen Zhao guang Zhu Key Laboratory of Spin Electron and Nanomaterials of Anhui Higher Education Institutes Suzhou UniversitySuzhou 234000China Key Laboratory of Leather of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China

The research for three-dimension(3D)printing carbon and carbide energy storage devices has attracted widespread exploration *** designable in structure and materials,graphene oxide(GO)and MXene accompanied with a direct ink writing exhibit a promising prospect for constructing high areal and volume energy density *** review not only summarizes the recent advances in 3D printing energy storage devices including printing methods,ink rheological properties,and different energy storage systems,but also discusses the printing methods related to energy *** addition,the binder or additive free of two-dimensional carbide materials is quite important for the present electrochemical energy storage devices,which also are presented.

关键词： 3D printing Two-dimensional materials Energy storage device Ink theological MXene

Power-law patterns in the Phanerozoic sedimentary records of carbon, oxygen, sulfur,and strontium isotopes

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Journal of Palaeogeography 2024年第1期13卷 116-126页

作者： Haitao shang Institute of Ecology and Evolution University of OregonEugeneOR97403USA

Power-law patterns appear in a variety of natural systems on the modern Earth;nevertheless,whether such behaviors appeared in the deep-time environment has rarely been studied. Isotopic records in sedimentary rocks, which are widely used to reconstruct the geological/geochemical conditions in paleoenvironments and the evolutionary trajectories of biogeochemical cycles, offer an opportunity to investigate power laws in ancient geological systems. In this study, I focus on the Phanerozoic sedimentary records of carbon, oxygen, sulfur, and strontium isotopes, which have well documented and extraordinarily comprehensive datasets. I perform statistical analyses on these datasets and show that the variations in the sedimentary records of the four isotopes exhibit power-law behaviors. The exponents of these power laws range between 2.2 and 2.9;this narrow interval indicates that the variations in carbon, oxygen, sulfur, and strontium isotopes likely belong to the same universality class, suggesting that these systematic power-law patterns are governed by universal, scale-free mechanisms. I then derive a general form for these power laws from a minimalistic model based on basic physical principles and geosystem-specific assumptions, which provides an interpretation for the power-law patterns from the perspective of thermodynamics. The fundamental mechanisms regulating such patterns might have been ubiquitous in paleoenvironments, implying that similar power-law behaviors may exist in the sedimentary records of other isotopes.

关键词： Power laws Phanerozoic sedimentary records Carbon isotope(δ~(13)C) Oxygen isotope(δ~(18)O) Sulfur isotope(δ~(34)S) Strontium isotope(~(87)Sr/~(86)Sr)

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江淮分水岭地区生态环境问题成因与控制对策

水土保持通报 2006年第2期26卷 12-16页

作者：茆长荣尚广萍合肥学院旅游系安徽合肥230001 东北师范大学城市与环境科学学院吉林长春130024

分析了江淮分水岭地区存在的森林生态系统脆弱,易旱多灾,水资源短缺,土壤贫瘠,矿山开采过度,水土流水严重,化肥、农药、农膜等农业化学品污染严重,农村生态环境退化等生态环境问题。从地质条件、气候因素、植被覆盖以及土壤条件等方面... 详细信息

分析了江淮分水岭地区存在的森林生态系统脆弱,易旱多灾,水资源短缺,土壤贫瘠,矿山开采过度,水土流水严重,化肥、农药、农膜等农业化学品污染严重,农村生态环境退化等生态环境问题。从地质条件、气候因素、植被覆盖以及土壤条件等方面对该地区的生态环境问题成因进行了探讨。针对研究区域的自然环境条件和社会经济状况,按照系统工程的原理,从遵守自然规律的角度出发提出了提高森林覆盖率,加强水利工程建设,改良土壤,因地制宜调整农业产业结构,工程措施与生物措施相结合进行矿山修复,治理水土流失,搞好生态环境保护规划,大力发展生态旅游,提高公众的环境意识,依靠科技进步促进地方经济发展的一系列改善江淮分水岭地区生态环境问题的对策。

关键词：江淮分水岭生态环境问题对策

Perinatal prevalence of birth defects in the Mainland of China,2000–2021:a systematic review and meta-analysis

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World Journal of Pediatrics 2024年第7期20卷 669-681页

作者： Liang-Yu Kang Zi-Rui Guo Wei-Jing shang Gui-Ying Cao Yi-ping Zhang Qiao-Mei Wang Hai-ping Shen Wan-Nian Liang Min Liu Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityNo.38Xueyuan RoadHaidian DistrictBeijing100191China Vanke School of Public Health Tsinghua UniversityNo.1Tsinghua GardenHaidian DistrictBeijing100084China Department of Maternal and Child Health National Health Commission of the People’s Republic of ChinaNo.1Xizhimenwai South RoadXicheng DistrictBeijingChina Institute of Healthy China Tsinghua UniversityNo.1Tsinghua GardenHaidian DistrictBeijing100084China Key Laboratory of Epidemiology of Major Diseases(Peking University) Ministry of Education BeijingNo.38Xueyuan RoadHaidian DistrictBeijing100191China

Background Although birth defects are of great concern globally,the latest national prevalence has not yet been quantified in *** conducted a systematic review and meta-analysis to estimate the perinatal prevalence of birth defects in the Mainland of China between 2000 and *** We performed a systematic literature search of six databases for relevant articles published between January 1,2000,and March 1,*** included published studies that reported data on the perinatal prevalence of birth defects in the Mainland of *** DerSimonian and Laird random-effects models were used to estimate the pooled prevalence and its 95%confidence interval(CI).We also conducted subgroup analyses and univariable meta-regressions to explore differences in prevalence by time period,geographic region,and other *** We included 254 studies reporting the perinatal prevalence of birth defects and 86 studies reporting only the prevalence of specific types of birth *** on 254 studies covering 74,307,037 perinatal births and 985,115 cases with birth defects,the pooled perinatal prevalence of birth defects was 122.54(95%CI 116.20–128.89)per 10,000 perinatal births in the Mainland of China during 2000–***,the perinatal prevalence of birth defects increased from 95.60(86.51–104.69)per 10,000 in 2000–2004 to 208.94(175.67–242.22)per 10,000 in 2020–*** were also significant disparities among different geographical *** heart defects(33.35 per 10,000),clefts of the lip and/or palate(13.52 per 10,000),polydactyly(12.82 per 10,000),neural tube defects(12.82 per 10,000),and inborn errors of metabolism(11.41 per 10,000)were the five most common types of birth *** perinatal prevalence among males was significantly higher than that among females(β=2.44×10^(−3),P=0.003);a higher perinatal prevalence of birth defects was observed among perinatal births whose mothers were≥35 years(β=4.34×10^(−3),P<0.001).Conclusion Compreh

关键词： Birth defects China Perinatal Prevalence

合肥市城市PM_(10)污染成因及控制对策

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安徽大学学报（自然科学版） 2005年第4期29卷 87-92页

作者：茆长荣尚广萍合肥学院旅游系安徽合肥230601 东北师范大学城市与环境科学学院

利用合肥市4个空气自动监测站2001-2003年3年PM10的监测结果,从4个监测点3年PM10年均值、月均值和日均值超标率的变化情况对PM10污染时空分布特征进行了详细分析,并从气象条件、下垫面性质和污染物排放三个方面对PM10污染的成因进行了... 详细信息

利用合肥市4个空气自动监测站2001-2003年3年PM10的监测结果,从4个监测点3年PM10年均值、月均值和日均值超标率的变化情况对PM10污染时空分布特征进行了详细分析,并从气象条件、下垫面性质和污染物排放三个方面对PM10污染的成因进行了分析研究。同时针对PM10污染的形成原因和影响因素,提出了加大执法力度,控制燃烧排放;采取综合措施,减少扬尘污染;加强机动车尾气治理与监督管理;加强生态环境建设,以增加城市大气环境容量等一系列减轻合肥市城市PM10污染、改善城市空气环境质量的综合治理对策。

关键词：合肥市可吸入颗粒物污染成因综合治理对策

CFD simulation of pumping ventilation in a three-story isolated building with internal partitioning:Effects of partition widths,heights and locations

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Building Simulation 2024年第2期17卷 267-284页

作者： Huai-Yu Zhong Jie Sun Chao Lin Song-Heng Wu Jin shang Hideki Kikumoto Fu-ping Qian Carlos Jimenez-Bescos Fu-Yun Zhao School of Energy and Environment Anhui University of TechnologyMa-An-ShanAnhui Province243002China State Key Laboratory of Green Building in Western China Xi’an University of Architecture&TechnologyXi’anShaanxi ProvinceChina School of Power and Mechanical Engineering Wuhan UniversityWuhanHubei Province430072China Institute of Industrial Science The University of Tokyo4-6-1 KomabaMeguro-kuTokyo153-8505Japan School of Built and Natural Environment University of DerbyDerbyUK

Pumping ventilation(PV),a special single-sided ventilation(SSV),has been certified as an effective strategy to improve the air exchange rate of ***,most studies targeted on the single space,and few studies have been focused on the effect of internal partitioning on *** paper aims to evaluate the ventilation performance of PV influenced by different configurations of internal *** fluid dynamics(CFD)simulation was used to predict the flow fields and ventilation *** width(w/H),height(h/H)and location(d/H)are the three main internal partition parameters considered in this *** simulation results showed that the total,mean and fluctuating ventilation rates all decrease with wider internal *** normalized total ventilation rate decreases by 7.6%when w/H is increased from 50%to 75%.However,the reduction rate is only 0.23%between w/H=0 and 25%,and only 0.61%between w/H=25%and 50%.The ventilation rate is hardly reduced by increasing the partition width when w/H50%.Increasing the partition height will reduce the mean ventilation rate but promote the fluctuating and total ventilation rate in some *** increase of total ventilation rate by 1.4%is observed from h/H=50%to 75%.The ventilation rate is larger when the internal partition is attached to the leeward or windward *** total,mean and fluctuating ventilation rates for d/H=50%are relatively higher than d/H=0 by 1.5%,3.1%and 0.8%,*** the internal partition should be mounted attached to the windward wall so as to obtain the greatest pumping ventilation *** periodicity of pumping flow oscillation and pumping frequency are independent of the partition *** peak power of pumping flow is the lowest for the widest internal partition and is negatively affected by the partition height,but it generally has a positive correlation with the distance between the partition and leeward wa

关键词： pumping ventilation single-sided ventilation internal partitioning periodic oscillation ventilation rate

Review on Security Defense Technology Research in Edge Computing Environment

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Chinese Journal of Electronics 2024年第1期33卷 1-18页

作者： Ke shang Weizhen HE Shuai ZHANG National Digital Switching System Engineering and Technological R&D Center

Edge computing, which achieves quick data processing by sinking data computing and storage to the network edge, has grown rapidly along with the Internet of things. The new network architecture of edge computing brings new security challenges. Based on this, this paper investigates the edge computing security literature published in recent years and summarizes and analyzes research work on edge computing security from different attack surfaces. We start with the definition and architecture of edge computing. From the attack surface between device and edge server, as well as on edge servers, the research describes the security threats and defense methods of edge computing. In addition, the cause of the attack and the pros and cons of defense methods is introduced. The challenges and future research directions of edge computing are given.

关键词： Cloud computing Systems architecture Computer architecture Network architecture Data processing Security Servers