Reducing process of sinter in COREX shaft furnace and influence of sinter proportion on reduction properties of composite burden

In order to reduce the materials cost of COREX ironmaking process,sinter has been introduced into the composite burden in China.This work explored the reducing process of sinter in COREX shaft furnace to clarify its reduction properties change and then the effect of sinter proportion on metallurgical performance of composite burden was investigated.The results show that the reducing process of sinter in COREX shaft furnace was basically same with that in blast furnace but sinter seems like breaking faster.Under reducing condition simulated COREX shaft furnace,sinter possessed the worst reduction degradation index(RDI)and undifferentiated reduction index(RI)compared with pellet and iron ore lumps.Macroscopic and microscopic mineralogy changes indicated that sinter presents integral cracking while pellet and lump ore present surface cracking,and no simple congruent relationship exists between cracks of the burden and its ultimate reduction degradation performance.The existence of partial metallurgical performance superposition between composite and single ferrous burden was confirmed.RDI_(+6.3)≥70%and RDI_(+3.15)≥80%were speculated as essential requirements for the composite burden containing sinter in COREX shaft furnace.

Numerical Analysis of Blast Furnace Performance Under Charging Iron-Bearing Burdens With High Reducibility

The reducibility of iron-bearing burdens was emphasized for improving the operation efficiency of blast furnace. The blast furnace operation of charging the burdens with high reducibility has been numerically evaluated using a multi-fluid blast furnace model. The effects of reaction rate constants and diffusion coefficients were investigated separately or simultaneously for clarifying the variations of furnace state. According to the model simulation results, in the upper zone, the indirect reduction of the burdens proceeds at a faster rate and the shaft efficiency is enhanced with the improvement under the conditions of interface reaction and intra-particle diffusion. In the lower zone, direct reduction in molten slag is restrained. As a consequence, CO utilization of top gas is enhanced and the ratio of direct reduction is decreased. It is possible to achieve higher energy efficiency of the blast furnace, and this is represented by the improvement in productivity and the decrease in consumption of reducing agent. The use of high-reducibility burdens contributes to a better performance of blast furnace. More efforts are necessary to develop and apply highreducibility sinter and carbon composite agglomerates for practical application at a blast furnace.

Reduce Tax and Alleviate the Burden

‘Tax reduction’must be one of the key words of the Chinese economy in 2018,during which various preferential tax policies were successively issued and tax-cut bonuses are continuously released.Since the beginning of the year,China has set a target of RMB 1.1 trillion in tax reductions throughout the year.In the second half of 2018,incremental policies were introduced.It is estimated that the annual economic burden will be reduced by more than RMB 1.3 trillion in 2018.

Examining the Burden Reduction Policy for Primary and Secondary School Teachers in China:A Framework Analysis Centered on the Rational Selection of Institutional Doctrine

The“burden reduction”policy aims to reduce the workload of primary and secondary school teachers to alleviate their burdens.While it has improved the quality of teachers,implementation challenges still exist.This study utilizes rational choice institutionalism and Ostrom’s institutional analysis and development framework to examine the policy.By considering the preferences of the Ministry of Education,local governments,schools,and teachers,it explores interactions and outcomes,identifies challenges,and provides policy suggestions.

Reducing the Tax Burden?Opportunity to Craft a Balanced Approach under Pillar Two

The global minimum tax impacts the effectiveness of tax incentives.Many countries view tax burden reduction as a necessary lever to promote foreign direct investment(FDI)and economic growth.In this article,the authors provide a broader perspective.The proposed holistic approach may offer insights to lowincome and emerging countries in facing current challenges in the sphere of taxation and economic growth.

Mathematical simulation of burden distribution in COREX 3000 shaft by discrete element method

The distribution of reducing gas in a shaft furnace dominates the temperature profile,gas utilization ratio,metallization degree and is the overwhelming factor for stable,high productivities and low-energy-consumption operation.At the same time,the distribution of gas flow is mainly determined by the position of gas inlet,the packed bed porosity distribution as well as its change due to the difference on the mode of top charge and bottom discharge.When injecting position of the process is fixed,the charge mode is the only means for regulating the gas flow distribution.In this paper,a numerical simulation model of burden distribution in the shaft furnace of COREX 3000 has been developed to analyze the porosity distribution under the different charge modes by means of Discrete Element Method(DEM).The effects of the particle size and its distribution under conditions of different charge batches,chute angle,stoke line on the burden surface shape and burden bed particle size distribution and segregation were investigated,and then the porosity distribution in the shaft of corresponding charging pattern was quantitatively accessed.Therefore,the results can be used to optimize the charge patterns base on required gas distribution.

国家建构视角下基层负担过重的结构性困境:理论与个案分析

基层政府负担过重问题近年来引发了政策界和学界的高度关注,现有文献从科层体制、形式主义、基层治理能力等方面展开研究。我们需在此基础上进一步将基层政府负担问题置于历史变迁背景之下,从国家权力下沉及其背后的国家建构策略的变迁视角出发,重新反思这一问题。通过对L镇机构改革及其实际效果的深度个案分析,本文发现这一旨在强化乡镇政府能力、减轻其负担的改革却未能有效强化乡镇政府能力反而加重了其负担。究其原因,在于机构改革本身存在放责多于放权、乡镇无力承接放权以及运动式治理削弱专业化治理,以及村两委自治能力不足等。本文结合制度漂移理论进一步分析了其背后机理,并探讨了其对国家建构微观策略的理论意涵。

STEAM教育助力“双减”政策落地的现实困境与可为路径

STEAM教育是我国基础教育改革的一种趋势,也是助力“双减”政策落地的重要抓手。STEAM教育具有情境性、实践性、项目式、过程性、跨学科性等特征,为“双减”政策的落地提供了可能。STEAM教育助力“双减”政策落地面临课后服务质量无法保障,课堂教学质量提升效果不佳,STEAM教师胜任力不足,STEAM教育存在区域、城乡、校际差异等困境。STEAM教育助力我国“双减”政策落地可从强化综合实践活动设计,拓展课后服务内容;以项目式学习为抓手,提高课堂教学质量;注重STEAM教师培养,提高教师综合素质;注重特色发展,以数字化转型推进STEAM教育均衡发展四个方面着手。

敏捷治理视角下基层数字负担的困境与破局——基于Y市“基层一张表”数字减负的研究

数字赋能基层治理被认为是减轻基层负担、提升治理效能的重要路径,但实践中数字系统冗杂、数据下沉困难等数字负担亦随之而来。敏捷治理理论注重技术的赋能价值,旨在采取灵活、协同、多元参与等手段快速响应复杂多变的社会问题,为基层数字负担破局提供了新视角。基于敏捷理念灵活性、协同性、回应性与参与性的特性,基层数字负担破局可从数据治理能力、条块协同能力、权责对等程度和专业分工程度四个维度展开。Y市“基层一张表”信息系统通过打造数据底座、赋能部门协同、规范任务派发、强化政企分工等措施,较好地减轻了基层数字负担,实现了基层治理效能的提升。在数字系统应用的基础上,进一步提升基层数据治理能力,增强政府各部门间数据“网络式共享”,明确各级政府的权责分配,加强多元主体合作共建,是有效化解数字负担的内在要求。

基层创新负担:现实形态、生成机理与治理路径

基层负担主要包括任务加码、监督规范和治理创新三种产生情境,其中治理创新可能通过流程化简为繁、职责化无为有和任务执行化夷为险三种路径增加基层负担。基层创新负担的生成源于基层治理评价的模糊性,创新成为评价基层治理工作的重要指标,由此形成了争先—强制、应激—配合、学习—合作、授权—松散四种纵向府际关系,不同府际关系中的创新负担形态和结构化程度存在差异。基层创新负担会增加基层治理的不确定性,表现为基层常规任务边缘化、权责失衡结构化、监督规范过密化和基层负担外部化。实现高效能的基层治理创新,一个可能路径在于建立目标均衡、内容适当、分工明确的集成创新体系。

教师减负中利益相关者的博弈困局与突围路径

中小学教师减负是党和国家基于新时代教师队伍建设综合考量下的重要举措。然而,教师减负是一项复杂的系统工程,涉及不同主体的利益。以行政部门为代表的权威利益相关者、以教师和中小学校为代表的核心利益相关者、以学生家长与学生为代表的主要利益相关者共同构成了教师减负的利益相关者群体。权威利益相关者与核心利益相关者合作博弈的异化、主要利益相关者与核心利益相关者的负和博弈、权威利益相关者与主要利益相关者的非合作博弈造成了教师减负复杂的博弈困局。究其根本,各利益相关者共识不清、权责模糊与利己决策是造成教师减负博弈困局的根源。为真正减轻教师负担,营造良好的教育教学氛围,建议广泛凝聚社会共识以营造良好的减负生态环境,明晰各主体的权责关系以形成各利益主体的共治格局,重视整体利益提升以缓解多元主体的利益冲突。

“双减”背景下中小学教师的多维负担与减负增能

“双减”政策落实的根本在于充分发挥学校育人主阵地的作用,而在学校组织中,教师群体作为教育改革的直接参与者,起关键作用。经调查发现,伴随政策的深入推进,教师群体负担显著增加,表现在:工作量与工作时间无限延长、课堂教学和学生作业设计难度加大、教师评价标准和模式单一,严重影响了教师群体的发展。而诱发这些负担的是教育教学改革的不确定性、学校管理体制机制的固化、学生家长需求的多样性和教师角色能力的多重性等多源因素。因此,为实现教师的减负增能,需在“赋权”与“增能”上双向发力:赋权学校,给予和扩大学校在学校管理和教师聘请等方面的权限;赋权教师,保障教师参与学校管理与决策、专业自主和自我发展等方面的权力;增能教师,激发创造力、增强教学力和提升沟通力。

论数学教与学中的“知新温故”

在“双减”背景下,为使学生掌握有效的数学学习方式,教师需要思考如何提升课堂教学的质量和效率。知识的对偶性、知识的层进与拓展、知识的传承与进化,使数学学习“知新温故”。知识产生的动力方式、知识运行的自然脉络、知识形式的逐级抽象、知识内涵的理解表征和知识本质的模式凝练,使得数学教学“知新温故”。这一发现启示教师基于知识分析和心理分析以学定教,在数学教学中实现“减负增效”,从而提升学生的数学素养。基于循证研究的实践也表明这种做法是行之有效的。

数字赋能基层治理的“有限性”及超越:基于适配困境的考察

迈向数字秩序的基层治理,如何应对从物理空间到数字空间的秩序与规则转变,如何进行多主体参与的确权与履责重塑,以超越数字赋能的“有限性”,是基层治理面临的又一难题与挑战。通过基层数字治理中“价值有限性”“结构有限性”以及“功能有限性”的理论性解读,深入剖析实践中基于“目标价值—业务标准—技术应用”的三维适配分析框架,发现技术驱动与赋能延伸在“人与数”“管与治”“整与碎”方面造成了多方供需失衡与规则失配,导致数字赋能基层治理向“数字负担”演化。应通过理念上重构数字生态价值规范、制度上构建标准化体系、业务上完善系统保障对接、技术上优化基础数据回流共享机制的多维协同耦合策略,不断完善“价值”与“技术”同频的基层数字治理。

基层负担实证研究的知识图景与理论基础

基层政府工作人员在政策执行中的繁重经历是社会治理中的热点话题。基于中英文期刊2001—2022年相关文献,本文对基层负担的研究特征、概念类型和理论基础进行总结分析。研究表明:基层负担研究快速增长,已有研究侧重于乡镇和村级行政组织的负担,更为关注扶贫、乡村政策、环保、机关事务等政策领域的负担;基层负担涉及职能扩张、中心工作、内部管理多种类型;理论解释更为多元和精细,研究设计更为完善,国家与社会关系、技术治理和制度逻辑构成基层负担解释的理论基础。已有研究很好解释了基层政府负担普遍偏重的现象,但在概念的清晰性、负担表现差异化的解释等方面存在一些不足。未来的研究应当清晰界定负担的概念内涵、建构不同基层政府负担差异的理论解释,将“时间”视角带入基层负担的研究之中。

基层减负背景下基层档案中心在档案规范化中的效用研究

随着国家对“基层减负”政策的深入推进,档案工作作为基层治理的关键环节,其规范化建设显得尤为迫切。在明确基层档案工作在减负过程中阻碍因素的基础上,提出档案规范化的具体作用路径。并以基层档案中心为核心,探讨如何通过社区、行政部门和居民三方的协同联动,充分发挥档案规范化的效用,以实现档案资源的高效利用,提升基层治理的质量和效率,为基层减负提供创新思路和实践方案。

初中“人体的营养”单元作业设计与实践

以初中生物学“人体的营养”单元作业的设计为例,运用系统化的作业设计方法,在提炼单元主题、确定单元作业目标的基础上,设计具体的课时作业并制定作业评价量规,以促进学生对学科重要概念的理解,综合提升学生的生物学核心素养。

差序同构:中国政府纵向职责体系的结构形态

科学完善的纵向政府职责体系是构建系统完备、科学规范、运行高效的党和国家机构职能体系的重要支撑。中国政府纵向职责体系从外观上看是“上下一般粗”的形态。事实上,经过历次职能转变、职责优化和政府机构改革,纵向政府职责体系开始呈现“差序同构”特征。渐次形成的职责体系圈层网络,中央政府位于圈层中心位置,其职责要求作为原则性规则为地方政府所遵循,即“同构性”;不同于政府职责范围自上而下逐渐递减,地方政府履事责任的清晰度与行政链条长短呈正比,即“差序性”。纵向政府职责差序同构形态有利于确保党和国家大政方针上下贯通、实现有限资源有效整合、满足人民群众利益诉求。

中小学作业的本质厘清、问题审视及形态再构——以北师大版五年级数学作业设计为例

基于作业的大课程属性,作业是课程与教学的重要构成环节;基于作业的学生知识应用属性,作业是化知识为学生素养的主战场;基于作业的学生自主完成属性,作业是促进学生自我发展的主阵地。当前中小学作业游离于课程体系之外,逐步演变为学生难以承受的学业负担,难以发挥育人功能。因此,应打破传统作业惯习,建构减负提质的中小学作业新形态:目标指向的“少而精”作业、回归生活的“妙而活”作业、大概念统整的“小而大”作业以及个性化满足的“同而分”作业,以有效发挥作业的育人功能,促进“双减”政策取得显著成效。

说作业教研的内涵意蕴与结构探析

随着“双减”政策的颁布,中小学作业正进行着重大改革,目标在于达到减负提质的效果。作业是连接课程、教学、学习和评价的关键环节,以作业为载体,以“说”为外化路径,以提升作业教学质量为目的,提出一种新型教研形式——说作业。研究认为,说作业结构框架包括说作业理念、说作业设计、说作业批改、说作业评讲、说作业反思,以语言为媒介展现作业教学全过程,在诊断、研讨、改进的过程中,可促使作业教学更加精细化、深入化、完备化,发挥说作业的理论价值与应用价值。