Abstract ：

We propose a new test for the heterogeneity of the spatial autoregressive parameter in semiparametric varying-coefficient spatial autoregressive models. Our specification test is built on the difference of parametric and nonparametric estimates of the spatial autoregressive coefficient, where the two estimates are obtained by the sieve GMM estimation method. Under mild conditions, we derive the limiting null distribution, the local power property and consistency of the test statistic. Numerical simulations show promising performance of the proposed test for finite samples in the considered cases, and the crime data of Tokyo is analyzed to illustrate the usefulness of the test. © 2025

Keyword ：

Spatial autoregression Sieve estimation Functional coefficient Consistent test Endogeneity

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Abstract ：

Ammonia serves as a viable medium for hydrogen storage owing to its significant hydrogen content and elevated energy density, and the absence of carbon dioxide emissions during ammonia-to-hydrogen production has inspired more research on ammonia decomposition. Despite growing interest, a significant gap persists between the depth of existing studies and the practical approach to on-the-spot hydrogen generation using ammonia decomposition. The creation of effective and accessible catalysts to feed ammonia decomposition is a critical step in addressing this daunting challenge. This paper systematically summarizes four key catalyst design strategies, including size effect, alkalinity modulation, metal-support interactions, and alloying, informed by experimental and theoretical investigations into ammonia decomposition. Each strategy's underlying mechanism for enhancing ammonia decomposition is elucidated in detail. Moreover, the paper categorizes catalysts employed in existing ammonia decomposition reactors to guide future catalyst development. The influence of diverse energy sources and reactor configurations on catalyst performance is also discussed to provide a comprehensive framework for advancing ammonia decomposition catalyst research.Keywords: Ammonia decomposition reaction; Catalyst design; Particle size effect; Adjustment of alkalinity; Strong metal-support interaction; Alloying effect.

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CULTIVATING students' software design capabilities through effective training has always been a challenge in software education. This paper is aimed at addressing this issue by adopting a multi-scenario case study approach to examine the independent design processes of 23 undergraduate students on an online teaching system. The selected case scenario models include transaction flow diagrams (TFDs), activity diagrams, sequence diagrams, and entity-relationship (ER) diagrams. By analyzing students' behavioral performances and design outcomes, a series of common phenomena are identified. These phenomena encompass common errors, such as overlooking key steps, struggling to distinguish similar data objects, and omitting critical entities or attributes. Common behaviors include offering various solutions, facing challenges in achieving specific design goals due to a lack of prior experience, and experiencing difficulties meeting requirements using prescribed syntax. Common approaches to assist students include providing reference software, adopting teamwork for idea generation, and allowing iterative modifications to improve outcomes. Based on these common phenomena exhibited by students, several recommendations are provided for software educators to enhance the development of students' software design capabilities, which mainly include considering students' prior experience in assignments, providing design references for unfamiliar software, encouraging peer discussions and multiple iterations, and guiding students towards continuous improvement rather than disregarding unconventional outcomes. The common phenomena identified in this paper seamlessly integrate with software design education, reflecting its distinct characteristics. Those common phenomena will help researchers understand student needs and challenges. Additionally, the research design, which analyzes student behaviors based on their software design outcomes, provides a fresh perspective in the field. Furthermore, the conclusions drawn in this paper offer valuable insights for educators who aim to enhance classroom experiences in software design courses.

Keyword ：

Software Design Education UML Object-Oriented Systems Analysis and Design

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Conventional pressure-type anchoring systems face challenges such as difficulty in recovery, low recovery efficiency, and insufficient durability over long-term use. Although the single-use cost of Carbon Fibre Reinforced Polymer (CFRP) strand anchors is higher than that of conventional steel strands, recovery and reuse can significantly reduce costs. Therefore, this study aims to investigate the bonded anchoring method of CFRP and proposes an innovative thermoplastic CFRP prestressed strand design that combines both anchoring strength and recoverability to address the shortcomings of existing anchoring systems. Two bonding materials, thermosetting resin and thermoplastic resin, were selected for bond strength tests under different conditions. The results indicated that epoxy resin had a bonding force of 280 kN and an anchoring efficiency of approximately 70%, making it the most suitable material. However, the anchoring efficiency still needs improvement. Based on this, an improved design scheme was proposed, which can increase anchoring efficiency to over 95%. Additionally, based on the dispersed bonding anchor system, this study explored a solution that involves adding a positioning plate at the end of the anchor strand and using epoxy resin for anchoring. The anchoring performance tests showed that the tensile strength of the CFRP strand ranged from 2.7-2.8 GPa, with an average anchoring efficiency of 100.5%, demonstrating excellent anchoring performance. Further thermoplastic recovery tests showed that when the temperature increased to 90 degrees C, the maximum recovery force of the strand was 17.2 kN, about 4.4% of the ultimate load. When the temperature increased to 150 degrees C, the maximum recovery force was 7.5 kN. The recovered CFRP strands were clean, with no resin residue, and had no damage, maintaining an intact structure. The proposed thermoplastic CFRP prestressed strand design demonstrates significant advantages in anchoring strength and recoverability. With the improved design, anchoring efficiency can be increased to over 95%, and the high-temperature recovery process shows good feasibility. Compared with traditional anchoring systems, CFRP strands offer higher anchoring efficiency, lower recovery force requirements, better economics, and sustainability, making them a promising solution for engineering applications.

Keyword ：

strand recovery thermal-meltable anchoring anchor cable carbon fibre reinforced polymer (CFRP)

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Abstract ：

Based on a follow-up study of Xizang Autonomous Region's ecological civilization construction and its clean energy development, this paper takes Chamdo as a case study and uses the SWOT matrix to analyze the basic conditions, challenges, and possible pathways for clean energy development. The purpose is to discuss whether Xizang can play a prominent role in the green and low-carbon transition. It demonstrates that, under the framework of nationwide planning, starting from Xizang's resource endowments and the practical demands of sustainable development, Xizang can capitalize on external opportunities, such as policy advantages and power assistance, to build a diversified clean energy system that integrates hydropower, wind, solar, and energy storage. By strengthening the coordination between the clean energy sector and other industries, Xizang can promote both local consumption of clean energy and its transmission to other regions. This not only enables Xizang to play a prominent role in the nation's green and low-carbon transition, but also uses clean energy as a bridge to reinforce collaborative efforts among eastern, central, and western regions in achieving dual carbon goals, while fostering common prosperity, and enhancing national unity. © 2024 Social Sciences Academic Press (China).

Keyword ：

Xizang climate change clean energy Green and low-carbon transition

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为解决传统吸收过程中存在的能耗高、溶剂挥发性损失大问题,提出离子液体高效吸收废气中1,2-二氯乙烷(DCE)技术,在预测型分子热力学理论的指导下,从分子尺度到过程尺度系统研究了其应用前景.首先采用COSMO-RS模型进行离子液体结构(阳离子骨架结构、羧酸盐阴离子链长及氟化)对分离性能(1,2-二氯乙烷与氮气的选择性及溶解度)的影响分析,并筛选出适宜的离子液体(1-丁基-3-甲基咪唑醋酸盐,[BMIM][Ac]).通过实验方法测定不同离子液体中DCE的饱和吸收容量,验证COSMO-RS模型的适用性;并进一步考察吸收温度和DCE初始含量对[BMIM][Ac]吸收性能的影响,结果表明在20℃、常压、进气DCE为饱和含量时[BMIM][Ac]对DCE的饱和吸收容量达到2177 mg/g.在分子尺度,采用量子化学计算和波函数分析,探讨了离子液体吸收1,2-二氯乙烷的微观机理.结果表明吸收过程阴离子起主导作用,表现为强氢键作用和范德华(vdW)色散作用,阳离子与DCE间主要以C—H…Cl相互作用和vdW色散作用结合.最后在过程尺度,对离子液体吸收DCE的工艺进行了概念设计和流程优化,在给定条件下,离子液体对1,2-二氯乙烷的去除率达到99.88%.通过与传统有机溶剂进行对比,发现离子液体具有更低的产品损失、溶剂损失和能耗.表明采用离子液体吸收 1,2-二氯乙烷是一种不错的策略,具有一定的工业应用潜力.

Keyword ：

2-二氯乙烷 1 COSMO-RS模型 量子化学计算 流程模拟 离子液体 吸收

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Abstract ：

索膜结构在运维过程中容易受到风荷载、温度等外界环境因素的影响,导致节点松动、构件失效进而严重影响了结构的安全性能.如何实现结构服役期安全状态的精准仿真,有效提高结构的抗倒塌性能,同时降低健康监测的成本是实现索膜结构智慧运维所面临的关键问题.本文提出了基于数字孪生的索膜结构构件失效机制分析方法.首先从几何和物理两个层面修正虚拟模型,形成高保真的数字孪生模型的建立方法,从而高效精准地映射结构受力状态.其次,在孪生模型的基础上,给出构件失效前后力学响应的分析流程.在孪生模型中设置构件失效工况,获取结构的力学响应规律.根据失效前后结构力学性能的变化情况,计算构件重要性系数,捕捉关键受力构件.在关键构件失效后分析结构内力分布情况,得到结构倒塌前的传力机理.以长春东收费罩棚索膜结构为研究对象进行方法应用,验证了理论方法的可行性.案例应用结果表明:所建立的孪生模型可以有效仿真结构的受力状态,计算误差在 3%以内;通过分析各类构件失效后的结构力学性能得到了力学响应表现规律和关键受力构件;基于关键受力构件失效前后的力学响应,建立了传力机理,获取了内力传递路径,明确了结构健康监测对象.本研究方法为制定结构安全的智慧运维策略和提高结构抗倒塌性能提供了可靠支撑.

Keyword ：

构件失效 索膜结构 数字孪生 力学响应 传力机理

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以北京市四惠枢纽为研究对象,探索以数据驱动为导向满足乘客需求的枢纽动态导向标识方案评估及优化设计方法.首先,搭建KANO乘客需求模型,通过桌面实验,形成动态导向标识在内容、样式及空间位置上的优化设计方案,与四惠枢纽现有方案形成对比.其次,基于寻路理论通过建筑信息建模(building information modeling,BIM)+虚拟现实(virtual reality,VR)仿真技术,实现人与枢纽的信息交互,提取新旧导向标识方案作用下乘客寻路过程的特征参数.最后,通过对寻路实验中主客观指标分析可知,被试在新版动态导向标识方案中寻路时间、犯错误点数及迷茫点数显著降低,且新版动态导向标识方案在内容、样式及空间位置上满意度均优于旧版.结果表明:研究搭建BIM+VR的虚拟仿真平台,形成以数据驱动为导向的枢纽动态导向标识方案综合评估及优化设计方法,为枢纽动态导向标识方案设计及合理应用提供技术与理论支撑.

Keyword ：

BIM+VR技术 KANO需求模型 优化设计 枢纽动态导向标识 综合评估 寻路理论

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交通部门是我国碳排放的主要贡献部门.通过收集2000-2020 年各省市的人口、经济、交通等相关资料,结合各省市已颁布的规划政策预测了2021-2035 年交通部门的活动水平,并采用排放因子法和情景分析法,估算了不同情景下东部、中部和西部地区不同交通部门的CO2 排放量,并对碳减排潜力进行了对比分析.结果表明,我国交通部门在基准情景下的碳排放呈持续增长的趋势,碳减排潜力最大的是调整运输结构情景,2035 年可降碳7.21 亿t,在该情景下,公路部门的碳减排潜力最大,减排效果从高到低依次为东部地区、西部地区、中部地区,航空部门仅在中部地区具有减排潜力,铁路、水路部门在该情景下的减排潜力均为负值.而铁路、航空和水路部门在优化能源结构情景下更具有减排潜力,2035 年将分别减排 49.30%、20.53%和 15.66%,在该情景下,铁路部门短期内在东部地区减排效果较好,长期在中部地区的减排潜力更大,航空部门的减排潜力在东部和西部地区更优,水路部门的减排效果在东部地区更显著.

Keyword ：

排放因子 减排潜力 碳排放 情景分析 交通部门 预测研究

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针对固体火箭发动机结构健康监测,本文提出并制备了一种新型马赫-曾德尔干涉型传感器,传感结构由多模光纤(multimode fiber,MMF)、氧化物掺杂光纤与多模光纤依次手动熔接而成.其中,掺杂光纤为传感单元,它的纤芯主要由Y2O3、Al2O3和P2O5掺杂构成,纤芯折射率(refractive index,RI)呈现类线性分布.建立了传感器理论模型,分析了传感器的光场传输特性.研制了传感器样品,开展了温度、弯曲和应变实验.实验结果表明,传感器温度、弯曲、应变灵敏度分别为57 pm/℃、9.41 nm/m 1、3 pm/με,相比较同类型的传感器,灵敏度具有较大提高,同时表现出了不同的特征光谱特性.该传感器制备工艺简单,结构紧凑,可应用于固体火箭发动机内部温度、弯曲、应变多个参数的测量.

Keyword ：

温度传感 马赫-曾德尔干涉仪 氧化物掺杂光纤 应变传感 弯曲传感

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