检索结果-南通市图书馆

Smoke and NO_(x)emission characteristics of in-use construction machinery base on substantial field measurement:A case study in Beijing,China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第3期149卷 386-393页

作者： Huawei Yi yangyang Cui Lijun Zhu yan shen Han Li Guanghan Huang Linzhen Qu Dongdong Guo Lei Nie Yifeng Xue National Engineering Research Center of Urban Environmental Pollution Control Beijing Municipal Research Institute of Eco-Environmental ProtectionBeijing 100037China Beijing Vehicle Emission Management Affairs Centre Beijing 100176China

To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration *** investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the *** results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance *** observed amongmachinery types,with low-power engine forklifts showing higher smoke *** NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively *** rated net power had the most significant impact on NO_(x)***,NO_(x)emissions from construction machinery need further ***,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission *** the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.

关键词： Fuel-oil construction machinery Smoke NO_(x) Emission level Regulatory suggestion

Tauroursodeoxycholic acid targets HSP90 to promote protein homeostasis and extends healthy lifespan

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2025年第2期68卷 416-430页

作者： Jia-Yu Liu Yao Wang Yue Guo Run-Qi Zheng Yun-Ying Wang yan-yan shen yan-Hong Liu Ai-Ping Cao Rui-Bo Wang Bo-yang Xie Shuai Jiang Qiu-Ying Han Jing Chen Fang-Ting Dong Kun He Na Wang Xin Pan Tao Li Tao Zhou Ai-Ling Li Qing Xia Wei-Na Zhang Nanhu Laboratory National Center of Biomedical AnalysisBeijing 100850China

As the elderly population expands,the pursuit of therapeutics to reduce morbidity and extend lifespan has become increasingly *** an FDA-approved drug for chronic cholestatic liver diseases,tauroursodeoxycholic acid(TUDCA),a natural bile acid,offers additional health benefits beyond liver ***,we show that TUDCA extends the lifespan and healthspan of ***,oral supplementation of TUDCA improves fitness in old mice,including clinically relevant phenotypes,exercise capacity and cognitive ***,TUDCA treatment drives broad transcriptional changes correlated with anti-aging ***,we discover that TUDCA targets the chaperone HSP90 to promote its protein refolding *** collaboration further alleviates aging-induced endoplasmic reticulum(ER)stress and facilitates protein homeostasis,thus offering resistance to *** summary,our findings uncover new molecular links between an endogenous metabolite and protein homeostasis,and propose a novel anti-aging strategy that could improve both lifespan and healthspan.

关键词： tauroursodeoxycholic acid lifespan healthspan protein homeostasis

在线全文

学校读者我要写书评

暂无评论

汉语场景主语句的容器体认机制研究

外语导刊 2025年第1期48卷 10-18,157页

作者：沈艳萍云南师范大学外国语学院云南昆明650500

目前对汉语存现句及翻转句的研究忽略了二者之间的共性特征。本文尝试用场景主语句统摄两类句式,以容器意象图式的体认识解理论为框架,解释场景主语句获得语言编码的容器体认机制,探讨容器体认方式对场景主语句语法结构的影响。研究表明... 详细信息

目前对汉语存现句及翻转句的研究忽略了二者之间的共性特征。本文尝试用场景主语句统摄两类句式,以容器意象图式的体认识解理论为框架,解释场景主语句获得语言编码的容器体认机制,探讨容器体认方式对场景主语句语法结构的影响。研究表明,容器具有具体性、抽象性、有界性、有定性等体认特征,容器与容纳物之间具有静态、动态、同构、包含等体认关系,体认特征和体认关系构成容器体认方式的两个层面,共同影响和制约场景主语句的语法表征。

关键词：汉语场景主语句体认识解理论意象图式体认方式

学会提问:大学生与生成式人工智能协同学习模式的研究

在线全文

学校读者我要写书评

暂无评论

华东师范大学学报(教育科学版) 2025年第2期43卷 34-48页

作者：何珊云沈演浙江大学教育学院杭州310058

以ChatGPT为代表的生成式人工智能的问世,给传统的学习模式带来了巨大的机遇与挑战。学生如何运用生成式人工智能促进学习成为教育教学改革亟待探索的问题。本研究在大学生课程学习过程中引入GAI,对学生与GAI的话语类型、提问水平、提... 详细信息

以ChatGPT为代表的生成式人工智能的问世,给传统的学习模式带来了巨大的机遇与挑战。学生如何运用生成式人工智能促进学习成为教育教学改革亟待探索的问题。本研究在大学生课程学习过程中引入GAI,对学生与GAI的话语类型、提问水平、提问策略以及自我报告进行编码分析,探究了大学课堂中学生如何与GAI进行协同学习。研究发现,在学生与GAI的对话中,学生是对话的发起主体,单个对话构成的对话单元居多,持续性的讨论较少。学生话语主要以初始提问、拓展提问和改述提问为主,评价和继续指令话语较少。同时学生提问的认知水平较低,以知识水平、理解水平提问为主,提问策略单一,较少使用角色提问、材料提问、方案提问等策略。在不同任务阶段、不同使用经验的学生与GAI的对话存在差异性,在任务后期人智之间展开更高频、更持续的互动对话,且提问认知水平更高、提问策略使用更熟练。使用GAI经验越丰富的学生产生更多的高认知水平对话。在呈现出不同话语特征的对话过程中,学生对在大学课堂教学中引入GAI整体上持积极态度但有所分化。学生普遍认为,GAI能够积极地辅助学习,具有回应优势、能够为学生提供信息价值、处理多类任务和促进学生能力发展,但同时也存在技术局限,引发对学生主体、学习评价和教育生态的挑战。在此基础上,本研究从提供提问训练、丰富提问场景、加强回答反思三个方面为进一步在课堂教学过程中引入生成性人工智能提供了有效的建议。

关键词：生成式人工智能对话提问项目化学习

Axial emission characteristics of an ionic liquid electrospray thruster with a circular emitter

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2025年第1期 302-310页

作者： Cheng yanG Jiawei LUO Xiangbei WU yan shen School of Aeronautics and Astronautics Sun Yat-sen University shenzhen Key Laboratory of Intelligent Microsatellite Constellation

Ionic Liquid Electrospray Thrusters(ILETs) are well suited for micro-nano satellite applications due to their small size, low power consumption, and high specific impulse. However,the limited thrust of a single-emitter ILET restricts its use in space missions. To optimize the performance of ILETs and make them suitable for a wider range of space missions, we designed a Circular-emitter ILET(CILET) to convert a one-dimensional(point) emission into a twodimensional(line) emission. The CILET can self-organize multiple Taylor cones *** cones were photographed and the axial emission currents were measured under different voltage and pressure difference conditions with a CILET experimental system. The emission can be divided into two stable states and one unstable state based on the flow and current *** current in Stable state I increases non-linearly with the voltage, while that in Stable state II is nearly linear with respect to the voltage. The number of cones increases with the voltage in stable states, while the cones become short and crowded under high-voltage conditions. The variation law of the number of cones can be explained with the self-organization theory. The variation in the current exhibits a good correlation with the number of cones. This study demonstrates the feasibility of circular emitters and experimentally indicates that the emission current is improved by approximately two orders of magnitude compared to that of a single capillary.

关键词：

数据要素对绿色物流效率的影响机制及效能研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

商业经济研究 2025年第2期 79-82页

作者：麻见阳沈燕桂林航天工业学院管理学院广西桂林541004 西安理工大学经济与管理学院陕西西安710054

数据要素是推动绿色物流效率提升的关键因素,通过精准的数据分析,企业能优化物流路径,减少无效运输,提升运输效率。同时,数据有助于监控物流过程中的能源消耗和排放,促进绿色技术的应用,从而降低环境影响。基于此,本文选取2013-2022年我... 详细信息

数据要素是推动绿色物流效率提升的关键因素,通过精准的数据分析,企业能优化物流路径,减少无效运输,提升运输效率。同时,数据有助于监控物流过程中的能源消耗和排放,促进绿色技术的应用,从而降低环境影响。基于此,本文选取2013-2022年我国30个省份数据来探究数据要素对绿色物流效率的影响机制及效能,最终显示,数据要素可以直接促进绿色物流效率提升,同时数据要素也可以通过科技创新中介变量促进绿色物流效率发展。

关键词：数据要素绿色物流效率科技创新

基于Gini-PSO-DPC算法的物联网数据异常检测

在线全文

学校读者我要写书评

暂无评论

软件导刊 2025年第2期24卷 98-106页

作者：罗碧沈艳成都信息工程大学计算机学院四川成都610000

随着物联网设备的海量增长,其产生的数据也呈指数级增长。只有当数据具有可接受的质量时,其才具有价值,而海量数据中难免存在噪声数据。针对该问题,提出一种基于基尼系数与粒子群优化算法的密度峰值聚类算法Gini-PSO-DPC。首先,采用基... 详细信息

随着物联网设备的海量增长,其产生的数据也呈指数级增长。只有当数据具有可接受的质量时,其才具有价值,而海量数据中难免存在噪声数据。针对该问题,提出一种基于基尼系数与粒子群优化算法的密度峰值聚类算法Gini-PSO-DPC。首先,采用基于所有数据点的基尼系数计算最优截止距离dc;其次,通过粒子群优化算法寻找K个近似最优初始聚类中心,生成K个初始类别集群;最后,通过基于密度的最近数据点所属类别将样本数据点分配到对应类别集群。仿真实验结果表明,Gini-PSO-DPC算法的平均准确率达到96.81%,分别相较改进K-means、DMGA-FCM、DPC 3种算法提高了2.44%、0.89%、0.9%;平均精确率达到94.3%,分别相较改进K-means、DMGA-FCM、DPC 3种算法提高了1.22%、2.02%、1.33%。在消融实验中,Gini-PSO-DPC算法截止距离dc参数设置更加稳定合理,聚类时间更短,表明该算法具有更强的全局搜索能力、更高的自适应性和更好的聚类效果。

关键词：物联网聚类算法 DPC Gini-PSO-DPC 异常检测

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

域泛化机械故障诊断研究进程与展望

中国科学:技术科学 2025年第1期55卷 14-32页

作者：邵海东肖一鸣颜深王杰彭颖湖南大学机械与运载工程学院长沙410082

分布偏移阻碍了智能故障诊断模型在实际工程中的部署.为缓解分布偏移,基于迁移学习的智能故障诊断研究正如火如荼地开展中.作为迁移学习的两种无监督变体,域适应和域泛化尤其受到学者的关注,其中域适应需利用目标域的无标签数据,而域泛... 详细信息

分布偏移阻碍了智能故障诊断模型在实际工程中的部署.为缓解分布偏移,基于迁移学习的智能故障诊断研究正如火如荼地开展中.作为迁移学习的两种无监督变体,域适应和域泛化尤其受到学者的关注,其中域适应需利用目标域的无标签数据,而域泛化解除了这一限制,因此更具灵活性和泛用性.自2020年域泛化首次被应用于故障诊断以来,各类域泛化诊断技术层出不穷,因此有必要对其进行全面调查.本文首先按任务类型总体划分了现有域泛化故障诊断研究,然后根据方法理论进一步细分了各任务下的研究,总结了各方法理论的核心思想,并回顾了基于各理论的故障诊断研究.最后,讨论了未来具有前景的研究方向.

关键词：分布偏移域适应域泛化机械故障诊断无监督迁移学习

同方期刊数据库

The Brezis–Nirenberg Problem for the Fractional p-Laplacian in Unbounded Domains

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2023年第11期39卷 2181-2206页

作者： yan sheng shen School of Mathematical Sciences Jiangsu UniversityZhenjiang 212013P.R.China

In this paper we study the existence of nontrivial solutions to the well-known Brezis–Nirenberg problem involving the fractional p-Laplace operator in unbounded cylinder type *** means of the fractional Poincaréinequality in unbounded cylindrical domains,we first study the asymptotic property of the first eigenvalueλp,s(ωδ)with respect to the domainωδ.Then,by applying the concentration-compactness principle for fractional Sobolev spaces in unbounded domains,we prove the existence *** present work complements the results of Mosconi–Perera–Squassina–yang[The Brezis–Nirenberg problem for the fractional p-Laplacian.C *** Differential Equations,55(4),25 pp.2016]to unbounded domains and extends the classical Brezis–Nirenberg type results of Ramos–Wang–Willem[Positive solutions for elliptic equations with critical growth in unbounded ***:Chapman Hall/CRC Press,Boca Raton,2000,192–199]to the fractional p-Laplacian setting.

关键词： Brezis–Nirenberg problem fractional Poincaréinequality fractional p-Laplacian unbounded cylinder type domains concentration–compactness principle