检索结果-南通市图书馆

Transportation Safety and Environment 2024年第1期6卷 83-92页

作者： Xinyu Liu shengjun huang Qun Chen Business school Foshan UniversityFoshan 528225GuangdongChina School of Traffic and Transportation Engineering Central South UniversityChangsha 410075HunanChina Hunan Provincial Expressway Traffic Police Station Law Enforcement DepartmentChangsha 410007HunanChina

Based on the 2012–2018 accident statistics on the Hunan Provincial Expressway in China,this paper analyses the proportion to which various factors contribute to accidents,as well as the trends over time.From 2012 to 2018,the total number of general procedure handling accidents(i.***.major accidents)increased first and then decreased,while the number of accidents and deaths per 1000 kilometres decreased year by year.The total number of simple procedure handling accidents(i.***.minor accidents)increased year by year,but the number of accidents per 1000 kilometres remained relatively stable.Speeding,fatigued driving,improper driving operation,failure to maintain a safe distance from the preceding vehicle and pedestrians entering the expressway are the main causes of general procedure handling accidents.Failure to maintain a safe distance from the preceding vehicle as required and improper driving operation accounted for approximately 2/3 of the simple procedure handling accidents.In view of the accidents caused by these factors,how to use law enforcement,education,science and technology and facilities construction to further reduce the occurrence of expressway traffic accidents is discussed.

关键词： expressway traffic accident cause analysis

Construction of monodispersed single-crystalline hierarchical ZSM-5 nanosheets via anisotropic etching

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 Energy Chemistry 2022年第9期31卷 516-521,I0014页

作者： Tianli Zhou Dazhi Zhang Yi Liu Yanwei Sun Taotao Ji shengjun huang Yi Liu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina Division of Fossil Energy Conversion Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Dalian Key Laboratory of Membrane Materials and Membrane Processes Dalian University of TechnologyDalian 116024LiaoningChina

Hierarchical zeolites and single-crystalline zeolite nanosheets(NSs)have been recognized as two separate types of targeting porous materials to overcome the diffusion limitations of traditional bulk zeolites.The synthesis of uniform single-crystalline hierarchical zeolite NSs featured with NS morphology and interconnected mesoporosity,remains rarely reported.In this work,we prepared ZSM-5 zeolites with the above microstructural features via simple alkaline etching.Moreover,both their microstructure and acid strength could be accurately tuned with this approach,resulting in not only higher conversion rate and BTX selectivity but also superior anti-coking performance in the subsequent methanol aromatization reaction.

关键词： ZSM-5 zeolite Hierarchical structure Nanosheet Alkaline etching Methanol aromatization reaction

Effect of Reaction Temperature and Pressure on the Metathesis Reaction between Ethene and 2-Butene to Propene on the WO_3/Al_2O_3-HY Catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2006年第2期15卷 93-99页

作者： shengjun huang Shenglin Liu Wenjie Xin Sujuan Xie Qingxia Wang Longya Xu Laboratory of Natural Gas and Applied Catalysis Chinese Academy of Sciences Dalian 116023 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Effect of reaction temperature and pressure on the metathesis reaction between ethene and 2-butene to propene was studied on the WO3/γ-Al2O3-HY catalyst. The activity is found to increase with elevated temperature and reaches a plateau at 150-240 ℃. After that, the activity undergoes a remarkable decrement at too high temperature. The effect of temperature is elucidated by the oxidation state of tungsten species. The evaluation results also indicate that the stability is dependent on this reaction parameter. Medium pressure （0.5-0.8 MPa） is favorable for stability, while atmospheric pressure or too high pressure （〉1.0 MPa） deteriorates the stability. For explanation, UV Vis, FT-IR, O2-TPO, and TG techniques are used to characterize the spent catalysts.

关键词： metathesis tungsten oxide catalyst temperature pressure ethene 2-butene propene

Production of propene from 1-butene metathesis reaction on tungsten based heterogeneous catalysts

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2009年第3期18卷 331-336页

作者： Huijuan Liu Ling Zhang Xiujie Li shengjun huang Shenglin Liu Wenjie Xin Sujuan Xie Longya Xu State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 Liaoning China Graduate University of Chinese Academy Sciences Beijing 100049 China

A new propene production route from 1-butene metathesis has been developed on heterogeneous 10WO3/Al2O3-HY catalysts with different HY contents. It is found that the catalysts play bi-functionally first for the isomerization of 1-butene to 2-butene and then for the cross-metathesis between 1-butene and 2-butene to propene and 2-pentene. The combination of HY zeolite and Al2O3 is prerequisite for the production of propene. The propene yield keeps increasing with the HY content in the range of 10-70 wt%, where 10WO3/Al2O3-70HY exhibits the highest propene yield. The MS-H2-TPR and MS-O2-TPO characterizations indicate that the increase of HY content in the catalysts weakens the interaction between W species and supports, whereas enhance the probability of coking on the metal species and acid sites.

关键词： propene 1-butene metathesis 10WO3/Al2O3-xHY bifunction

在线全文

学校读者我要写书评

暂无评论

基于负学习的样本重加权鲁棒学习方法

计算机应用 2024年第5期44卷 1479-1484页

作者：邹博士杨铭宗辰辰谢明昆黄圣君南京航空航天大学计算机科学与技术学院南京211106

噪声标记学习方法能够有效利用含有噪声标记的数据训练模型,显著降低大规模数据集的标注成本。现有的噪声标记学习方法通常假设数据集中各个类别的样本数目是平衡的,但许多真实场景下的数据往往存在噪声标记,且数据的真实分布具有长尾现... 详细信息

噪声标记学习方法能够有效利用含有噪声标记的数据训练模型,显著降低大规模数据集的标注成本。现有的噪声标记学习方法通常假设数据集中各个类别的样本数目是平衡的,但许多真实场景下的数据往往存在噪声标记,且数据的真实分布具有长尾现象,这导致现有方法难以设计有效的指标,如训练损失或置信度区分尾部类别中的干净样本和噪声样本。为了解决噪声长尾学习问题,提出一种基于负学习的样本重加权鲁棒学习(NLRW)方法。具体来说,根据模型对头部类别和尾部类别样本的输出分布,提出一种新的样本权重计算方法,能够使干净样本的权重接近1,噪声样本的权重接近0。为了保证模型对样本的输出准确,结合负学习和交叉熵损失使用样本加权的损失函数训练模型。实验结果表明,在多种不平衡率和噪声率的CIFAR-10以及CIFAR-100数据集上,NLRW方法相较于噪声长尾分类的最优基线模型TBSS(Two stage Bi-dimensional Sample Selection),平均准确率分别提升4.79%和3.46%。

关键词：噪声标记学习长尾学习噪声长尾学习样本重加权负学习

在线全文

学校读者我要写书评

暂无评论

多规格转台轴承组件的自动紧钉装置

制造技术与机床 2024年第6期 183-188页

作者：王凯韩银平贾长安黄胜军西安精雕精密机械工程有限公司陕西西安710000 北京精雕科技集团有限公司北京102308

在装配转台轴承组件时,需要按照十字交叉顺序分三步拧紧固定螺钉,现有的装紧钉方式存在效率低和紧钉质量低等问题。文章设计了一种多规格转台轴承组件的自动紧钉装置,实现了多规格转台轴承组件的自动定位夹紧、装钉、按照十字交叉顺序... 详细信息

在装配转台轴承组件时,需要按照十字交叉顺序分三步拧紧固定螺钉,现有的装紧钉方式存在效率低和紧钉质量低等问题。文章设计了一种多规格转台轴承组件的自动紧钉装置,实现了多规格转台轴承组件的自动定位夹紧、装钉、按照十字交叉顺序分三步加扭力和加胶功能。实际使用表明,该设备工作可靠、效率高,紧钉质量得到很大提高。

关键词：转台轴承组件自动拧紧力矩螺钉

在线全文

学校读者我要写书评

暂无评论

珠海地区海陆风对臭氧污染的影响

环境科学学报 2024年第1期44卷 74-85页

作者：张亮林洁萍邵英贤黄盛君范绍佳魏婉沛董妍汝李文淑梁秀姬广东省珠海生态环境监测站珠海519000 壹点环境科技(广州)有限公司广州510220 中山大学大气科学学院珠海519000 珠海市公共气象服务中心珠海519000

近年来珠三角夏秋季大气臭氧污染愈发严重并受到广泛关注.每年9—10月珠三角会有多个城市出现臭氧连续超标,呈现污染时间长、污染范围广的特点,2022年情况尤为突出.利用2016—2022年珠海市气象观测数据统计了该地区的海陆风发生规律,结... 详细信息

近年来珠三角夏秋季大气臭氧污染愈发严重并受到广泛关注.每年9—10月珠三角会有多个城市出现臭氧连续超标,呈现污染时间长、污染范围广的特点,2022年情况尤为突出.利用2016—2022年珠海市气象观测数据统计了该地区的海陆风发生规律,结合内陆站点和沿海站点空气质量监测数据,分析了海陆风对臭氧的影响.结果表明:夜间陆风将内地高污染气团向沿海方向传输,使夜间珠海地区VOCs增加及一部分的污染气团吹至海面,第二日上午开始海风将前一日夜间高污染气团从海面吹回陆地,到下午海风气团才逐渐变的较为清洁.整体来看,海陆风影响时本地VOCs增加明显,上午臭氧的增长速度较无海陆风时更快.O_(x)原位生成速率平均值和最大小时生成速率平均值均高于无海陆风日.珠海海陆风日海风与陆风影响臭氧生成前十OFP物种基本一致,与珠三角其他城市来源相似.

关键词：海陆风影响臭氧(O_(3)) 生成速率珠海

家属参与的多维度护理对乳腺癌根治术患者心理应激和功能恢复的影响

在线全文

学校读者我要写书评

暂无评论

中国当代医药 2024年第19期31卷 158-162页

作者：叶乐黄胜君刘丽华张琼郑洁江西省上饶市人民医院头颈乳腺外科江西上饶334000

目的探讨家属参与的多维度护理对乳腺癌根治术患者心理应激和功能恢复的影响。方法选取2022年6月至2023年6月上饶市人民医院头颈乳腺外科收治的60例乳腺癌患者作为研究对象。按照随机数字表法分为对照组(30例)与观察组(30例),对照组采... 详细信息

目的探讨家属参与的多维度护理对乳腺癌根治术患者心理应激和功能恢复的影响。方法选取2022年6月至2023年6月上饶市人民医院头颈乳腺外科收治的60例乳腺癌患者作为研究对象。按照随机数字表法分为对照组(30例)与观察组(30例),对照组采用常规护理,观察组采用家属参与的多维度护理。比较两组的心理应激反应、心理状况、上肢功能障碍、上肢活动度、肩关节活动能力恢复情况及生活质量,入院后检查收缩压(SBP)和心率(HR),分别采用心理弹性量表(CD-RISC)、焦虑自评表(SAS)、汉密尔顿焦虑量表(HAMA)、抑郁自评量表(SDS)、汉密尔顿抑郁量表(HAMD)、上肢功能障碍量表(Quick-Dash)、上肢关节活动度量表(ROM)、肩关节功能量表(Constant-Murley)、肿瘤患者生活质量量表(QLQ-C30)及乳腺癌患者特异量表(FACT-B)评估。结果观察组患者干预后CD-RISC评分高于对照组,且SBP、HR低于对照组,差异有统计学意义(P<0.05);观察组患者干预后SAS、HAMA、SDS、HAMD评分低于对照组,差异有统计学意义(P<0.05);观察组患者干预后Quick-Dash评分低于对照组,且ROM、Constant-Murley评分高于对照组,差异有统计学意义(P<0.05);观察组干预后上肢外展、前屈、后伸、内旋、外旋角度、手指爬墙高度高于对照组,差异有统计学意义(P<0.05);观察组患者干预后QLQ-C30、FACT-B评分高于对照组,差异有统计学意义(P<0.05)。结论家属参与的多维度护理能改善乳腺癌根治术患者心理应激情况及心理状况、降低患者上肢功能障碍,提高上肢及肩关节功能恢复,增加上肢活动范围,提高生活质量。

关键词：家属参与多维度护理乳腺癌根治术心理应激功能恢复

昆明长水机场“跑道切换”特征分析及激光雷达典型个例研究

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

民航学报 2024年第3期8卷 94-98+87页

作者：黄盛军袁金龙江春明刘星俞中国民用航空西南地区空中交通管理局云南分局南京信息工程大学中国东方航空云南有限公司中国民航科学技术研究院

本文基于昆明长水机场“跑道切换”数据统计分析,对造成机场跑道风频繁切换的主要影响天气系统进行分型,结合类型典型个例分析发现,激光雷达对风的精密监测产品在民航业内运行具有一定的辅助效果,根据个例积累应用经验,建立业内应用模型... 详细信息

本文基于昆明长水机场“跑道切换”数据统计分析,对造成机场跑道风频繁切换的主要影响天气系统进行分型,结合类型典型个例分析发现,激光雷达对风的精密监测产品在民航业内运行具有一定的辅助效果,根据个例积累应用经验,建立业内应用模型,利用其对机场区域风要素的的监测及预警应用经验,为管制运行“跑道切换”期间的安全保障和运行效率提供精细化气象信息服务参考。

关键词：激光雷达跑道切换辅助决策

Nanosecond and femtosecond lasers based on black arsenic-phosphorus alloys saturable absorber

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2022年第2期20卷 106-110页

作者：黄圣钧王祎然何京良苏现翠刘杰 Shandong Provincial Engineering and Technical Center of Light Manipulations&Shandong Provincial Key Laboratory of Optics and Photonic Device School of Physics and ElectronicsShandong Normal UniversityJinan 250358China Shandong Key Laboratory of Optical Communication Science and Technology School of Physics Science and Information TechnologyLiaocheng UniversityLiaocheng 252059China State Key Laboratory of Crystal Materials Institute of Novel SemiconductorsShandong UniversityJinan 250100China

In this paper, the high-repetition-rate passively Q-switched(PQS) and the femtosecond continuous-wave mode-locked(CWML) lasers are successfully obtained with 2 D black arsenic-phosphorus(b-As P) nanosheets as saturable absorber(SA) at 1 μm for the first time, to the best of our knowledge. The saturable absorption properties and ultrafast carrier dynamics of the 2 D b-As P SA are explored by Z-scan and pump-probe techniques. Moreover, according to the measurement of desired nonlinear optical characteristics of the relaxation time of 27 ps and the modulation depth of 7.14%, the PQS and CWML lasers are demonstrated with the highest repetition rate of 2.26 MHz in the PQS laser and the pulse width of 470 fs in the CWML laser. The results show 2 D b-As P SA has enormous potential for pulse modulation in solid-state bulk lasers.

关键词： ultrafast lasers mode-locked lasers passively Q-switched lasers nonlinearity