检索结果-南通市图书馆

Exhaust emission inventory of typical construction machinery and its contribution to atmospheric pollutants in Chengdu, China

引用

Journal of Environmental Sciences 2023年第3期125卷 761-773页

作者： Wubo Fan Wenju Jiang junhui Chen Fumo Yang jun qian Hong Ye Institute of New Energy and Low-Carbon Technology Sichuan University(Wangjiang Campus)Chengdu 610207China Sichuan Academy of Environmental Sciences Chengdu 610041China Tsinghua University Beijing 100084China

To study the emission characteristics of typical construction machinery in Chengdu,12 construction machinery (excavators,bulldozers,loaders,and forklifts) under idling mode,moving mode,and working mode,were tested using a portable emission measurement system(PEMS).Under three operating modes,the typical construction machinery in the working mode was higher in the fuel-based average emission factors of PM_(2.5)and NOx,while the fuel-based average emission factors of HC and CO were higher in idling *** the results of investigation on ownership and activity levels of construction machinery,an exhaust emission inventory of typical construction machinery of Chengdu in 2018 was established according to the recommendation *** annual emission of PM_(2.5),NOx,HC,and CO were 1.67×106,1.61×108,3.83×106,and 1.26×107kg,respectively,and the excavator contributed the maximum emissions,accounting for an average proportion of 43.95%.The emission of construction machinery in Chengdu exhibited a clear monthly trend,with the highest from April to October and the lowest from November to *** addition,the exhaust emissions presented an obvious spot-like characteristics,and the high-value areas were mainly concentrated in the surrounding suburban counties such as Shuangliu Wenjiang *** reduce pollution from construction machinery and improve the quality of the atmospheric environment,more effective measures on housing construction and municipal construction should be taken in those districts in Chengdu.

关键词： Construction equipment PEMS Emission factor Emission inventory Contribution Chengdu

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

航母舰载无人机全自动着舰技术特点分析

引用

舰船科学技术 2024年第8期46卷 185-189页

作者：何肇雄郑震山李翀伦胡江玉钱仁军中国人民解放军92728部队上海200436

全自动着舰技术是无人机上舰必须解决的“使能”技术。2013年,美军已完成X-47B无人机验证机在航母上的全自动着舰试验验证,为其发展MQ-25A“黄貂鱼”航母舰载无人机装备奠定了良好的技术基础。在梳理飞机着陆与着舰差异的基础上,给出航... 详细信息

全自动着舰技术是无人机上舰必须解决的“使能”技术。2013年,美军已完成X-47B无人机验证机在航母上的全自动着舰试验验证,为其发展MQ-25A“黄貂鱼”航母舰载无人机装备奠定了良好的技术基础。在梳理飞机着陆与着舰差异的基础上,给出航母舰载无人机全自动着舰的通用流程;从地位作用、工作范围、系统构架、系统要求、实现手段以及关键技术支撑等角度,对比有人机重点分析了航母舰载无人机全自动着舰的特点,为后续关键技术研究和武器装备建设发展提供参考。

关键词：航母舰载无人机全自动着舰

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Aurivillius compound Bi_(5)Ti_(3)CrO_(15) as a visible-light-active photocatalyst for hydrogen production from water

引用

Journal of Energy Chemistry 2021年第11期30卷 572-580,I0013页

作者： Zeming Gu jun qian Ran Wang Meilin Lv Xiaoxiang Xu Chun Luo Clinical and Central Lab Shanghai Putuo District People’s HospitalTongji UniversityShanghai 200060China Department of Neurosurgery Tongji HospitalTongji University School of MedicineShanghai 200065China Shanghai Key Lab of Chemical Assessment and Sustainability School of Chemical Science and EngineeringTongji UniversityShanghai 200092China State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027ZhejiangChina

Layered Aurivillius compound Bi_(5)Ti_(3)CrO_(15) has been synthesized by a hydrothermal method for the application as a photocatalyst to liberate hydrogen from water. Bi_(5)Ti_(3)CrO_(15) owns a narrow band gap (Eg ~2.46 eV) and shows stable photocatalytic activity under both full range (λ ≥250 nm) and visible light illumination (λ ≥420 nm). A short hydrothermal reaction time is critical to achieve high photocatalytic activity as defects such as Cr^(6+) and Bi^(5+) can be avoided. An AQE as high as 3.66% at 420 nm ± 20 nm has been recorded, warranting promising application in the field of solar energy conversions. DFT calculation reveals the important role of Cr^(3+) cations for visible light sensitivity of Bi_(5)Ti_(3)CrO_(15).

关键词： Bi_(5)Ti_(3)CrO_(15) Aurivillius phase Photocatalyst Water splitting Visible light DFT

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

肱骨小头软骨损伤碎片扦插桡骨头骨折缝隙的诊治误区分析

引用

中国临床解剖学杂志 2024年第4期42卷 463-467页

作者：陈群杜世浩刘军吴永伟马运宏王建兵钱俊殷渠东扬州大学附属医院骨科江苏扬州225003 无锡市第九人民医院骨科江苏无锡214062

目的探讨肱骨小头软骨损伤(CCI)碎片扦插桡骨头骨折(RHF)缝隙临床特点和诊治误区。方法回顾性分析2011年1月至2022年12月RHF术中探查证实伴CCI,且CCI碎片扦插RHF缝隙9例患者临床资料。男6例,女3例;年龄17~69岁,平均为36.1岁。分析其临... 详细信息

目的探讨肱骨小头软骨损伤(CCI)碎片扦插桡骨头骨折(RHF)缝隙临床特点和诊治误区。方法回顾性分析2011年1月至2022年12月RHF术中探查证实伴CCI,且CCI碎片扦插RHF缝隙9例患者临床资料。男6例,女3例;年龄17~69岁,平均为36.1岁。分析其临床特点。RHF按Mason分型,CCI按王健方法分型。随访13~30个月,平均随访14.2个月。患肢功能按Mayo肘关节功能评分标准(MEPS)评价。结果该骨折占RHF的6.8%,占RHF伴CCI的25%。跌伤6例,坠落伤3例。均有明显肘关节屈伸和前臂旋转活动受限,4例局部有骨擦音。6例因RHF较重、3例RHF较轻但局麻后体检试验阳性行手术。Mason Ⅰ、Ⅱ和Ⅲ型各1、7和1例。CCI分型Ⅰ、Ⅱ、Ⅲ型各3、4和2例。CCI仅1例Ⅲ型术前获MRI诊断,其余8例影像学检查均阴性。CCI位于肱骨小头外侧、后外侧和前外侧各4、3和2例;范围12~100 mm^(2),平均19.8 mm^(2)。RHF均内固定;CCI摘除8例,缝合固定1例,Ⅱ型行微骨折处理2例。RHF均愈合。末次随访,MEPS评价优良率88.9%。结论CCI碎片扦插RHF缝隙临床少见,易漏诊,但患者活动明显受限、局部骨擦音和局麻后体检试验阳性常提示该骨折可能;手术探查仍是诊断金标准,值得重视;CCI应按类型选择不同处理方法。

关键词：桡骨头骨折伴发伤肱骨小头软骨损伤局麻后体检术中探查

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

K/KCC-1催化碳酸二甲酯和乙醇酯交换合成碳酸甲乙酯

引用

精细化工 2024年第10期41卷 2266-2272,2309页

作者：钱俊刘飞李欢欢徐鑫汤吉海张竹修乔旭东华工程科技股份有限公司安徽合肥230024 南京工业大学化工学院材料化学工程国家重点实验室江苏南京210009 国家“江苏先进生物与化学制造协同创新中心” 江苏南京210009

以水热合成法制备的树突纤维状二氧化硅(KCC-1)为载体、乙酸钾为前驱体,采用等体积浸渍法制备了不同K理论负载量(x,x为K与Si物质的量的比值,分别为0.3、0.5、0.7、0.9、1.1)的固体碱催化剂(x K/KCC-1)。采用XRD、FTIR、BET、CO_(2)-TPD... 详细信息

以水热合成法制备的树突纤维状二氧化硅(KCC-1)为载体、乙酸钾为前驱体,采用等体积浸渍法制备了不同K理论负载量(x,x为K与Si物质的量的比值,分别为0.3、0.5、0.7、0.9、1.1)的固体碱催化剂(x K/KCC-1)。采用XRD、FTIR、BET、CO_(2)-TPD和SEM对x K/KCC-1进行了表征,评价了其对碳酸二甲酯(DMC)和乙醇进行酯交换反应合成碳酸甲乙酯(EMC)的催化性能。结果表明,x K/KCC-1具有2种碱性位,分别是由K_(2)SiO_(3)提供的弱碱性位和由K_(2)CO_(3)提供的中强碱性位,且随着K理论负载量的增加,弱碱性位点逐渐下降,中强碱性位点逐渐增强,催化剂的反应活性增强。K理论负载量≤0.9的x K/KCC-1仍保持KCC-1的树突纤维结构,使反应物分子能够较好地扩散到活性位点上,0.9K/KCC-1具有最高的催化活性。在反应温度为80℃、反应时间为5 h、乙醇与DMC(4.494 g)的物质的量比为4∶1、0.9K/KCC-1用量为DMC质量的5%的最佳反应条件下,DMC的转化率为91.0%,EMC的选择性为95.5%,且其具有良好的循环稳定性,重复使用5次后,DMC的转化率为86.7%,EMC的选择性为95.2%。

关键词：树突纤维状二氧化硅固体碱碳酸甲乙酯酯交换催化技术

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An intelligent method for controlling the ECP braking system of a heavy-haul train

引用

Transportation Safety and Environment 2020年第2期2卷 133-147页

作者： Chun Tian Mengling Wu Lu Zhu jun qian Institute of Rail Transit Tongji University United Automotive Electronic Systems Co. Ltd.

An intelligent control method is proposed for the electronically controlled pneumatic(ECP)braking system of a heavy-haul train. The gradient of the ramp is estimated using a Kalman filter in real time and the braking force is adjusted by the backstepping method, so that vehicles on different gradients change their brake pressure with the change in the gradient to keep the instantaneous deceleration of each vehicle consistent, thus reducing the longitudinal impact between vehicles. The longitudinal impact of heavy-haul trains with and without intelligent control under different gradients, initial braking speeds, loads and complex terrains are simulated and analysed. The results show that when the intelligent control is applied, each vehicle can adjust its brake pressure in time according to the change of gradient. The intelligent control method can effectively alleviate the longitudinal impact of vehicles, and the reduction rate remains greater than 40% under the influence of various factors.

关键词： electronically controlled pneumatic braking system heavy-haul train Kalman filter longitudinal impact

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rapid determination of pharmaceuticals from multiple therapeutic classes in wastewater by solid-phase extraction and ultra-performance liquid chromatography tandem mass spectrometry

引用

Chinese Science Bulletin 2009年第24期54卷 4633-4643页

作者： SUI qian HUANG jun DENG ShuBo YU Gang POPs Research Centre Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

A new analytical method utilizing ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) has been developed to determine 16 pharmaceuticals from 8 therapeutic classes in wastewater: bezafibrate, clofibric acid, carbamazepine, caffeine, chloramphenicol, diclofenac, gemfibrozil, indomethacin, ketoprofen, mefenamic acid, metoprolol, nalidixic acid, N,N-diethyl-metatoluamide, propranolol, sulpiride and trimethoprim. Key parameters of MS/MS, UPLC and solid phase extraction (SPE) were optimized. In general, recovery of target pharmaceuticals was over 70% for the wastewater effluent samples and 50% for the influent samples. The effects of matrix suppression, loss during the pretreatment as well as instrument variability were successfully corrected by two internal standards, and acceptable relative recovery was obtained. Target compounds were quantitatively analyzed using multiple reaction monitoring (MRM) mode, and the detection limits ranged from 0.3 to 20 ng/L. A detailed study, matrix effect in effluent wastewater was also present. The method was applied to detecting pharmaceuticals in the wastewater from three wastewater treatment plants (WWTPs) in Beijing, China and the results demonstrated that most target compounds were detectable in both the influent and effluent, with the mean concentrations ranging from 20.5 to 5775.6 ng/L and 4.6 to 418.6 ng/L, respectively.

关键词：高效液相色谱串联质谱法固相萃取废水药品快速测定治疗污水处理厂

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

玻璃与碳纤维混杂增强复合材料3D打印与实验

引用

材料科学与工程学报 2024年第2期42卷 200-204页

作者：栾丛丛牛成成林志伟钱俊傅建中浙江大学机械工程学院浙江杭州310058

本研究基于热塑性材料熔融沉积成型工艺,研制了双喷头连续玻璃纤维与碳纤维混杂增强热塑性复合材料结构增材制造平台,制备了不同混杂比的纤维增强热塑性复合材料结构试件,分析了不同结构试件的弯曲力学性能与失效模式,探索了嵌入碳纤维... 详细信息

本研究基于热塑性材料熔融沉积成型工艺,研制了双喷头连续玻璃纤维与碳纤维混杂增强热塑性复合材料结构增材制造平台,制备了不同混杂比的纤维增强热塑性复合材料结构试件,分析了不同结构试件的弯曲力学性能与失效模式,探索了嵌入碳纤维智能层的混杂纤维增强热塑性复合材料的力阻行为。结果表明:比较纯热塑性材料结构件,玻璃纤维增强复合材料结构件弯曲强度提高了115.99%,碳纤维增强复合材料结构件弯曲强度提高了198.76%;玻璃纤维与碳纤维混杂增强复合材料结构件具有负弯曲强度混杂效应和正弯曲模量混杂效应。可根据碳纤维电阻相对变化率对混杂增强复合材料结构的应变与断裂破坏状态进行实时自感知。研究结果为连续玻璃纤维与碳纤维混杂增强热塑性复合材料结构件的高质高效制造与智能化提供了新工艺与新思路。

关键词：三维打印碳纤维玻璃纤维混杂增强复合材料增材制造

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization of three-loop missile autopilot gain under crossover frequency constraint

引用

Defence Technology（防务技术） 2016年第1期12卷 32-38页

作者： M.A.ABD-ELATIF Long-jun qian Yu-ming BO School of Automation University of Science and TechnologyNanjing

The open-loop crossover frequency is pointed as an important parameter for practical autopilot design. Since different gain designs may achieve the same open-loop crossover frequency, it should be neither considered as a performance objective of the optimal autopilot design-schemes nor neglected. Besides, the main assignment of the autopilot is to drive the missile to track the acceleration commands, so the autopilot gain design should be evaluated directly according to the resultant tracking performance. For this purpose, an optimal design methodology of the three-loop missile autopilot is introduced based on constraint optimization technique, where the tracking performance is established analytically as the design objective and the open-loop crossover frequency is formed as inequality constraint function, both are manipulated in terms of stable characteristic parameters of the autopilot closed-loop. The proposed technique is implemented with the assistance of a numerical optimization algorithm which automatically adjusts the design parameters. Finally, numerical simulation results are provided to demonstrate the effectiveness and feasibility of the proposed approach compared with that in some references.

关键词：导弹自动驾驶仪频率约束优化技术三回路增益设计方法跟踪性能数值模拟

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Hydrothermal Synthesis and Crystal Structure of a New 2D Layered Cadmium(II) Coordination Polymer:[Cd(bimc)_2]_n(bimc=1H-Benzimidazole-5-carboxylate)

引用

Chinese Journal of Structural Chemistry 2006年第8期25卷 975-978页

作者： DENG qian-jun ZENG Ming-Hua LIANG Hong HUANG Ke-Long College of Chemistry and Chemical Engineering Central South-University Changsha Hunan 410000 China Department of Chemistry and Chemical Engineering Guangxi Normal University Guilin Guangxi 541004 China Science School Foshan University Foshan Guangdong 528000 China

A new coordination polymer [Cd（bimc）2]n was obtained by the reaction of Hbimc with Cd（NO3） 2·4H2O in NaOH solution, and characterized by elemental analysis, IR and singlecrystal X-ray diffraction. The crystal belongs to orthorhombic, space group Pbcn with a = 12.533（4）, b = 15.705（5）, c = 15.200（5） A, V= 2991.8（15） A^3, Mr = 434.68, Z = 8, Dc = 1.930 g/cm^3, F（000） = 1712,μ（MoKa） = 1.492 mm^-1, the final R = 0.0410 and wR = 0.0804 for 1661 observed reflections （I 〉 2σ（I））. The Cd atom exhibits a distorted six-coordinate CdNzOa octahedral coordination geometry. The complex molecules are linked by both μ2-（η2-O, O^-）, NI and μ2-（η2-O, O^-）, N3 coordination modes of ligands to form cross-like wave （4, 4） layer structures which are further stacked through interlayer hydrogen bonds and π-π stacking interactions in an offset fashion to form a 3D supramolecular structure.

关键词： hydrothermal synthesis cadmium(Ⅱ) polymer 1H-benzimidazole-5-carbonate 2D layer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：