检索结果-南通市图书馆

Spatiotemporal estimation of hourly 2-km ground-level ozone over China based on Himawari-8 using a self-adaptive geospatially local model

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2022年第1期13卷 204-216页

作者： Yuan Wang Qiangqiang Yuan liye zhu Liangpei Zhang School of Geodesy and Geomatics Wuhan UniversityWuhanHubei 430079China School of Atmospheric Science Sun Yat-sen UniversityGuangzhouGuangdong 510275China The Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan UniversityWuhanHubei 430079China The State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanHubei 430079China

Ground-level ozone(O_(3))is a primary air pollutant,which can greatly harm human health and *** present,data fusion frameworks only provided ground-level O_(3) concentrations at coarse spatial(e.g.,10 km)or temporal(e.g.,daily)*** photochemical pollution continues increasing over China in the last few years,a high-spatial–temporal-resolution product is required to enhance the comprehension of ground-level O_(3) formation *** address this issue,our study creatively explores a brand-new framework for estimating hourly 2-km ground-level O_(3) concentrations across China(except Xinjiang and Tibet)using the brightness temperature at multiple thermal infrared *** the spatial heterogeneity of ground-level O_(3),a novel Self-adaptive Geospatially Local scheme based on Categorical boosting(SGLboost)is developed to train the estimation *** results show that SGLboost performs well in the study area,with the R2 s/RMSEs of 0.85/19.041 lg/m^(3) and 0.72/25.112 lg/m^(3) for the space-based cross-validation(CV)(2017–2019)and historical space-based CV(2019),***,SGLboost achieves distinctly better metrics than those of some widely used machine learning methods,such as e Xtreme Gradient boosting and Random *** to recent related works over China,the performance of SGLboost is also more *** the spatial distribution,the estimated results present continuous spatial patterns without a significantly partitioned boundary *** addition,accurate hourly and seasonal variations of ground-level O_(3) concentrations can be observed in the estimated results over the study *** is believed that the hourly 2-km results estimated by SGLboost will help further understand the formation mechanisms of ground-level O_(3) in China.

关键词： Spatiotemporal estimation Air pollution Ground-level O_(3) SGLboost China

Tribological Properties of Functionalized Ionic Liquids Containing Ester-group as Lubricants for Steel-Steel System

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2012年第2期14卷 60-65页

作者： zhu liye Chen Ligong Xiang Shuo Chen Guoxu Yang Xin Department of Oil Application&Management Engineering PLA Logistical Engineering UniversityChongqing 401311

A series of functionalized ionic liquids （ILs） containing ester-group were synthesized and their tribological prop- erties as lubricants for steel-steel contact were studied and compared with a non-functionalized ionic liquid and perfluo- ropolyethers （PFPE）. The morphology and chemical composition of the worn scars were analyzed by scanning electron mi- croscopy and X-ray photoelectron spectroscopy, respectively, and the possible lubrication mechanism of ILs was discussed. As a result, all ILs demonstrated a better lubricity and a much higher load-carrying capacity than PFPE used as lubricants for the steel-steel tribomates system. The functionalized ILs with ester-group showed slightly worse friction reducing abil- ity than their nonfunctionalized counterparts at relatively lower loads owing to their higher viscosity, but then exhibited better antiwear ability because the ester group they contained had not only physical but also strong chemical reactions with the freshly exposed steel surface and formed chemical adsorption boundary films on the worn surface during friction pro- cess. Under high loads, some triboehemical reactions took place between the active elements, such as fluorine which were released from the ILs, and fresh metal surfaces of rubbing pairs to form the admixture reaction films, which were mainly composed of ferric fluoride mixed with ferric oxide, leading to lower friction coefficients and good wear resistance.

关键词： functionalized ionic liquid 1-ethoxycarbonylmethyl-3-methyl bis(trifluoromethylsulfonyl)imide tribological behavior lubricant

Diester Derivatives from Chemically Modified Waste Cooking Oil as Substitute for Petroleum Based Lubricating Oils

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2015年第2期17卷 76-83页

作者： Xiang Shuo Chen Ligong Xu Lan Li Liang Yang Xin zhu liye Department of Military Oil Application & Management Engineering Logistical Engineering University of PLA School of Chemistry and Chemical Engineering Southwest University Oil Technical Supervision Office Logistical Department of Chengdu Military Area

In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.

关键词： waste cooking oil diester derivative lubricating oil physicochemical property tribological property

A peroxidase-like single-atom Fe-N_(5)active site for effective killing human lung adenocarcinoma cells

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第4期16卷 5216-5225页

作者： liye zhu Hong Zhong Dan Du Tao Li Hoai Nguyen Scott PBeckman Wentao Xu Jin-Cheng Li Nan Cheng Yuehe Lin Beijing Laboratory for Food Quality and Safety College of Food Science and Nutritional EngineeringChina Agricultural UniversityBeijing 100083China School of Mechanical and Materials Engineering Washington State UniversityPullmanWA 99164USA Faculty of Chemical Engineering Yunnan Provincial Key Laboratory of Energy Saving in Phosphorus Chemical Engineering and New Phosphorus MaterialsKunming University of Science and TechnologyKunming 650500China Department of Chemistry and Biochemistry Northern Illinois University1425 W.Lincoln Hwy.DeKalbIL 60115USA X-ray Science Division Argonne National Laboratory9700 S.Cass AveLemontIL 60439USA Material Science Division Argonne National Laboratory9700 S.Cass AveLemontIL 60439USA

Single-atom catalyst(SAC)is one of the newest catalysts,and attracts people’s wide attention in cancer therapy based on their characteristics of maximum specific catalytic activity and high *** designed and synthesized a Fe-N decorated graphene nanosheet(Fe-N5/GN SAC)with the coordination number of *** enzymology and theoretical calculations,the Fe-N5/GN SAC has outstanding intrinsic peroxidase-like catalytic activity due to single-atom Fe site with five-N-coordination *** explored its potential on lung cancer therapy,and found that it could kill human lung adenocarcinoma cells(A549)by decomposing hydrogen peroxide(H_(2)O_(2))into toxic reactive oxygen species(ROS)under acidic microenvironment in threedimensional(3D)lung cancer cell *** study demonstrates a promising application of SAC with highly efficient single-atom catalytic sites for cancer treatment.

关键词： single-atom catalyst three-dimensional(3D) cancer cell model peroxidase-like catalytic activity cancer therapy

区块链系统节点私钥泄露的电力数据防篡改方法与验证机制设计

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

电力自动化设备 2021年第12期41卷 87-94页

作者：吉斌昌力朱丽叶曹斌南瑞集团有限公司(国网电力科学研究院有限公司) 江苏南京211106 国电南瑞科技股份有限公司江苏南京211106

基于区块链技术的电力应用系统中,私钥泄露节点的签名电力数据存在被恶意篡改或伪造的风险,且当前缺乏有效的防护措施,为此,提出数据加密方法和数据交互验证机制。结合区块链基础加密技术原理,提出随机数与电力数据的组合方法,利用非对... 详细信息

基于区块链技术的电力应用系统中,私钥泄露节点的签名电力数据存在被恶意篡改或伪造的风险,且当前缺乏有效的防护措施,为此,提出数据加密方法和数据交互验证机制。结合区块链基础加密技术原理,提出随机数与电力数据的组合方法,利用非对称加密算法和Hash算法进行多重加密,构造数据发出节点私钥泄露后的数据防篡改加密方法;为了防止恶意节点利用数据发出节点的私钥对电力数据进行伪造和替换,设计电力数据交互验证机制,利用数据发出节点私钥进行加密并利用接收节点公、私钥进行解密验证;抽象加、解密和数据交互验证机制的数据模型。算例分析验证了所提数据加密方法和数据交互验证机制的有效性。

关键词：区块链私钥泄露加密方法数据交互验证防篡改防伪造

考古学视域下集安地区高句丽的“城”与“都”

在线全文

学校读者我要写书评

暂无评论

社会科学战线 2024年第6期348卷 142-151页

作者：王志刚祝立业吉林大学考古学院吉林长春130012 吉林省社会科学院吉林长春130033

中国正史中涉及3—427年之间高句丽都城,或记为“丸都城”,或记为“都于丸都之下”,并无以国内城为都的明确记载,甚至作为区域指称的“国内”字样也出现较晚。“都于丸都之下”而不是“都于丸都之下某某城”,这似乎也表明彼时丸都山下... 详细信息

中国正史中涉及3—427年之间高句丽都城,或记为“丸都城”,或记为“都于丸都之下”,并无以国内城为都的明确记载,甚至作为区域指称的“国内”字样也出现较晚。“都于丸都之下”而不是“都于丸都之下某某城”,这似乎也表明彼时丸都山下并无平地城,至少平地城进入中原史家的视野较晚。这样,“都于丸都之下”究竟是怎样一种形态,就成为需要探讨的问题。从《三国史记》记载看,“国内城”城名的出现年代,不早于342年。从目前考古工作看,国内城的始建年代在4世纪以后,且建筑等级低于丸都山城,而与同位于通沟平原的梨树园南、东门外、北门外等建筑遗址相当。基于历史文献并结合当下考古发现推断,国内城未建成前,高句丽当以通沟平原诸建筑遗址共同组成的“平地都邑”和丸都山城共同作为王都。国内城营建以后,可能仍不具有单独的都城职能,而仍与通沟平原诸建筑遗址和丸都山城共同行使王都职能。根据集安地区不同类型高句丽遗址的空间分布特点可以大致推定文献所记“国内”的地理空间范围。高句丽都“国内”期间,充分利用自然地理环境,结合人为规划,形成了“平地都邑”“陵墓区”“王畿区”三级区划以及山城与平地都邑相结合的独特王都模式。

关键词：考古学高句丽王都国内城丸都山城

在线全文

学校读者我要写书评

暂无评论

薄带连铸熔池液位AFPS控制策略

吉林大学学报（工学版） 2004年第z1期34卷 245-249页

作者：朱丽业吴惕华上海交通大学自动化系上海200030

主要研究了薄带连铸中关系到成品带材质量的熔池液位的控制问题.首先设计了采用CCD的熔池液位检测方法.其次给出熔池液位的波动模型,并提出一种带有监督控制的自适应模糊比例控制器(AFPS),利用Lyapunov定理证明了系统的稳定性.通过在模... 详细信息

主要研究了薄带连铸中关系到成品带材质量的熔池液位的控制问题.首先设计了采用CCD的熔池液位检测方法.其次给出熔池液位的波动模型,并提出一种带有监督控制的自适应模糊比例控制器(AFPS),利用Lyapunov定理证明了系统的稳定性.通过在模型、转速变化时的仿真结果,证明了这种控制器可以使非线性时变耦合系统具有很强的稳定性和鲁棒性.

关键词：薄带连铸熔池液位 CCD 自适应模糊PID 监督控制

基于MFD的模拟超饱和路网交通控制策略优化

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

武汉科技大学学报 2020年第1期43卷 74-80页

作者：朱丽叶张勇苏州大学城市轨道交通学院

为了缓解城市路网频繁出现的超饱和交通堵塞,本文以堵塞区域路网各条路段上行驶的车辆数作为状态变量,建立路网交通的状态方程,分析路段上车辆数变化规律;同时,基于交通流宏观基本图,以路网中路段累积车辆数最优作为控制目标,建立关于... 详细信息

为了缓解城市路网频繁出现的超饱和交通堵塞,本文以堵塞区域路网各条路段上行驶的车辆数作为状态变量,建立路网交通的状态方程,分析路段上车辆数变化规律;同时,基于交通流宏观基本图,以路网中路段累积车辆数最优作为控制目标,建立关于堵塞区域路网系统的离散状态优化控制模型,并将该模型在某城市新区进行模拟算例应用。结果表明,这种基于交通流宏观基本图的优化控制策略能有效缓解城市路网中超饱和交通堵塞,使路网整体输出效率得到明显提升。

关键词：超饱和路网交通控制车辆数宏观基本图输出效率策略优化

基于自适应遗传算法的DGPS整周模糊度快速解算

在线全文

学校读者我要写书评

暂无评论

航空学报 2013年第2期34卷 371-377页

作者：徐定杰刘明凯沈锋祝丽业哈尔滨工程大学自动化学院黑龙江哈尔滨150001

鉴于遗传算法(GA)所具有的全局搜索特性,也为了更快速准确地解算差分全球定位系统(DGPS)整周模糊度,将自适应遗传算法(AGA)引入DGPS整周模糊度的搜索中。首先根据全球定位系统(GPS)载波相位双差方程求解出双差整周模糊度的浮点解,并以... 详细信息

鉴于遗传算法(GA)所具有的全局搜索特性,也为了更快速准确地解算差分全球定位系统(DGPS)整周模糊度,将自适应遗传算法(AGA)引入DGPS整周模糊度的搜索中。首先根据全球定位系统(GPS)载波相位双差方程求解出双差整周模糊度的浮点解,并以基线长度作为约束条件确定整周模糊度的搜索范围;然后利用白化滤波的方法对整周模糊度进行降相关处理,降低整周模糊度各分量之间的相关性;最后将自适应遗传算法应用在整周模糊度的解算过程中,搜索整周模糊度的最优解。仿真计算结果表明,与LAMBDA算法和简单遗传算法相比,自适应遗传算法能够快速地求解整周模糊度,也具有较好的可靠性和鲁棒性。

关键词：全球定位系统载波相位整周模糊度白化滤波降相关自适应遗传算法