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成像激光雷达与摄像机外部位置关系的标定

光学精密工程 2011年第4期19卷 938-943页

作者：胡峰胡春生王省书焦宏伟国防科技大学光电科学与工程学院湖南长沙410073

为了确定成像激光雷达与摄像机两种不同传感器的相互位置参数,建立两者的一一映射关系,在现有激光雷达与摄像机外部参数标定方法的基础上,通过引入奇异值分解技术,对现有标定算法进行了改进。首先,介绍了改进标定算法的基本原理,采用奇... 详细信息

为了确定成像激光雷达与摄像机两种不同传感器的相互位置参数,建立两者的一一映射关系,在现有激光雷达与摄像机外部参数标定方法的基础上,通过引入奇异值分解技术,对现有标定算法进行了改进。首先,介绍了改进标定算法的基本原理,采用奇异值分解方法求解超定方程组,得到成像激光雷达坐标系与摄像机坐标系之间的投影变换矩阵。为了降低噪声影响,使用非线性优化算法优化初值。然后,利用自制的立体标定靶进行了标定实验,并使用已标定出的结果对成像激光雷达图像和摄像机图像进行了融合实验来验证提出的标定算法。实验结果表明,该算法平均标定精度达到13.33μm,标准差为7.49μm,比原始算法提高了1倍,基本满足图像融合对标定精度的一般要求。

关键词：成像激光雷达摄像机外部参数标定图像融合

Nitrate Leaching in an Irrigated Wheat-Maize Rotation Field in the North China Plain

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Pedosphere 2005年第2期15卷 196-203页

作者： ZHANGYu-Ming huchun-sheng ZHANGJia-Bao CHENDe-Li LIXiao-Xin InstituteofGeneticandDevelopmentalBiology ChineseAcademyofSciencesShijiazhuang050021（China） InstituteofSoilScience ChineseAcademyofSciencesNanjing210008（China） DepartmentofResourceManagementandHorticulture InstituteofLandandFoodResourcetheUniversityofMelbourneParkville3052Victoria（Australia）

Soil water deep drainage and nitrate (NO-3) leaching losses below the root zone were investigated in a 1 ha wheat-maize rotation field under traditional agricultural management that local farmers generally follow in the North China Plain, using the soil water balance method and NO3-N concentration in suction samples. Water drainage, and NO3-N distribution and leaching losses exhibited pronounced spatial and temporal variability. Soil water deep drainage and NO3-N leaching loss mostly occurred during the sum…

关键词： deep drainage nitrate leaching soil water

激光散射理论在汽轮机蒸汽湿度及水滴直径测量中的应用

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动力工程 2006年第2期26卷 241-244页

作者：黄竹青杨继明孙春生黄宗升胡春生贾宏进国防科技大学光电学院长沙410073 长沙理工大学能源与动力工程学院长沙410076

蒸汽湿度的存在不但降低汽轮机组的运行效率,而且会引起严重的叶片水蚀,给汽轮机组的经济性和安全性带来很大的危害。根据激光散射理论和Mie散射理论,利用半导体激光器发射出三个不同波长的光能够在线测出汽轮机末级蒸汽湿度及水滴颗粒... 详细信息

蒸汽湿度的存在不但降低汽轮机组的运行效率,而且会引起严重的叶片水蚀,给汽轮机组的经济性和安全性带来很大的危害。根据激光散射理论和Mie散射理论,利用半导体激光器发射出三个不同波长的光能够在线测出汽轮机末级蒸汽湿度及水滴颗粒大小和分布,为监控和减少湿蒸汽对汽轮机的危害提供最直接的数据。

关键词：动力机械工程汽轮机激光散射蒸汽湿度经济性安全性

Effect of post rolling stress on phase transformation behavior of microalloyed dual phase steel

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Journal of Iron and Steel Research International 2024年第3期31卷 688-699页

作者： Wen-quan Sun sheng-yi Yong Tie-heng Yuan Ting-song Yang An-rui He Chao Liu Rui-chun Guo National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing 100083China

The slow phase transformation of microalloyed dual phase steel makes the nonuniform stress and temperature fields during the post rolling cooling process have a significant impact on the phase transformation *** the relatively slow phase transformation of DP780 steel within the microalloyed dual phase steel series,the influence of stress on the phase transformation behavior of DP780 steel was *** quantify the nonuniform thermal and stress conditions in the steel coil,a thermo-mechanical coupled finite element model of the hot-rolled strip cooling process was *** on the simulation data,DP780 steel was chosen as the research material,and Gleeble 3500 thermal simulation equipment was used for experimental *** thermal expansion curves were analyzed through regression to establish the dynamic model of DP780 steel phase transformation under ***,metallographic analysis was conducted to determine phase transformation type and grain size of DP780 *** results confirmed that the stress promotes the occurrence of semi-diffusion-type bainite ***,an appropriate level of stress facilitates the growth of bainitic grains,while the increased stress inhibits the growth of ferritic grains.

关键词： Microalloyed dual phase steel Stress Bainitic transformation Grain Finite element method

Targeting methyltransferase-like 5-mediated sphingomyelin metabolism:A novel therapeutic approach in gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第10期16卷 4060-4063页

作者： Jin-Juan Zhang Chang Yuan sheng-chun Dang Department of General Surgery The Affiliated Hospital of Jiangsu UniversityZhenjiang 212001Jiangsu ProvinceChina

Gastric cancer(GC)is a global health problem and a leading cause of cancerrelated deaths,with its mortality rate ranking third among all *** etiology and progression of GC are characterized by a complex interplay of genetic and epigenetic changes,which present challenges for its early diagnosis and effective *** the mechanisms underlying the occurrence and development of GC and identifying novel biomarkers for early detection and prognosis are crucial to improving patient *** editorial examines the role of methyltransferase-like 5(METTL5)in the progression of GC through sphingomyelin metabolism by considering an article published by Zhang et al in the World Journal of Gastrointestinal Oncology in 2024,which is entitled“METTL5 promotes GC progression via sphingomyelin metabolism”.These authors investigated the biological behavior of METTL5 in GC by examining its expression patterns,clinical relevance,functional effect,and potential mechanisms,as well as its response to *** editorial provides valuable insights into the role of METTL5 in the progression of GC and its potential as a therapeutic target.

关键词： Gastric cancer Methyltransferase-like 5 Sphingomyelin metabolism Biomarkers Chemotherapy response

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华北井灌区节水技术模式集成与实践

干旱地区农业研究 2007年第4期25卷 141-145,150页

作者：秦潮胡春胜山西省农业技术推广站山西太原030002 中国科学院遗传与发育生物学研究所农业资源研究中心河北石家庄050021

基于多年的节水农业试验实践,分析了粮田关键节水技术及其节水潜力,集成了7种粮田节水模式,其中以调亏灌溉、秸秆覆盖、少耕覆盖等农艺节水技术为主的综合节水模式的水分利用效率比对照模式提高12%-21.3%,适合华北井灌区一般经济条件的... 详细信息

基于多年的节水农业试验实践,分析了粮田关键节水技术及其节水潜力,集成了7种粮田节水模式,其中以调亏灌溉、秸秆覆盖、少耕覆盖等农艺节水技术为主的综合节水模式的水分利用效率比对照模式提高12%-21.3%,适合华北井灌区一般经济条件的区域推广。

关键词：节水农业节水灌溉井灌区华北

Ammonia Volatilization and Deriitrification Losses from an Irrigated Maize-Wheat Rotation Field in the North China Plain

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Pedosphere 2004年第4期14卷 533-540页

作者： ZHANGYu-Ming CHENDe-Li ZHANGJia-Bao R.EDIS huchun-sheng ZhuAn-Ning InstituteofGeneticsandDevelopmentalBiology ChineseAcademyofSciencesShijiazhuang050021（China） DepartmentofResourceManagementandHorticulture InstituteofLandandFoodResourcetheUniversityofMel-bourneParkville3052Victoria（Australia） InstituteofSoilScience ChineseAcademyofSciencesNanjing210008（China）

Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from denitrification and NH3 volatilization was assessed. The micrometeorological gradient diffusion method in conjunction with a Bowen Ratio system was utilized to measure actual NH3 fluxes over a large area, while the acetylene inhibition technique (intact soil cores) was employed for measurement of denitrification losses and N2O emissions. Ammonia volatilization loss was 26.62% of the applied fertilizer nitrogen (N) under maize, while 0.90% and 15.55% were lost from the wheat field at sowing and topdressing, respectively. The differences in NH3 volatilization between different measurement events may be due to differences between the fertilization methods, and to differences in climatic conditions such as soil *** losses in the fertilized plots were 0.67%-2.87% and 0.31%-0.49% of the applied fertilizer N under maize and wheat after subtracting those of the controls, respectively. Nitrous oxide emissions in the fertilized plots were approximately 0.08%-0.41% and 0.26%-0.34% of the applied fertilizer N over the maize and wheat seasons after subtracting those of the controls, correspondingly. The fertilizer N losses due to NH3 volatilization were markedly higher than those through denitrification and nitrous oxide emissions. These results indicated that NH3 volatilization was an important N transformation in the crop-soil system and was likely to be the major cause of low efficiencies with N fertilizer in the study area. Denitrification was not a very important pathway of N fertilizer loss, but did result in important evolution of the greenhouse gas N2O and the effect of N2O emitted from agricultural fields on environment should not be overlooked.

关键词： ammonia volatilization denitrification gaseous N loss N_2O emission

河流对0.8MaB.P.环境突变事件的地貌响应研究

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地理科学 2014年第5期34卷 614-620页

作者：胡春生周迎秋安徽师范大学国土资源与旅游学院安徽芜湖241000 安徽自然灾害过程与防控研究省级实验室安徽芜湖241000

以兰州盆地0.8 Ma B.P.阶地为例证,运用古地磁测年方法,通过收集相关文献,分析讨论了0.8 Ma B.P.阶地与0.8 Ma B.P.环境突变事件的联系。结果表明:①0.8 Ma B.P.环境突变事件主要表现在气候转型、构造运动等方面,具有群发性和全球性特点... 详细信息

以兰州盆地0.8 Ma B.P.阶地为例证,运用古地磁测年方法,通过收集相关文献,分析讨论了0.8 Ma B.P.阶地与0.8 Ma B.P.环境突变事件的联系。结果表明:①0.8 Ma B.P.环境突变事件主要表现在气候转型、构造运动等方面,具有群发性和全球性特点;②兰州盆地以及其他区域0.8 Ma B.P.阶地存在的证据,表明河流在0.8 Ma B.P.前后普遍发生过一次下切事件;③0.8 Ma B.P.阶地是河流对0.8 Ma B.P.环境突变事件的地貌响应,构造运动为提供了下切驱动力,而气候变化则控制了下切时间。

关键词：河流阶地 0.8MaB.P. 环境突变事件地貌响应兰州盆地

Mechanism and control of nonuniform phase transformation of microalloyed dual-phase steel during cooling process after hot rolling

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Journal of Iron and Steel Research International 2024年第2期31卷 428-441页

作者： Wen-quan Sun sheng-yi Yong Tie-heng Yuan Chao Liu San-bao Zhou Rui-chun Guo Meng-xia Tang National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing100083China Strip Production Plant Xichang Steel and Vanadium Corporation of Pangang GroupXichang615000SichuanChina

After cooling in the hot rolling process,the metallographic structure of microalloyed dual-phase steel is nonuniform along the rolling direction,while the thickness fluctuation of microalloyed dual-phase steel with a nonuniform metallographic structure will occur during cold *** mechanism of nonuniform phase transformation of microalloyed dual-phase steels was studied during the cooling process after hot rolling,and the nonuniform phase transformation of microalloyed dual-phase steel was regulated during the cooling process after hot rolling through process ***,the empirical equation of phase transformation temperature was measured by a dilatometer considering thermal ***,the phase field and temperature field of laminar cooling process were calculated to provide initial boundary conditions for the finite element *** that,the coupling finite element model of the temperature phase transformation of the strip steel in coiling transportation process was *** simulation results show that the different thermal contact conditions of the microalloyed dual-phase steel during coil transportation lead to uneven cooling of the coil,which leads to nonuniform transformation of the coil along the rolling *** addition,by prolonging the time interval from coiling to unloading,the phenomenon of nonuniform phase transformation of microalloyed dual-phase steel can be effectively *** simulation results are applied to industrial *** application results show that prolonging the time interval from coiling to unloading can effectively improve the nonuniform phase transformation of microalloyed dual-phase steel in the cooling process after hot rolling.

关键词： Microalloyed dual-phase steel Thickness fluctuation Cooling Heat conduction Nonuniform phase transition Finite element method