期刊文献+
共找到42篇文章
< 1 2 3 >
每页显示 20 50 100
基于改进变分模态分解算法的海洋绝对重力数据滤波处理
1
作者 乔中坤 袁鹏 +4 位作者 张宗宇 李林玲 张家俊 吴彬 林强 《地质论评》 CAS CSCD 北大核心 2023年第S01期385-388,共4页
原子重力仪具有采样率高、精度高及长期稳定性好等优点,适用于远洋深海高精度绝对重力测量工作。受恶劣海况影响,原子重力仪测量的绝对重力数据中存在大量非平稳、非线性的噪声信号,影响重力测量的精度,进而影响地质构造解释的准确性。... 原子重力仪具有采样率高、精度高及长期稳定性好等优点,适用于远洋深海高精度绝对重力测量工作。受恶劣海况影响,原子重力仪测量的绝对重力数据中存在大量非平稳、非线性的噪声信号,影响重力测量的精度,进而影响地质构造解释的准确性。为了消除重力测量数据中的噪声,本文分析了创新性地引入改进变分模态分解(improved variatio nal modal decomposition,IVMD)算法进行滤波处理。 展开更多
关键词 海洋绝对重力测量 原子重力仪 改进变分模态分解算法 数据滤波处理
下载PDF
美国山核桃在云南的引种研究进展及发展前景 被引量:25
2
作者 习学良 XI +12 位作者 XUE LIANG 范志远 FAN ZHI yuan 董润泉 DONG RUN QUAN 张雨 ZHANG YU 《江西林业科技》 2001年第6期39-41,共3页
总结了云南53a来对美国山核桃引种、选种、生物学特性、生态适应性、苗木繁殖、丰产栽培、虫害防治的研究进展和示范推广情况。认为美国山核桃市场潜力大,在云南栽培效益高、适栽区域广、符合该省经济林树种结构调整需要,将来定会得到... 总结了云南53a来对美国山核桃引种、选种、生物学特性、生态适应性、苗木繁殖、丰产栽培、虫害防治的研究进展和示范推广情况。认为美国山核桃市场潜力大,在云南栽培效益高、适栽区域广、符合该省经济林树种结构调整需要,将来定会得到大力推广发展。 展开更多
关键词 美国山核桃 云南 引种 研究进展 发展前景
下载PDF
周口店野外地质教学实习中环境地质教学之我见 被引量:2
3
作者 贾建称 王根厚 +3 位作者 QIN yuan GAO Chun-guang 《中国地质教育》 2005年第1期74-76,共3页
素有“龙的故乡”美称的北京周口店地区环境污染严重、地质灾害频发, 本文在剖析其形成原因基础上提出在该区从事野外地质教学过程中不仅要注重学生基本地质知识、方法和技能的培养, 而且要对学生开展经常性的环境保护法律法规教育, 引... 素有“龙的故乡”美称的北京周口店地区环境污染严重、地质灾害频发, 本文在剖析其形成原因基础上提出在该区从事野外地质教学过程中不仅要注重学生基本地质知识、方法和技能的培养, 而且要对学生开展经常性的环境保护法律法规教育, 引导和帮助学生树立正确的环保意识。 展开更多
关键词 周口店 野外地质教学实习 环境地质
下载PDF
从连续到离散 关于2018威尼斯建筑双年展中国馆“云市”的建造实验 被引量:5
4
作者 袁烽 张立名 陈哲文 《时代建筑》 2018年第5期76-83,共8页
文章梳理了机器人空间打印工艺的前期实验室研究脉络,通过对2018年威尼斯建筑双年展中国馆室外展亭"云市"进行"实验室研究-数字设计-数字建造"的全流程详细介绍,从建造方式和材料两方面详细探究了机器人数字建造为... 文章梳理了机器人空间打印工艺的前期实验室研究脉络,通过对2018年威尼斯建筑双年展中国馆室外展亭"云市"进行"实验室研究-数字设计-数字建造"的全流程详细介绍,从建造方式和材料两方面详细探究了机器人数字建造为未来乡村建造带来的新的可能性。 展开更多
关键词 乡村建造 机器人空间打印 离散化 实验室研究 结构性能优化
下载PDF
HPLC法测定中偏康合剂中黄芪甲苷的含量 被引量:6
5
作者 邓绍友 袁建平 +3 位作者 李玲瑞 杜瑶 李孟林 吕艳 《中国民族民间医药》 2019年第16期60-62,共3页
目的:建立高效液相色谱法(HPLC)测定中偏康合剂中黄芪甲苷含量的方法。方法:采用Agilent ZORBAX C18色谱柱(250 mm×4.6 mm,5μm);以乙腈:水(32∶68)为流动相;流速为1.0 mL/min;柱温30℃,ELSD参数:氮气流速为350 kpa。结果:黄芪甲... 目的:建立高效液相色谱法(HPLC)测定中偏康合剂中黄芪甲苷含量的方法。方法:采用Agilent ZORBAX C18色谱柱(250 mm×4.6 mm,5μm);以乙腈:水(32∶68)为流动相;流速为1.0 mL/min;柱温30℃,ELSD参数:氮气流速为350 kpa。结果:黄芪甲苷进样质量在2.177~13.062μg范围内与峰面积呈良好线性关系,r=0.9994,平均回收率为98.2%,RSD为0.95%。结论:该方法准确、快速、简便可靠,结果稳定,可用于中偏康合剂中黄芪甲苷的含量测定。 展开更多
关键词 中偏康合剂 黄芪甲苷 HPLC
下载PDF
A New Compound from Chaenomeles sinensis (Thouin) Koehne 被引量:4
6
作者 Hui yuan +3 位作者 GAO Masanori KUROYANAGI 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第3期274-275,共2页
A new dihydrochromone derivative, named chaenomone, was isolated from the twigs of Chaenomeles sinensis (Thouin) Koehne. The structure was determined by spectroscopic methods.
关键词 木瓜 植物药 抗癌活性 有效成分 结构 核磁共振 木瓜酮
下载PDF
Spatial distribution of near-fault ground motion 被引量:2
7
作者 LIU Qi-fang(刘启方) +3 位作者 yuan Yi-fan(袁一凡) JIN Xing(金星) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第2期200-210,共11页
Near-fault strong ground motion of strike-slip and dip-slip of vertical and inclined rectangular fault in half-space and layered half-space is analyzed by dislocation source model. The Fourier spectra ratio of ground ... Near-fault strong ground motion of strike-slip and dip-slip of vertical and inclined rectangular fault in half-space and layered half-space is analyzed by dislocation source model. The Fourier spectra ratio of ground motion is adopted to study the characteristics of near-fault ground motion. For both slip models, near-fault strong ground motion with high amplitude is located in a narrow belt area along the projection of the fault on the ground and mainly controlled by the sub-faults nearby. Directivity of strike-slip fault is more dominant in long period for components perpendicular to the fault, and more dominant in long period for components parallel to the fault for dip-slip fault. The deeper the location of the source is, the more slowly the amplitude of ground motion attenuates.There is obvious hanging wall effect in ground motion of inclined fault, and the spatial distribution of ground motion is asymmetric which coincides with observational data. Finally, a fitting function of spatial distribution for near-fault ground motion is proposed and compared with near source factors of the 1997 Uniform Building Code of USA. 展开更多
关键词 NEAR-FAULT STRONG ground motion DISLOCATION model directivity NEAR source factor
下载PDF
双面对切进口结构的湿法烟气脱硫喷淋塔内流场的数值模拟和实验研究 被引量:4
8
作者 卜奔 乔昭毓 +2 位作者 刘付永 原水东 董川 《科学技术与工程》 北大核心 2018年第16期323-328,共6页
烟气脱硫喷淋塔一般直径大高度低,处理的烟气量很大,气体进入塔内的几何结构一定程度上影响着塔内流场的分布,从而对SO2的有效吸收及运行性能产生至关重要的影响。常规情况下,烟气从单侧进口以自由射流方式进入喷淋塔,在进口处容易形成... 烟气脱硫喷淋塔一般直径大高度低,处理的烟气量很大,气体进入塔内的几何结构一定程度上影响着塔内流场的分布,从而对SO2的有效吸收及运行性能产生至关重要的影响。常规情况下,烟气从单侧进口以自由射流方式进入喷淋塔,在进口处容易形成回流区、死滞区、涡流区。湿法烟气脱硫系统中的喷淋塔进口结构设计为双面对切进口。通过数值模拟和实验测试相结合的方法,研究了双面对切进口对塔内流场分布的影响。结果表明,采用双面对切进口结构,可以使喷淋塔得到近似于活塞流的均匀流场,从而使烟气均匀一致地通过脱硫喷淋塔,提高了脱硫效率。 展开更多
关键词 烟气脱硫喷淋塔 双面对切进口 塔内流场 数值模拟 实验测试
下载PDF
上海市社区全科团队成员工作绩效影响因素研究 被引量:3
9
作者 魏媛 魏新萍 《中国全科医学》 CAS 北大核心 2019年第S02期16-19,共4页
目的研究上海社区全科团队成员工作绩效影响因素,以提出有效的激励措施。方法2018年12月—2019年1月采用便利抽样法选择上海市社区卫生服务中心全科团队成员为研究对象,采用个人基本信息调查表和工作绩效量表对其进行调查。采用Pearson... 目的研究上海社区全科团队成员工作绩效影响因素,以提出有效的激励措施。方法2018年12月—2019年1月采用便利抽样法选择上海市社区卫生服务中心全科团队成员为研究对象,采用个人基本信息调查表和工作绩效量表对其进行调查。采用Pearson相关性分析探讨调查对象的基本情况与其工作绩效的相关性;采用多元线性回归分析探讨工作绩效的影响因素。结果工作绩效量表的平均得分的中位数为5.00(4.63,5.38)分。量表各维度的平均得分如下:任务绩效平均得分的中位数为5.00(4.67,5.33)分,关系绩效平均得分的中位数为5.00(5.00,6.00)分,学习绩效平均得分的中位数为5.00(4.00,5.00)分。不同学历的全科团队成员关系绩效、学习绩效、工作绩效得分比较,差异均有统计学意义(P<0.05)。不同职称的任务绩效、关系绩效、工作绩效得分比较,差异均有统计学意义(P<0.05)。不同工种的全科团队成员任务绩效、关系绩效得分比较,差异均有统计学意义(P<0.05)。不同工作岗位的全科团队成员关系绩效得分比较,差异有统计学意义(P<0.05)。多元线性回归分析结果显示,本科学历的全科团队成员的工作绩效得分低于大专学历的全科团队成员,中级职称的全科团队成员的工作绩效得分低于初级职称的全科团队成员(P<0.05)。结论学历和职称是全科团队成员工作绩效的独立影响因素,本科学历、中级职称的全科团队成员的工作绩效相对较低。社区卫生管理部门应改善基层人才的培训进修机会、收入待遇等职业环境。 展开更多
关键词 社区卫生服务 全科团队成员 工作绩效 影响因素
下载PDF
Coastal geomorphic evolution at the Denglou Cape, the Leizhou Peninsula 被引量:1
10
作者 Wang Lirong(王丽荣) +7 位作者 Zhao Huanting(赵焕庭) Song Chaojing(宋朝景) yuan Jiayi(袁家义) Yu Hongbing(于红兵) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2002年第4期597-611,共15页
关键词 Tropical COASTAL geomorphology CORAL reef mangrove tidal flat barrier-lagoon system cape Leizhou PENINSULA
下载PDF
Computer Simulation of Gd(III) Speciation in Human Interstitial Fluid 被引量:1
11
作者 Jin Ping +4 位作者 WANG Hai yuan ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第2期217-218,共2页
The speciation and distribution of Gd(III) in human interstitial fluid was studied by computer simulation. Meantime artificial neural network was applied to the estimation of log ?values of complexes. The results show... The speciation and distribution of Gd(III) in human interstitial fluid was studied by computer simulation. Meantime artificial neural network was applied to the estimation of log ?values of complexes. The results show that the precipitate species, GdPO4 and Gd2(CO3)3, are the predominant species. Among soluble species, the free Gd(III), [Gd(HSA)] , [Gd(Ox)] and then the ternary complexes of Gd(III) with citrate are main species and [Gd3(OH)4] becomes the predominant species at the Gd(III) total concentration of 2.2?0-2mol/L. 展开更多
关键词 计算机模拟 钆(Ⅲ) 表面物种形式 人体 细胞液 神经网络 稀土 生物效应
下载PDF
Medical Additive Manufacturing: From a Frontier Technology to the Research and Development of Products 被引量:1
12
作者 Guixing Qiu Wenjiang Ding +36 位作者 Wei Tian Ling Qin Yu Zhao Lianmeng Zhang Jian Lu Daijie Chen Guangyi yuan Chengtie Wu Bingheng Lu Ruxu Du Jimin Chen Mo Elbestawi Zhongwei Gu Dichen Li Wei Sun yuanjin Zhao Jie He Dadi Jin Bin Liu Kai Zhang Jianmo Li Kam WLeong Dewei Zhao Dingjun Hao Yingfang Ao Xuliang Deng Huilin Yang ShaoKeh Hsu Yingqi Chen Long Li Jianping Fan Guohui Nie Yun Chen Hui Zeng Wei Chen Yuxiao Lai 《Engineering》 SCIE EI 2020年第11期1217-1221,共5页
1.Research and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many ... 1.Research and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many other fields,making them an important basis in the field of three-dimensional(3D)printing.Problems and challenges related to material types,powder properties,formability,viscoelasticity,and so forth also share common features.For example,many metal materials are used in the field of aviation,while metals,polymers,and inorganic materials are used in the field of biomedicine.The most widely used materials in biomedicine are biocompatible.Various homogeneous and non-homogeneous composites are also available for 3D printing,and impose an additional challenge in additive manufacturing;the use of heterogeneous composites in 3D printing is particularly challenging. 展开更多
关键词 COMPOSITES PRINTING ADDITIVE
下载PDF
区域中小学德育活动课程化的实践探索 被引量:2
13
作者 袁弘 《大连教育学院学报》 2018年第1期64-65,共2页
落实德育为先、立德树人的育人目标,只有基层教育管理和业务指导部门在实践中不断创新、完善德育工作机制,引领广大中小学校的德育工作通过"课程化、校本化、特色化"的过程,建构起适合本地区域中小学生发展需要的德育活动课... 落实德育为先、立德树人的育人目标,只有基层教育管理和业务指导部门在实践中不断创新、完善德育工作机制,引领广大中小学校的德育工作通过"课程化、校本化、特色化"的过程,建构起适合本地区域中小学生发展需要的德育活动课程体系,才能够使立德树人落地生根。 展开更多
关键词 区域中小学 德育活动 德育活动课程化
下载PDF
中国为何没有乔布斯?
14
作者 Li yuan 何耀莹(译注) 《大学英语》 2011年第12期11-12,共2页
在过去两天中,成千上万中国人涌向人气极旺的新浪微博网站发帖,表达对乔布斯逝世的哀悼。他们也提出这样的问题:为何中国没有乔布斯?讨论的语气几乎全部是悲观的,甚至冷嘲热讽。
关键词 乔布斯 中国人 新浪 人气
下载PDF
A Novel Heat-resisting Surfactant for the Modification of Alumina Nanoparticles
15
作者 Yu Fen +4 位作者 CHANG yuan Bo LIN 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第1期104-107,共4页
An easy preparation of controlled alumina nanoparticles by the solution precipitate method has been carried out using dendrimer as surfactant. The effects of the amount and size of surfactant on morphological control ... An easy preparation of controlled alumina nanoparticles by the solution precipitate method has been carried out using dendrimer as surfactant. The effects of the amount and size of surfactant on morphological control of powder have also been discussed. 展开更多
关键词 氧化铝 纳米颗粒 表面活性剂 化学修饰 溶液沉淀法 制备
下载PDF
STATISTICAL PROPERTY OF THRESHOLD-CROSSING FOR ZERO-MEAN-VALUED, NARROW-BANDED GAUSSIAN PROCESSES
16
作者 HE Wu-zhou(贺五洲) +1 位作者 yuan Ming-shun(苑明顺) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第6期701-710,共10页
Based on a comprehensive discussion of the calculation method for the threshold- crossing statistics of zero mean valued, narrow banded Gaussian processes of various practical engineering problems, including the thres... Based on a comprehensive discussion of the calculation method for the threshold- crossing statistics of zero mean valued, narrow banded Gaussian processes of various practical engineering problems, including the threshold-crossing probability, average number of crossing events per unit time, mean threshold-crossing duration and amplitude, a new simple numerical procedure is proposed for the efficient evaluation of mean threshold-crossing duration. A new dimensionless parameter, called the threshold-crossing intensity, is defined as a measure of the threshold-crossing severity, which is equal to the ratio of the product of average number of crossing events per unit time and mean threshold-crossing duration and amplitude over the threshold. It is found, by the calculation results for various combinations of stochastic processes and different thresholds, that the threshold-crossing intensity, irrelevant of the threshold and spectral density of the process, is dependent only on the threshold-crossing probability. 展开更多
关键词 STOCHASTIC process threshold-crossing STATISTICAL PROPERTY
下载PDF
ARRHYTHMIA INDUCED BY NICOTINE ACTIVATING CARDIAC INTRINSIC NEURONS IN CANINE ATRIAL AND VENTRICULAR GANGLIAL PLEXUS
17
作者 yuan Bingxiang(袁秉祥) +5 位作者 Liu Shuqin(刘书勤) Li Ping(李萍) Li Xinhua(李新华) 《Academic Journal of Xi'an Jiaotong University》 2002年第2期155-158,共4页
Objective To study the arrhythmia induced by stimulation of nicotine-sensitive neurons in cardiac ganglial plexuses. Methods When nicotine (100 μg ) was injected into canine right atrial ganglial plexus (RAGP) and ga... Objective To study the arrhythmia induced by stimulation of nicotine-sensitive neurons in cardiac ganglial plexuses. Methods When nicotine (100 μg ) was injected into canine right atrial ganglial plexus (RAGP) and ganglial plexus between aorta and pulmonary artery (A-PGP) in 33 anesthetized open-chest dog, electrocardiogram, atrial force and ventricular intramyocardial pressures (IMP) were recorded. The responses were also recorded following administration of atropine or propranolol and after heart acute decentralization. Results Ventricular arrhythmia (VA) was induced by injections of nicotine into A-PGP, but not by injections of nicotine into RAGP in 13 dogs. Atrioventricilar (A-V) block was induced by nicotine activating RAGP in 10 dogs, but not by nicotine activating A-PGP. Propranolol could reduce the frequency of VA elicited by stimulating A-PGP, atropine could reduce the frequency of A-V block elicited by stimulating RAGP. After acute decentralization, VA was still induced by activation of A-PGP in 9 dogs, but A-V block elicited by stimulating RAGP was decreased. Conclusion VA is induced by stimulating N receptor in cardiac nicotine-sensitive efferent sympathetic neurons of ventricular ganglial plexus (A-PGP), and then modifying β receptor of ventricles. A-V block is elicited by stimulating N receptor in atrial ganglial plexus (RAGP), then modifying M receptor of A-V node not only via efferent parasympathetic neurons, but also via afferent pathway. 展开更多
关键词 NICOTINE ARRHYTHMIA ganglial plexuses efferent NEURONS AFFERENT NEURONS
下载PDF
THE CONSTRUCTION AND PRELIMINARY APPRAISEMENT OF HSV-2 gD GENE DNA VACCINE
18
作者 Wang Junyang(王军阳) +5 位作者 Fan Guixiang(范桂香) Sheng li(胜利) yuan Yukang(袁育康) 《Academic Journal of Xi'an Jiaotong University》 2002年第2期163-165,共3页
Objective To prevent infection from herpes simplex virus type 2(HSV-2),and make the foundation for the construction of multi-valent DNA vaccine. Methods The complete DNA sequence,which encoded the amino acid sequence ... Objective To prevent infection from herpes simplex virus type 2(HSV-2),and make the foundation for the construction of multi-valent DNA vaccine. Methods The complete DNA sequence,which encoded the amino acid sequence of the viral glycoprotein D(gD),was obtained from the HSV-2 genome by polymerase chain reaction(PCR).The fragment was inserted into the lower stream of Cytomegalovirus(CMV) promoter in the eukaryotic expression plasmid pcDNA3.1(+), then immunized mice by bilateral intramuscular injection into the rear legs with this recombinant plasmid and tested the specific antibodies against glycoprotein D by ELISA. Results Animal experiment have demonstrated that the recombinant plasmid(pcDNA-gD2)inoculated into mice could induce the production of specific antibodies against glycoprotein D. Conclusion The eukaryotic plasmid pcDNA-gD2 constructed by us could correctly express gD gene and induce the production of specific antibodies. 展开更多
关键词 HSV-2 GLYCOPROTEIN D DNA VACCINE PCR
下载PDF
A Real-time Face/Hand Tracking Method for Chinese Sign Language Recognition
19
作者 刘晋东 yuan +4 位作者 Kui Zou Wei Luo Bencheng 《High Technology Letters》 EI CAS 2002年第4期80-84,共5页
This paper introduces a new Chinese Sign Language recognition (CSLR) system and a method of real time tracking face and hand applied in the system. In the method, an improved agent algorithm is used to extract the reg... This paper introduces a new Chinese Sign Language recognition (CSLR) system and a method of real time tracking face and hand applied in the system. In the method, an improved agent algorithm is used to extract the region of face and hand and track them. Kalman filter is introduced to forecast the position and rectangle of search, and self adapting of target color is designed to counteract the effect of illumination. 展开更多
关键词 CSLR improved agent REAL-TIME tracking KALMAN FILTER
下载PDF
Constructions of highly nonlinear resilient plateaud functions
20
作者 张卫国 Chen yuan 《High Technology Letters》 EI CAS 2011年第2期220-222,共3页
关键词 非线性弹性 稳定 多输出 理想
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部