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砂田白兰瓜小行棚塑料 大棚双覆盖生产技术规程
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作者 张延河 赵连德 李金玉 《农业科技与信息》 2001年第7期12-12,共1页
关键词 白兰瓜 小行 塑料大棚 双覆盖促成栽培 品种选择 播种 园艺管理
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砂田小行棚塑料大棚双覆盖白兰瓜促成裁培技术
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作者 张延河 《甘肃科技》 1999年第5期16-16,共1页
关键词 白兰瓜 栽培技术 小行 砂田 塑料大棚 覆盖
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南京地铁小行车辆段大修、架修能力的研究 被引量:13
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作者 韦苏来 周鸣语 吴桂虎 《城市轨道交通研究》 北大核心 2012年第12期36-39,共4页
基于南京地铁已开通线路的列车年走行公里超过规定里程的现状,使车辆检修周期缩短,小行车辆段原设计检修规模已不能满足南京地铁1、2、10号线列车检修的需要。从理论与实际两方面的需求剖析了小行车辆段应扩建的规模,提出了小行车辆段... 基于南京地铁已开通线路的列车年走行公里超过规定里程的现状,使车辆检修周期缩短,小行车辆段原设计检修规模已不能满足南京地铁1、2、10号线列车检修的需要。从理论与实际两方面的需求剖析了小行车辆段应扩建的规模,提出了小行车辆段大修、架修扩能改造工程实施的建议,并分析了由此给新线车辆段设计带来的启示。 展开更多
关键词 南京地铁 小行车辆段 大修和架修 扩能改造
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南京地铁小行车辆段主要设计原则及要求 被引量:1
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作者 李勇 《铁道车辆》 2000年第B12期97-98,共2页
关键词 南京市 地铁工程 小行车辆段 车辆检修 设计要求
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旱砂田小行棚洋香瓜栽培技术
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作者 魏公河 高发 《农业科技与信息》 2002年第11期16-16,共1页
1茬口选择选择在5年左右未种瓜类作物的旱砂田,以防瓜类萎病的发生.
关键词 旱砂田 小行 洋香瓜 栽培技术
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小行基地电客车进入无电区的原因分析及对策
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作者 李大新 《交通世界》 2019年第8期145-146,共2页
在地铁车辆停车基地内的行车、施工组织工作中,电客车进入无电区域的事故时有发生,该事故对作业人员生命安全和地铁设备性能构成严重威胁。为了避免此类事故的发生,从南京地铁一号线小行基地作业特点、调度员业务素质、规章制度、现场... 在地铁车辆停车基地内的行车、施工组织工作中,电客车进入无电区域的事故时有发生,该事故对作业人员生命安全和地铁设备性能构成严重威胁。为了避免此类事故的发生,从南京地铁一号线小行基地作业特点、调度员业务素质、规章制度、现场管理等方面入手,分析电客车进入无电区的原因,进而提出加强人员培训、完善规章制度、建立安全卡控、建立互控防护等措施,以防止小行基地内电客车进入无电区事故的发生。 展开更多
关键词 调度员 电客车 小行基地 无电区
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对金斯定则的几点认识 被引量:1
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作者 高崇伊 《天文学报》 CSCD 北大核心 2002年第4期366-374,共9页
用物理学基本定律可导出金斯经验定则,它似应称为金斯定则.该定则的速度、高度或能量等表述完全等效,可随意选用.用能量观点更容易解释此定则.满足金斯定则只是给定的粒子成为具有稠密大气的行星或卫星的主要大气成分的必要条件.该定则... 用物理学基本定律可导出金斯经验定则,它似应称为金斯定则.该定则的速度、高度或能量等表述完全等效,可随意选用.用能量观点更容易解释此定则.满足金斯定则只是给定的粒子成为具有稠密大气的行星或卫星的主要大气成分的必要条件.该定则的适用范围可用方程或其图像表示,也能用诺模图确定;它适用于太阳系内的行星、卫星、小行星、流星体和像柯伊伯带天体与半人马族星这样的外太阳系天体.此定则现在仍有普遍的现实意义. 展开更多
关键词 金斯定则 卫星 柯伊伯带 小行 行星大气 行星物理学
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三七精密播种机漏播重播检测系统设计与试验 被引量:11
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作者 谯睿 杨文彩 +3 位作者 韩文霆 郎冲冲 阚成龙 张冰 《传感技术学报》 CAS CSCD 北大核心 2019年第7期1115-1122,共8页
针对小行株距三七精密播种存在的重播漏播问题,设计了一套基于双层对射式激光传感器的五管集排式重播漏播检测系统。该检测系统以加法电路作为落种信号检测电路,利用窝眼滚筒端面圆形阵列的磁铁片结构将排种信号转换为霍尔脉冲信号,通过... 针对小行株距三七精密播种存在的重播漏播问题,设计了一套基于双层对射式激光传感器的五管集排式重播漏播检测系统。该检测系统以加法电路作为落种信号检测电路,利用窝眼滚筒端面圆形阵列的磁铁片结构将排种信号转换为霍尔脉冲信号,通过STC89C58单片机内部程序算法把霍尔脉冲信号转换为实时株距值,并与设定理论株距值相对比,建立起三七小行株距作物的重播漏播检测方法。试验表明,该检测方法能满足播种机在不同工况下的播种检测需求,对单粒漏播重播检测的准确率达99.967%,对种子上下紧密跟随的重播现象的检测准确率在93.07%~94.09%。本文设计的检测系统对三七这种小行株距作物的单粒漏播以及种子上下紧密跟随的双粒重播检测功能上有着特有的优势。 展开更多
关键词 漏播重播检测 加法电路 圆形阵列 霍尔脉冲信号 株距值 小行株距 种子上下紧密跟随
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Effects of 5-hydroxytryptophan on morphine-induced sensitization in mice 被引量:1
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作者 李俊旭 陈素清 +1 位作者 邓艳萍 梁建辉 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第1期1-5,共5页
To investigate the involvement of central serotonergic system in behavioral sensitization to morphine in mice. Male Kunming mice were treated (i.p.) with saline or morphine 10 mg/kg twice daily for 3 d and then drug... To investigate the involvement of central serotonergic system in behavioral sensitization to morphine in mice. Male Kunming mice were treated (i.p.) with saline or morphine 10 mg/kg twice daily for 3 d and then drug manipulation was suspended for 5 d. On day 9, a challenge dose of morphine (10 mg/kg) was given and the locomotor activity was measured for 60 rain to confkrm the establishment of behavioral sensitization in mice. Moreover, 5-hydroxytryptophan (5-HTP), a precursor of serotonin, at the doses of 20-80 mg/kg was given i.p. in combination with daily morphine treatment (induction), during the morphine treatment suspension (transfer) or prior to the challenge dose of morphine (expression) and locomotor activity was measured on day 9 after the challenge dose of morphine. Twice daily of morphine injection induced robust behavioral sensitization in mice as evidenced by significantly higher locomotion on day 9 for multiple treatment with morphine than saline in mice. 5-HTP treatment selec- tively and dose-dependently blocked the induction, but not the transfer nor the expression of morphine induced behavioral sensitization. This study provides clear evidence that up-regulation of central serotonergic system may suppress the induction of morphine sensitization in mice. 展开更多
关键词 5-HYDROXYTRYPTOPHAN MORPHINE Behavioral sensitization MICE
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Analysis on Marginal Superiority and Yield of Different Wheat Varieties in Wheat-cotton Intercropping System
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作者 王树林 祁虹 +4 位作者 王燕 张谦 冯国艺 林永增 梁青龙 《Agricultural Science & Technology》 CAS 2016年第5期1077-1079,共3页
In wheat-cotton intercropping system,the spike number per unit area,grains per spike,thousand-grain weight and yield of side line and inner line were investigated in six wheat varieties to study the marginal superiori... In wheat-cotton intercropping system,the spike number per unit area,grains per spike,thousand-grain weight and yield of side line and inner line were investigated in six wheat varieties to study the marginal superiority and select suitable wheat varieties intercropped with cotton.The results showed that Xingmai No.4had obvious marginal superiority with the yield of 6 919.0 kg/hm2,so it was the suitable variety for wheat-cotton intercropping system. 展开更多
关键词 Wheat-cotton intercropping Wheat variety Marginal superiority
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Effects of Sowing Rate on Marginal Superiority and Yield of Wheat in Wheat-cotton Intercropping System
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作者 王树林 祁虹 +4 位作者 王燕 张谦 冯国艺 林永增 梁青龙 《Agricultural Science & Technology》 CAS 2015年第12期2649-2652,共4页
In the wheat-cotton intercropping system, total 6 sowing rates (187.5, 225.0, 262.5, 300.0, 337.5 and 375.0 kg/hm2) were arranged, and the effects of sowing rate on marginal superiority and yield of wheat were inves... In the wheat-cotton intercropping system, total 6 sowing rates (187.5, 225.0, 262.5, 300.0, 337.5 and 375.0 kg/hm2) were arranged, and the effects of sowing rate on marginal superiority and yield of wheat were investigated. The re- sults showed that the effect of sowing rate on inner-line wheat was greater than that on side-line wheat; with the increased sowing rate, the marginal superiority of panicle number was reduced in overall, and the difference in panicle number be- tween inner and side lines was decreased from 9.0×10^5/hm2 (sowing rate of 187.5 kg/hm2) to 7.8×10^5/hm2 (sowing rate of 375.0 kg/hm2); the marginal superiority of grains per spike was increased first and then reduced, and the largest difference in grains per spike between the inner and side lines reached 4.6 under the sowing rate of 300.0 kg/hm2; the marginal superiority of 1 000-grain weight and yield was gradually increased, and the largest difference in 1 000-grain weight between the inner and side lines reached 3.9 g under the sowing rate of 337.5 kg/hm2, and in yield reached 3 136.5 kg/hm2under the sowing rate of 375.0 kg/hm2. The effects of sowing rate on the three yield factors of intercropped wheat ranked as panicle number 〉 grains per spike 〉 1 000-grain weight. The appropriate sowing rate of wheat was 225.0-262.0 kg/hm2 in the wheat-cotton intercropping system. 展开更多
关键词 Wheat-cotton intercropping WHEAT Sowing rate Marginal superiority YIELD
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上了路我们就是一家
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作者 小行马 《商业时代》 北大核心 2005年第7期18-18,共1页
印尼海啸,吞噬了一个叫做巴厘岛的地方,同时,也在劫后余生的人们之间衍生出一个纯度极高的名词,叫做依靠.就在两年前,美国911,几乎所有的幸存者都在幸免于难的同时,发现自己的人生观竟然也发生了翻天覆地的改变不再有莫名的嫉妒和永无... 印尼海啸,吞噬了一个叫做巴厘岛的地方,同时,也在劫后余生的人们之间衍生出一个纯度极高的名词,叫做依靠.就在两年前,美国911,几乎所有的幸存者都在幸免于难的同时,发现自己的人生观竟然也发生了翻天覆地的改变不再有莫名的嫉妒和永无休止的欲望,剩的只是感怀生命的释然和宽容. 展开更多
关键词 《上了路我们就是一家》 中国 当代 随笔 小行
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遥测地球未来
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作者 刘明 李之 《科技潮》 1994年第3期50-52,共3页
在宇宙中诞生的任何物质都躲不过演化和死亡的命运,地球也不例外。地球诞生至今已46亿年,这大约是其生涯的一半。以往地球自己不断整理环境,孕育生命并供养它们。往后剩下的50亿年,地球又将如何?现代科学不仅知道它的过去,也逐渐能预知... 在宇宙中诞生的任何物质都躲不过演化和死亡的命运,地球也不例外。地球诞生至今已46亿年,这大约是其生涯的一半。以往地球自己不断整理环境,孕育生命并供养它们。往后剩下的50亿年,地球又将如何?现代科学不仅知道它的过去,也逐渐能预知它的未来。我们遥测地球的未来,或许可从万物之母地球的一生中找到人类应走的道路。 100年后。 展开更多
关键词 地球 全球变暖 小行 碰撞 磁场 冰期
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Car-following model featured with factors reflecting emergency evacuation situation
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作者 胡红 魏恒 +1 位作者 刘小明 杨孝宽 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期216-221,共6页
A new emergency evacuation car-following model (EECM) is proposed. The model aims to capture the main characteristics of traffic flow and driver behavior under an emergency evacuation, and it is developed on the bas... A new emergency evacuation car-following model (EECM) is proposed. The model aims to capture the main characteristics of traffic flow and driver behavior under an emergency evacuation, and it is developed on the basis of minimum safety distances with parts of the drivers' abnormal behavior in a panic emergency situation. A thorough questionnaire survey is undertaken among drivers of different ages. Based on the results from the survey, a safety-distance car-following model is formulated by taking into account two new parameters: a differential distributing coefficient and a driver' s experiential decision coefficient, which are used to reflect variations of driving behaviors under an emergency evacuation situation when compared with regular conditions. The formulation and derivation of the new model, as well as its properties and applicability are discussed. A case study is presented to compare the car-following trajectories using observed data under regular peak-hour traffic conditions and theoretical EECM results. The results indicate the consistency of the analysis of assumptions on the EECM and observations. 展开更多
关键词 emergency evacuation CAR-FOLLOWING minimum safety distance driving behavior
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Nonlinear Auto-Companding Method for Behavioral Modeling of Switched-Current Circuits
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作者 王伟 曾璇 +2 位作者 陶俊 苏仰峰 唐璞山 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第12期1254-1261,共8页
A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distri... A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distribution obtained through approximating the input output function of the SI circuit by conventional wavelet collocation method.In practical applications,the proposed method is a general purpose approach,by which both the small signal effect and the large signal effect are modeled in a unified formulation to ease the process of modeling and simulation.Compared with the published modeling approaches,the proposed nonlinear auto companding method works more efficiently not only in controlling the error distribution but also in reducing the modeling errors.To demonstrate the promising features of the proposed method,several SI circuits are employed as examples to be modeled and simulated. 展开更多
关键词 wavelet collocation method behavioral modeling switched current circuits nonlinear auto companding
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Study on Epidemic Characteristics and Its Causes of Wheat Stripe Rust in Nanchong City 被引量:1
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作者 彭昌家 丁攀 +7 位作者 白体坤 冯礼斌 陈如胜 王婉秋 尹怀中 龙维国 肖立 文旭 《Agricultural Science & Technology》 CAS 2015年第2期292-297,共6页
On basis of the research result of stripe rust for 16 years since 1999,the epidemic characteristics and trend of stripe rust in the city were determined.Namely,the earlier the initial stage appeared,the heavier the di... On basis of the research result of stripe rust for 16 years since 1999,the epidemic characteristics and trend of stripe rust in the city were determined.Namely,the earlier the initial stage appeared,the heavier the disease would be.Furthermore,stripe rust has two introduction infection peaks,of which the first peak plays a key role.In farmlands,there are one to three epidemic peaks,and the infection area of the first peak plays the key role on the epidemic area of that year.In addition,the accumulated areas of late January was in significantly positive correlation with annually total area,with a correlation coefficient of 0.769 2.In recent 16 years,the frequency of severe stripe rust was as high as 81.25% which was 50% higher than that before 1995.The slight stripe rust became just in 2013,with a frequency of 6.3%,which indicated that the city has become a region hit by severe stripe rust.The internal reason is the reduction or loss of wheat variety's resistance to tripe rust for a new physiological race of rust is becoming pathogenic stronger and be the major race.Big fluctuation of temperatures in warm winter and spring,foggy and dew days slants much would be the external reason. 展开更多
关键词 WHEAT Stripe rust Occurrence characteristics Epidemic rule WARNING Improvement
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Design of MGA trajectories for main belt asteroid 被引量:2
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作者 崔祜涛 乔栋 +1 位作者 崔平远 栾恩杰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第4期443-446,共4页
Asteroid exploration is one of the most sophisticated missions currently being investigated. Gravity-assist trajectories have proven valuable in interplanetary missions such as the Pioneer, Voyager and Galileo. In thi... Asteroid exploration is one of the most sophisticated missions currently being investigated. Gravity-assist trajectories have proven valuable in interplanetary missions such as the Pioneer, Voyager and Galileo. In this paper, we design interplanetary trajectory for main belt asteroid exploration mission with the Mars gravity-assist (MGA) using “pork chop” plots and patched-conic theory and give some initial valuable trajectory parameters on main belt asteroid exploration mission with MGA. 展开更多
关键词 Design trajectory Gravity assist trajectory Rendezvous with asteroid
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Ivar asteroid rendezvous mission system scenario and trajectory design 被引量:2
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作者 崔平远 李立涛 +3 位作者 崔祜涛 栾恩杰 吴伟仁 田玉龙 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第3期338-342,共5页
The asteroid exploration opportunities are searched and calculated with launch dates in 2006 to2010, and with asteroid Ivar 1627 as the target, the spacecraft and its subsystems are designed and analyzed,and the trans... The asteroid exploration opportunities are searched and calculated with launch dates in 2006 to2010, and with asteroid Ivar 1627 as the target, the spacecraft and its subsystems are designed and analyzed,and the transfer trajectory is designed using △VEGA technology for the asteroid rendezvous. The design resultssatisfied the energy requirements for small explorers. 展开更多
关键词 trajectory design RENDEZVOUS spacecraft system design asteroid exploration
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Autonomous determination of orbit for probe around asteroids using unscented Kalman filter 被引量:1
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作者 崔平远 崔祜涛 +1 位作者 黄翔宇 栾恩杰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第3期229-234,共6页
The observed images of the asteroid and the asteroid reference images are used to obtain the probe-to-asteroid direction and the location of the limb features of the asteroid in the inertial coordinate. These informa-... The observed images of the asteroid and the asteroid reference images are used to obtain the probe-to-asteroid direction and the location of the limb features of the asteroid in the inertial coordinate. These informa-tion in combination with the shape model of the asteroid and attitude information of the probe are utilized to ob-tain the position of the probe. The position information is then input to the UKF which determines the real-timeorbit of the probe. Finally, the autonomous orbit determination algorithm is validated using digital simulation.The determination of orbit using UKF is compared with that using extended Kalman filter (EKF), and the resultshows that UKF is superior to EKF. 展开更多
关键词 unscented Kalman filter extended Kalman filter autonomous determination of orbit probe around asteroids
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Biomechanical behavior study of dog‘s small intestines 被引量:3
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作者 陈柏 周银生 《Journal of Zhejiang University Science》 CSCD 2002年第5期549-552,共4页
The biomechanical behavior of dog's duodenum and jejunum were studied and a formulation of the stress strain relation is presented in this paper. The results obtained indicated that the exponential coefficient α... The biomechanical behavior of dog's duodenum and jejunum were studied and a formulation of the stress strain relation is presented in this paper. The results obtained indicated that the exponential coefficient α and the incremental duodenum of the elastic modulus are both larger than those of the jejunum. It means that the duodenum is more deformable than the jejunum. The experimental results of this work provide basal data for kinematics study of a robotic endoscope. 展开更多
关键词 BIOMECHANICS INTESTINES Biomechanical model
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