期刊文献+
共找到29篇文章
< 1 2 >
每页显示 20 50 100
谨防基金拉高套现后波段做空
1
作者 阮华 《股市动态分析》 2004年第43期49-49,共1页
周末新老蓝筹齐齐发力而带领大盘反弹,无疑是基金在其三季度组合披露前夕所下的一着棋。这着棋的神韵或者要旨,是声老蓝筹之东而击新蓝筹之西,前者是为后者服务的。而又由于其下在即将披露新持仓组合之际,而格外令人寻味。如不出意外的... 周末新老蓝筹齐齐发力而带领大盘反弹,无疑是基金在其三季度组合披露前夕所下的一着棋。这着棋的神韵或者要旨,是声老蓝筹之东而击新蓝筹之西,前者是为后者服务的。而又由于其下在即将披露新持仓组合之际,而格外令人寻味。如不出意外的话,我们将看到新的季度组合中大肆增仓新蓝筹,而老蓝筹因受宏观调控之累成为明日黄花。至于基金为何近期如此操作,并不需要多高的智商也能猜到。倒是在另一方面须提醒大家注意的:在进入三季度后至今, 展开更多
关键词 后波 宏观调控 系统风险 现实的可能性 调整趋势 中国股市 行情 调控影响 中集集团 最佳时段
下载PDF
浪后波纹
2
作者 刘长春 《棋艺(象棋)》 1995年第11期48-48,共1页
关键词 后波 先胜
下载PDF
低佛氏数水跃跃后最大波高的研究
3
作者 李强 郑国华 《石河子大学学报(自然科学版)》 CAS 2001年第2期148-150,共3页
对低佛氏数水跃消能水跃跃后最大波进行了理论分析和试验研究 ,研究表明 ,低佛氏数Fr =1. 0~ 1. 7情况下的水跃消能率低 ,跃后水面波动是造成下游河床和岸壁冲刷的主要原因。
关键词 水面 动量方程 低佛氏数水跃 水跃消能率 后波 水工建筑 最大
下载PDF
波形刃锥度立铣刀优化设计
4
作者 王建军 吴娜 周乐安 《机床与液压》 北大核心 2017年第8期9-14,共6页
基于Advant Edge仿真软件,利用二维正交切削数值模拟对2226-148合金锥度铣刀几何角度进行优化,获得最佳实际前角、法向前角、径向前角、刃口半径以及螺旋角等刀具制造参数。试验结果证明:基于切削过程数值模拟设计的后波刃锥度铣刀切削... 基于Advant Edge仿真软件,利用二维正交切削数值模拟对2226-148合金锥度铣刀几何角度进行优化,获得最佳实际前角、法向前角、径向前角、刃口半径以及螺旋角等刀具制造参数。试验结果证明:基于切削过程数值模拟设计的后波刃锥度铣刀切削性能优异,综合性能达到进口山高(SECO)同类刀具水平,刀具抗崩刃性能有明显改善,具备大批量推广运用的条件。 展开更多
关键词 锥度铣刀 后波 刀具参数 优化设计
下载PDF
1950—1980年间的波兰人口结构及主要演变过程
5
作者 库兹诺斯基 朱刚 刘瑛瑛 《人口与经济》 CSSCI 北大核心 1989年第1期58-60,共3页
一、人口增长与性比例 战后波兰人口呈增长趋势,1980年时,总人口中男性为17411000人;女性为18324000人。这一时期,波兰人口的性比例也由战后的失调逐步趋于平衡。
关键词 兰人 80年 演变过程 性比例 生育率 农村出生率 妇女生育 城市人 后波 家庭
下载PDF
波兰学者谈波兰近况
6
作者 王龙 《俄罗斯研究》 1996年第6期54-55,共2页
不久前,波兰科学院安托明·卡明斯基教授和加利可夫斯基教授在沪与华东师大国际问题研究所的研究人员、研究生等进行座谈。两位教授介绍了当前波兰的政治、经济、对外关系等情况,现将有关内容简介如下。 1989年是波兰各方面发生变... 不久前,波兰科学院安托明·卡明斯基教授和加利可夫斯基教授在沪与华东师大国际问题研究所的研究人员、研究生等进行座谈。两位教授介绍了当前波兰的政治、经济、对外关系等情况,现将有关内容简介如下。 1989年是波兰各方面发生变革的重要一年。有人将1989年的变革称为继一战、二战等之后波兰上层建筑在本世纪的第四次大变动。波兰的外部环境也发生很大变化,邻国由3个变为7个,苏联、捷克、东德都已不复存在。从1989年至今。 展开更多
关键词 兰学 加入欧盟 议会 后波 中欧国家 总统制 欧洲安全 对外关系 卡明斯 俄罗斯
下载PDF
洗衣机波轮不转的原因及排除
7
作者 杨锡林 《山东农机化》 1995年第8期23-23,共1页
本人有台金鱼牌洗衣机,使用多年后出现波轮不转的故障。开始检查时,发现三角皮带轮太松,使皮带打滑,紧固好皮带轮后,波轮能转动,但加水后波轮又不转。卸下减速器,发现减速齿轮严重磨损,
关键词 金鱼牌洗衣机 三角皮带轮 减速器 皮带打滑 后波 减速齿轮 紧固 严重磨损 锡林
下载PDF
波峰和波谷相遇后波会消失吗?
8
作者 何文明 《中学物理教学参考》 1999年第5期17-18,共2页
在一次高三摸底考试中,有一道关于波的选择题,颇引人深思.题目如图1,两个等幅对称的波峰和波图1谷在拉紧的绳上相向运动,下列选项中正确的是:A.波峰和波谷相遇碰撞后,都将沿反方向被弹回B.波峰和波谷相遇的瞬间,绳上波形... 在一次高三摸底考试中,有一道关于波的选择题,颇引人深思.题目如图1,两个等幅对称的波峰和波图1谷在拉紧的绳上相向运动,下列选项中正确的是:A.波峰和波谷相遇碰撞后,都将沿反方向被弹回B.波峰和波谷相遇的瞬间,绳上波形消失;相遇后,波峰和波谷仍将各自继... 展开更多
关键词 的叠加原理 后波 动方程 矢量和 最弱点 速度方向 合成法则 速度和加速度
原文传递
COMBINATION OF DISTRIBUTED KALMAN FILTER AND BP NEURAL NETWORK FOR ESG BIAS MODEL IDENTIFICATION 被引量:3
9
作者 张克志 田蔚风 钱峰 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第3期226-231,共6页
By combining the distributed Kalman filter (DKF) with the back propagation neural network (BPNN),a novel method is proposed to identify the bias of electrostatic suspended gyroscope (ESG). Firstly,the data sets ... By combining the distributed Kalman filter (DKF) with the back propagation neural network (BPNN),a novel method is proposed to identify the bias of electrostatic suspended gyroscope (ESG). Firstly,the data sets of multi-measurements of the same ESG in different noise environments are "mapped" into a sensor network,and DKF with embedded consensus filters is then used to preprocess the data sets. After transforming the preprocessed results into the trained input and the desired output of neural network,BPNN with the learning rate and the momentum term is further utilized to identify the ESG bias. As demonstrated in the experiment,the proposed approach is effective for the model identification of the ESG bias. 展开更多
关键词 model identification distributed Kalman filter(DKF) back propagation neural network(BPNN) electrostatic suspended gyroscope(ESG)
下载PDF
惊涛骇浪扑面来——读《大江千古事》等长江漂流报告文学
10
作者 李士文 《当代文坛》 1987年第5期42-44,共3页
前年和去年,我和亿万人一样,一颗心紧紧追随漂流长江的皮筏,从沱沱河到通珈峡,从通珈峡到上海。我们读新闻消息、短篇速写,看电视,惊叹过,激动过,感佩过,悲痛过,却仍不“过瘾”,想了解详情。戴善奎同志的报告文学给人以满足,我关心他的... 前年和去年,我和亿万人一样,一颗心紧紧追随漂流长江的皮筏,从沱沱河到通珈峡,从通珈峡到上海。我们读新闻消息、短篇速写,看电视,惊叹过,激动过,感佩过,悲痛过,却仍不“过瘾”,想了解详情。戴善奎同志的报告文学给人以满足,我关心他的作品象关心长江漂流一样。《壮士一去不复返》和《身后波澜亦轩然》(《现代作家》1985年12月号、1986年4月号) 展开更多
关键词 报告文学 骇浪 过长江 等长 探险 轩然 后波 沱沱河 新闻消息 生活真实
下载PDF
Therapeutic approaches for portal biliopathy: A systematic review 被引量:10
11
作者 Irene Franceschet Alberto Zanetto +2 位作者 Alberto Ferrarese Patrizia Burra Marco Senzolo 《World Journal of Gastroenterology》 SCIE CAS 2016年第45期9909-9920,共12页
Portal biliopathy(PB) is defined as the presence of biliary abnormalities in patients with non-cirrhotic/nonneoplastic extrahepatic portal vein obstruction(EHPVO) and portal cavernoma(PC). The pathogenesis of PB is du... Portal biliopathy(PB) is defined as the presence of biliary abnormalities in patients with non-cirrhotic/nonneoplastic extrahepatic portal vein obstruction(EHPVO) and portal cavernoma(PC). The pathogenesis of PB is due to ab extrinseco compression of bile ducts by PC and/or to ischemic damage secondary to an altered biliary vascularization in EHPVO and PC. Although asymptomatic biliary abnormalities can be frequently seen by magnetic resonance cholangiopancreatography in patients with PC(77%-100%), only a part of these(5%-38%) are symptomatic. Clinical presentation includes jaundice, cholangitis, cholecystitis, abdominal pain, and cholelithiasis. In this subset of patients is required a specific treatment. Different therapeutic approaches aimed to diminish portal hypertension and treat biliary strictures are available. In order to decompress PC, surgical porto-systemic shunt or transjugular intrahepatic porto-systemic shunt can be performed, and treatment on the biliary stenosis includes endoscopic(Endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy, balloon dilation, stone extraction, stent placement) and surgical(bilioenteric anastomosis, cholecystectomy) approaches. Definitive treatment of PB often requires multiple and combined interventions both on vascular and biliary system. Liver transplantation can be considered in patients with secondary biliary cirrhosis, recurrent cholangitis or unsuccessful control of portal hypertension. 展开更多
关键词 Portal biliopathy Portal cavernoma Magnetic resonance cholangiopancreatography Endoscopic retrograde cholangiopancreatography Porto-systemic shunt
下载PDF
EXACT ANALYSIS OF OS MODIFIED VERSIONS WITH NONCOHERENT INTEGRATION 被引量:2
12
作者 Mohamed B.El Mashade 《Journal of Electronics(China)》 2004年第4期265-277,共13页
This paper deals with the exact detection analysis of the Ordered-Statistic(OS) processor along with OS Greatest Of(OSGO) and OS Smallest Of(OSSO) modified versions, for M postdetection integrated pulses when the oper... This paper deals with the exact detection analysis of the Ordered-Statistic(OS) processor along with OS Greatest Of(OSGO) and OS Smallest Of(OSSO) modified versions, for M postdetection integrated pulses when the operating environment is nonhomogeneous. Analytical results are presented in multiple-target case as well as in regions of clutter power transitions. The primary and the secondary interfering targets are assumed to be fluctuating in accordance with the SWII target fluctuation model. As the number of noncoherently integrated pulses increases,lower threshold values and consequently better detection performances are obtained in both homogeneous and multiple target background models. However, the false alarm rate performance of OSSO-CFAR(Constant False Alarm Rate) scheme at clutter edges is worsen with increasing the postdetection integrated pulses. As predicted, the OSGO-CFAR detector accommodates the presence of spurious targets in the reference window, given that their number is within its allowable range in each local window, and controls the rate of false alarm when the contents of the reference cells have clutter boundaries. 展开更多
关键词 Adaptive radar detectors Ordered-Statistic(OS) modified versions Interfering targets Clutter boundaries Postdetection integration
下载PDF
Unanticipated Bond Failure over Supporting Band Beams in Grouted Post-Tensioned Slab Tendons with Little or No Initial Prestress
13
作者 Raymond Ian Gilbert 《Journal of Civil Engineering and Architecture》 2013年第11期1343-1352,共10页
After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall (in excess of 1.5 km2 in plan), doubts arose concerning the level of initial prestress and the stre... After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall (in excess of 1.5 km2 in plan), doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons. 展开更多
关键词 ANCHORAGE development length post-tensioned slabs stress development TENDONS unbonded construction.
下载PDF
Experimental Research on Erbium-doped Superfluorescent Fiber Source 被引量:2
14
作者 CHENSheng-ping LUKe-cheng LIYi-gang LIJia-fang ZHUJian-ping FENGMing LIJing 《Semiconductor Photonics and Technology》 CAS 2004年第2期122-126,共5页
The effects of the variations in fiber length,fiber mirror reflectance on efficiency and output power are experimentally investigated for erbium-doped double pass backward superfluorescent fiber sources (SFSs).The inf... The effects of the variations in fiber length,fiber mirror reflectance on efficiency and output power are experimentally investigated for erbium-doped double pass backward superfluorescent fiber sources (SFSs).The influence of fiber length on mean wavelength stability (MWS) has also been demonstrated.By incorporating a short section of un-pumped erbium-doped fiber (EDF) at the output port,the pump power dependent on MWS becomes independent of pumped EDF length.This is a novel phenomenon that hasn’t been reported up to now,and should be helpful to SFS fabrication and theory analysis.By using a fiber Michelson interferometer as spectrum slicing component,a multi-wavelength fiber source (MWFS) with ~20 channels (from 1 542 nm to 1 559 nm) is got.The MWFS has a channel spacing of ~0.8 nm which satisfies ITU-standard.The intensity fluctuation among channels is less than 0.5 dB,and the extinction ratio of all channels is above 14 dB.This kind of MWFS should be useful to wavelength division multiplexing systems. 展开更多
关键词 Superfluorescent fiber source Erbium-doped fiber Double pass backward configuration Mean wavelength stability Multi-wavelength fiber source
下载PDF
Hybrid ToA and IMU indoor localization system by various algorithms 被引量:4
15
作者 CHEN Xue-chen CHU Sheng +1 位作者 LI Fan CHU Guang 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第8期2281-2294,共14页
In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accele... In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accelerated and angular rotated speed of moving objects. Meanwhile, the ranges from the object to beacons, which are sensor nodes with known coordinates, are collected by time of arrival (ToA) approach. These messages are simultaneously collected and transmitted to the terminal. At the terminal, we set up the state transition models and observation models. According to them, several recursive Bayesian algorithms are applied to producing position estimations. As shown in the experiments, all of three algorithms do not require constant moving speed and perform better than standalone ToA system or standalone IMU system. And within them, two algorithms can be applied for the tracking on any path which is not restricted by the requirement that the trajectory between the positions at two consecutive time steps is a straight line. 展开更多
关键词 indoor localization time of arrival (ToA) inertial measurement unit (IMU) Bayesian filter extended Kalman filter MAP algorithm
下载PDF
Improved Sinusoid Analysis and Post-Processing in Parametric Audio Coding
16
作者 周宏 陈健 《Journal of Shanghai Jiaotong university(Science)》 EI 2003年第2期163-168,共6页
This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids... This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids. The sinusoid which contributes most to the reduction of overall NMR is chosen. Combined with our improved parametric psychoacoustic model and advanced peak riddling techniques, the number of sinusoids required can be greatly reduced and the coding efficiency can be greatly enhanced. A lightweight version is also given to reduce the amount of computation with only little sacrifice of performance. Secondly, we propose two enhancement techniques for sinusoid synthesis: bandwidth enhancement and line enhancement. With little overhead, the effective bandwidth can be extended one more octave; the timbre tends to sound much brighter, thicker and more beautiful. 展开更多
关键词 parametric audio coding SINUSOID POST-PROCESSING
下载PDF
Impact of Fiscal Policy on Economy After Accession to the Euro Area: The Case of Poland
17
作者 Piotr Kraj ewski 《Journal of Modern Accounting and Auditing》 2012年第5期733-739,共7页
The impact of Polish fiscal policy on economy after accession to the euro area is analyzed in the article. It was found that government spending financed by distortionary taxation affects output in a different way tha... The impact of Polish fiscal policy on economy after accession to the euro area is analyzed in the article. It was found that government spending financed by distortionary taxation affects output in a different way than in case of government spending financed by bonds. Poland's accession to the Economic and Monetary Union will reduce the possibility of increased government spending financed by bonds, which in light of the presented model will greatly reduce the possibility of stimulating the economy through fiscal policy. 展开更多
关键词 fiscal policy government spending real business cycle (RBC) EURO
下载PDF
Epigenetic changes in virus-associated human cancers 被引量:12
18
作者 HsinPaiLI YuWeiLEU YuSunCHANG 《Cell Research》 SCIE CAS CSCD 2005年第4期262-271,共10页
Epigenetics of human cancer becomes an area of emerging research direction due to a growing understanding ofspecific epigenetic pathways and rapid development of detection technologies. Aberrant promoter hypermethylat... Epigenetics of human cancer becomes an area of emerging research direction due to a growing understanding ofspecific epigenetic pathways and rapid development of detection technologies. Aberrant promoter hypermethylation is aprevalent phenonmena in human cancers. Tumor suppressor genes are often hypermethylated due to the increasedactivity or deregulation of DNMTs. Increasing evidence also reveals that viral genes are one of the key players inregulating DNA methylation. In this review, we will focus on hypermethylation and tumor suppressor gene silencing andthe signal pathways that are involved, particularly in cancers closely associated with the hepatitis B virus, simian virus40 (SV40), and Epstein-Barr virus. In addition, we will discuss current technologies for genome-wide detection ofepigenetically regulated targets, which allow for systematic DNA hypermethylation analysis. The study of epigeneticchanges should provide a global view of gene profile in cancer, and epigenetic markers could be used for early detection,prognosis, and therapy of cancer. 展开更多
关键词 EPIGENETICS DNA methylation cancer HBV SV40 EBV.
下载PDF
Constructing a New Polish Architecture: Critical Regionalism and Resistance to Globalization after 1989
19
作者 Krystyna Januszkiewicz 《Journal of Civil Engineering and Architecture》 2014年第12期1518-1526,共9页
This paper explores the critical regionalism which could play a role in the continued development of global era Polish architecture, and the advancements achieved by those few contemporary Polish architects who have s... This paper explores the critical regionalism which could play a role in the continued development of global era Polish architecture, and the advancements achieved by those few contemporary Polish architects who have sought to combine modern tastes and techniques with culturally meaningful designs. The new culture of Poland is very much reflected in the design of many of its new buildings that have been completed since the political and economic changes in 1989. The architecture of Poland appears to have lurched from an inappropriate socialist modernism that was so horridly imposed during the communist era to an equally inappropriate post modernist hegemony in the new enterprise culture. In accordance with Poland, now is rejection of the centrally imposed system of building and architecture, and with the greater emphasis on individual initiative in the new culture, it seems a pity that the country should automatically adopt western modes of architectural expression. This paper suggests that with its newly founded freedom, Poland should be careful that it does not suffer a loss of identity and that, in its architecture, it should seek a way forward through a critical regionalism. 展开更多
关键词 ARCHITECTURE CULTURE critical regionalism GLOBALIZATION RESISTANCE Poland.
下载PDF
A dosimetric evaluation of flattening filter-free volumetric modulated arc therapy for postoperative treatment of cervical cancer 被引量:1
20
作者 Fuli Zhang Huayong Jiang +10 位作者 Weidong Xu Yadi Wang Junmao Gao Qingzhi Liu Ping Wang Na Lu Diandian Chen Bo Yao Jun Hou Heliang He Jianping Chen 《Oncology and Translational Medicine》 2016年第4期179-184,共6页
Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retro... Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retrospective planning study.Methods VMAT plans of FFF beams and normal FF beams were designed for a cohort of 15 patients. The prescribed dose was 45 Gy to 1.8 Gy per fraction, and at least 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system using a Monte Carlo(MC) algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices(HI and CI), as well as organs at risk(OAR) dose and volume parameters. Results FFF-VMAT was similar to FF-VMAT in terms of CI, but inferior to FF-VMAT considering HI. No statistically differences were observed between FFF-VMAT and FF-VMAT in following organ at risks including pelvic bone marrow, small bowel, bladder, rectum, and normal tissue(NT)..Conclusion For patients with cervical cancer after hysterectomy, the FFF beam achieved target and OAR dose distribution similar to that of the FF beam. Reduction of beam-on time in cervical cancer is beneficial. 展开更多
关键词 flattening filter-free(FFF) cervical cancer dosimetry volumetric modulated arc therapy(VMAT)
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部