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变螺距螺纹曲面的精密测量
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作者 孙克权 袁伟利 孙兆洁 《上海第二工业大学学报》 1996年第1期23-26,共4页
诱导轮是由变螺距螺纹曲面组成的另件,用于航天火箭装置,它的几何形体复杂,一般机械方法难以加工。为提高诱导轮加工精度,必需解决变螺距误差的精密测量问题。本文作者探索在万能工具显微镜上用间接测量方法测量变螺距误差并进行精... 诱导轮是由变螺距螺纹曲面组成的另件,用于航天火箭装置,它的几何形体复杂,一般机械方法难以加工。为提高诱导轮加工精度,必需解决变螺距误差的精密测量问题。本文作者探索在万能工具显微镜上用间接测量方法测量变螺距误差并进行精度估算。测量误差小于±5μm。为线切割加工诱导轮提供了可靠的数据。 展开更多
关键词 诱导轮 变螺蚊曲面 测量 加工精度
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关于钻尖的变导程拟螺面磨法的研究 被引量:2
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作者 唐余勇 刘开昌 +1 位作者 郭青田 田广悦 《高校应用数学学报(A辑)》 CSCD 北大核心 1993年第3期326-331,共6页
本文介绍了确保钻尖质量的变导程拟螺面磨法、相应的几何优化模型及其算法,由于经过实例计算和3659开刃机上的试验的验证,因而本文为磨得高质量钻尖提供了可靠依据。
关键词 钻头 钻尖 导程拟 磨尖法
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不规则螺旋槽的数控加工 被引量:2
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作者 聂秋根 肖尧先 《制造技术与机床》 CSCD 1996年第7期13-14,共2页
文章针对螺杆上不规则螺旋槽,提供了具体的数控加工方法及程序编制方法。
关键词 变螺 数控加工 旋槽
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Application of fast wavelet transformation in signal processing of MEMS gyroscope 被引量:6
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作者 吉训生 王寿荣 许宜申 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期510-513,共4页
Decomposition and reconstruction of Mallat fast wavelet transformation (WT) is described. A fast algorithm, which can greatly decrease the processing burden and can be very easy for hardware implementation in real-t... Decomposition and reconstruction of Mallat fast wavelet transformation (WT) is described. A fast algorithm, which can greatly decrease the processing burden and can be very easy for hardware implementation in real-time, is analyzed. The algorithm will no longer have the processing of decimation and interpolation of usual WT. The formulae of the decomposition and the reconstruction are given. Simulation results of the MEMS (micro-electro mechanical systems) gyroscope drift signal show that the algorithm spends much less processing time to finish the de-noising process than the usual WT. And the de-noising effect is the same. The fast algorithm has been implemented in a TMS320C6713 digital signal processor. The standard variance of the gyroscope static drift signal decreases from 78. 435 5 (°)/h to 36. 763 5 (°)/h. It takes 0. 014 ms to process all input data and can meet the real-time analysis of signal. 展开更多
关键词 wavelet transformation signal processing GYROSCOPE THRESHOLD
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仙姑·妖精·贤妇·辣妹——螺女在古代小说中的变身及其文化意蕴 被引量:2
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作者 石麟 《明清小说研究》 CSSCI 北大核心 2016年第3期45-61,共17页
螺女是中国民间故事中出镜率颇高的一个艺术形象,而且,在不同时间、不同地域、不同民族的传说故事中的螺女形象又不断变身,充分显示了她性格上的多姿多彩。中国古代小说史上,许多作者都写到螺女形象,有的神秘,有的淫邪,有的贤惠,有的聪... 螺女是中国民间故事中出镜率颇高的一个艺术形象,而且,在不同时间、不同地域、不同民族的传说故事中的螺女形象又不断变身,充分显示了她性格上的多姿多彩。中国古代小说史上,许多作者都写到螺女形象,有的神秘,有的淫邪,有的贤惠,有的聪慧,当然,也有辣妹子型的抗暴者。对这些形形色色的螺女形象进行综合研究,并从中挖掘出深刻而富有情味的文化内涵,是中国古代小说研究者的一件幸事、一件趣事。 展开更多
关键词 古代小说 文化蕴涵
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Design of 2.5GHz Low Phase Noise CMOS LC-VCO 被引量:3
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作者 张海清 章倩苓 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第11期1154-1158,共5页
A 2 5GHz fully integrated LC VCO is fabricated in a standard single poly 4 metal 0 35μm digital CMOS process,using a complementary cross coupled topology for lowering power dissipation and reducing the effect of... A 2 5GHz fully integrated LC VCO is fabricated in a standard single poly 4 metal 0 35μm digital CMOS process,using a complementary cross coupled topology for lowering power dissipation and reducing the effect of 1/ f noise.An on chip LC filtering technique is used to lower the high frequency noise.Accumulation varactors are used to widen frequency tuning.The measured tuning range is 23 percent.A single hexadecagon symmetric on chip spiral is used with grounded shield pattern to reduce the chip area and maximize the quality factor.A phase noise of -118dBc/Hz at 1MHz offset is measured.The power dissipation is 4mA at V DD =3 3V. 展开更多
关键词 2.5GHz LC VCO phase noise accumulation varactors on chip spiral inductor
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Application of wavelet package filtering in the de-noising of fiber optic gyroscopes 被引量:2
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作者 王其 徐晓苏 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期46-49,共4页
To reduce the drift error existing in the output signal of fiber optic gyroscopes (FOG), a mathematical model of the FOG output signal is set up; the error characteristics of the FOG output signal are analyzed, and ... To reduce the drift error existing in the output signal of fiber optic gyroscopes (FOG), a mathematical model of the FOG output signal is set up; the error characteristics of the FOG output signal are analyzed, and semi-soft threshold filtering is chosen based on the comparison of hard threshold and soft threshold filtering. The semi-soft threshold wavelet package filtering method is applied in the filtering of the FOG output signal. Experiments of the stationary and dynamic FOG output signals filtered with the wavelet package analysis are carried out in a lab environment, respectively. Experiments done with the real-time measured FOG signal show that the method of semi-soft threshold wavelet package filtering reduces the mean square error from 5 (°)/h to 1 (°)/h, so it is effective in eliminating the white noises and the fractal noises existing in the FOG. The novel method proposed here is proved valid in reducing the FOG drift error, satisfying the technical demands of high precision and realtime processing. 展开更多
关键词 wavelet package analysis signal processing fiber optic gyro threshold filtering
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On Spirallike Mappings in Several Complex Variables 被引量:7
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作者 刘浩 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第1期62-72, ,共11页
In this paper,the parametric representation of a kind of spirallike mappings is given. As a direct application,the growth Theorem is set up. Moreover,a character of starlike mappings and a kind of spirallike mappings ... In this paper,the parametric representation of a kind of spirallike mappings is given. As a direct application,the growth Theorem is set up. Moreover,a character of starlike mappings and a kind of spirallike mappings is obtained. 展开更多
关键词 spirallike mappings parametric representation growth theorem
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Evaluation of Normal Adrenal Gland Volume by 64-slice CT 被引量:4
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作者 Xuan Wang Zheng-yu Jin +4 位作者 Hua-dan Xue Wei Liu Hao Sun Yu Chen Kai Xu 《Chinese Medical Sciences Journal》 CAS CSCD 2012年第4期220-224,共5页
Objective To measure volume and other parameters of normal adrenal glands in Chinese adults with 64-slice multidetector CT, to evaluate the relationship of volume result with age, sex and body size, and to explore the... Objective To measure volume and other parameters of normal adrenal glands in Chinese adults with 64-slice multidetector CT, to evaluate the relationship of volume result with age, sex and body size, and to explore the correlations between adrenal volume and other measurements. Methods This study was based on 125 acquired contrast-enhanced upper abdominal CT scans performed with a 64-slice CT. The final study group consisted of 81 patients (49 males, 32 females). Portal venous phase images were studied for the measurements. Both the reconstruction interval and thickness were 1.5 mm. Each adrenal gland was outlined manually with computer-assistant technology to calculate its volume. The maximal sectional area, length, width and thickness of each adrenal gland were also measured. Results The mean age of total population was 47.9±13.0 (range: 20-76) years. The left, right, and total adrenal gland volumes were 4.23±0.74 (range: 2.85-5.83) cm 3 , 4.26±0.86 (2.59-6.56) cm 3 , and 8.50±1.40 (5.80-11.39) cm 3 , respectively. These volumes increased with weight (r=0.381, 0.389, and 0.437 respectively, all P<0.001), height (r=0.386, P<0.001; r=0.297, P=0.007; r=0.384, P<0.001) and body surface area (r=0.406, 0.392, and 0.452, all P<0.001). There was no significant difference in left, right or total adrenal volume with regard to sex after applying General Linear Model procedure to reduce the impact of weight (F=1.304, 0.064, and 0.597, all P>0.05), nor did volume change significantly with age (r=-0.033, -0.014, and -0.026, all P>0.05). Nearly all descriptors of bilateral adrenal glands correlated with ipsilateral volume except thickness (r=-0.027, P=0.814) and width (r=0.166, P=0.138) in the left side. Among these parameters, length had a stronger correlation with volume than others in the both left (r=0.412, P<0.001) and right (r=0.516, P<0.001) adrenal glands. Conclusion Our study has defined the volume distribution and other parameters of normal adrenal glands in Chinese adults, which provide a baseline for future studies. 展开更多
关键词 adrenal gland VOLUMETRY volume determination computed tomography
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Local Spiral Curves Simulating Based on Hough Transformation and Center Auto-Locating of Developing Typhoon 被引量:1
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作者 王萍 郭传澍 罗颖昕 《Transactions of Tianjin University》 EI CAS 2006年第2期142-146,共5页
In the developing phase of typhoon formation, the spiral belt partly emerges in satellite cloud images. This research starts from images and moves on to graphics and then to representation and recognition. Following t... In the developing phase of typhoon formation, the spiral belt partly emerges in satellite cloud images. This research starts from images and moves on to graphics and then to representation and recognition. Following this route, local spiral cloud belt is segmented from the raw images using image segmentation, the spiral information is extracted using mathematic morphology, and local spiral curves are detected using Hough transformation. The problem of center locating of developing typhoon has finally been solved through a search algorithm of spiral curve. For No. 99082008 cloud image, the result produced by the algorithm in this paper is at 122..3 degree west longitude, 117.5 degree north latitude. The real typhoon center location was at 122.4 degree west longitude, 18 degree north latitude. 展开更多
关键词 Hough transformation spiral curve simulating infrared satellite cloud images center locating of developing typhoon
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Temperature and Precipitation Variations at Two Meteorological Stations on Eastern Slope of Gongga Mountain,SW China in the Past Two Decades 被引量:17
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作者 WU Yan-hong LI Wei +1 位作者 ZHOU Jun CAO Yang 《Journal of Mountain Science》 SCIE CSCD 2013年第3期370-377,共8页
Gongga Mountain, locates on the eastern edge of Tibetan Plateau of China, is the highest mountain in China except summits in Tibet. Only limited meteorological data on Gongga Mountain have been published so far. Here ... Gongga Mountain, locates on the eastern edge of Tibetan Plateau of China, is the highest mountain in China except summits in Tibet. Only limited meteorological data on Gongga Mountain have been published so far. Here we present the meteorological records from two stations, Moxi Station (at 1,621.7 m above sea level (a.s.1.), 1992- 2010) and Hailuogou Station (at 2,947.8 m a.s.l., 1988-2010), on the eastern slope of Gongga Mountain. In the past two decades, the annual precipitation decreased while the annual mean temperature increased at Hailuogou Station. Both precipitation and temperature increased at Moxi Station. The precipitation variation on the eastern slope of Gongga Mountain is influenced by both East Asian Monsoon and Indian Monsoon, so that the precipitation concentrated between May and October. The temperature variation on the eastern slope of Gongga Mountain in the past two decades showed similar trends as that of the northern hemispheric and global. In the past two decades, the temperature increased o.35℃ and o.3℃/decade at Hailuogou Station and Moxi Station respectively, which was higher than the increase extents of northern hemispheric and global temperature. The most intense warming occurred at the first decade of 21St century. The winter temperature increased more at Hailuogou Station than at Moxi Station. A remarkable increase of temperature in March was observed with only a little precipitation at both high and low altitude stations. 展开更多
关键词 Temperature Precipitation Variation Global change Gongga Mountain
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Antibiotic resistance and cagA gene correlation:A looming crisis of Helicobacter pylori 被引量:15
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作者 Adnan Khan Amber Farooqui +3 位作者 Hamid Manzoor Syed Shakeel Akhtar Muhammad Saeed Quraishy Shahana Urooj Kazmi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第18期2245-2252,共8页
AIM:To determine antibiotic resistance of Helicobacter pylori(H.pylori) in Pakistan and its correlation with host and pathogen associated factors.METHODS:A total of 178 strains of H.pylori were isolated from gastric b... AIM:To determine antibiotic resistance of Helicobacter pylori(H.pylori) in Pakistan and its correlation with host and pathogen associated factors.METHODS:A total of 178 strains of H.pylori were isolated from gastric biopsies of dyspeptic patients.Susceptibility patterns against first and second-line antibiotics were determined and trends of resistance were analyzed in relation to the sampling period,gastric conditions and cagA gene carriage.The effect of cagA gene on the acquisition of resistance was investigated by mutant selection assay.RESULTS:The observations showed that monoresistant strains were prevalent with rates of 89% for metronidazole,36% for clarithromycin,37% for amoxicillin,18.5% for ofloxacin and 12% for tetracycline.Furthermore,clarithromycin resistance was on the rise from 2005 to 2008(32% vs 38%,P = 0.004) and it is significantly observed in non ulcerative dyspeptic patients compared to gastritis,gastric ulcer and duodenal ulcer cases(53% vs 20%,18% and 19%,P = 0.000).On the contrary,metronidazole and ofloxacin resistance were more common in gastritis and gastric ulcer cases.Distribution analysis and frequencies of resistant mutants in vitro correlated with the absence of cagA gene with metronidazole and ofloxacin resistance.CONCLUSION:The study confirms the alarming levels of antibiotic resistance associated with the degree of gastric inflammation and cagA gene carriage in H.pylori strains. 展开更多
关键词 Helicobacter pylori Antibiotic resistance cagA Pakistan Clarithromycin Metronidazole Fluoroquinolones
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蒸发器芯体管路组件焊接夹具的设计 被引量:3
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作者 张毅 李志刚 +1 位作者 施会庆 李明涛 《汽车电器》 2017年第9期77-80,共4页
通过对某车用空调总成蒸发器芯体中的芯体管路组件焊接夹具的设计,使得产品的尺寸与位置精度得到保证的同时,又保证了焊接品质与焊接生产效率。对其它类似的芯体管路组件在进行组焊焊接时对其焊接夹具的设计起到了一定的借鉴意义。
关键词 蒸发器芯体 芯体管路组件 焊接夹具 调节板
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Improvement of machining quality of copper-plated roll mold by controlling temperature variation 被引量:4
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作者 Tae-Jin JE Eun-Chae JEON +3 位作者 Sang-Cheon PARK Doo-Sun CHOI Kyung-Hyun WHANG Myung-Chang KANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第A01期37-41,共5页
Micro prism film used in LCD industry can be manufactured by roll to roll method with copper-plated roll mold. As copper-plated roll mold is getting larger, pitch error is getting severer. The pitch error drops the qu... Micro prism film used in LCD industry can be manufactured by roll to roll method with copper-plated roll mold. As copper-plated roll mold is getting larger, pitch error is getting severer. The pitch error drops the quality of micro prism film. The main cause of the pitch error was investigated during machining large roll mold whose machined length was 1 200 mm. The temperature of machining system was elevated during machining roll mold, and this elevation induced thermal expansion of the system. The temperature variation around the roll mold also made thermal expansion of the roll mold. The amount of thermal expansion had strong relationship to the amount of pitch error. Therefore, the roll mold was machined after warming-up of machining system and precise temperature controller around copper-plated roll mold was installed, which minimized the temperature variation. Finally, precise micro prism patterns without pitch error were machined on the large roll mold. 展开更多
关键词 copper-plated roll mold MACHINING prism pattern temperature variation
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Finite element analysis of deformation characteristics in cold helical rolling of bearing steel-balls 被引量:2
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作者 曹强 华林 钱东升 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1175-1183,共9页
Due to the complexity of investigating deformation mechanisms in helical rolling(HR) process with traditional analytical method, it is significant to develop a 3D finite element(FE) model of HR process. The key formin... Due to the complexity of investigating deformation mechanisms in helical rolling(HR) process with traditional analytical method, it is significant to develop a 3D finite element(FE) model of HR process. The key forming conditions of cold HR of bearing steel-balls were detailedly described. Then, by taking steel-ball rolling elements of the B7008 C angular contact ball bearing as an example, a completed 3D elastic-plastic FE model of cold HR forming process was established under SIMUFACT software environment. Furthermore, the deformation characteristics in HR process were discovered, including the forming process, evolution and distribution laws of strain, stress and damage based on Lemaitre relative damage model. The results reveal that the central loosening and cavity defects in HR process may have a combined effect of large negative hydrostatic pressure(positive mean stress)caused by multi-dimensional tensile stresses, high level transverse tensile stress, and circular-alternating shear stress in cross section. 展开更多
关键词 cold helical rolling finite element(FE) simulation rotary forming bearing steel-balls
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Helicity Amplitude Analysis of η_c Decays into Hyperon-Antihyperon Pairs
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作者 PANG Cai-Ying PING Rong-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第6期1091-1094,共4页
The helicity amplitudes for the processes of e^+e^- →J/ψ→γηc→γYY(Y: hyperon) are presented, together with the joint angular distributions for ηc decays into ∧∧,∑^0 ∑^0, and [1]-[1]+. The sensitivities... The helicity amplitudes for the processes of e^+e^- →J/ψ→γηc→γYY(Y: hyperon) are presented, together with the joint angular distributions for ηc decays into ∧∧,∑^0 ∑^0, and [1]-[1]+. The sensitivities to measure the hyperon decay parameters in these decays are evaluated based on the helicity amplitudes. The prospects to test the Bell inequality in experiment using the decay of ηc→∧∧ are discussed. 展开更多
关键词 ηc helicity amplitude hyperon decay parameter Bell inequality
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Experimental study on the bolt–cable combined supporting technology for the extraction roadways in weakly cemented strata 被引量:14
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作者 Meng Qingbin Han Lijun +3 位作者 Sun Jingwu Min Fengqing Feng Wei Zhou Xing 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第1期113-119,共7页
Aiming at the characteristics of the poor steady ability, the short stable time and severe deformation behavior of weakly cemented soft surrounding rock around extraction roadway, a bolt–cable combined supporting tec... Aiming at the characteristics of the poor steady ability, the short stable time and severe deformation behavior of weakly cemented soft surrounding rock around extraction roadway, a bolt–cable combined supporting technology was proposed. Numerical simulation was performed by using FLAC3 D software to study the effects of different supporting systems. The simulation result proves that those supporting systems have good practical values. Based on real-time monitoring and analysis of the deformation of surrounding rock and the stress of supporting structure, real time information of deformation of surrounding rock and stress state of supporting structure of extraction roadway within weakly cemented strata was obtained. Monitoring results show that large deformation and failure of surrounding rock of extraction roadway within weakly cemented strata can be effectively controlled by the bolt–cable combined supporting technology, which ensures the long-term stability and safety of surrounding rock and supporting structure. 展开更多
关键词 Weakly cemented strataExtraction roadwayBolt-cable combined supporting technologyReal-time monitoring
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Improved production of spiramycin by mutant Streptomyces ambofaciens 被引量:4
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作者 金志华 岑沛霖 《Journal of Zhejiang University Science》 EI CSCD 2004年第6期689-695,共7页
Strain improvement and medium optimization to increase the productivity of spiramycin were carried out. Of oil tolerant mutant strains screened, one mutant, Streptomyces ambofaciens XC 2-37, produced 9% more spiramyc... Strain improvement and medium optimization to increase the productivity of spiramycin were carried out. Of oil tolerant mutant strains screened, one mutant, Streptomyces ambofaciens XC 2-37, produced 9% more spiramycin than the parent strain S. ambofaciens XC 1-29. The effects of soybean oil and propyl alcohol on spiramycin production with S. ambofaciens XC 2-37 were studied. The potency of S. ambofaciens XC 2-37 was improved by 61.8% with addition of 2% soybean oil in the fermentation medium and 0.4% propyl alcohol at 24 hours after incubation. The suitable time for feeding propyl alcohol is at 24 hours after incubation in flask fermentation and at 20 hours after incubation in fermentor fermentation. The new process with S. ambofaciens XC 2-37 was scaled up for industrial scale production of spiramycin in a 60 m3 fermentor in Xinchang Pharmaceutical Factory, Zhejiang Medicine Company, Ltd., China, and the potency and productivity of fermentation were improved by 42.9%. 展开更多
关键词 SPIRAMYCIN Streptomyces ambofaciens Strain improvement FERMENTATION
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Analysis of deformation of rotor and influence on the performance of Gyro based on B-Spline wavelet FEM
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作者 LIU Jian-feng YUAN Gan-nan ZHOU Wei-dong 《Journal of Marine Science and Application》 2005年第4期12-17,共6页
Some construct characteristics and composing material of the new Gyro' s rotor are introduced. Some factors resulting in deformation of the rotor surface are analyzed. Under different loads such as the fo,'ce of def... Some construct characteristics and composing material of the new Gyro' s rotor are introduced. Some factors resulting in deformation of the rotor surface are analyzed. Under different loads such as the fo,'ce of deflecting center, the change of temperature, the fo,ce of pressure and couple factors, the deformation of rotor is analyzed with the wavelet finite element simulation software. The vector distributing map of rotor reformation is given. The deformation resulting from the pressure force of photon is studied. Finally, the influence on Gyro' s performance because of anomalous surface of rotor due to deformation of rotor is researched and the result is useful to forecast the performance of the drift of gyroscope. The disturbing moment resulting from the deformation of rotor can be compensated using the mathematic method, and provides an important reference for both design and optimization of the rotor. 展开更多
关键词 the rotor of new Gyro the deformation of rotor the wavelet finite element the drift of Gyro
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A linear rotary magnetorheological damper for vehicles
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作者 JIANGJiandong LIANGXichang ZHANGBo XIAOJunli 《Journal of Chongqing University》 CAS 2004年第1期11-15,共5页
A new type of linear rotary magnetorheological damper (MRD) is proposed, which consists of a cylinder-type MRD and a screw mechanism to transform a linear motion into revolving motion. It is found that the structure p... A new type of linear rotary magnetorheological damper (MRD) is proposed, which consists of a cylinder-type MRD and a screw mechanism to transform a linear motion into revolving motion. It is found that the structure parameters of MRD have complex relationship with the force of the damper, especially the lead angle, width and radius of the inner rotor. The analyses and simulation calculation of the static magnetic field give some usable data, and experiments of the damping component indicate that the proposed methods is feasible for developing linear rotary MRD. 展开更多
关键词 MR damper (MRD) screw mechanism automotive suspension
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