Method of Time -Frequency Analysis of Engineering Signals Using Wavelet

The method to carry out time frequency analysis of engineering signal using wavelets transform is discussed and the formuli of quantitative relationship between the position & width of time frequency window of wavelet transform and the scale & sampling interval is put forward.     

Envelope Analysis Technique and Its Application in the Gear Failure Vibration Diagnosis

The gear failure vibration diagnosiS in a gearbox is of great importance in manyfields.Through theoretical analysis and engineering application,two methods of gear vibration en-velope analysis technique are discussed in this paper.Zoom Hilbert transform en velope and zcomnarrow-band en velope are formed by applying zoom technique to Hilbert transform demodulationand narrow-band demodulation in order to increase the frequency resolution of demodulation spec-trum.     

Smooth blasting design and optimization of large spanurban highway tunnels

Vibration resistance can be incorporated into blasting designs to avoid damages caused by the excavation of large span tunnels in busy urban areas, but only by basing excavation design schemes on actual situations. In view of the actual situation in the Jahua tunnel in Chongqing, P. R. China, research was conducted to identify a relevant explosion scheme. The research was based on theoretical analysis and in situ testing. Face step excavation was considered in the broadening band A, and upper drift excavation was adopted in broadening bands B, C, D and E. We simultaneously proposed selection criteria for smooth blasting parameters and the construction layout of broadening band B. Based on a regression analysis of the blasting vibration monitoring results, a spread orderliness of blasting vibration was drawn. Explosion parameters optimization measures were put forward, selected from the maximum charge quantity, millisecond blasting, reasonable blasting time difference, and the excavation plan. Field testing achieved satisfactory results. These findings will play an important role in guiding excavation blasting construction of tunnel projects and assuring the safety of ground buildings.     

播期播量对胶东小麦植株性状及产量的影响

为探讨冬小麦适宜播期播量,以烟农5158为材料,采用裂区试验设计进行了试验。结果表明:随播期推迟株高降低、主茎叶龄减少,随播量增加株高增加、主茎叶龄变化不大。不同的播期播量对冬小麦产量及产量性状的影响均达极显著水平。随播期(9月27日除外)推迟,产量、成穗数降低,穗粒数和千粒重提高;随播量的增加,产量、成穗数增加,穗粒数和千粒重降低。播期播量最佳组合为10月3日播种、180万株/hm²播量,产量达7746.0kg/hm²。成穗数是决定产量的关键因素。     

Analysis on Critical Buckling Condition on Sheet Metal Deformation Under a Pressure Load

In this paper,the peak particle velocity and main vibration frequency are put forward as a monitoring measure of blast vibrations based on the analysis of blast vibrations damage to the structure.In this paper,the damage criteria and the safety standards of vibration in some countries are shown.In addition,this paper analyzes the influence factors of the blast and give suggestions on effective control of the blast.     

Analysis of Vehicle-Bridge Coupled Vibrations for Simply Supported Girder Bridge Considering Bridge Surface Roughness

Bridge surface roughness is usually considered to be the main Influencing factors of vehicle-bridge coupled vibrations.The way that obtaine Bridge surface roughness by the transformation of power spectral density is effective and rapid.The Bridge surface roughness is obtained by Fourier inverse transform method and trigonometric series method respectively. It can be concluded from the comparision that the precision of Fourier inverse transform method is higher than trigonometric series method. The vibration functions for 4-dofs Vehicle and bridge were derived with the employment of d'Alembert principle and computational procedures for vehicle-bridge coupled vibration were compiled. The dynamic response of a simply supported beam and vehicle was analyzed considering bridge surface roughness which was obtained by Fourier inverse transform method.The research shows that the influence due to the bridge surface roughness is significiant and vehicle speed also effects the bridge vibrations by changing the frequency of the force acting on the bridge due to vehicle and the force acting on the vehicle due to bridge deformation.     

不同种植布局对稻瘟病孢子发生量的影响研究

为研究水稻不同种植模式对稻瘟病发生影响,通过试验设计、采样设计,以稻瘟病病原菌为研究对象。通过定时捕捉稻瘟病病原菌孢子,并与温度、光照强度、相对湿度、不同试验区间进行研究分析。试验结果表明：孢子量变化与温度、光照强度和相对湿度呈正相关;同一种植模式及布局接壤的试验区孢子量变化间呈显著正相关;研究还发现多样性种植的试验区孢子总量略低于单一种植的试验区孢子总量,说明多样性种植能较好地抑制稻瘟病的发生。同时,利用分形理论研究了整个试验区的分形维,研究表明：分形维为小数,说明整个试验区具有一定的混沌特性。     

超晚播条件下密度和追氮时期对淮北地区小麦产量及品质的影响

为了实现安徽淮北地区晚播小麦高产优质栽培,以目前该地区种植面积最大的强筋小麦品种‘烟农19’为材料,采用两因素随机区组设计,研究了小麦超晚播（11月21日,较适宜播期晚30天左右）条件下,密度、追氮时期对小麦产量和品质的影响。结果表明：密度和追肥时期对超晚播小麦籽粒产量影响差异显著,以密度450×104株/hm2、孕穗期追肥处理的产量最高,为7846.5 kg/hm2。密度对穗数和穗粒数影响显著,每公顷穗数随着密度的增加而增加;穗粒数随密度的增加而减少。追氮时期对千粒重影响显著,随追氮时期的推迟而增加。增加密度和推迟追氮时期,旗叶叶片光化学最大效率(Fv/Fm)和PSⅡ的活性(Fv/Fo)提高,增大了PSⅡ的潜在活性,有利于叶片所吸收的光能较充分地用于光合作用。追氮时期对小麦品质的影响差异显著,随着追氮时期的延迟,蛋白质含量、湿面筋含量和沉降值呈增加趋势,试验结果表明推迟追肥至孕穗期可以改善超晚播条件下强筋小麦的籽粒品质。     

Statistical Model on the Time and Time Difference Error of Arrival in TDOA Location Estimation

Additional time delay of arrival resulted from non-line of sight(NLOS)propagation and muti-path effect in(cellular) environment is the dominant factor resulting in TDOA location error,study on the statistical property of TDOA error is useful for improving the accuracy of TDOA location.Based on the exponential distribution property of NLOS propagation delay,and considering the system error resulted from the signal detection,the authors establish a statistical model of arrival time and a model of TDOA error distribution by statistics when non-light of sight and multi-path propagation exist.The models reflect the statistical property of arrival time and TDOA error in cell network,the simulation shows that the proposed models have a good accuracy and a satisfactory behavior.     

Wind Vibration Analysis on the Large -span Curtain Wall

The large-span structure requires wind vibration analysis when computing the wind load;however,the formula in current code on wind vibration coefficient can hardly be applied in large-span structure,making its computation difficult and troublesome.This paper makes wind vibration analysis on the large-span curtain wall combined with certain engineering background in the methods of both time domain and frequency domain,and then the derived results are compared.The analytical results demonstrate identical distribution and contiguous numerical value of wind vibration coefficient concluded from the two varied methods;furthermore,even if the method in time domain is higher in computational complexity,more data on the response of structure under wind can be obtained,which provides reference for the theoretical analysis and engineering design.     

播期和种植密度对超高产小麦济麦22产量及其构成因素的影响

为给‘济麦22’大面积推广提供适宜栽培措施,选择4个生态区5个试验点,通过大田试验研究了播期和种植密度对该品种产量及其构成因素的影响。结果表明,播期对单位面积穗数、千粒重及产量产生显著的影响,但对穗粒数影响不大;种植密度对产量及构其成因素均有显著影响。在一定范围内,‘济麦22’单位面积穗数随着播期的推迟而减少,随密度的增加而增加;穗粒数随播期的推迟而增加,随密度的增加而减少;千粒重随播期的推迟先增加后下降,随密度的增加而降低。产量构成因素稳定性分析发现环境差异对‘济麦22’千粒重影响较大,而对单位面积穗数和穗粒数影响较小。2008年4个生态区‘济麦22’适宜播期范围分别为：鲁南地区10月8日至14日、鲁东地区10月6日至12日、鲁北地区10月1日至7日、鲁西地区10月10日至16日;适宜种植密度范围为180×104/hm2~240×104/hm2。研究还表明,在中高肥或高肥地力条件下,增加粒重对充分发挥‘济麦22’高产潜力似乎更有效。因此,选择适宜播期播量的同时,应在栽培技术中注意采取相应的措施,获得足够的单位面积穗数的基础上,稳步提高粒重。     

Error Analysis between Relative Motion Solving Method and Absolute Displacement Direct Solving Method

Under multi-support earthquake excitation, the damping is proportional to the relative velocity in relative motion method, While the damping is proportional to the absolute velocity in method of direct solving absolute displacement, and the damping assuming difference may cause the calculation errors on structural responses. The structural response errors of the dynamic component of power spectral density between the two solving methods are derived by random vibration theoretical analysis in Rayleigh damping model, which include damping ratio and the ratio between excitation frequency and fundamental frequency of the structures. Based on probability theory, the variation errors of dynamic component response between the two solving methods are also derived by theoretical analysis, and some numerical examples are provided to verify the error analysis. At last, it is pointed out that the calculation errors between the two solving methods decrease with damping ratio, and it is negligible when the damping ratio of structure is less than 5%.     

Systems Analysis Based on Continuous Wavelet Transform

The linear time invariant vibration system is analyzed by Continuous Wavelet Transform(CWT),the relationship of wavelet transform of output signal with the pulse response of system and input signal is put forward.As an exapmle,the wavelet transform of the output signal of system with single degree of freedom is calculated and compared with the direct wavelet transform result of the actual output signal,it shows that the two results are in complete agreement.     

水稻两用核不育系龙S抗稻瘟病主效基因的定位

龙S是一个广谱抗稻瘟病的水稻两用核不育系,利用分子标记技术精细定位其主效抗性基因,对于培育抗稻瘟病水稻新品种具有重要意义。采用来自国内外的41个稻瘟病菌系通过接种鉴定方式对龙S进行了稻瘟病抗谱分析,结果显示龙S的抗性频率为100%,对其中39个菌系表现高水平抗性,与Pi9的携带品种75-1-127抗性频率和抗病级别基本相当。群体遗传分析表明龙S的抗性基因表现为显性遗传方式,对于不同菌系龙S表现出不同的抗病遗传模式,其中龙S对稻瘟菌系318-2的抗性由单基因控制。通过抗病亲本龙S与感病亲本日本晴构建F₂分离群体,采用BSA (bulk segregant analysis)及RCA (recessive class analysis)分析方法,将龙S的主效抗病基因精细定位于第9染色体上的SSR标记M1-M2所在的1.31 cM区间,与已克隆的广谱抗稻瘟病基因Pi5位于相邻的染色体区域。抗谱分析表明,龙S与Pi5、Pii单基因系的抗性频率差异明显,抗谱较后二者更广。龙S主效抗性基因的精细定位,为进一步揭示其与Pi5、Pii的等位关系以及通过分子标记辅助选择培育抗病水稻新品种奠定了基础。     

Application of higher density wavelet transform to composite fault diagnosis of rolling bearing

Aiming at the difficulties in accurate reorganization of several weak faults currently, a composite fault diagnosis method based on higher density discrete wavelet transform and envelope spectrum is proposed. Firstly, the higher density discrete wavelet transform is used to decompose acquired vibration signals of rolling bearings. Then, the single-subband reconstruction is performed on the wavelet coefficients and scaling coefficients at each scale in order to solve frequency aliasing. Finally, the envelope spectra of all subband signals are calculated, and all faults can be recognized according to the characteristic frequencies of the typical faults. The proposed method is applied to the diagnosis of the rolling bearings with composite faults, and is compared with other common fault diagnosis method. The results show that the proposed method can be effectively used for the early composite fault diagnosis of rolling bearings.     

Partial resistance to neck blast influenced by stage of panicle development and rice genotype

Summary Neck nodes of eight rice genotypes were inoculated with a virulent isolate of the blast pathogen at four slightly different, increasingly older stages of panicle development shortly after flowering. Resistance to infection as well as resistance to growth of the pathogen after infection was assessed. Significant differences between genotypes were found for both components of resistance. Resistance to growth of the pathogen sharply increased with aging of the neck node as was indicated by a large reduction of the length of the lesions on the culm, but resistance to infection did not change much. The lesion length was closely related to yield loss. A small delay in time of infection can lead to a large decrease in yield reduction. Meaningful comparison of partial resistance to neck blast between genotypes therefore requires infection at an identical stage of panicle development. In the field, where panicles are in different stages of development, selection of genotypes that do show the symptoms of neck blast together with relatively little yield loss in infected panicles is recommended.     

Speedy Recognition of Noise in Real Time Signal Based on Wavelet Transform

It's necessary to process position and gesture of rocket on real time within the flight of rocket. This work should base exact data. But much noise has been found in the data and the noise recognize is regarded as a focus. A speedy online arithmetic recognizing noise is proposed based on wavelet transform. The computing complexity measured by time of this arithmetic is a constant which is greatly reduces the works of calculation of wavelet transform. It can recognize the noise fast when the signal is gathered. The applications in these problems show that the effective arithmetic satisfies the needs of real time and can handle the real time data measured in other yields.     

施氮量和栽插密度对抛秧晚稻穗颈瘟的影响

穗颈瘟是湖南晚稻的主要病害之一,本研究通过氮肥用量与抛秧密度互作,研究其对晚稻穗颈瘟发生的影响,以期从栽培角度为晚稻穗颈瘟的防治提供理论支撑。试验设置4个氮肥用量(N0、N1、N2、N3)与3个抛秧密度(D1、D2、D3)。结果表明：在相同氮肥条件下,各发病参数随密度的增加均呈“凹”形趋势,而在同一密度条件下,各发病参数伴随施氮量的增加而增加。处理(N3D1)穗颈瘟发生最严重,其病穗率、病蔸率、病情指数分别为10.76%、69.56%、12.65%。SPAD值与病穗率、病蔸率、病情指数之间的相关系数R²分别为0.7294、0.8325、0.746,达显著水平。单穴叶面积与病穗率、病蔸率、病情指数之间的相关系数R²分别为0.8259、0.8481、0.8407,均达极显著水平。施用氮肥为180 kg/hm²、栽植密度为26.25万兜/hm²时,既有利于促进晚稻生长,还可减少穗颈瘟的发生。     

三黄占2号稻瘟病抗性与稻米直链淀粉含量的关系研究

以高抗稻瘟病、直链淀粉含量（AC）较高的三黄占2号和高感稻瘟病、AC较低的丽江新团黑谷衍生的重组自交系群体为研究材料，从性状的相关性和控制两性状的基因在染色体上的位置关系剖析稻瘟病抗性和稻米AC的内在关系。结果表明，两性状间没有显著的相关性。3个与AC相关的QTL分别被定位在第5、6和7染色体上，其加性效应均来自丽江新团黑谷，起降低AC的作用。比较这些QTL与先前对同一群体鉴定的稻瘟病抗性基因（主效基因和QTL）在染色体上的位置，表明控制这两性状的基因上没有紧密连锁关系, 亦没有显著的基因间互作。据此认为，通过亲本的合理选择和分子标记辅助选择可以把三黄占2号稻瘟病持久抗性与理想AC整合到同一品系中，育成优质、抗病的优良品种。     

A valve camshaft load torque calculation and camshaft vibration control analysis

Aiming at the overhead camshaft valve mechanism,the theoretical and numerical solutions of camshaft load torque are calculated respectively by a derived formula and transient finite element analysis. The two solutions show good agreement,thus the correctness of the transient finite element model is verified. By combining with camshaft instantaneous constraint modal analysis and vibration response with consideration of gas pressure,it is found the position of camshaft which easily excites resonance and the main influence factors of camshaft vibration. Then the effect of the width of bearing seat on the camshaft vibration is investigated and the results show that the vibration of camshaft is mainly bending vibration,appropriate width of bearing seat can effectively control the camshaft vibration.