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1.
为了加强基层政府应灾各部门之间的应灾协同,提高基层的应灾效率,通过文献研究法、问卷调查法、模型方法等方法对基层政府协同应灾平台的构建进行研究。本研究得出基层计算机和互联网的普及率低、基层应灾人员的知识层次低和基层应灾信息系统建设滞后,是导致基层协同应灾平台构建滞后的主要原因。另外,提出了构建基层协同应灾平台的思路,并根据该思路构建了基层协同应灾平台的模型。总之,协同应灾平台的构建能提高基层的应灾效率,降低基层的灾害损失。 相似文献
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In the drive response method of Pecora and Carroll (the PC method), the response system is copied directly from drive system and is steady subsystem of drive system. But sometimes the PC method is disabled. Therefore, another method of realizing the drive response of chaos systems is put forward in this paper. The response system is not copied directly from steady subsystem of drive system, but is constructed from arbitrarily state variable of drive system. At the same time, the driving function is added in the response system, and the method of construction is pointed out. The method can realize the chaos synchronization that can not be realized by PC method. 相似文献
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Summary The inheritance of flowering time and its component processes, vernalization and photoperiod response, were studied in two crosses of subterranean clover (Trifolium subterraneum L.) using a field sowing and four controlled environment sowings with different combinations of vernalization and photoperiod. Time to flowering was under polygenic control and was highly heritable. For both vernalization and photoperiod response, there was dominance for a low response, or earliness. A simple genetic control was indicated for photoperiod response. The results for vernalization response were not clear cut, although the character appeared to be under polygenic control. An interaction between vernalization and photoperiod response was evident in three of the four cultivars studied. This made it impossible to separate the effect of these two component processes and complicated the study of their inheritance. Node of first flower on the main stem was closely related to flowering time and its use led to similar conclusions in the inheritance studies. 相似文献
5.
Nonlinear planar response of a cable under plannar narrow band radom excitation is studied.A response equation for the mean square deflection is obtained under a single mode approximation by using the equivalent linearization technique.It is shown that the response is triple valued,if the center frequency of excitation lies in a certain specified range.The triple valued response occure only if the excitation of excitation lies in a certain specified range.The triple valued response occures only if the excitation bandwidth is smaller than a critical value which is monotonically increasing function of the intensity of excitation. 相似文献
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Thirty‐nine barley varieties of different origin, representing different growth types, were included in a series of experiments aimed at analysing the variability in vernalization response, photoperiod sensitivity and earliness per se and establishing the types of ecoclimatic adaptability using multivariate analysis. In the case of spring barley varieties there was no correlation between any of the three traits. For winter barleys, a negative correlation was found between photoperiod sensitivity and vernalization response and between photoperiod sensitivity and earliness per se. Vernalization response and earliness per se showed a positive correlation. Among the winter barley varieties large variations were apparent in photoperiod sensitivity, vernalization response and earliness per se, which resulted in a tremendous variation in flowering patterns and frost tolerance. Between the spring barley varieties only wider variations in photoperiod sensitivity were detected. Based on the cluster analysis, the 39 varieties could be separated into seven groups. The spring barley varieties were placed in two groups, and the winter barleys in five groups representing different adaptational types. Among these five groups two represented the two opposing extreme combinations of photoperiod sensitivity and vernalization response. The combination of large photoperiod sensitivity and no vernalization response resulted in better frost tolerance than did the combination of photoperiod insensitivity and large vernalization response. 相似文献
7.
The accuracy of modal parameters identification has the influence on the quality of dynamic characteristics analysis of mechanical structure directly. And the precision of the frequency response function estimation has the great influence on the accuracy of modal parameters identification. In the engineering the frequency response function can be estimated by the average power spectrum and cross-power spectrum with the hel Pof FFT. As the result of limited frequency resolution in the course of FFT and the noise, the accuracy of modal parameters identification is influenced by the frequency response function estimation. This paper has put forward a least-square-based optimization of frequency response function estimation in modal parameters identification. According to the optimized frequency response function, the peak value can be searched to identify the damped natural frequencies and damping ratio directly. An experiment has been made to validate the proposed method. The result indicates that the damped natural frequencies and damping ratio identified by the optimized frequency response function are closer to the true results than which without the optimized frequency response function. So the accuracy of modal parameters identification can be improved by adopting the proposed method. 相似文献
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Response Spectrum Method for Seismic Response Calculation of Pipeline System Multiply Supported on Structures 总被引：1，自引：0，他引：1
In order to ensure the function of building in the earthquake, reduce economic losses and facilitate post-disaster relief, it is necessary to accurately evaluate the seismic performance of pipeline system on the structure under seismic excitation. Considering this practical need, seismic response calculation methods of piping systems on structures were systematically studied. Firstly, theoretical derivation was performed based on the pseudo-excitation method for seismic response of pipeline system. It is found that the formula in previous studies has obvious defect: the accurate relative displacement values of degree of freedom near the supports can not be obtained in the formula. Thereby, the theoretical basis for derivation was mended to correct the defect, and the uniform combination expressions available for pipeline's seismic response calculation which is in the form of ground response spectrum or floor response spectrum were presented. Moreover, the simplified formulas and calculation method of correlation coefficients in the obtained expressions were put forward according to the assumption of white noise earthquake excitation. Finally, case studies were adopted to verify the proposed method's effectiveness and applicability in the seismic response calculation of pipeline system. 相似文献
9.
GONG Xian sheng 《保鲜与加工》1999,(3):15-23
A method which is used for calculating steady vibration response of shipping propulsion shafting connecting with a coupling with nonlinear hysteresis characteristics are studied. On condition that the nonlinear dynamic stiffness and hysteresis damping of the coupling be considered, on the basis of GLM(Galerki Levenberg Marquard) method, a method called SSGILM(Separate System Galerkin and Improved Levenberg-Marquardt)to be used for calculating steady vibration response of propulsion shafting with local nonlinear dynamic stiffness and hysteresis damping, is proposed. A simple example is given out and the analyses show that it is effective to calculate steady vibration response of the shafting with local nonlinear dynamic stiffness and hysteresis damping by SSGILM method. From initial response values given arbitrarily, the automatic search algorithm in SSGILM method can converge the given initial response values to the response values accorded with required accuracy quickly; nonlinear dynamic stiffness and hysteresis damping of the coupling have different effect on vibration response of the shafting at different range of frequency. At the area of close nature frequency of the shafting ,displacement amplitude of the shafting is bigger. Beyond the range, the characteristics of the coupling have restraint effect on vibration of the shafting. 相似文献
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为研究自噬相关基因ATG8g在香蕉中的潜在功能,以及在过表达植株中对植株形态发育的影响,本研究通过农杆菌转化法获得MaATG8g拟南芥过表达植株。结果发现,MaATG8g对植株的外观形态不产生影响。同时将MaATG8g启动子连入pGreenⅡ0800-LUC载体,并对MaATG8g启动子序列分析,发现该启动子片段含有生长素应答元件、脱落酸响应元件、抗氧化反应元件、低温胁迫相关元件、水杨酸响应元件、赤霉素应答元件和其他逆境响应相关的顺式作用元件,推测目的基因具有胁迫相关性,可以进一步研究MaATG8g胁迫相关的生物学功能。 相似文献
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G. M. Halloran 《Euphytica》1976,25(1):489-498
Summary Photoperiodic respose, as assessed by a regression technique, exhibited complete dominance averaged over the crosses of an eight parent diallel in the vernalized condition. Photoperiodic response as final leaf number for the vernalized 8-hour photoperiod diallel was closely related to photoeriodic response of the regression method. However, the diallel analyses of both sets of data showed little agreement in terms of respectieve array positions.The inheritance of photoperiodic response in diallels using regression values showed little agreement between the vernalized and unvernalized conditions. This difference was postulated to be due to interaction of vernalization and photoperiodic response in the unvernalized situation. In the unvernalized condition photoperiodic response exhibited non-allelic interaction, attributable mainly to the cultivar Pinnacle in general behaviour in its crosses. Its removal gave a situation of high average dominance for photoperiodic response with a clear indication that high photoperiodic sensitivity was dominant to comparative insensitivity.Days to ear emergence (vernalized and 18-hour photoperiod) exhibited non-allelic interaction in its expression, due mainly to the general behaviour of the cultivar Pinnacle in its crosses. Removal of its array gave a situation of a moderately strong degree of overdominance in the expression of days to ear emergence. Maturity differences amongst parents and F1's, vernalized and under 18-hour photoperiod, are postulated to be due to a factor other than vernalization or photoperiodic response beheved to be growth temperature in differentially in fluencing growth and/or developmental rates between genotypes. 相似文献
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Zhang Xiangwei Xu Meihe 《保鲜与加工》1991,(2):47-55
A simplified procedure is presented for the determintion of rates of change of frequency response function matrix of system for the non-proportional changeable damping ,by means of the second order perturbation technique in conjunction with complex modal analysis. Consequently, when excitation information in frequency domain is known,the sensitivity of the response power spectra and the response time history can be obtained. 相似文献
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This paper studies the response of A-share market to the announcement on the related-party transactions, with the method of excess earnings and multiple regression analysis. The evidence shows that stock market makes weakly positive response to the announcement. Results also suggest the surplus announcement is of informational content. Finally, some reasons resulting in weak response are presented. 相似文献
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编码非特异性脂质转移蛋白的基因nsLTPs在植物应答生物和非生物胁迫以及植物的生长发育中起到重要作用。为了研究植物nsLTPs基因响应生物及非生物胁迫的分子机制,本文归纳了非特异性脂质转移蛋白nsLTPs的结构特点及分类,分析了nsLTPs的亚细胞定位情况,并重点总结了nsLTPs基因在植物逆境胁迫应答方面的相关研究进展,提出了植物不同物种中nsLTPs基因参与植物逆境胁迫的分子调控途径,为完善nsLTPs基因参与植物逆境胁迫应答调控机制提供理论基础。 相似文献
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Summary We tested three sets of oat varieties for grain yield in a series of environments and observed that generally more than 80% of the yield variation for individual varieties was due to linear regression response. Mean yields for varieties were significantly variable in all three sets, and regression response indexes were significantly variable in two of them.Mean yields over the three sets were correlated with regression response indexes with r=0.61. Associations of mean yield with the three stability parameters (i.e., coefficient of determination, mean square for deviations from regression, and ecovalence) were low and usually not significant. The correlation of regression response indexes with coefficients of determination was 0.42, but neither of the other stability parameters was associated with the response indexes. The three stability parameters were closely correlated with one another.Our materials were selected varieties, so evidently our results suggest what can be accomplished in breeding for combinations of mean production, production response, and productiom stability.Journal Paper No.J-9092 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, USA 50011. Project 1752. This work was supported in part by the International Atomic Energy Agency, vienna, Austria, in the form of a fellowship for the senior author. 相似文献
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The objective of this study was to compare the yield response of several present day winter wheat cultivars of different origin with the aim of broadening breeders' information from multi-year/location tests by using an appropriate cluster procedure. Yield response of 18 cultivars was analysed using data from two series of official yield performance tests in Germany. Similarity of yield response between two cultivars is defined by a positive correlation coefficient (nearly one) for the yields over all test environments. A hierarchical agglomerative procedure was used to establish clusters of similarly responding cultivars. The smallest distances in yield response were established between closely related cultivars of equal maturity. Clusters of cultivars with distinct maturity and also the groups of East and West German cultivars tested exhibited clear differences in yield response. 相似文献
17.
Field and controlled environment studies revealed significant genetic variation in nitrogen uptake and utilization within an F2 population of spring rape. However, narrow-sense heritabilities of measures of these characters were consistently low, and were less than that of seed yield in the field. Flowering time in the field had a much higher heritability than seed yield and the expected yield response to selection for this character was 34 % greater than the response to direct yield selection. An even greater yield response was expected from selection based on an index combining measurements of flowering time, nitrogen uptake and nitrogen utilization. The expected yield response to selection for an index incorporating these characters and seed yield was SI % greater than that for direct yield selection. 相似文献
18.
The research of asymmetric structures' seismic response is quite active in foreign countries, but there area few research works in China. There are many structure's factors that influence the asymmetric structure's inelastic seismic response, so it is difficult to form consistent points for each factor which influences the structure's torsional response. In this paper, the status of research in this field is reviewed. 相似文献
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Considering the three-dimensional inhomogeneity of soil surrounding the pile, the response of non-uniform viscoelastic pile under axial dynamic loading is studied. Firstly, combining the boundary condition, the complex stiffness of axial different soil layers are obtained by the complex stiffness transfer model of radial multi-zone plane strain. Then, the analytical solution of dynamic response at pile top in frequency domain is proposed by solving the dynamic equation of non-uniform viscoelastic pile section one by one from the bottom up to the top, and the relevant semi-analytical solution response in time domain is adopted by the convolution theorem and the Inverse Fourier Transform. At last, the effect of parameters of pile and soil are investigated to get the nature of the dynamic response of pile top in frequency domain and time domain. 相似文献
20.
The spatial variability of yields and optimal N rates is well documented for several crops and the benefit of studying site-specific N response seems self-evident. Unfortunately, trials established to examine site-specific N response are mostly quite large and expensive, since those trials usually cover nearly the whole field. Selecting only small subareas of a field to host an N fertilization trial will reduce costs and therefore possibly allow more trials on different locations. On the other hand, the evaluation of small trials can become difficult, resulting from a low number of observations compared to the number of parameters that need to be estimated. Aim of this study was to develop a framework that allows evaluating yield response from small site-specific trials by reducing the number of parameters of the response curves.The framework was tested on a data-base of a two-year site-specific N fertilization trial in northern Germany. Three different types of N response curves were evaluated individually for each subarea: Linear plus plateau (LP), quadratic (Q) and quadratic plus plateau (QP). In a second step an alternative parameterization that includes a shape parameter was introduced. For each type of response curve, this shape parameter was set to a common value for all subareas within a field and year, thus reducing the number of parameters that need to be estimated. Results show that the reduction of parameters did not reduce the goodness of fit when describing yield response, since the yield response of each subarea still depends on different maximum yields and different N amounts to attain their maximum yield. It turned out that the models using a common shape parameter allowed to evaluate even subareas with separately indetermined parameter values. Furthermore, agronomically meaningful correlations of the estimated response curves to the empirically observed characteristics of their respective subareas were improved. 相似文献