浅谈赤霉素在蔬菜上的使用技术

赤霉素(GA)又名920,是一种具有植物生理活性的赤霉酸。天然赤霉素最初(1926年)由日本科技人员在水稻"恶苗病"的赤霉菌中发现,至今已发现60余种,但其中生理活性最强的是GA3,使用也最广。人工生产是采用赤霉菌液体发酵来提取赤霉素。     

采用遗传算法的旋转机组状态趋势预测之探讨

探讨了采用遗传算法 (GA)进行旋转机组工作状态趋势预测的新途径 ,指出了适合度的选择是实现 GA算法趋势预测的关键。提出了 GA预测的方案 ,探讨了神经网络 GA预测、时间序列模型 GA预测 ,以及灰色模型 GA预测的适合度选择 ,提供了进行遗传算法预测的操作步骤。     

基于过桥车辆响应的遗传算法桥梁损伤识别

在考虑线路不平顺的基础上建立了移动车辆过桥的有限元模型,基于移动车辆动力响应采用遗传算法(genetic algorithm,简称GA)实现了桥梁结构不同损伤状态的识别。以桥梁损伤位置和损伤程度作为识别因子,首先,利用GA算法生成不同桥梁损伤状态;其次,采用有限元车桥模型分别计算不同状态下的车辆动力响应作为分析数据;最后,采用模拟实测数据与分析数据构建目标函数进行识别。针对不同损伤工况进行多次独立重复计算,选用成功率及首次出现最优解平均迭代代数分析GA算法识别效率。研究发现:GA算法能以较高效率实现桥梁单目标和多目标损伤的识别;识别过程中搜索空间大小对GA算法识别效率影响较大;GA算法对桥梁跨中及3/4跨位置的损伤识别结果较桥梁端部更为稳定。     

MENDED GENETIC BP NETWORK AND APPLICATION TO ROLLING FORCE PREDICTION OF 4-STAND TANDEM COLD STRIP MILL

In order to make good use of the ability to approach any function of BP (back propagation)network and overcome its local astringency, and also make good use of the overall search ability of GA(genetic algorithms), a proposal to regulate the network's weights using both GA and BP algorithms issuggested. An integrated network system of MGA (mended genetic algorithms) and BP algorithms hasbeen established. The MGA-BP network's functions consist of optimizing GA performance parameters,the network's structural parameters, performance parameter, and regulating the network's weightsusing both GA and BP algorithms. Rolling forces of 4-stand tandem cold strip mill are predicted by theMGA-BP network, and good results are obtained.     

GA VSD~+系列变速驱动喷油螺杆压缩机拓展至75kW

正2013年,阿特拉斯·科普柯推出革命性的GA VSD+系列变速驱动压缩机,与传统的压缩机相比平均节能50%,比GA系列的占地面积更小。阿特拉斯·科普柯正逐步扩展这一新技术的应用。从2016年6月中旬开始,阿特拉斯·科普柯将全面推出采用VSD+技术的GA 37、GA 45、GA 55和GA 75压缩机(包含标准机型和全性能机型)。阿特拉斯·科普柯GA VSD+压缩机采用永磁电机、新型压     

企业

正阿特拉斯·科普柯GA VSD~+系列变速驱动喷油螺杆压缩机拓展至75k W2 0 1 3年,阿特拉斯·科普柯推出革命性的GA VSD+系列变速驱动压缩机,与传统的压缩机相比平均节能50%,比GA系列的占地面积更小。阿特拉斯·科普柯正逐步扩展这一新技术的应用。从2016年6月中旬开始,阿特拉斯·科普柯将全面推出采用VSD+技术的GA 37、GA45、GA 55和GA 75压缩机(包含标准机型和全性能机型)。     

遗传算法优化的SVM在航空发动机磨损故障诊断中的应用

研究遗传算法(GA)优化的支持向量机(SVM)在航空发动机磨损故障诊断中的运用。介绍基于GA优化SVM算法的实现过程,对算法中关键参数进行分析,并用改进的GA对SVM中的惩罚参数和核参数进行优化。采用GA优化的SVM对某型号航空发动机的油液磨粒数据进行诊断,并从诊断精度、计算时间、抗噪能力三方面比较GA优化的SVM、BP神经网络和RBF神经网络的诊断精度。结果表明:GA优化的SVM能够有效地诊断航空发动机磨损故障; GA优化的SVM的诊断精度明显高于RBF和BP神经网络,且在有噪声的情况下,其诊断准确度依旧高于RBF和BP神经网络,但由于GA-SVM的结构和训练方法其训练时间较长。     

GA-BP网络在钢轨磨损量预测中的应用

基于GA算法及BP神经网络优点,将GA算法优化的BP网络应用于钢轨磨损量预测。通过赫兹模拟试验方法,在JD-1轮轨模拟试验机上获得不同曲线半径、轴重、运行速度工况下对应的钢轨磨损量,即神经网络所需样本,建立GA算法优化三层BP神经网络,对钢轨磨损量进行预测。结果表明:GA算法优化的BP神经网络对钢轨磨损量具有良好的预测性能,较好地反映了曲线半径、轴重、运行速度对钢轨磨损量的影响规律。     

盛花期喷施外源物质对临泽大枣产量及品质的影响

以河西走廊中部的临泽大枣为试材,研究了盛花期4种不同配比外源物质在不同浓度处理下对临泽大枣产量及果实品质的影响,以期为该地区枣树花期增产提质提供技术支撑。结果表明:添加微肥(Fe,Zn,B)的低浓度(25 mg/kg)赤霉素(GA_3)处理中单株产量和单果重分别平均高于其他处理20.57%和18.57%;另外,喷施适当浓度的赤霉素(GA_3)和生长素(IAA)、配合加入适量微肥对临泽大枣果实品质的改良有显著作用。     

数控机床维修改造系列讲座 第7讲 SINUMERIK 880GA的维修（上）

西门子开发的大中型机床用数控系统中最早的是8系统,但由于8系统的故障率较高、硬件结构较为复杂,电路板比较庞大,导致维修费用居高不下。因此1986年西门子采用与8系统同期的3系统电路板标准(230mm高),NC—PLC双口 RAM藕合方式,INTEL80186CPU芯片,生产出SINU-MERIK850系统,它的PLC还是沿用130WB或150U。1988年西门子针对850系统的缺陷,又推出全新的80186CPU处理的SINUMERIK880GA1型数控系统。1989年在880GA1的基础上推出改进型的880GA2数控系统。 1.SINUMERIK 880GA的特点 SINUMERIK 880GA1/880GA2型数控系统最     

Identification of <i>PtGai</i> (a DELLA protein) in trifoliate orange and expression patterns in response to drought stress

Gibberellins (GAs) are an important hormone in regulating plant growth and development, and DELLA protein is an essential negative regulator of GA signal transduction. The aim of the study was to clone a GA-inhibiting protein DELLA from trifoliate orange (Poncirus trifoliata L. Raf.) and to analyze the bioinformations and expression patterns of the protein gene in tissues and in response to drought stress. A DELLA protein was isolated from trifoliate orange and named as PtGai (Genebank number: MZ170959). The PtGai protein had 1731 bp open reading frames, along with 576 amino acid codes, and also grouped with sweet orange (XM_006430552.4). The PtGai protein sequence was 65% homology with the sequences of DELLA proteins in other plant families. PtGai protein existed in the nucleus based on the prediction of subcellular localization. PtGai protein could be expressed in roots, stems, and leaves, along with the highest expression in stems. PtGai was upregulated by drought stress in leaves and roots, along with the decrease of root total GA concentration and the inhibition of shoot and root biomass production. It indicated the characteristics of PtGai protein and the roles of PtGai in GA synthesis and plant growth.     

Effects of glutaraldehyde fixative osmolarities on smooth muscle cell volume,and osmotic reactivity of the cells after fixation

The contribution of glutaraldehyde (GA) to the effective osmolarity of GA fixatives, the osmotic reactivity of the cells after fixation in GA, and also the duration of fixation in GA on cell volume, were investigated using cultured smooth muscle cells (SMC) and spiral aortic strips. Four fixation procedures were studied. We found that GA contributes to the total effective osmolarity of the fixatives, and that the type of buffers used for the fixatives can also affect the cell volume differently during GA fixation. After GA fixation, the cells were still osmotically reactive, regardless of the buffer types for making up the GA fixatives, so that the osmolarity of the wash buffer after GA fixation is important. However, OsO₄ eliminates osmotic responses, thus the osmolarity of OsO₄ fixative and wash buffer have negligible influence on the cell volume. Longer fixation time up to 4 h had no effect on the cell volume.     

基于等效油耗最小的四驱混合动力汽车能量管理

提出了一种基于遗传算法优化的四驱混合动力汽车等效油耗最小控制策略。针对四驱混合动力的特点,建立了整车动力学模型,设计了基于等效油耗最小的瞬时能量管理优化策略。为进一步提高四驱混合动力汽车的燃油经济性,采用遗传算法优化了等效油耗最小策略的关键参数。硬件在环仿真结果表明,基于遗传算法优化的等效油耗最小策略可以实现整车能量优化管理,与基于规则的能量管理策略相比,其在典型工况下的平均燃油经济性高8.94%,比优化前的等效油耗最小策略的燃油经济性高2.68%。     

Prediction of contraction scour using ANN and GA

This paper emphasizes on the application of soft computing tools such as artificial neural network (ANN) and genetic algorithm (GA) in the prediction of scour depth within channel contractions. The experimental data of earlier investigators are used in developing the models and ANN and GA Toolboxes of MATLAB software are utilized for the purpose. The multilayered perceptron (MLP) neural networks with feed-forward back-propagation training algorithms were designed to predict the scour depth. The mean squared error and correlation coefficient are used to check the performance of networks. It is found that the ANN architecture 4-16-1 having trained with Levenberg-Marquardt ‘trainlm’ function had best performance having mean squared error of 0.001 and correlation coefficient of 0.998. In addition, the suitability of ‘trainlm’ method over other training methods is also discussed. The scour depths predicted by ANN model were compared with those computed by the two analytical models (with and without sidewall correction for contracted zone) and an empirical model proposed by Dey and Raikar [1]. In addition, heuristic search technique called genetic algorithm is used to develop the predictor for maximum scour depth within channel contraction. The population size for GA was 500 members with total generations of 1000, crossover fraction of 0.8 and Gaussian operator for mutation. It is promising to observe that the GA model predicts the maximum scour depth equally well as that of empirical model of Dey and Raikar [1]. Hence, both ANN and GA models can be satisfactorily used to predict the scour depth within channel contractions.     

A hybrid genetic algorithm to minimize makespan for the single batch machine dynamic scheduling problem

This paper considers a single batch machine dynamic scheduling problem, which is readily found in the burn-in operation of semiconductor manufacturing. The batch machine can process several jobs as a batch simultaneously, within the capacity limit of the machine, and the processing time is represented by the longest processing time among all jobs in a batch. For a single batch machine problem with arbitrary job release time, we proposed an improved algorithm (merge-split procedure) to refine the solution obtained by the LPT-BFF heuristic, and two versions of a hybrid genetic algorithm (GA) are introduced in this paper. Each version of the hybrid GA diversifies job sequences using the GA operators in stage 1, forms batches in stage 2, and finally sequence the batches in stage 3. The difference is that merge-split procedures are involved in the second version of the hybrid GA. Computational experiments showed that the hybrid GA would obtain satisfactory average solution quality and the merge-split procedures would be good at reinforcing the solution consistency of the hybrid GA.     

神经网络遗传算法在粉体流量测量的应用

利用浓度和速度电容式传感器分别测量粉体的浓度和速度,结合阀门开度、喷吹罐压力、温度等参数构造神经网络粉体流量测量模型,考虑BP算法训练神经网络测量模型时收敛速度慢、动态特性不够理想等不足,用遗传算法来优化神经网络测量模型的参数,以提高测量系统的精度。在现场与电子秤比对,最大满量程误差小于4.2%,具有工程应用价值。     

通航小型发动机的滑油监控系统研究

针对通航飞机的发动机特点和飞行特征,设计发动机滑油监控系统的监控流程和处理程序,结合滑油监控过程中的典型现象进行原因和故障分析,提出适用于通航小型发动机的运行和维修建议。该系统的研究对提高通航企业的安全水平、降低通航企业的维修成本具有较广的应用前景和较高的应用价值。     

遗传算法在产品人机形态设计中的应用

分析了产品人机形态设计的特点、现状和存在的不足,以及遗传算法的原理和应用范围。在探讨了人机交互的特性、接触点集和曲面形态的建立方法的基础上,提出了将遗传算法应用于产品人机形态设计中的基因编码、初始种群的产生、适应度函数的构造和种群选择等运算方法。最后以轮椅靠背的曲面设计和优化为例,阐明了遗传算法在产品人机形态方面的设计和优化方法。