Two Stations of Asymmetric Polling System with One Buffer

The authors consider two stations of asymmetric polling system with one-message buffer,give the state probability of each station at polling instants,and the distributions and mathematical expections of polling cycle time,intervisit time and wating time.The loss probability at each station has been evaluted.     

基于REMCC-BPNN的稻瘿蚊发生量预测研究

为了提高预测稻瘿蚊发生量的准确度,有效防控稻瘿蚊虫害成灾面积,采用基于K近邻样本拟合相对误差绝对值与时序相关系数最小原则优化的BP神经网络预测模型REMCC-BPNN,选取广为认可的气温和降水量为影响因子,对稻瘿蚊的发生量进行独立预测。通过2个实例（化州市晚稻稻瘿蚊发生程度和广西邕宁县稻瘿蚊发生程度）验证显示：REMCC-BPNN模型的独立预测精度分别为94%和100%,明显优于经典回归分析、SVR-CAR、MIV-BPNN等参比模型。可见,REMCC-BPNN模型在虫害发生量预测方面有良好的应用前景。     

土霉素在黄颡鱼肌肉组织中残留消除规律的研究

为研究土霉素在黄颡鱼肌肉组织中残留消除规律。在水温25℃条件下,以每天100 mg/kg 的剂量,连续5天口灌土霉素后定时取样,采用高效液相色谱法检测。结果显示：黄颡鱼肌肉组织中土霉素的平均回收率为80.2%,方法检出限为0.05 μg/g。研究结果表明：土霉素在黄颡鱼肌肉组织中消除缓慢,其含量降到0.1 μg/g的休药期为46天。     

中华金叶榆“小枝冷粘皮”嫁接技术研究

为了使中华金叶榆的芽接嫁接苗木当年成为商品苗,缩短培育周期,在传统“热粘皮”芽接技术的基础上研究开发新的嫁接技术“小枝冷粘皮”嫁接。采用“小枝冷粘皮”嫁接,就不同嫁接时间处理对中华金叶榆嫁接成活率、成苗率、苗木当年生长量进行了对比试验,筛选出最佳的“小枝冷粘皮”嫁接时期。结果表明,“小枝冷粘皮”和“热粘皮”2种嫁接的成活率并不存在明显差异,但“小枝冷粘皮”嫁接成苗率显著高于“热粘皮”,苗木当年平均生长量可以达到1.42m;结合苗木生长量确定4月15日—5月30日为“小枝冷粘皮”最佳嫁接时间。     

澳洲坚果花粉保存及生活力测定

为研究澳洲坚果花粉最佳保存方法,为人工授粉提高产量及杂交育种亲本组合提供理论依据,以澳洲坚果品种D的花粉为材料,采用自然干燥,干燥皿干燥,40 ℃烘箱干燥3种干燥方式,分别干燥2 h,6 h,10 h,24 h,并在低温（4 ℃）条件下保存5 d、10 d、15 d、20 d、25 d、30 d,以琼脂培养法测定花粉萌发率。结果表明：自然干燥和干燥皿干燥方式下花粉萌发率差异不显著,但两者均极显著高于40 ℃烘箱干燥方式下的花粉萌发率;自然干燥下4个干燥时间在保存了20 d内的花粉萌发力均能用于人工授粉;干燥皿干燥2 h、6 h保存20 d内的花粉萌发率均在15%以上,可以在生产中应用;40 ℃烘箱干燥方式处理下,所有干燥时间和保存时间的花粉萌发力均在15%以下,对于人工授粉没有价值;在低温（4 ℃）保存下,澳洲坚果花粉萌发率以自然干燥方式下干燥2 h保存5 d最佳,为42.24%;但是综合考虑外界环境调控的容易程度,在生产中选择干燥皿干燥方式为最佳。     

Service Gated Discrete-time Polling System with Bernoulli Feedback

This paper analyzes asymmetric limited gated service polling system with Bernoulli feedback. By the imbedded Markov chain theory and the probability generating function method,The authors derive the generating function of intervisit time , polling cycle time , service time of each station and queue length in the each station .Furthermore , the successive sojourn time of customer C in ith station (i=1,2,...N) and queue length after the (m-1)th service are obtained.     

小麦高分子量谷蛋白亚基功能的体外鉴定

通过SDS-PAGE方法回收纯化小麦高分子量谷蛋白亚基1Ax1、1Dx5、1Dy10、1Bx7、1By8和1By9,然后利用微量配粉方法将单个亚基分别添加到对照“京411”面粉中,经过揉混仪分析单个亚基对揉面特性的影响,进而确定各个亚基的功能特性。根据揉面时间、稳定时间等参数的变化,6个小麦高分子量谷蛋白亚基对面粉品质的影响表现为1Dy10 > 1Ax1 > 1Dx5 > 1By8 > 1Bx7 > 1By9。研究结果表明,通过揉混仪进行体外配粉检测是快速鉴定高分子量谷蛋白亚基功能的一种有效方法。     

甘蓝类作物抽薹期及开花期数量性状的研究进展

从甘蓝类作物抽薹开花期数量性状研究的历史、甘蓝类作物抽薹期开花期性状的传统遗传学研究、甘蓝类作物与其它十字花科抽薹期和开花期的分子标记研究及与其它十字花科作物的抽薹及开花期的比较作图研究等几个方面,概述了甘蓝类作物抽薹期与开花期等数量性状的研究进展,并对以后的研究方向提出了建议。     

Comparative analysis of methods for designing digital control point of load converters

To make the biomass tablets heated fully in a fluidized pyrolysis liquefaction process, it ought to be ensured that sufficient biomass granules stay long enough in the bed so as to meet or exceed the expected pyrolysis temperature. That is, the prerequisite is that the staying time must be more than or equal to the pyrolysis time. However, the staying time is decided by the flow speed and CFB parameters, and the pyrolysis time is controlled by the heat transfer process of biomass particles in a fluidized bed both of which are closely related to the parameters of biomass particles. This paper analyses the heat transfer process of the biomass in the pyrolysis reaction tower, establishes a simplified model of heat transfer with a gas solid flow, studies the rule of pyrolysis time and staying time changing with the biomass size and finds out a theoretical method of selecting the expected parameters of biomass granule to ensure the full pyrolysis of biomass materials.     

小麦产量与品质性状杂种优势的研究

本试验在河南省从北到南4个不同纬度的地点上连续进行2年(共8个环境类型).材料包括7个小麦亲本和由此按不完全双列杂交模式组配、人工去雄授粉产生的12个杂种组合.研究结果,小麦杂种单株籽粒产量平均杂种优势及其变异幅度分别为22.01%、11.90—40.64%.每穗粒数的杂种优势大于千粒重和单株穗数的杂种优势.面团形成时间,面团稳定时间,拉伸仪面积、峰值、延伸度及其拉伸仪峰值与延伸度的比值均呈现正向杂种优势;籽粒蛋白质含量、吸水率、面筋含量和弱化度表现负向杂种优势.但单株籽粒蛋白质产量表现正向杂种优势,平均17.20%.容重表现正向杂种优势,且变异范围较窄.杂种优势的环境变异主要是受地点以及地点、年份和杂种间二级互作的显著影响.     

大豆光周期反应与生育期基因研究进展

20世纪20年代,植物学家Garner与Allard在研究大豆与烟草等植物的光反应时发现了植物光周期现象。大豆作为模式植物对光周期现象的理论形成起了重要作用。但大豆基因组的复杂性及与相关功能基因关系的不明确性严重阻碍了学者对大豆光周期现象本质的认识。近年来,随着控制大豆生育期主要QTL基因的相继克隆,特别是对大豆生育期贡献最大的E1基因的成功破译,学者们逐步认识到大豆光周期调控开花的独特性。遗传学及分子生物学研究表明,大豆中具有拮抗关系的E1和FT基因位于大豆光周期调控开花主要通路的中心节点(integrator),但两者间的作用机制及相关的调节因子尚待明晰。对大豆光周期反应及生育期基因的深入研究,在生产实践上可为大豆品种的栽培区划、合理布局及分子育种等提供理论依据。     

不同分散温度、时间对双波长法测定高粱直、支链淀粉及总淀粉含量的影响

为了测定高粱直、支链淀粉及总淀粉含量,采用双波长比色法研究了不同分散温度、时间处理对高粱淀粉直、支链淀粉及总淀粉含量的影响。结果表明,在试验温度70~100℃范围内,75℃分散15 min时支链淀粉百分含量最高,85℃分散5 min时支链淀粉百分含量最低。对于直链淀粉,95℃以后,随着分散的时间延长,测得的高粱直链淀粉百分比不断增高。样品分散温度与时间对高粱中总淀粉含量影响与支链淀粉相同,其测定值在75℃分散15 min时最高。由此可知,不同分散温度、时间处理对双波长法测定高粱淀粉直、支链淀粉及总淀粉含量影响不一样。     

燕麦—小麦混合粉的粉质特性研究

以小麦粉为对照,研究不同配比的燕麦—小麦混合粉的粉质特性。结果表明,随着燕麦粉质量分数的增加,燕麦全粉—小麦粉混合粉和燕麦精粉—小麦粉混合粉的吸水率均呈增大趋势,稳定时间均是先增大后减小;在燕麦粉质量分数为5%～40%,随着燕麦粉质量分数的增加,形成时间的变化趋势均是先减小后增大,弱化度的变化趋势均是先减小后增大。     

溴乙烷破除马铃薯休眠的效果及激素变化研究

研究溴乙烷破除马铃薯休眠的效果及其在此过程中内源激素含量的变化,并在激素水平上初步探讨了溴乙烷破除马铃薯休眠的机理,以期为生产上应用溴乙烷破除马铃薯休眠提供参考。以‘薯引1号’、‘大西洋’和‘克新1号’3个马铃薯品种的试管薯为材料,利用溴乙烷打破块茎的休眠,测定休眠强度、休眠幅度和内源激素含量的变化。结果表明,适宜浓度的溴乙烷使3个品种的休眠期分别缩短了33天、45天、46天,效果显著。另外,在休眠过程中,块茎的内源IAA和ABA含量比较高,而GA和ZR的含量较低。GA和ZR的含量呈现单峰曲线变化,溴乙烷处理会使波峰出现提前;在处理起始阶段,GA的含量高于对照。溴乙烷可能通过调节GA和ZR的含量来破除试管薯的休眠。     

A NEW REDUCED-ORDER PREDICTIVE SELF-TUNING CONTROL ALGORITHM

This paper presents a new self-tuning controller for pure time-lag controlled processes. The experimental results of digital simulation and real-time control on the high temperature diffuse furnaces prove that the algorithm suits the mimimum or non - minimum systems which have large time-lag, and it has distinguished characteristics in real-time and control precision.     

Analysis of Heat Transfer during the Response Time of Temperature Sensor Fire Detector

This paper analyzes the heat transfer principle of temperature sensor fire detector, establishes mathematical model of heat transfer with considering the effect of radiation heat transfer and presents a new calculation method for the response time. The results of calculation show that when the environment temperature is rather low and the response temperature is set higher, the effect of radiation heat transfer on response time shouldn't be neglected. This paper may be helpful in appraising fire safety and designing alarm system.     

喷雾干燥法制备速溶枣粉及其冲调性分析

以红枣为原料,通过发酵工艺制备枣浆,采用喷雾干燥法制备速溶枣粉,以速溶枣粉的润湿时间和分散时间为考察指标,在单因素试验的基础上,采用响应面法优化速溶枣粉制备工艺。结果表明,喷雾干燥法制备速溶枣粉最佳工艺条件为:进风口温度130℃,进料流量1.27 m L/h,料液浓度22.31%,此条件下制备枣粉的润湿时间为44.12 s,分散时间为8.23 s,外观呈浅棕红色,具有红枣特有香气,冲调性良好。     

Using Genomic Information for Altering Bolting and Flowering Behaviour of Crop Plants

Altering the phenological development of a plant is a major target of many plant breeding programs and can be exploited to achieve different outcomes. For example, in seed crops, the transition from the vegetative to the reproductive phase （flowering） should be as early as possible if unfavourable environmental conditions （drought, heat, cold） endanger seed harvest. By contrast, delayed flowering favours higher biomass production and increased yield potential by extending the grain filling phase. Flowering time is also important in crops where only vegetative parts of the plant are harvested because shoot elongation and flowering would substantially reduce yields.     

K近邻的自适应谱聚类快速算法

利用时域递归展开算法对墙体内热湿耦合传递方程进行求解。以木板为例,应用该算法进行了热湿耦合传递的分析计算,在时间域和空间域上分别运用递归展开法和控制容积法进行离散,从而得到递归形式的线性方程组,运用MATLAB软件对这一过程进行求解。计算结果与有限差分算法、解析解计算结果以及实验数据吻合良好,表明该算法能够用于求解多孔介质热湿耦合传递模型。时间步长的改变对计算结果影响较小,可通过增加时间步长方法来减少工作量。     

Application of a FDTD/MOMTD Hybrid Method to the Scattering Problem of the Ground Penetrating Radar

In order to analyze and research the scattering problem of the ground penetrating radar under the ground, a hybrid method combining FDTD and MOMTD is constructed to solve the problem. The curve of current on central feeding point of pick-up antenna is obtained by simulating when different distance between the ideal conductor and the ground is considered, correctness of the result gained by employing the hybrid method is proved through qualitative and quantitative analysis.