干旱胁迫下常春藤响应的生理生化机制

为了给优化种质资源改良提供理论依据,选用不同常春藤品种作为供试材料,研究不同程度干旱胁迫处理对叶片生理生化指标的影响,并探寻逆境条件下常春藤生理生化指标的变化规律。结果表明,随着干旱胁迫的加剧,常春藤叶片中叶绿素a、叶绿素b和类胡萝卜素含量表现为上升趋势;相对电导率和丙二醛含量表现为升高的趋势;气孔孔径长度表现为先变小后变大的趋势;相对含水量和水分饱和亏分别表现为上升和下降趋势;过氧化物酶活性表现出现了分化,在轻度胁迫(10% PEG)条件下,表现为过氧化物酶活性上升的趋势,在重度胁迫(30% PEG)条件下,过氧化物酶活性上升和下降2种趋势。在供试的10个常春藤品种中,‘蝴蝶叶’和‘白尖刺叶’在多项指标上均表现出较强的抗旱性。     

不同穗型水稻剑叶光合特性及叶绿素荧光参数的研究

环境对光合作用影响可以通过叶绿素荧光的变化反应出来,农艺措施中以种植密度和施N量的变化对光合作用的影响尤为明显。本研究以不同穗型水稻品种（穗重型品种‘龙粳27’和穗数型品种‘龙粳25’）为材料,设4个密度处理和4个施肥时期处理,研究密度和氮肥运筹对不同穗型水稻光合指标及叶绿素荧光参数的影响。结果表明,穗重型水稻‘龙粳27’的叶绿素含量、光合速率、光合功能期均显著高于穗数型品种‘龙粳25’。适当稀植和氮肥后移对水稻剑叶的光合特性有明显的促进作用,穗重型品种‘龙粳27’在D2 (29.7 cm×13.2 cm)密度处理下,穗数型品种‘龙粳25’在D3 (33 cm×9.9 cm)密度处理下,N肥后移会显著提高二者产量。     

杉木幼苗光合及叶绿素荧光特征对氮沉降的短期响应

为了探究模拟氮沉降条件下杉木幼苗光合及叶绿素荧光特征变化规律,从光合生理的角度探讨不同季节杉木幼苗对氮沉降的短期响应。选取杉木幼苗为实验对象,模拟氮沉降实验,设置4个处理水平对照(N0)、低氮（N30:30 kg/(hm²·a)、中氮（N60:60 kg/(hm²·a)、高氮(N90:90 kg/(hm²·a)。结果表明：添加氮以后,杉木幼苗的净光合速率(Pn),初始荧光产量(F₀)、最大荧光产量(F_m)、最大PSII光能转换效率(F_v/F_m)、PSII潜在活性(F_v/F₀)显著降低,水分利用率(Wue)显著增高(P<0.05)。随着氮沉降水平的增加,气孔导度(Gs)与蒸腾速率(Tr)呈现先升高后下降趋势,水分利用率呈现先下降后升高趋势。在中氮和高氮处理下,F_v/F_m、F_v/F₀值显著降低(P<0.05)。在冬季,净光合速率与气孔导度、蒸腾速率和胞间二氧化碳浓度呈极显著正相关(P<0.01),春季,净光合速率与气孔导度和蒸腾速率呈极显著正相关(P<0.01),与胞间二氧化碳浓度呈负相关。氮沉降累积达一定阈值后,增加蒸腾失水,从而降低植株的水分利用效率。在冬季,净光合速率主要受到气孔限制的影响,热耗散增加,PSII反应中心出现光抑制现象,到春季,过量的氮沉降累积破坏了幼苗的光合结构,导致胞间二氧化碳浓度上升而净光合速率下降,非气孔限制成为影响净光合速率的主要原因。中氮处理可能使叶绿体中PSII潜在活性减弱,光反应中心光合电子的传递能力降低,导致光合效率下降。     

美洲鲥应激反应机理的研究

将美洲鲥(Alosa sapidissima)1龄幼鱼捕捞后放入较小容器中,研究了美洲鲥出现应激反应后血液生理生化指标和血清中皮质醇激素的变化,探讨了应激机理.结果表明:与深度麻醉的对照相比,美洲鲥应激后血液中红细胞数目、血红蛋白含量极显著降低(P<0.01),血细胞比容显著降低(P<0.05),红细胞沉降率、红细胞渗透脆性极显著增加(P<0.01);血清皮质醇含量迅速增加到对照组的48倍左右;应激后总蛋白、球蛋白含量均极显著降低(P<0.01),白蛋白显著降低(P<0.05),谷丙转氨酶、碱性磷酸酶、胆碱酯酶极显著增加(P<0.01),谷草转氨酶、乳酸脱氢酶、酸性磷酸酶、血糖、甘油三酯显著增加(P<0.05),血清中肌酸和尿素氮无显著变化(P>0.05).血液生理生化指标明显变化表明,美洲鲥应激后皮质醇含量迅速增加,引起机体血液中血糖和乳酸脱氢酶的增加,导致了机体缺氧,出现了应激性急性出血.     

谷子和玉米叶片光合荧光参数对烟嘧磺隆胁迫的响应差异

为探明谷子和玉米对烟嘧磺隆胁迫差异的光合生理机制,采用盆栽试验,选用谷子（张杂10号和晋谷21号）及玉米（迪甜8号和农大108号）为试验材料,在四叶一心期喷施5个不同剂量的烟嘧磺隆,分别在处理后7d和15d测定幼苗株高、叶面积、SPAD值、净光合速率（P_n）、气孔导度（G_s）、蒸腾速率（T_r）、胞间CO₂浓度（C_i）、叶片最大光化学产量（F_v/F_m）、实际光化学效率[Y(Ⅱ)]、光化学猝灭系数（q_P）和非光化学猝灭系数（NPQ）的变化。结果表明,除7.5g/hm²的烟嘧磺隆处理之外,张杂10号、晋谷21号和迪甜8号的株高、叶面积、SPAD值、P_n、G_s、T_r、F_v/F_m、Y(Ⅱ)和q_P在用药后7d和15d时均显著低于对照,各指标在用药浓度15.0~60.0g/hm²处理之间的下降幅度均随烟嘧磺隆剂量的升高而增大;而C_i和NPQ却呈相反趋势。在15.0~120.0g/hm²处理之间,处理后7d和15d农大108号的所有指标均与对照差异不显著。综上所述,谷子对烟嘧磺隆的抗性弱于玉米,品种间也存在差异,部分原因是烟嘧磺隆显著降低了敏感品种叶片的叶绿素含量,虽然增加了光能热耗散,但PSⅡ功能还是受到抑制,导致光合能力下降。     

新颖袋泡茶工艺参数的优化

研究了原料颗粒大小、浸泡时间以及冲泡次数对新颖袋泡茶品质的影响。结果表明,袋泡茶选择40~60目的颗粒原料最佳,汤色黄绿、浸出率高,冲泡5min、冲泡3次为最佳,3次氨基酸、咖啡碱、茶多酚浸出率分别占到总量的96.74%、96.24%、95.76%。     

与冬小麦籽粒蛋白质有关的几项生理参数

1986—1988年在田间种植7个籽粒蛋白质含量不同的冬小麦品种,于开花、开花后10天、20天和收获各生育期测定茎、叶、穗、粒各部位的氮素含量,旗叶硝酸还原酶活性(NRA),30厘米耕层内的根干重和根活力。结果表明,开花到开花后10天的根干重、根活力、旗叶 NRA 和旗叶叶氮量(N/LA)都继续上升,并维持较高水平;开花后地上部氮同化量     

胡麻主要经济性状遗传参数的研究

本文估算了胡麻主要经济性状的广义遗传力、遗传相关系数、遗传进度和选择指数等遗传参数.结果表明;千粒重、株高、工艺长度的遗传力、遗传进度较高,遗传变异系数较大,在早代进行一次选择即可;每果着粒、开花期的遗传力和遗传进度也较高,而变异系数较小.对其也应加强早代选择,并加大选择群体;单株粒数、主茎分枝的遗传力和遗传进度中等,应进行几代连续选择;单株粒重、单株结果的遗传参数值均较小,直接选择效果差,可通过显著相关的性状进行间接选择.特别是对于单株粒重,还可以用相对效率高的选择指数进行间接选择.     

The Setting of Acoustic Emission Detecting Parameters in Concrete Structure

In order to solve the problem that the choice of acoustic emission (AE) parameters in concrete detection are determined only by experience, several tests were conducted. Through lead-breaking and stimulant loading tests, the reasonable value of threshold at which noise can be efficiently insulated was obtained. Through lead-breaking tests, time parameters (PDT, HDT, HLT) which fit concrete samples were obtained. The velocity and attenuation of AE signals in concrete also were measured through lead-breaking tests. This method of ascertaining detection parameters by testing is practical for AE detection in concrete structures.     

Optimization of Structure Parameters for Self Recirculation Burner

In the paper,the relationship between the structure parameters and P V characteristics and recirculation ratio of the burner are studied by the simulated experiment of a self recirculation burner.The optimum structure parameters of the burner are analysed and tested in the cases that the produced recirculation amaunt of optimal controlled NO x consumpting the lowest energy can be ensured.     

A Method of Modeling with Structural Stochastic Parameters

In order to reflect the stochastic characteristic of a structure more completely and accurately,this paper presents a theory and method of modeling with structural stochastic parameters using probabilistic finite element method and perturbant finite element method,on the basis of modeling with deterministic parameters.It is applied to double decker space frame,good results are gained.     

播距和播量对张杂谷10号生长特性及产量的影响

为提高丘陵山地谷子机械化播种水平,明确机械精量播种模式下播距和播量对张杂谷10号生长特性及产量的影响,通过自走式多功能小粒种子播种机JAS-502B播种,研究不同播种参数对张杂谷10号生长发育和产量的影响。结果表明,随着播距减小和播量增大,谷子株高、叶绿素b含量、胞间CO₂浓度、最大光化学量子产量和结穗数明显升高,茎粗、叶面积、干重、叶绿素a含量、类胡萝卜素含量、净光合速率、蒸腾速率、气孔导度、表观光合电子传递速率、硝酸还原酶活性、可溶性蛋白含量和穗粒重明显降低,叶绿素（a+b）含量、非光化学猝灭系数和光化学猝灭系数无显著差异。在本试验条件下,使用F轮和X轮播种均可提高张杂谷10号产量,使用YJ轮播种谷子产量较低。不同播距条件下谷子产量差异不显著,张杂谷10号是通过分蘖数来调节穗数,实现低密度条件下的增产。     

酶法制取桑葚汁的工艺研究

测定了桑葚中果胶含量,测定结果为0.36%;利用正交试验确定制汁过程中的用酶量、pH值、温度和时间4个工艺参数的最佳水平。结果表明,最佳的工艺参数为用酶量0.04%,pH值3.5,温度45℃,时间3 h。利用最佳工艺参数制取桑葚汁,使出汁率提高17.2%。     

结构参数对水润滑橡胶合金轴承摩擦噪声的影响分析

为了研究水润滑橡胶合金轴承结构参数对其低速重载工况下摩擦噪声的影响,使用复模态分析方法建立了水润滑橡胶合金轴承系统仿真模型,采用专业仿真软件分析了不同摩擦系数及结构参数条件下摩擦噪声产生的概率,进而研究结构参数对摩擦噪声的影响,进行了平板型和圆弧型结构的水润滑橡胶合金轴承摩擦噪声的对比实验。研究结果表明,水润滑橡胶合金轴承的水槽半径大小、摩擦面形状以及摩擦副的摩擦系数对水润滑橡胶合金轴承的摩擦噪声有较大影响,而水槽的形状对轴承摩擦噪声的影响不大。对一定结构尺寸的水润滑橡胶合金轴承,水槽半径为4 mm、平面型摩擦面的结构可以大大减少轴承出现摩擦噪声的可能性,相关实验结果与计算结果是吻合的。     

Simulation Research of Control Parameters in Induction Motor Vector Control System

In order to obtain the effect rules of control parameters of speed regulator on performance indexes of induction vector-controlled system and the setting rules of control parameters of speed regulator,according to rotor flux oriented control principle,a vector control model of induction motor is established and simulated with the software of Matlab/Simulink.This vector control system is proved that it possesses good static and dynamic performance.This paper analyzes the effect of control parameters' variations of speed regulator on performance indexes and gives simulation results.     

An Estimating Method of Ultimate Gain and Ultimate Period

At tuning PID controller,ultimate gain Ku and ultimate period Tu of the proceseare usually the desired parameters.To lessen disturbance of tuning action and av oid to drive thesvstem to the verge of instability,a new estimating methed of Ku and Tu is developed,which based onthe charactristic areas of the u nit step response of the procase,By this method,it is easy forauto-tuning PID controller with Ziegler-Nichols like tuning formula. Results of digital simulationshow that this method is effective.     

The Component Type Choosing and Parameter Matching of ISA HEV

This paper briefly introduces the structure and main function of a mild hybrid system based on ISA. The components of the whole powertrain system include ISA,engine and battery. Transmission is choosed according to its typical configuration and functions. In addition,the specific parameters of power and torque of ISA,engine power,the number and capacity of battery,the gear ratio of gearbox are determined according to the required performance and fuel economy. In order to achieve the design target, the Genichi Taguchi method is used to optimize the gear ratio. At the same tine, the simulation of ISA mild hybrid vehicle is carried out and compared with conventional vehicle by using the ADVISOR software.     

Dynamic characteristics and static response analysis of interval parameters structure

Determining the interval parameters of structural dynamic characteristics and the extreme value of static response can solve some structural uncertainties. The dynamic characteristics and static response of structures are always closely linked with the parameters. Finding the intrinsic link between them can make the calculation of the dynamic characteristics and the extreme value of interval structure simple and effective. Through function derivation of elastic modulus E and mass density ρ, it can be found that they are related to structural dynamic characteristics and static response. And the dynamic characteristics of trusses are taken as an example to calculate the maximum displacements of loading direction and unloading direction, their parameters are compared and the relation between elastic modulus and the displacement of loading direction are verified.     

响应曲面法优化高粱挤压最佳操作参数的研究

以高粱为原料,研究系统操作参数,包括:物料含水率、喂料速度、螺杆转速、机筒温度对目标参数的影响,并以响应曲面法优化最佳操作参数,优化得到的最佳操作参数为:物料含水率15.77%,喂料速度26.97r/min,螺杆转速181.20r/min,五区温度158.28℃。     

Genotype-environment interactions and phenotypic stability analyses of linseed in Ethiopia

Seed yield of 10 linseed genotypes, tested in a randomized block design with four replications across 18 environments of Ethiopia was analysed using different stability models. The objectives were to assess genotype‐environment (G‐E) interactions, determine stable genotypes, and to compare the stability parameters. Year by location and location variability were the dominant source of interactions. The stability analyses identified ‘R12‐N10D’, ‘Chilalo’ and ‘P13611’ב10314D’ as more stable genotypes, while ‘R11‐N1266’, ‘R10‐N27G’ and ‘R12‐D24C’ were specifically adapted to some environments. The highly significant rank correlations found among the deviations from regression, additive main effects multiplicative interaction, stability values, coefficients of determination, and stability variances indicated their close similarity and effectiveness in detecting stable genotypes over a range of Ethiopian environments.