油菜生育期动态模拟模型的构建

在13个不同熟期甘蓝型油菜品种的2年大田试验中,调查不同播期条件下各品种的生育进程及发育状态。依据油菜生理发育时间恒定原理、生理生态理论及各生育阶段与温度、光周期等外部环境关系,采用Logistic曲线描述油菜光周期效应,谐波分析法分析气温昼夜变化,分段正弦指数函数分析热效应和低温春化效应,结合上述因素构建油菜生育期动态模拟模型;确定模型光周期敏感因子、温度敏感性、生理春化时间和角果期因子4个遗传参数;模型的检验分析表明,对不同播期模拟值与观测值的根均方差平均值为2.67 d,对不同品种模拟值与观测值的根均方差平均值为3.74 d;4个遗传参数值对13个油菜品种聚类分析的结果符合品种特性。因此,该模型在一定范围内可准确揭示油菜对温、光的反应规律,具有较强的可靠性和预测性。     

基于不同发育阶段协同的小麦品种抗旱性综合评判

筛选抗旱性鉴定指标并建立评价模型,可以为抗旱小麦品种的选育以及布局提供依据。以黄淮海麦区主推的23个冬小麦品种为试验材料,设置干旱胁迫和充分灌溉2种处理,在拔节、孕穗、开花和灌浆期测定小麦12项形态生理指标,计算各项指标的抗旱系数,采用主成分分析、隶属函数法、灰色关联度法、聚类分析和逐步回归分析方法对小麦品种的抗旱性进行综合评价。结果表明,干旱胁迫下孕穗期和灌浆期各性状变异幅度较大(7.4%～41.7%),而拔节期和开花期的性状变幅相对较小(9.63%～31.63%)。通过对12个指标的相关分析发现,在各时期下各指标之间均存在显著或极显著相关性。进一步利用主成分分析分别将拔节期、孕穗期和开花期的12个性状参数转换为6个相互独立的综合指标,而将灌浆期转换为5个相互独立的综合指标,4个时期的累积贡献率依次达到89.03%、88.69%、87.68%和85.83%。利用隶属函数法计算各时期的综合抗旱评价值(SD值),并对各时期SD值与产量抗旱指数(DRI)间进行定量关系分析,开花期拟合精度最高(0.744),而灌浆期最低(0.679)。为更好地将不同时期的抗旱性信息综合起来,通过灰色关联度分...     

考虑驾驶员视觉适应的公路隧道入口段亮度确定方法

驾驶员的视觉适应过程直接影响交通安全。为考虑驾驶员的视觉适应过程,在确定公路隧道入口段亮度时,通过实测得到驾驶员驾车进入隧道过程中的瞳孔大小变化数据,建立了描述驾驶员驾车进入隧道过程中瞳孔面积变化速率最大值与各相关参数之间关系的数学模型。以驾驶员不发生视觉障碍的瞳孔面积变化临界速率为基准,计算得到了驾驶员瞳孔面积变化达到临界速率时,隧道入口段的最低亮度,分析了隧道入口段所需最低亮度与洞外亮度之间的关系,通过回归分析建立了隧道入口段亮度与洞外亮度之间关系的数学模型,得到了考虑驾驶员视觉适应的公路隧道入口段亮度确定方法。     

花岗岩残积土的土-水特征曲线参数概率

土-水特征曲线（SWCC）用于描述非饱和土中含水量与基质吸力的关系，在非饱和土力学中具有重要的作用。在SWCC拟合模型中有多个拟合参数，各值通过实验方法获得且具有很大的不确定性。采用贝叶斯理论对拟合参数的不确定性进行分析，将SWCC拟合参数作为随机变量，采用Van Genuchten模型拟合花岗岩残积土的土-水特征曲线试验数据。以马尔可夫链蒙特卡罗方法的延迟拒绝适应性算法获得模型参数后验分布抽样，获得了不同置信区间的SWCC及其对应参数值。     

实测确定公路隧道洞外景物亮度的方法

分析比较了查表法、环境简图法和黑度法3种确定洞外亮度的方法,发现3种方法均未完全考虑隧道所处区域的环境和光气候条件。为了能快速准确地确定隧道洞外景物亮度,以从莞高速公路的7座隧道为测量对象,通过现场实测,建立了洞外景物亮度与水平面照度之间的关系。在对当地光气候数据进行统计分析的基础上,确定隧道洞外景物亮度标准值、东莞地区隧道洞外典型景物亮度设计参考值,并得到了东莞地区4个朝向隧道洞外典型景物亮度值。     

小麦不同指标对紫外辐射UV-B增加反应敏感性差异的比较

本文比较了小麦不同生育时期和不同部位的指标对紫外辐射UV-B增加反应敏感性的差异,结果表明：小麦不同指标对紫外线增加响应的敏感性存在显著的差异,主要趋势表现为生理指标＞形态指标;生殖生长指标＞营养生长指标。在拔节－孕穗期小麦各指标对紫外线增加响应的敏感性最大,且不同器官、不同部位对紫外线增加响应的敏感性也有显著的差异。试验结果对评价不同作物和不同品种对紫外线增加响应的敏感性适用指标以及合理的选育抗紫外线品种指标具有一定的参考价值。     

气象参数对成都地区办公建筑能耗的影响及预测

气象参数是影响建筑热环境和供暖空调能耗的主要因素之一。基于成都地区1971—2000年共30 a的历史观测数据，生成了建筑能耗模拟软件EnergyPlus所需要的逐时气象数据文件。比较分析了该地区30 a干球温度、太阳辐射等各气象参数月均值的变化，模拟分析了该地区建筑的采暖、制冷及总能耗，利用多元回归建立了建筑能耗与气象参数之间的关系式，并检验了该关系式的准确性。结果表明：成都地区办公建筑能耗变化与各气象参数没有呈现明显的规律性；建筑月总能耗与各气象参数呈纯二次多项式关系，月采暖能耗、月制冷能耗与各气象参数呈交叉二项式关系；建筑月能耗回归模型能够较准确地预测建筑月能耗与各气象参数的关系，且月采暖能耗和月制冷能耗回归模型预测的准确性优于月总能耗模型。     

直接接触式换热器传热性能优化

建立了以容积换热系数为目标函数,工质流率U₀、喷头喷孔直径d_i、导热油液位高度Z为决策变量的直接接触式换热器性能优化模型,同时进一步将液滴群行为与传热协同关系作为约束条件引入优化模型中,重点分析该约束条件对优化过程及结果的影响。运用遗传算法对原模型和补充模型进行了优化分析,结果表明：原模型优化后的容积换热系数达到了初始值的6.7倍;而补充模型最优值的迭代次数比原模型减小了约55%,同时最优值比原模型提高了0.3%。所以该约束条件不仅提高了迭代速率,还提高了寻求全局最优值的概率,使得最优解更逼近全局最优值。     

PI模型在乌兰察布市土壤生产力评价中的适用性研究

为了给乌兰察布市土壤生产力评价提供一种简单、实用、客观的评价方法,在PI模型及后人修正的PI模型(MPI)的基础上,结合研究区土壤特点,对PI模型进行了修正(MPI-Ⅱ),主要修改了MPI模型中有机质指标的计算方法,并增加了碳酸钙指标。利用MPI模型和MPI-Ⅱ模型,评价了43个土种的土壤生产力,并与研究区第2次土壤普查中综合评价法的评价值进行了比较。结果表明：（1）MPI-Ⅱ模型的评价值与综合评价法的评价值之间的相关性(R2=0.589,P<0.01)比MPI模型与综合评价法之间的相关性(R2=0.305, P<0.01)高,MPI-Ⅱ的评价值可能更接近研究区的实际情况;（2）总体而言,MPI-Ⅱ模型的评价值与综合评价法的评价值较一致,但有5种土壤的评价值差异较大,可能是综合评价法的主观性较强所致。因此,MPI-Ⅱ模型对研究区的土壤生产力评价可能有较好的适用性。     

山西高粱的淀粉特性分析

运用淀粉黏度速测仪(RVA)分析了61份山西高粱品种(系)淀粉糊化特性的差异.结果表明,品种(系)的膨胀势、RVA参数等指标的变异幅度较大,其中消减值的变异系数最大,达到了51%,变异范围在6.60-130.42BU;淀粉中糊化温度的变异系数最小,只有3%,变异范围在83.67-94.25℃.对各品质性状进行相关性分析发现,直链淀粉含量与膨胀势间存在极显著差异,主要淀粉特性,特别是回冷恢复值、崩解值、消减值等变异范围较大,且RVA各参数之间的相关性非常显著.     

Photoperiod sensitivity in three rice crosses

Summary The degree of photoperiod sensitivity was studied in the F₅ and F₆ of three crosses between sensitive and insensitive rice cultivars under field conditions. Photoperiod sensitive lines could be identified as nonflowering lines in a February-seeded nursery. These lines had a short critical daylength (i.e. late flowering date). The strongly sensitive lines also had a high degree of photoperiod sensitivity, measured as the ratio of the difference in growth duration for two seeding dates to the difference in seeding dates in the main wet season. Some lines, however, with a relatively high degree of sensitivity and a longer critical daylength, were able to flower in the February-seeded nursery. In the cross KDML 105 × IR42, photoperiod sensitivity showed a bimodal distribution, suggesting major gene control. In Latisail × IR28 and KDML 105 × IR50, the inheritance was not clear. In KDML 105 × IR42, 37 out of 97 F₅ lines were strongly sensitive and in KDML 105 × IR50, 7 out of 95 F₅ lines were strongly sensitive. Thus the choice of the insensitive parent greatly influenced the number of strongly sensitive lines recovered. Degree of photoperiod sensitivity was positively correlated with plant height in the wet season. In the dry season this was not observed, because the sensitive lines flowered earlier.     

A global sensitivity analysis of cultivar trait parameters in a sugarcane growth model for contrasting production environments in Queensland,Australia

New sugarcane cultivars are continuously developed to improve sugar industry productivity. Despite this sugarcane crop models such as the ‘Sugar’ module in the Agricultural Productions System sIMulator (APSIM-Sugar) have not been updated to reflect the most recent cultivars. The implications of misrepresenting cultivar parameters in APSIM-Sugar is difficult to judge as little research has been published on the likely values of these parameters and how uncertainty in parameter values may affect model outputs. A global sensitivity analysis can be used to better understand how cultivar parameters influence simulated yields. A Gaussian emulator was used to perform a global sensitivity analysis on simulated biomass and sucrose yield at harvest for two contrasting sugarcane-growing regions in Queensland, Australia. Biomass and sucrose yields were simulated for 42 years to identify inter-annual variability in output sensitivities to 10 parameters that represent physiological traits and can be used to simulated differences between sugarcane cultivars. Parameter main effect (S_i) and total effect (ST_i) sensitivity indices and emulator accuracy were calculated for all year-region-output combinations. When both regions were considered together parameters representing radiation use efficiency (rue), number of green leaves (green_leaf_no) and a conductance surrogate parameter (k_L) were the most influential parameters for simulated biomass in APSIM-Sugar. Simulated sucrose yield was most sensitive to rue, sucrose_fraction (representing the fraction of biomass partitioned as sucrose in the stem) and green_leaf_no. However, climate and soil differences between regions changed the level of influence cultivar parameters had on simulation outputs. Specifically, model outputs were more sensitive to changes in the transp_eff_cf and k_L parameters in the Burdekin region due to lower rainfall and poor simulated soil conditions. Collecting data on influential traits that are relatively simple to measure (e.g. number of green leaves) during cultivar development would greatly contribute to the simulation of new cultivars in crop models. Influential parameters that are difficult to measure directly such as transp_eff_cf and sucrose_fraction are ideal candidates for statistical calibration. Calibrating crop models either through direct observation or statistical calibration would allow crop modellers to better test how new cultivars will perform in a range of production environments.     

植被覆盖度计算机模拟模型与参数敏感性分析

植被覆盖度是重要的生态学参数,对水文、生态、全球变化等研究具有重大意义。目前使用的目测估算法和数码照相法都具有一定的主观性,另外通过自然界中相似样方的大量测量获得稳定的统计规律具有很大的难度,因此建立叶面积指数和植被覆盖度之间的统计模型是估算植被覆盖度的有效方法。本文以大豆为例,利用椭圆来模拟大豆的叶片,选取大豆植株结构的关键参数,通过随机分布函数来模拟植株叶片位置、倾角和大小的分布,获得不同植被结构参数下单位面积上的植被覆盖度,建立植被覆盖度计算机模拟模型。通过实测数据和理论研究结论来验证模拟结果。对模型的参数敏感性进行分析结果表明,叶半短轴是比叶半长轴更为敏感的植被结构参数。该模型为植被覆盖度的研究提供了一种新的思路和方法。     

Uncertainty analysis for SOFC-PEM hybrid systems

This article takes SOFC-PEM hybrid systems as the research object and considers the operating parameters to be uncertainty. Uncertainty analysis method based on Latin hypercube sampling involves quantifying the uncertainty in the input parameters in the form of appropriate distribution functions, propagating the uncertainty through a deterministic model to construct the output variability distributions, and analyzing the effects of operational parameter uncertainty on system output. Furthermore, non-traditional sensitivity analysis approach is used to evaluate the relative importance of various parameters considering this distribution structure. Results show that higher operating temperature of SOFC stack, lower fuel rate and lower fuel utilization of SOFC stack can reduce the influence of uncertainty on system output at the expense of system output. Uncertainty analysis can provides more credible basis for the optimization of design parameters under uncertainty.     

Chromosomes responsible for sensitivity of embryo to abscisic acid and dormancy in wheat

The sensitivity of the embryo to abscisic acid (ABA) has been reported toplay an important role in seed dormancy. Using ditelocentric lines of wheatcv. Chinese Spring (CS, nondormant and ABA insensitive), F₂ seedsbetween monosomic lines of CS and a wheat line Kitakei-1354 (dormant,ABA sensitive) and deletion lines of CS chromosome 4A, germinability ofseeds and embryo-half seeds incubated in water and ABA were examined. The results indicated that the long arm of chromosome 4A carried majorgene(s) for the embryo sensitivity to ABA and dormancy. Chromosome2D might be also involved in the sensitivity to ABA.     

AquaCrop模型在东北黑土区作物产量预测中的应用研究

东北黑土区是我国玉米和大豆生产基地,为了实现利用AquaCrop模型优化管理和预测产量,本文基于作物小区田间试验和大田观测数据,采用OAT(one factor at a time)法分析了该模型参数的敏感性,率定了敏感性高的参数,并对率定后的模型进行了验证。结果表明:玉米和大豆产量均对影响经济产量的收获指数十分敏感,二者虽然对冠层和根系生长参数都敏感,但有所差异:玉米对冠层衰减系数(canopy decline coefficient,CDC)更为敏感,而大豆则对限制冠层伸展的水分胁迫系数曲线的形状因子(shape factor for water stress coefficient for canopy expansion,Pexshp)更为敏感;玉米因根系深对最大有效根深(maximum effective rooting depth,Zx)更敏感,大豆因根系浅对根区根系伸展曲线的形状因子(shape factor describing root zone expansion,Rexshp)更敏感。由于玉米需水量大,对冠层形成和枯萎前的作物系数(crop coefficient before canopy formation and senescence,KcTr,x)和归一化水分生产力(normalized water productivity,WP*)很敏感,大豆则是一般敏感。率定后模型模拟玉米产量与实测产量的回归系数由0.34提升至0.89,模拟大豆产量与实测产量的回归系数由0.80提升至0.88。进一步用大田实测产量的验证结果表明:预测的玉米与大豆产量与实测产量间回归方程的决定系数(coefficient of determination,R2)分别为0.775和0.779,均方根误差(root mean square error,RMSE)分别为1.076 t hm^–2和0.299 t hm^–2,标准均方根误差(normalized root mean square error,NRMSE)分别为0.097和0.178,模拟效率(model efficiency,ME)分别为0.747和0.730,率定后的AquaCrop模型能较精准地模拟东北黑土区玉米和大豆产量,可用于产量预测或优化管理。     

Probability Statistics and Sensitivity Analysis of Parameters of Soil-Water Characteristic Curves

To study the characteristic of soil-water characteristic curves (SWCC) of several different types of soils, a number of data sets of matric suction-volume water content were studied for UNSODA clay, UNSODA sand, Guangxi expansive soil and Hefei expansive soil. Three types of Fredlund-Xing models and three types of van Genuchten models were used to study the influence of SWCC models, and three types of functions in the scientific programming language MATLAB were applied to analyze the effect of different fitting methods. Through the data fitting and statistic analysis, the probabilistic characteristics of the fitting parameters of SWCCs for the four types of soils were obtained. For analyzing the relative sensitivity of the normalized volume water content to the three fitting parameters of SWCC, a formula which considers the correlation of parameters was proposed. Through the data fitting of many data sets, it is found that the fitting methods influence the value of parameters of SWCC, while the influence is less than that of fitting models from the statistical point of view. The SWCCs of all the models are nearly the same when the suction is low. With the increase of the suction, the SWCCs of FX2 and VG2 are very close, and the SWCCs of FX3 and VG3 are the same. The sensitivity analysis shows that the normalized volume water content is more sensitive to parameters n and m than to parameter a.     

AquaCrop模型在东北黑土区作物产量预测中的应用研究

Northeast black soil area is the production area of maize and soybean in China. In order to optimize the agricultural management and forecast crop yield with AquaCrop model, we use OAT (one factor at a time) method to analyze the sensitivity of the model parameters based on the experiment and field observation data, and to validate the model after calibrated the high sensitivity parameters. The results of sensitivity analysis showed that the yields of maize and soybean were both extremely sensitive to the reference harvest index (HI₀) and the parameters of canopy growth and root growth. The difference was that maize was more sensitive to the canopy decline coefficient (CDC), while soybean was more sensitive to the shape factor for water stress coefficient for canopy expansion (Pexshp). Maize was more sensitive to the maximum effective rooting depth (Z_x) because of its deep root, while soybean was more sensitive to the shape factor describing root zone expansion (Rexshp) because of its short roots. Maize was extremely sensitive to the crop coefficient before canopy formation and senescence (Kc_Tr,x) and the normalized water productivity (WP^*) due to the large water demand, while soybean was only generally sensitive. After calibrated the high sensitivity parameters with experiment data, the regression coefficient of simulated yield and measured yield of maize increased from 0.34 to 0.89, and the regression coefficient of simulated yield and measured yield of soybean increased from 0.80 to 0.88. Furthermore, the validation results of field observation data indicated that the determination coefficients (R²), the root mean square error (RMSE), the normalized root mean square error (NRMSE) and the model efficiency (ME) of the AquaCrop model of maize and soybean were 0.775 and 0.779, 1.076 t hm^-2 and 0.299 t hm^-2, 0.097 and 0.178, 0.747 and 0.730, respectively. The calibrated AquaCrop model can accurately simulate the yield of corn and soybean in the black soil area of Northeast China, and is useful for yield prediction and optimal management.     

基于光谱参数的棉花叶面积指数监测和敏感性分析

研究棉花冠层光谱参数对不同叶面积指数的响应,建立棉花叶面积指数光谱参数最佳估测模型,并对所选光谱参数进行敏感性分析.利用高光谱仪测定不同时期不同叶面积指数条件下的棉花冠层光谱反射率.结果表明,694 nm和1099nm分别为可见光和近红外波段区域内与叶面积指数相关性最好的波段,并用于改进前人所建立的光谱参数;宽范围动态...     

The Monitoring Measurements and Country Rock Control of NATM in Tunnel of Express Road during Construction

In this paper the author' s study on the monitoring measurement technique of NATM,the regularity and conditions of the country rock deformation are analysed based on the site measurement data in the west section of Zhongliangshan tunnel. The regression analysis of measure data for different measure lines of vavious country rock is done by the use of self-compiled CRAP program. The stability criterion for various rockmass and optimum time for primary and permanent support are provided. The conclusion available could conduct the theoretical research of NATM deeply as well as tunnel design and construction.