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1.
通过控制土壤含水量,定量研究了红壤相对含水量(SWC)对温州蜜柑幼树茎叶生长参数的影响.结果表明,柑橘叶面积、叶周长、叶宽,梢长、茎长和距根部10cm茎直径,均在SWC75处理时达最大值,分别为12.25±2.61cm、13.84±1.43cm、3.19±0.39cm,23.64 cm、56.08 cm和1.78em,且与SWC30、SWC45、SWC60、SWC75处理间差异显著.柑橘茎叶生长与土壤相对含水量(SWC)之间有一定的相关性,并随着SWC的增加或减少,其生长量都受到了一定程度的影响.柑橘茎叶的生长指标表明,红壤上种植温州蜜柑的土壤相对含水量在75%为宜. 相似文献
2.
春季柑橘叶片对红壤水分调节的响应 总被引：1，自引：0，他引：1
通过调节红壤含水量不同的层次水平.研究了土壤相对含水量(SWC)对春季柑橘叶长、叶宽、叶梢长的影响,并比较了,在SWC处理下柑橘叶片与根系氮、磷、钾含量变化及特点.结果表明,SWC在75%左右.最适柑橘叶片的生长.氮素在叶与撤系中差别不大,但叶磷、钾含量远低于根系磷、钾含量;适当缺水有利于柑橘叶中氮素的积累,柑橘叶中磷含量与SWC呈显著正相关,而各SWC处理间柑橘叶片钾含量没有差异. 相似文献
3.
基于归一化法的烤烟干物质积累建模与特征分析 总被引：1，自引：0，他引：1
为探讨不同株型烤烟品种干物质积累动态模型和变化特征,实现不同品种烤烟干物质积累的有效预测,以不同株型品种云烟97、NC71、K326为材料,采用田间实测和数值模拟方法研究4个密度(13 890、15 150、16 660和18 510株hm~(–2))水平下烤烟干物质积累动态,分析关键生长参数特征,以期为烤烟合理密植、烟叶增产提供新的理论与方法。结果表明:(1)基于归一化法筛选并建立了相对干物质积累量与相对生长时间的干物质积累动态模型(MMF),方程表达式为y=(ab+cx~d)/(b+x~d),模拟准确度k值在0.9032~1.0482之间,决定系数R~2在0.94以上,进一步推导发现,方程具有过原点性、有界性、单调递增性等特点,符合生物学意义,能较好地模拟烤烟干物质积累动态特征;利用该模型分析积累特征参数,将烤烟干物质积累过程划分为缓慢增长期、快速增长期、减速增长期。(2)随着种植密度的增加,烤烟速率峰值出现时间(T_m)、快速增长期开始时间(RT_1)、结束时间(RT_2)均有不同程度提前;密植条件下(D3、D4),NC71和K326快速增长期持续时间(T_d)及其积累比例(R_a)明显提升;通径分析表明,T_d、R_a均能影响烤烟最终干物质积累水平,其与干物重均显著(0.6500*)或极显著(0.7758**)正相关,其中R_a对干物重直接通径系数达1.7097,对回归方程的总贡献率也达1.3264。(3)耐密性表现为筒型鼓型塔型,对应品种K326、NC71、云烟97的适宜密度分别为18 510株hm~(–2)(D4)、16 660株hm~(–2)(D3)、15 150(D2)~16 660(D3)株hm~(–2)。 相似文献
4.
不同贮藏条件下棉花和大豆种子的水分变化规律及其预测模型 总被引：2，自引：1，他引：1
以不同初始水分(IMC)大豆和棉花种子为试材,研究不同贮藏条件下的吸湿解吸规律,并建模验证。结果表明,大豆种子,贮温15℃、25℃和40℃时,4%IMC在相对湿度(RH)≤18.78%、8%和12% IMC在RH≤48.10%条件下解吸,其他条件下吸湿。棉花种子,15℃时,4% IMC在RH≤7.49%、8%IMC在RH≤18.78%和12% IMC在RH≤48.10%条件下解吸,其他条件下吸湿;25℃时,4% IMC在RH≤18.78%、8%和12%IMC在RH≤48.10%条件下解吸,其他条件下吸湿;40℃时,4%IMC在RH≤7.49%、8%和12% IMC在RH≤48.10%条件下解吸,其他条件下吸湿。棉花种子,4% IMC在15℃ RH>55%、25℃ RH>55%和40℃ RH>50%时的安全水分(SWC)依次为10.5%、9.5%和6.5%;8%IMC在15℃RH>60%、25℃ RH>55%和40℃ RH>45%时的SWC分别为10.5%、9.5%和6.5%;12% IMC在15℃ RH>55%、25℃ RH>55%和40℃ RH>45%时的SWC分别为10.5%、9.5%和6.5%。辽豆11在15℃ RH>60%、25℃ RH>55%和40℃RH>45%时,其平衡水分(EMC)超过其SWC(依次为12%、11%和8%);菏豆13在相同条件下水分平衡时的RH比辽豆11高5%。棉花种子EMC在15和25℃ RH>55%、40℃ RH>60%时超过其SWC;大豆种子EMC在25℃ RH>55%、25℃和40℃ RH>60%时超过其SWC。棉花种子的水分平衡时间(d)与IMC(x)、RH(y)和温度(z)的预测模型为d =36.97+1.78x–0.58y–0.58z–0.016xy–0.021xz–0.0012yz+0.007y2,辽豆11的为d =23.29+3.72 x–0.19 y–0.86 z–0.02 xy–0.09 xz–0.008 yz+0.005 y2+0.03 z2,菏豆13的为d =48.64+0.36x–0.44y–1.49z–0.008yz +0.006y2+0.026z2。模型经检验,预测性良好。 相似文献
5.
普通小麦主要农艺性状的全基因组关联分析 总被引：1，自引：0，他引：1
为解析小麦复杂农艺性状的遗传机制,本研究以150份小麦品种(系)为自然群体,在4个环境条件下测定了9个主要农艺性状,利用小麦35K SNP芯片,结合5种关联模型(Q、PCA、K、PCA+K、Q+K),进行全基因组关联分析。结果表明,全基因组多态性信息量PIC的范围为0.0950～0.5000,最小等位基因频率MAF值为0.0500～0.5000;群体结构分析和PCA分析均表明参试材料可分为两个亚群;连锁不平衡分析发现A基因组、B基因组、D基因组和全基因组的LD衰减距离分别为4.7、8、11和6 Mb。9个性状共检测到652个显著的关联位点(P≤0.001),其中21个SNP在2个或2个以上的环境中被重复检测到,分布在1A(1)、1B(4)、2A(3)、2D(2)、3A(1)、5A(1)、5B(5)、6A(1)、6B(2)和7D(3)染色体上; 1个SNP标记的物理位置未知, 3个SNP标记同时与2个性状显著关联;单个SNP的表型贡献率为7.67%～18.79%。8个优势等位变异在供试群体中所占比例较低,筛选出14个可能与小麦农艺性状相关的候选基因,其中TraesCS5B02G237200、TraesCS7D02G129700和TraesCS1B02G426300可能在植物抵御生物与非生物胁迫中起作用,TraesCS5B02G010800和TraesCS7D02G436800可能与植物激素的合成和响应有关,TraesCS2A02G092200可能与植物细胞壁的增强有关, TraesCS5A02G438800可能参与叶绿体发育,另外7个候选基因的功能未知。 相似文献
6.
用变异系数(CV)、回归系数(b)、环境区分指数(YM)以及AMMI模型和SREG模型下试点到原点的距离(D)对2007年四川省区域试验(平丘组)9个试点对玉米品种的判别能力进行了比较研究,结果表明,AMMI模型和SREG模型下的D统计数间秩次相关系数为0.833,达到0.05显著水平,而与变异系数、回归系数和环境区分指数间秩次相关系数不显著,是评价试点对品种判别能力的2个比较理想的统计数。SREG模型的分析结果表明,大竹、武胜、雅安、温江、宜宾5个试点对品种判别能力较强,而达州、乐山、南充、内江4个试点对品种的判别能力相对较弱。 相似文献
7.
干旱胁迫对小麦叶片细胞膜透性效应的染色体定位研究 总被引：5，自引：0，他引：5
通过测定干旱胁迫下小麦中国春-Synthetic 6x染色体代换系及其亲本品种中国春(受体)和Synthetic 6x(供体)叶片的相对电导率和K 相对渗出率,对调控干旱胁迫下功能叶片细胞膜稳定性的染色体进行了定位研究。结果表明,1D,2D,2B,3A,3D,4A,4B,6A,6B,7D和7A等染色体代换系的相对电导率和K 相对渗出率均显著或极显著低于中国春,而其他代换系差异均不显著。表明Synthetic 6x的1D,2B,2D,3A,3D,4A,4B,6A,6B,7D和7A染色体上具有耐旱性基因,而其他染色体与Synthetic 6x的耐旱性无关。研究结果可为小麦抗旱遗传育种研究提供参考依据。 相似文献
8.
桃蚜作为世界范围内农作物主要害虫,在我国主要蔬菜种植区均有发生。因其繁殖能力强以及对蔬菜尤其是辣椒质量造成危害而成为重要防治对象。为了明确四川省成都主要辣椒种植区桃蚜空间分布格局,本试验运用2种回归方法和8个聚集度指标(K, C, CA, I, M*, m*/m, L*, L*/(1+m))对桃蚜盛发期种群的空间格局进行了研究;同时,通过Iwao回归法和Taylor幂法计算桃蚜种群理论抽样数,Iwao和kuno序贯抽样技术拟合桃蚜的序贯抽样模型。结果表明桃蚜种群呈聚集分布,聚集强度随种群密度的升高而增加,且个体间相互吸引,其聚集原因是由桃蚜习性与环境因素共同引起的,但8月下旬开始聚集原因主要有环境因素决定;通过种群密度与聚集度指标相关性分析表明,用平均拥挤度(m*/m)、负二项分布指标(K),久野指数(CA)及L*/(m+1)分析桃蚜空间分布型更具说服力;并利用空间格局参数确定了理论抽样数和序贯抽样模型。 相似文献
9.
10.
不同贮藏条件下小麦和玉米种子的水分变化规律及其建模验证 总被引：3，自引：0，他引：3
种子平衡水分(EMC)是评价种子吸湿或解吸动态变化的重要指标。本研究以不同初始水分(IMC)小麦和玉米种子为试材,研究了不同贮藏条件下的吸湿解吸规律,并建模验证。结果表明,玉米种子在8.0%IMC、15℃、相对湿度(RH)<18.8%, 25°C或40℃和RH<48.1%条件下; 以及在13.5%IMC或18.0%IMC、15°C、25°C或40℃、RH<48.1%条件下呈解吸变化; 而在其他条件下均呈吸湿变化。小麦种子在贮温15、25和40℃时,8.0%IMC在RH≤18.8%、18.0%IMC在RH≤48.1%时解吸,其他条件下吸湿; 13.5%IMC在15℃和RH<48.1%以及25、40℃和RH<18.8%时解吸,其他条件下吸湿。小麦种子在15℃和RH=53.0%、25℃和RH=48.0%以及40℃和RH=43.0%时的安全水分(SWC)依次为13%、11%和9%; 玉米种子在15℃和RH=55.0%、25℃和RH=50.0%以及40℃和RH=40.0%时,其SWC依次为14%、12%和9%。小麦种子EMC在15℃和RH>50.0%、25℃和RH>50.0%、40℃和RH>48.0%时超过其对应条件下的SWC; 玉米种子EMC在15℃和RH>50.0%、25℃和RH>47.0%以及40℃和RH>47.0%时超过其对应条件下的SWC。玉米郑单958的平衡时间(d)与IMC(x)、RH(y)和温度(z)的预测模型为d = 35.34 + 4.32x - 0.28y - 0.35z - 0.031xy - 0.012xz - 0.0011yz + 0.003y2,农大108为d = 39.76 + 2.35x - 0.39y - 0.27z - 0.022xy - 0.014xz - 0.0057yz + 0.008y2,小麦山农15为d = 25.69 + 7.65x - 0.27y - 0.89z - 0.12xy - 0.07xz - 0.007yz + 0.006y2+ 0.04z2,泰农18为d = 46.67 + 0.39x - 0.28y - 1.72z - 0.006yz + 0.006y2+ 0.017z2。模型经验证,预测性良好。 相似文献
11.
2 is a program for estimating soil parameters. It allows: (1) storing soil data in a georeferenced database, (2) computing estimates of soil hydrological parameters using 15 procedures, (3) comparing the estimates against measured data using both statistical indices and graphics, and (4) creating maps using the ESRI format. An interface to/from Excel and CropSyst is provided. Eleven methods estimate one or more of the following characteristics: soil water content at predefined soil matrix tension, saturated hydraulic conductivity, and bulk density. Three methods estimate the parameters of well-known soil water retention functions (Brooks-Corey, Hutson-Cass, van Genuchten), and one estimates both saturated soil hydraulic conductivity and the soil water retention curve parameters (Campbell). The software runs under Windows 98/NT/2000/XP and is freely downloadable via internet. 相似文献
12.
Probability Statistics and Sensitivity Analysis of Parameters of Soil-Water Characteristic Curves 总被引：1，自引：0，他引：1
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. 相似文献
13.
Tan Yanyi Yu Zhongming 《保鲜与加工》1989,(1):36-44
In this paper, an analytical solution,approximate solution of initial retention, steady-state solution and numerical solution of separator equations of high gradient magnetic separation are discussed. A backward-vave method used to improve the steady-state solution and Treanor-four order Taylor numerical method are suggested for magnetic separator equations and are compared with experimental results. 相似文献
14.
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。 相似文献
15.
为了更好地对山东省农业气象自动观测站进行评估,研究土壤水分运动规律,根据山东省120个测墒站测定的不同土壤质地类型及其凋萎湿度资料,利用Van Genuchten模型来描述土壤水分特征曲线（h-?曲线）,建立山东省农业气象自动观测站土壤体积含水率和土壤水势的关系。综合分析表明,壤土、粘土的田间稳定有效水含量高于砂土的,稳定向植物供水能力较强,对水分的自身协调能力较强,因而对旱涝灾害的抵抗力也强。 相似文献
16.
六道沟流域不同坡位不同土地利用方式下 的土壤持水特征研究 总被引：3，自引：0，他引：3
为了恢复黄土高原典型水蚀风蚀交错带六道沟流域的脆弱的生态环境,本文对六道沟流域不同坡位不同土地利用方式的土壤进行采样调查,利用高速离心机测定土样的水分特征曲线,评价了该流域土壤的持水特征和水分有效性。结果表明：A值、S(C(θ)=10-2)值及A*B值适合用于评价六道沟流域内的风沙土的土壤持水性能;在坡上位,土壤持水性能及水分有效性顺序为：农地＞柠条、沙蒿地＞杨树林地;在坡中位,农地的土壤持水性能与土壤水分有效性最高,杨树林地的最差;在坡下位,柠条地的持水性能及土壤水分有效性高于荒草地、杨树地和柠条、沙蒿地。本区域应选择土壤持水性能和水分有效性高的柠条、沙蒿灌木植物进行生态恢复。 相似文献
17.
《Soil Technology》1991,4(3):297-314
In this study, soil properties were measured along two parallel 100-m transects separated by 60 cm. Soil samples were taken at the 30 and 60 cm depths at 1 m intervals along each transect, for a total of 400 samples. Soil-water-characteristic curves, determined in the laboratory on these samples, were fitted to van Genuchten's five-parameter model which was simplified by assuming that the residual water content was negligible. Particle size measurements from each soil sample were fitted to a three-parameter model. In addition, saturated hydraulic conductivity KS and bulk density were measured. Several spatial correlations beyond lag 0 were found to be statistically significant for the van Genuchten model parameter n, for lnKs and for B1, which is an empirical parameter in the particle size distribution model. The cross-correlation functions also contain significant values beyond lag 0 for n versus lnKs, n versus B1 and lnKs versus B1. The parameter B1 was positively correlated with lnKs and n. Most of those properties, especially B1 and n, revealed a strong periodic behaviour with a main cycle of 100 and 50 m at the 30-cm and 60-cm depths, respectively. Removing these cycles resulted in short lags with a spatial dependence of only 1 m. A state-space analysis was employed for predicting saturated hydraulic conductivity. The best result was obtained using a four-dimensional model containing Θs, n, lnKs and bulk density. 相似文献
18.
Abrasive water jets can incise objects with strong rigidity under water. The analytical means of kinetic theory is optimal for theoretical problems of submerged abrasive water jets. The flow characteristics in submerged abrasive water jets were analyzed based on kinetic theory for multiphase flows. The impact characteristics of every phase in submerged abrasive water jets was analyzed and continuity and momentum equations subsequently were developed for solid, gas and liquids in submerged abrasive water jets. It is shown that if the distributing function of every phase were given, the law of its movement could be ascertained. 相似文献
19.
《Netherlands Journal of Sea Research》1988,22(3):185-198
In a one-dimensional analytical model the origin of constant flows between connected tidal basins, as well as the origin of the associated residual levels, is examined. Linearized shallow water equations are used to describe the propagation and damping of a tidal wave in schematized (uniform width and depth) connected basins. Analytical expressions are derived for the tidal stress terms, including the contribution of the non-linear bottom-friction term, which serve as the forcing functions in the equations for the mean field. It is shown that in a first approximation the residual levels in the tidal inlets, which give boundary conditions for the tidally-averaged equations, are dependent on the tidal velocities in the inlet because of a “Bernoulli effect”. The model shows that in general differences between the fluctuating water levels at the inlets influence the residual flow more than morphological differences between two connected basins. The tidally-driven mass transport in the western Dutch Wadden Sea, directed southwards from the Vlie basin towards the Marsdiep basin, can be explained from the larger water-level amplitude at the inlet of the Vlie basin. 相似文献
20.
The water retention capacities of commonly used roof greening matrices, concluding ceramsite, peat and super absorbent polymer, under fully saturated, cyclic wetting-drying and natural evaporation conditions were studied. The saturated water retention capacity of matrices were obtained by vacuum saturated test. It showed that the fully measured saturated degree of saturation of mixed matrix was greater than that calculated by the combination of all components. The reason which increases the water contents to porous skeleton was analysed. In cyclic wetting-drying tests, the water retention capacities of ceramsite and peat were almost unchanged. However, due to the main molecular chain broken under drying in relatively high temperature, the water retention capacity decreased rapidly after several wetting-drying cycles. In natural evaporation tests, the evaporation rates of ceramsite, peat, super absorbent polymer and free water were almost identical in the condition of high water content. As the water content decreasing, the evaporation rate of the matrix which had lower water retention capacities decreases faster. The matrix with a reasonable proportion of super absorbent polymer can remarkably improved its water retention capacity. 相似文献