Latent heat flux over Cabernet Sauvignon vineyard using the Shuttleworth and Wallace model

The Shuttleworth and Wallace model (SW) was evaluated to estimate latent heat flux above a drip-irrigated Cabernet Sauvignon vineyard, located in the Pencahue Valley, Region del Maule, Chile (35°22′ LS; 71°47′ LW; 150 m above sea level). The performance of the WS model (LE_ws) was evaluated against the eddy-covariance method (LE_ed) on a 30 min time interval. Results indicate that the root mean square error (RMSE) and mean absolute error (MAE) were 29 W m⁻² and 22 W m⁻², respectively. For the vine evapotranspiration (ETv), RMSE was 0.42 mm day⁻¹ and MAE was 0.36 mm day⁻¹. The largest disagreements between LE_ed and LE_ws were observed under dry atmospheric conditions. Also, the sensitivity analysis indicates that predicted ETv by the SW model was sensitive to errors of ±30% in leaf area index and mean stomatal resistance, but it was not affected by errors in the estimation of aerodynamic resistances.     

水分胁迫对赤霞珠葡萄主要抗旱生理指标及品质的影响

试验以3a生赤霞珠为材料,根据黎明前叶片的基础水势(Ψb),设置重度水分胁迫(T1)、中度水分胁迫(T2)、轻度水分胁迫(T3)3个处理,以无水分胁迫(CK)为对照,研究了不同程度水分胁迫对赤霞珠葡萄主要抗旱生理指标及品质的影响。结果表明,与CK相比,水分胁迫能提高赤霞珠葡萄叶片中丙二醛(MDA)、脯氨酸(Pro)和可溶性糖的量,增加CAT活性,导致可溶性蛋白呈先下降后上升趋势,POD活性呈"抛物线"变化,SOD活性则呈"双峰"变化趋势,且随着胁迫程度加深,上述变化趋势越显著。轻度水分胁迫条件下(T3),累计胁迫灌水量148.44L/株,全生育期共计灌水量447.46L,与CK(624.68L)相比较,不仅节水28.37%,而且促使赤霞珠葡萄可溶性固形物增加3.23%,总酸降低2.97%,花色苷增加22.58%,单宁增加29.70%,总酚增加15.13%,新梢生长量降低15.20%,单株增产7.2%。     

基于电学参数的贺兰山东麓赤霞珠葡萄酒子产区判别

本研究以宁夏贺兰山东麓5个子产区(银川、青铜峡、红寺堡、石嘴山和农垦产区)自然发酵的赤霞珠干红葡萄酒为研究对象,测定其基本理化指标和电学特性,分析不同产区葡萄酒间电学特性的差异,筛选出区分不同产区葡萄酒的特征频率和有效电学参数,初步探索基于电学特性识别宁夏贺兰山东麓不同子产区葡萄酒的能力,以期为简捷快速有效识别产区葡萄酒提供新方法。结果表明,宁夏贺兰山东麓5个子产区的葡萄酒理化指标间存在显著性差异,农垦产区的葡萄酒可滴定酸含量最高,而还原糖含量最低;银川产区的葡萄酒挥发酸含量最低,石嘴山产区的葡萄酒酒精度最高。通过相关性分析、方差分析和多重比较,筛选出电压2 V下,区分不同产区葡萄酒的电学特性特征频率为0.1 kHz,有效电学参数为Z、L_p、X、C_p和Q。主成分分析和判别分析均显示,利用葡萄酒电学参数能够明显区分贺兰山东麓5个子产区,采用Fisher-判别分析建立的预测模型,其回代检测和交叉验证正确率均为100%。因此,利用葡萄酒电学特性识别产区具有可行性。     

Performance irrigation parameters and their relationship to surface-irrigation design variables and yield

Several parameters that measure the irrigation performance were analyzed for their relation to surface-irrigation design variables and yield. Application efficiency (AE), requirement efficiency (RE), uniformity coefficient (UC), deficit efficiency distribution (DED) and requirement distribution efficiency (RDE) were examined with respect to surface irrigation design variables (inflow discharge, length of the run, and time of irrigation cutoff). RE, RDE and UC were correlated with relative yield. Surface-irrigation models were used to simulate furrow and border irrigation and to determine the value of the performance irrigation parameters. A linear crop-water-production function was used to estimate yield. The RE and RDE were very well correlated with the design variables in border and furrow irrigation, and they were the parameters best correlated with the relative yield. The UC was not correlated with the design variables and gave a poor correlation with the relative yield. The AE was well correlated with the design variables.     

灯具与居室环境照明的整体关系

随着人们生活水平逐渐提高,人们对于家装设计的要求也越渐完美。近年来随着房地产的牛市现象,进而家装也随之火爆,人们在家居装修中所要求的标准也在逐渐提高,灯饰也成为了家装中的重中之重,它能够体现业主的家庭品味,并衬托室内装修风格,已经不仅仅具有实用和功能的价值,更加具有美化环境烘托氛围的作用。     

武功地区气候变化及其对夏玉米单产的影响

基于陕西武功站1935-2010年的逐月气象数据及夏玉米产量等资料,采用Mann-Kendall法、直线滑动平均模拟法和通径分析法,分析了武功地区1935-2010年各个气象因子的变化特征以及气候变化对夏玉米单产的影响．结果表明:该地区最低气温呈上升趋势,风速、日照时数呈下降趋势;夏玉米生育期最低气温和相对湿度呈上升趋势,最高气温、日照时数和风速均呈下降趋势,变化速率分别为0116 ℃／10a,0006／10a,-0158 ℃／10a,-26707 h／10a和-0063 m／(s·10a),SPI呈减小趋势,气候朝干旱演变;夏玉米生育期各气象因素能综合其他气象因素的信息对单产产生作用,日照时数对夏玉米单产综合决定能力最高,决策系数为2309％,降水量呈减小趋势是夏玉米单产增加的主要限制性气象因素,决策系数为-673％;通过技术创新等人为因素作用,可在一定程度上缓解气候变化给武功地区夏玉米生产带来的负面影响．     

FMS及其结构组成与发展趋势分析

柔性制造系统是由统一的信息控制系统、物料储运系统和一组数字控制加工设备组成,能适应加工对象变换的自动化机械制造系统.FMS的软硬件系统大多已比较成熟,今后的发展方向集中在:加快发展各种工艺内容的柔性制造单元和小型FMS;完善FMS的自动化功能;不断推出新型控制软件.     

废水中悬浮物与COD的关系研究

悬浮物指悬浮在水中的固体物质,包括不溶于水中的无机物、有机物及泥砂、黏土、微生物等。水中悬浮物含量是衡量水污染程度的指标之一。悬浮物是造成水浑浊的主要原因。水体中的有机悬浮物沉积后易厌氧发酵,使水质恶化。而这些有机物和还原性无机物又是影响污水COD的主要因素。所以本试验探讨废水中悬浮物与COD的关系,以便能够用易于测定悬浮物来间接反映污水的污染程度以及对污水的处理效果。     

The relationship between impact and internal bruising in potato tubers

A pendulum impact tester was developed which was capable of measuring rebound angle and tuber deformation and recording an acceleration/time curve of an impact. Impact tests were conducted on two varieties of potato: Record, which is susceptible to blackspot bruising and King Edward, which is susceptible to internal crushing and shattering. The impact conditions were varied by altering the mass and drop angle of the pendulum. The dimensions and volume of each bruise following each impact were determined. The relationships between different impact measurements and bruise types were compared.Precise relationships between the impact a potato tuber receives and the occurrence of different types of internal bruising are defined. Impact duration was found to have a critical effect on the type of amount of resultant bruise. For the same energy absorption, impacts of relatively long duration resulted in more blackspot and internal crushing whereas impacts of relatively short duration resulted in more internal shattering.     

Combined effects of KNO3 and salinity on yield and chemical composition of lettuce and Chinese cabbage

Summary The effect of N and K nutrition on the salt tolerance of lettuce (Lactuca saliva L. cv. Saunas) and Chinese cabbage (Brassica campestris L., Pekinensis cv. Kazumi) was evaluated in three greenhouse experiments under a controlled aero-hydroponic system of cultivation. Three levels of KNO₃ (1, 5 and 10 mM) were tested in all the experiments with rapidly circulated saline and nonsaline nutrient solutions. Two experiments, carried out between January and March 1989, with lettuce (Exp. I) and Chinese cabbage plants (Exp. III), consisted of two salinity levels, EC = 1.75 and 6.0 dS m^–1, the former representing a nonsaline nutrient solution. In the third experiment with lettuce (Exp. II., conducted between March and May 1989), three saline nutrient solutions having EC levels of 4.7, 7.75 and 10.75 dS m^–1 were compared to the nonsaline solution. The nutrient solutions were salinized with NaCl and CaCl₂, in a 4:1 molar ratio. The highest yields of fresh weight of both crops were obtained from the 5 mM KNO₃ under both saline and non-saline conditions. The 10 mM treatment caused yield reduction in Chinese cabbage, probably due to a severe tipburn disorder. The relatively high fresh weight yield obtained at the lowest (1 mM) KNO₃ level can be explained by the positive effect of circulation velocity on nutrient uptake. The threshold salinity damage value for the vegetative yield of lettuce plants fed by 5 or 10 mM KNO₃ was approximately 5 dSm^–1 and the yield decreased by 6.5% per unit dS m^–1 above the threshold. No yield improvement due to the addition of KNO₃ occurred under highly saline conditions (Exp. II). The fresh weight of Chinese cabbage obtained from the saline 1 and 5 mM KNO₃ treatments was approximately 15% lower than the non-saline-treatment (Exp. III). Salinity increased tipburn and the effect was not altered by the addition of KNO₃. No significant interaction between nutrition (KNO₃ level) and salinity was found. The application of salts increased the concentration of Na and Cl in plant tissue and reduced the levels of N and K; the opposite occurred in plants fed by the medium and high levels of KNO₃.Contribution from Institute of Soils and Water, ARO, Volcani Center, PO Box 6, Bet Dagan 50250, Israel. No. 3092-E 1990 series     

Modeling the relationship between reproductive performance and net-revenue in dairy herds

A dynamic stochastic simulation model to study the relationship between reproductive performance and net-revenue in dairy herds is described. Herds included cows, heifers and calves described by individual characteristics and state variables. The latter were updated using time steps of one week in conjunction with calculations of milk revenue, sales revenue, feed costs, breeding costs, additional costs and net-revenue. Discrete events at the animal level, e.g. involuntary culling, estrous detection and conception were triggered stochastically. Voluntary culling was modeled using the future profitability of cows and potential replacements as determined by dynamic programming. Management and production system were defined by decision variables, e.g. estrous detection rate (EDRT), impregnation factor (IF) and rebreeding policy (RBP). Increases in net-revenue (NR) due to a 1% improvement in EDRT ranged from Cdn. $−2·9 at an EDRT of 75% to Cdn. $22·5 at an EDRT of 35% and were influenced by RBP. Hence, highest increase in NR due to improvement of EDRT can be expected at low reproductive efficiency.     

中西心物观简论

心物关系是美学研究的基本问题,本文通过对中西艺术的分析来比较中西心物观念的差异。中国艺术的传统是心物感应说,在心物关系上强调的是心物感应、相互融合、物我合一,提倡天地人三个纬度的和谐对应。西方艺术的心物关系是建立在反映论、摹仿说基础上的,主张物我分离、主客观对立。     

高校与学生的法律关系之研究综述

近年来我国高校与学生之间的诉讼案件大量增加,高校与学生之间的法律关系成为人们日益关注的问题,因此有必要将关于这一主题的研究进行梳理.国外的重要性理论对我国有借鉴意义.     

Response of Navel Lane Late citrus trees to regulated deficit irrigation: yield components and fruit composition

The effects of mid-summer regulated deficit irrigation (RDI) treatments were investigated on Navel Lane Late citrus trees over four seasons. Water restrictions applied from July until mid-September were compared with irrigation at full crop evapotranspiration (ETc). Two degrees of water restrictions were imposed: (1) RDI-1, irrigated at around 50% ETc and, (2) RDI-2, irrigated at 30–40% ETc. In addition, threshold values of midday stem water potential (Ψs) of ?1.3 to ?1.5 MPa for RDI-1 and of ?1.5 to ?1.7 MPa for RDI-2 were also taken into account. Results showed that Navel Lane Late is a citrus cultivar sensitive to water deficit since both RDI strategies reduced fruit size every year and water use efficiency in RDI trees was similar to control trees. However, the RDI-1 strategy allowed water savings up to 19% without reduction in yield when the water stress integral did not surpass 70 MPa day. RDI improved fruit quality, increasing total soluble solids and titratable acidity, while the fruit maturity was delayed. In conclusion, we suggest that RDI-1 strategy since it did not significantly impair the economic return can be applied in commercial orchards in case of water scarcity. Nevertheless, Navel Lane Late fruit is sensitive to water deficit and the fruit weight can be detrimentally affected.     

EPS与MBR中污泥活性关系研究

采用Eckenfelder模型建立了MBR污泥系统COD降解动力学方程来表征污泥活性，确定了运行时间为19、27、34、43、50、59、67和76d时COD的降解速率，实验结果表明，污泥活性随着运行时间的延长呈先上升后下降趋势，当运行时间为50d时降解速率K1达到最大值2.72，污泥活性最好；单位体积污泥内EPS含量随运行时间的变化与污泥活性的变化规律相似，当运行时间为43d时达到了最大值252.08mg/L；COD降解速率K1与EPS浓度关系为y = 42.553K1 + 141，两者呈良好正相关，说明单位体积污泥中EPS含量越高，COD的降解速率越快，单位体积污泥的活性也越好。     

论社会舆论与法律的相互关系

社会舆论与司法是现代社会两股重要力量.由于我国的舆论和法制还未成熟,致使两者在很多方面出现了紧张的对立.在法治改革中要努力实现两者的良性互动,加强社会舆论对法律的监督,加快法治民主化进程,同时,也要对社会监督进行法制保障和规范,从而发挥两者的优势,共同促进社会主义民主法治建设.     

农业机械总动力与影响因素关系分析

分析了影响农业机械化发展的主要因素，包括生产规模、需求和经济条件；建立了农业机械化发展的总动力分析模型，该模型反映了农机总动力与农民收入水平、农业劳均粮食播种面积和粮食单产的关系；依模型对农机总动力发展进行预测。     

Osmotic adjustment of sugar beets in response to soil salinity and its influence on stomatal conductance,growth and yield

Sugar beets were grown in tanks filled with loam and clay, and were irrigated with waters of three different levels of salinity. Osmotic adjustment was determined by analyzing the pressure-volume curves at three growth stages. Sugar beets showed osmotic adjustment in two ways: with their phenological development and towards salinity. Owing to the latter adjustment sugar beets are able to maintain the turgor potential at the same value for lower values of the leaf water potential, to maintain stomatal conductance and photosynthesis and finally their production under severe water stress.Salinity affected the pre-dawn leaf water potential, stomatal conductance and evapotranspiration on both soils, but leaf area and yield only on loam.Soil texture affected stomatal conductance, evapotranspiration, leaf area and yield. As the latter was about 35% lower on clay, whereas the evapotranspiration decreased 10 to 15%, the water use efficiency was about 25% lower on clay compared with loam.     

Relationships between crop temperature,grain yield,evapotranspiration and phenological development in two hybrids of moisture stressed sorghum

Summary Recent studies have shown that the grain yields of corn (Zea mays L.) and wheat (Triticum aestivum L.) are related to the degree of water stress they undergo. The purpose of the study reported here was to establish relationships between crop temperature and the grain yields, phenological development, evapotranspiration rates (ET) and leaf water potential ( _l ) of two hybrids of grain sorghum (Sorghum bicolor L. Moench) subjected to varying levels of plant water stress. The study was conducted at the University of Nebraska Sandhills Agricultural Laboratory in 1978 on a Typic Ustipsamment (Valentine fine sand) soil. The sorghum hybrids used were RS 626 and NB 505. Four irrigation treatments were applied in order to subject the crops to varying levels of water stress during each of three major growth stages. Soil moisture was monitored with a neutron probe. ET was estimated with the water balance technique. Crop temperature was measured with an IR thermometer and leaf water potential was measured with a Scholander pressure bomb. Grain yields were reduced by water stress occuring at anytime during the growing season. Yield reductions were largest when stress occurred during only the grainfill period and were least when stress occurred during the entire growing season. The percentage reduction in sorghum grain yield can be described by an index involving the seasonal accumulation of the daily mid-day temperature differences between well-watered and stressed crops ( TSD). As TSD values increased, ET decreased. However, the correlation of ET with TSD was relatively low (R² = 0.60) probably due to the limited amount of data available for analysis and inaccuracies in the soil water balance method used to estimate ET. The mid-day temperature of well-watered rows ranged between 18.0 and 32.8 °C with a mid-day temperature range of about 0.5 °C between the well-watered rows in various plots for several days following an irrigation. However, in certain instances, the mid-day temperature range increased to 1–2 °C for a few days before irrigation. This suggests that certain of the rows experienced water stress and should have been irrigated earlier. Yield data support that conclusion. Range in crop temperature within a field appeared to be a sensitive indicator of crop water stress in sorghum. No significant difference in the phenological development of sorghum resulted from water stress except in one NB 505 plot in which plants were stressed throughout the entire season. In that plot, the stressed plants lagged in development behind non-stressed plants by approximately ten days. The differences in mid-day leaf water potentials ( _l ) and crop temperatures (T) between stressed and non-stressed vegetation were examined. As T increased up to about 4 °C, _l , also increased. Beyond that point, _l decreased while T continued to increase. This behavior was attributed to stomatal closure which permitted an increase in _l of the stressed plants (hence reducing _l ) even as T continued to increase.Published as Paper No. 6551, Journal Series, Nebraska Agricultural Experiment Station. The work reported was conducted under Regional Research Project 11–33 and Nebraska Agricultural Experiment Station Project 11–50. The work upon which this publication is based was supported in part by funds provided by the Office of Water Research and Technology B-044-NEB, US Department of the Interior, Washington, DC, as authorized by the Water Research and Development Act of 1978. This article was sponsored in part by the Nebraska Water Resources Center, Institute of Agriculture and Natural Resources, University of Nebraska-LincolnResearch Assistant, Associate Professor, Research Assistant, and Associate Professor, University of Nebraska, Lincoln. Contents of this puplication do not necessarily reflect the views and policies of the Office of Water Research and Technology, US Dept. of the Interior, nor does mention of trade names or commercial products constitute their endorsement or recommendation for use by the United States Government