Stabilizing steep slopes with soil conditioners and plants

The approach in this study of runoff and erosion control on steep slopes was to combine soil stabilizers with the planting of drought-resistant, perennial plants.The effect of 10 t ha⁻¹ phosphogypsum (PG) + 70 kg ha⁻¹ polysaccharide (PS), 10 t ha⁻¹ PG and 20 kg ha⁻¹ polyacrylamide (PAM), and 200 kg ha⁻¹ PS on the erosion of steep slopes (30–60%) was studied in plots 2 m in width and of different lengths (12–20 m), at three of different sites in Israel (semiarid conditions), and under natural rainfall conditions. Likewise, observations on the establishment and development of nonirrigated, drought-resistant, perennial plants on steep slopes (40–60%), combined with 10 t ha⁻¹ PG + 70 kg ha⁻¹ PS, were conducted at two sites in Israel.PS + PG and PAM + PG treatments were very efficient in erosion control in a wide range of soil types, ESP, CaCO₃ level, and weather conditions. These treatments reduced erosion six- to eleven-fold in comparison with the control. No significant difference was found between PS + PG and PAM + PG treatments. However, the application of PAM was problematic due to its very low dissulution rate and its high viscosity in water. Two-hundred kg PS without PG was found efficient only at one experimental site with calcic haploxeralf soil and 300 mm average annual rainfall.The combination of PS + PG, and drought-resistant, perennial plants was very sucessful. The plants developed very well without irrigation throughout the long, dry summer. Only one year later, the creeper plant canopy covered an area of 0.75–1.5 m, and the bushes were 0.8–1.2 m in height.     

稳定我国大蒜生产效益的主要途径

对我国近年来大蒜的生产和销售情况、大蒜的出口数量和金额、批发市场大蒜平均参考价格,以及大蒜经营者的收益情况变化进行了总结与回顾,提出了今后稳定我国大蒜生产效益的主要途径:一是稳定大蒜种植面积,防止"蒜多伤农";二是强化大蒜加工转化,特别是产地大蒜的精深加工能力。分析了大蒜主要加工品的生产前景。     

基于随机场的岩石边坡三维稳定性分析

基于随机场理论,考虑了岩石材料属性的空间变异性对岩石边坡稳定性的影响,将边坡主滑面上的摩擦系数和粘聚力视为高斯随机变量,确定了主滑面上的摩擦系数和粘聚力的均值、方差和协方差,获得了两个随机量之间的相关系数和互相关长度。在此基础上,对岩石边坡进行了三维稳定性分析,确定了岩石边坡的稳定系数和失效概率。数值计算结果表明,摩擦系数和粘聚力的空间变异性对边坡稳定性有重要影响。     

Development of a sub-nanosecond steep pulse generatorfor simulating weak PD UHF signal

In need of ultra-high frequency partial discharge location and correction of electrical equipment, we designed a sub-nanosecond steep pulse generator, and constructed the corresponding circuit model through the circuit simulation software Pspice. The influence of the storage capacitor and the supply voltage to the pulse waveform is analyzed. When the storage capacitor is 10 pF and 20pF respectively, the output pulse waveforms have been measured in the conditions of pulse rise time being 0.68 ns and 0.90 ns, pulse width being 0.98 ns and 1.18 ns, pulse peek being 8.72 V and 12.2 V respectively, and partical discharge capacity of charge being 320 pC and 600 pC. The picked multi-pulse singnals are steady with the developped sleeve monopole antenna, the error is less than 70 ps. It can be used for the experimental study of ultra-high frequency partial discharge location and correction of electrical equipment.     

Study on high and steep slope stability Based on 3D laser scanning

Dangerous mountain construction projects block of high and steep slope stability is the important issue of security and disaster prevention, investigation on the surface of the dangerous mountain high and steep slope rock mass structure is the key to the analysis of the problem. The high slope of a major project of the Lancang River, the application of 3D laser scanning technique to study the long-distance survey analysis of rock mass structure analysis method to analyze the distribution of the surface space of the high and steep slope rock mass structure, statistical analysis direction of the advantages of the structure surface and the distribution of rock blocks, as the basis for the application of limit equilibrium analysis method to study the stability of rock blocks of the high and steep slope.     

Numerical analysis on the evolutionary features of deformation and failure modes of slopes

The failure of slope is a gradual accumulation process. Under the effect of many interior and exterior factors, some parts in the slope reach yield with the increase of stress, and sliding surface forms gradually till complete transfixion. With continuous increase of the plastic strain, overall failure happens on the slope. Traditional analysis method cannot display the mechanic conditions and the whole process of deformation, transfixion of sliding surfaces and failure. Meanwhile, FEM strength reduction can quantitatively show the deformation features and the process of occurrence and development of sliding surface. Based on the previous researches, the paper classifies slopes according to the features of rock and soil and the slope structure. Through analyzing the graphs of deformation and the nephograms of plastic strain under different reduction factors or safety factors, the researchers can directly find the deformation tendency of slopes and the whole process of the extension, transfixion and failure of sliding surface with the reduction of safety factor. So, the failure mechanism of slope can be found intuitively, which can provide effective basis for the prevention and governance of slopes.     

水平与竖向加速度-时程曲线叠加效应下边坡永久位移计算的极限上限分析

实际边坡动力稳定性受地震竖向与水平方向效应共同作用,传统边坡地震永久位移计算方法较少考虑竖向地震波影响,采用实际地震的竖向与水平方向加速度-时程曲线共同效应更符合工程实际。基于极限分析上限法和Newmark刚塑性滑块模型,提出一种基于实际水平向与竖向地震加速度-时程曲线的边坡永久位移计算改进方法,以3个工程边坡为例,探讨了两组具有代表性实测典型水平和竖向地震地面运动记录对边坡地震永久位移计算的影响。研究结果表明:不考虑竖向地震加速度时程曲线时,本文方法可蜕化为与前人方法兼容;不同地震波的竖向与水平地震动时程曲线的叠加效应不同,竖向地震对边坡永久位移的影响不可忽略。     

热风与微波干燥胡萝卜的工艺研究

用热风干燥、热风和微波组合干燥对胡萝卜进行干制,检测不同干燥方法对胡萝卜干制品感观品质、复水比、VC含量的影响。结果表明,利用不同的干燥方法所获得的胡萝卜干制品的复水性能和感官品质有明显差异,热风与微波联合干燥胡萝卜制品的品质最优。降低热风温度,缩短热风干燥时间,减小热风速率和微波加热功率,均可提高干制品的复水性、VC含量及其品质。     

Fertilisation of irrigated maize with pig slurry combined with mineral nitrogen

Maize (Zea mays L.) is a very important crop in many of the irrigated areas of the Ebro Valley (NE Spain). Intensive pig (Sus scrofa domesticus) production is also an important economic activity in these areas, and the use of pig slurry (PS) as a fertiliser for maize is a common practise. From 2002 to 2005, we conducted a field trial with maize in which we compared the application of 0, 30 and 60 m³ ha⁻¹ of PS combined with 0, 100 and 200 kg ha⁻¹ of mineral N at sidedress. Yield, biomass and other related yield parameters differed from year to year and all of them were greatly influenced by soil NO₃⁻-N content before planting and by N (organic and/or mineral) fertilisation. All years average grain yield and biomass at maturity ranged from 9.3 and 18.9 Mg ha⁻¹ (0 PS, 0 mineral N) to 14.4 and 29.6 Mg ha⁻¹ (60 m³ ha⁻¹ of PS, 200 kg ha⁻¹of mineral N), respectively. Grain and total N biomass uptake average of the studied period ranged from 101 and 155 kg ha⁻¹ (0 PS, 0 mineral N) to 180 and 308 kg ha⁻¹ (60 m³ ha⁻¹ of PS, 200 kg ha⁻¹of mineral N), respectively. All years average soil NO₃⁻-N content before planting and after harvest were very high, and ranged from 138 and 75 kg ha⁻¹ (0 PS, 0 mineral N) to 367 and 457 kg ha⁻¹ (60 m³ ha⁻¹ of PS, 200 kg ha⁻¹of mineral N), respectively. The optimal N (organic and/or mineral) rate varied depending on the year and was influenced by the soil NO₃⁻-N content before planting. For this reason, soil NO₃⁻-N content before planting should be taken into account in order to improve N fertilisation recommendations. Moreover, the annual optimal N rates also gave the lowest soil NO₃⁻-N contents after harvest and the lowest N losses, as a consequence they also could be considered as the most environmentally friendly N rates.     

甘蔗间种大豆的试验

以甘蔗品种新台糖22号和大豆品种桂早1号为试材,研究了纯种甘蔗和间种大豆两种条件下作物的生长情况、农艺性状、产量及效益。结果表明,甘蔗间种大豆后,分蘖数明显减少,前期长势比较慢,后期不受影响;间种大豆的甘蔗有效茎数比对照稍低,但茎长、茎径和单茎重均高于对照,产量比对照提高6.84%;间种大豆处理比对照的产值多12503.9元/hm²。说明在前期间种大豆虽然影响甘蔗分蘖和长势,但后期大豆的固氮和枯根落叶,增加了土壤有机质和养分,促进甘蔗增产。     

Process Method of Face-gear Drive with Spur Involute Pinion with the Shaping Machine

In order to research face-gear drives, a face-gear drive with spur involute pinion is considered. The genera, tion of a face gear is based on application of a conventional shaping machine and an involute shaper. The functions of theoretic shaping surface and processing surface about the face gear are deduced. Computer programs are developed for simulation of these surfaces. In shaping time, mutual position of two surfaces, theoretic shaping surface and processing surface, is analyzed by simulation. In the end, the feasibility of the process method is concluded.     

可食性CW-GML涂膜结合热处理保鲜鸡蛋研究

以新鲜鸡蛋为试材,对其分别进行热处理(50℃下20 min)、热处理结合巴西棕榈蜡-单月桂酸甘油脂(CW-GML)涂膜(50℃下20 min后常温涂膜)、热处理结合热CW-GML涂膜(50℃下20 min后热涂膜),以不进行加热及涂膜处理为对照组,在30℃恒温培养箱中进行为期35 d的保鲜试验,探究CW-GML涂膜剂配合热处理对鸡蛋保鲜的效果。结果表明:在第35天时,热处理结合CW-GML热涂膜的保鲜效果最好,失重率为4.53%,没有出现散黄,挥发性盐基氮含量低,菌落总数为4.1×103 CFU/g。     

Improvement of quality and shelf-life of strawberries with edible coatings enriched with chitosan

Strawberry fruit have a very short shelf-life and senescent period due to their high degree of perishability and infection caused by several pathogens that can rapidly reduce fruit quality. The aim of this study was to determine the efficacy of carboxymethyl cellulose (CMC), hydroxypropylmethyl cellulose (HPMC) and composites with chitosan (CH) coatings on the shelf-life and overall quality of strawberry fruit. Strawberry fruit dipped for 2 min in solutions of CMC (1%), HPMC (1%), CMC (1%) + CH (1%) and HPMC (1%) + CH (1%) were stored at 11 ± 1 °C, 70–75% RH, while the uncoated fruit served as controls. Fruit coated with edible coatings showed significant delays in the change of weight loss, decay percentage, titratable acidity (TA), pH, total soluble solids (TSS) and ascorbic acid content as compared to uncoated control fruit. In addition, the edible coatings had a positive effect on maintaining higher concentrations of total phenolics and total anthocyanins, which decreased in control fruit due to over-ripening and senescence processes. Compared to the controls, all the coatings had positive effects on the inhibition of cell wall degrading enzymes and among all the tested coatings, CMC + CH and HPMC + CH was superior in inhibiting enzyme activity. These findings suggest that the use of CMC 1% + CH 1% and HPMC 1% + CH 1% coatings are useful for extending the shelf-life and maintaing quality of strawberry fruit.     

A Selection Index to Cope with Genotype-Environment Interaction with an Application to Wheat Breeding

The objective of this study was to develop a genetic selection index for the combination of quantitative observations repeated in different environments when there may be genotype-environment interactions and heterogeneity of the variance. A distinction is made between the index for local ranking of strains for each environment on its own and the index for a joint ranking which predicts mean genotypic value averaged over all environments. The resulting index was applied to field trial observations on the yield of wheat at two locations, involving 276 newly developed strains in six trial groups of equal size, in order to study the efficiency of the index and the sampling variance of index weights. The index for local ranking of strains was found to be consistently more efficient than ranking without the index, though only marginally so in trials with low coefficients of error variation. Limitations on general use of the index, as related to trial size and the standard errors of index weights, are discussed.     

Integration of continuous biofumigation with Muscodor albus with pre-cooling fumigation with ozone or sulfur dioxide to control postharvest gray mold of table grapes

An integrated approach was evaluated that combined biological and chemical fumigation of table grapes to control postharvest gray mold caused by Botrytis cinerea. After fumigation of the grapes with ozone or sulfur dioxide during pre-cooling, the fruit were then exposed to continuous biofumigation by the volatile-producing fungus Muscodor albus during storage. Biofumigation was provided by in-package generators containing a live grain culture of the fungus. This grain formulation of M. albus survived the initial ozone or sulfur dioxide fumigation, but sulfur dioxide reduced its production of isobutyric acid, an indicator of the production of antifungal volatiles. Gray mold incidence was reduced among inoculated ‘Autumn Seedless’ grapes from 91.7 to 19.3% by 1 h fumigation with 5000 μL L^?1 ozone, and further reduced to 10.0% when ozone fumigation and M. albus biofumigation were combined. The natural incidence of gray mold among organically grown ‘Thompson Seedless’ grapes after 1 month of storage at 0.5 °C was 31.0%. Ozone fumigation and M. albus biofumigation reduced the incidence of gray mold to 9.7 and 4.4, respectively, while the combined treatment reduced gray mold incidence to 3.4%. The use of commercial sulfur dioxide pads reduced the incidence to 1.1%. The combination of ozone and M. albus controlled decay significantly, but was less effective than the standard sulfur dioxide treatments. Although less effective than sulfur dioxide treatment, ozone and M. albus controlled decay significantly, and could be alternatives to sulfur dioxide, particularly for growers complying with organic production requirements.     

Selection of cassava accessions with multiple resistance to pathogens associated with root rot disease

Cassava root rot disease (CRRD) severely affects productivity in several countries. The objective of this study was to estimate genetic parameters and to identify multiple resistance sources against pathogens associated with CRRD. The symptoms caused by Fusarium spp., Phytophthora spp., and Botryosphaeriaceae species in peel and pulp from the roots were evaluated in 277 accessions using a whole tuberous root inoculation method. The resistance data were obtained by REML/BLUP (restricted maximum likelihood/best linear unbiased predictor). The classic selection index (CI), multiplicative (MI), and sum of ranks (SRI) were used to identify the accessions with multiple resistance. For all pathogens, the environmental variance (\(\sigma_{e}^{2}\)) was the most important component. Individual heritability \(\left( {h_{g}^{2} } \right)\) was of low magnitude for resistance to most pathogens (0.16 ± 0.02—peel and 0.31 ± 0.03—pulp for Fusarium spp.; 0.26 ± 0.03—peel and 0.30 ± 0.03—pulp for Phytophthora spp.; and 0.28 ± 0.03—peel and 0.27 ± 0.03—pulp for Botryosphaereacea species). The distribution of CRRD symptoms indicated the presence of quantitative inheritance. The direct selection of the 15 more resistant accessions based on the genotypic predicted values result in high reductions of disease (>50%). However, there was a low matching rate of the most resistant accessions for each pathogen and the different parts of the tuberous roots (peel and pulp). The CI and MI were the most promising compared to the SRI to ensure high and balanced resistance for each pathogen. Understanding the genetic basis of resistance to CRRD and the identification of sources with multiple resistance may be useful in various management strategies to control the disease.     

First-order load with pulse-width modulation

For the limitation of the dynamic and time-varying characteristics of the load simulator, a novel design method for the first-order electrical load is presented. By adjusting the turn-on time of switches, the first-order load with the parameters in a certain range can be simulated. The simulation degree of the electrical load might be judged with the area percent of function distance in the load response. For the simulations on three loads with cut-off frequencies as 20,50,80 Hz, the PWM period is 1 ms. The duty cycles are 9.9%,39.4% and 69.1%. The simulation deviations are 1.48%,3.92% and 3.57%. The results show that the first-order electrical load designed with this method can simulate any first-order load with the parameters in a certain range .