汽轮机静叶片除湿结构对比分析

采用数值模拟的方法,对3种常用的静叶除湿结构的除湿效果进行了数值模拟,从除湿效果、工艺、强度等方面,对比分析了3种结构的优缺点,从而为汽轮机除湿静叶工程设计提供了一些有益的指导。

叶露仪的研制和初步测试

植物叶面结露时间长短及露量与农作物病虫害,特别是真菌病害的发生有密切的关系。为监测叶露情况我们设计制作了叶露仪。该仪器适合在植物病虫害发生规律的科学研究和大田作物病害预测预报工作中使用。

香椿中黄酮类化合物的提取研究

讨论了影响黄酮类化合物提取率的主要因素,并确定了较好的提取工艺。结果表明:在5g湿样中加80m l 70%乙醇水溶液提取剂,浸泡24h后,索氏回流提取1h,提取液用石油醚连续萃取2次。香椿中黄酮的提取率为4.82%。

10种杀虫剂对温室白粉虱成虫抗药性的检测

采用琼脂保湿浸叶法对温室白粉虱(Trialeurodes vaporariorum)田间抗性品系对阿克泰、吡虫啉、啶虫脒、阿维菌素、苦参碱、抑太保、溴氰菊酯、联苯菊酯、毒死蜱、辛硫磷10种杀虫剂进行了抗药性检测,其抗性指数分别为3.69倍、2.39倍、2.11倍、1.02倍、1.23倍、2.09倍、1.70倍、1.08倍、1.91倍和2.21倍,表明新烟碱类杀虫剂抗性增长速率大于其它类。

烟粉虱常用药剂抗性监测研究

为了解设施瓜菜上烟粉虱成虫抗药性,采用琼脂保湿浸叶法连续3年测定了8种不同药剂对海南设施甜瓜上烟粉虱成虫的毒力。结果表明,烟粉虱成虫对3.2%阿维菌素乳油的LD_(50)分别为0.013、0.003、0.056 mg/L;对60 g/L乙基多杀菌素悬浮剂的LD_(50)分别为0.059、0.010、0.062 mg/L;对22%氟啶虫胺腈悬浮剂的LD_(50)分别为4.994、6.035 mg/L;对5%甲氨基阿维菌素苯甲酸盐微乳剂的LD_(50)为2.689 mg/L,其他药剂在防治烟粉虱上易产生抗性,不建议使用,建议轮换使用阿维菌素、乙基多杀菌素、氟啶虫胺腈、甲维盐4种药剂。

河北省苔藓植物新记录及其地理分布

报道了河北省藓类植物新分布记录6种1变种:毛叶泽藓PhilonotislancifoliaMitt.,齿缘泽藓PhilonotisseriataMitt.,舌叶木灵藓OrthotrichumcrenulatumMitt.,薄网柳叶藓Amblystegiumriparium(Hedw.)B.S.G.,大叶湿原藓Calliergongiganteum(Schimp.)Kindb.,大湿原藓Calliergonellacuspidata(Hedw.)Loesk.和仰叶细湿藓多态变种Campyliumstellatumvar.protensum(Brid.)Bryhn.exGrout.简要介绍了它们的识别特征及地理分布,并根据标本对其中6个种绘制了形态解剖图.

陈达祥等6户养蚕高产情况调查

平南县大成乡河口村大塘二队陈达祥、陈克文、陈来学、陈达庆、陈开文、陈柱文等6户,1990年共有桑园1.45公顷全年养蚕236.5张共产茧6586kg,平均公顷桑产茧4560kg,最高户陈达祥户,公顷桑产茧4823kg,公顷桑产值42045元,纯收入2272元,为本年度高产增收尖子,现将调查情况概述如下:

全区木薯蚕种场繁种技术座谈会

受区农业厅的委托,区蚕业指导所于1989年6月6日至8日在崇左县召开全区木薯蚕蚕种场站繁种座谈会.参加会议的有部份地、县农业局和23个场站的负责人共33人.区农业厅经作处于志善同志、崇左县王付县长等领导也亲临会议指导.会议指出,当前正是我区木薯蚕繁种的高峰期,也正遇上高温季节,我区的蚕种场站目前生产条件还比较差,如何搞好木薯蚕的蚕种繁育,事关重要,必须认真对待,既不能盲目乐观,又不能麻痹大意,才能完成今年的制种任务.

Status and Application of Tobacco Leaf Preconditioning in China

In the process of tobacco production, the moisture content of tobacco leaves directly affects the quality of tobacco leaf. Since the water content in the leaf is low, it needs to process with the conditioning treatment for a short time beforetobacco grading, so as to improve the tobacco moisture content and reduce breakage, as well as ensure the quality and yield of tobacco, ahd meet the requirements of the follow-up process of tobacco. Therefore, a comprehensive overview was given to the pre-conditioning method for tobacco leaf, and the current application status of tobacco leaf pre-conditioning equipment in China was explored.

汽轮机静叶除湿方法的数值研究

本文针对蒸汽轮机末级湿蒸汽形成现象,分析湿蒸汽非平衡凝结流动的控制方程及物理模型。对Moses and Stein喷嘴进行了计算分析,得出湿蒸汽形成过程的特点,并与实验结果相比,契合度可以证明数值计算模型及方法的正确性。最后对某汽轮机静叶进行数值计算,分析湿度及过冷度分布,提出一种新型的静叶除湿结构,并对除湿效果进行计算分析。结果表明,随着通道直径的增加,静叶出口位置的平均湿度降低,湿汽损失减小。

Application of remote sensing,an artificial neural network leaf area model,and a process-based simulation model to estimate carbon storage in Florida slash pine plantations.

Carbon sequestration in forests is of great interest due to concerns about global climate change.Carbon storage rates depend on ecosystem fluxes（photosynthesis and ecosystem respiration）,typically quantified as net ecosystem exchange（NEE）.Methods to estimate forest NEE without intensive site sampling are needed to accurately assess rates of carbon sequestration at stand-level and larger scales.We produced spatially-explicit estimates of NEE for 9 770 ha of slash pine（Pinus elliottii） plantations in North-Central Florida for a single year by coupling remote sensing-based estimates of leaf area index（LAI） with a process-based growth simulation model.LAI estimates produced from a neural-network modeling of ground plot and Landsat TM satellite data had a mean of 1.06（range 0-3.93,including forest edges）.Using the neural network LAI values as inputs,the slash pine simulation model（SPM2） estimates of NEE ranged from-5.52 to 11.06 Mg·ha^-1·a^-1with a mean of 3.47 Mg·ha^-1·a^-1Total carbon storage for the year was 33920 t,or about 3.5 tons per hectare.Both estimated LAI and NEE were highly sensitive to fertilization.

Soil Microbial Population Dynamics along a Chronosequence of Moist Evergreen Broad-leaved Forest Succession in Southwestern China

Little is known about whether soil microbial population dynamics are correlated with forest succession.To test the hypotheses that(1) soil microbial composition changes over successional stages,and(2) soil microbial diversity is positively correlated with plant species diversity,we determined the soil microbial populations,community composition,and microflora diversity in evergreen broad-leaved forests along a chronosequence of vegetation succession from 5 to 300 years in southwestern China.The soil microbial community was mainly composed of bacteria(87.1-98.7% of the total microorganisms and 10 genera identified),fungi(0.3-4.0%,7 genera),and actinomycetes(2.1-9.1%,8 species and 1 genus).There were significant differences in soil microbial populations among different successional stages and within the four seasons.The seasonal variations of the soil microbial community may be associated with the seasonal changes in environmental conditions.The changes in soil microbial diversity(Shannon-Wiener index) with successional time followed one-humped,convex curves peaked at-100 years since restoration,which is identical with the trends of the aboveground plant diversity.Higher plant diversity resulting in enhanced nutrient flow and root exudation may contribute to positive relationships between the soil microbial diversity and plant diversity.Hence,decreases in soil microbial diversity in the late-successional stages appear to be related to the net loss in species richness that occurs after 100 years since restoration.Our findings confirm the intermediate disturbance hypothesis that suggests diversity peaks at midsuccessional stages.

Simulation Study on Purification Efficiency for Nitrogen in Different Types of Wetlands in Sanjiang Plain, China

The purification law of nitrogen in Deyeuxia angustifolia, Carex lasiocarpa and Deyeuxia angustifolia-Carex lasiocarpa combined wetland systems in the Sanjiang Plain, China was studied by field simulation experiment. The results indicate that the removal rates of TN, NH4^＋-N and NO3^--N in above three types of wetlands present an obvious logarithm growth trend along with the time. There are evident removal effects for NH4＋-N and NOa--N in water bodies of wetlands after the 30th day of experiment, with the removal rates over 80.0%, but the removal rate of TN is slightly low, being 63.1%-74.3%. NO3 -N is most quickly removed by the combined wetland, and NH4^＋-N by Deyeuxia angustifolia wetland. The removal speeds of TN by the three wetland systems are comparatively slow, of which the Deyeuxia angustifolia wetland is the fastest. In consideration of plant growth season, Deyeuxia angustifolia wetland has much more practical application value in purifying nitrogen. These results can provide references for the study on the purification function of wetlands and the control of non-point source pollution in Northeast China.

Tomato Leaf Photosynthetic Responses to Humidity andTemperature Under Salinity and Water Deficit

Greenhouse tomato plants (Lycopersicon esculentum Mill cv. Capello) were grown on peat-based substrate and treated with high (4.5 mS cm-1) and low (2.3 mS cm-1) nutrient solution electric conductivity(EC) under high and low substrate water contents. FOur weeks after the beginning of the treatments, photosynthesis (Th) was measured under different humidity and temperatures to examine the interactive effectswith rhizosphere salinity and water deficit. A rectangular hyperbolic model fitted the light-photosynthesiscurve. Photosynthetic capacity (PC) was decreased but quantum yield (YQ) was increased by rhizospheresalinity caused by high EC. PN was decreased by low humidity only in high EC- and/or water-stressed plants.Under high photosynthetic photon flux (PPF), low humidity induced PC decline in water-stressed plants andPN oscillation in high-EC-treated plants. PN increased steadily as the leaf temperature changed from 18 Cto 23 and then decreased steadily from 23 to 38 . At 34 , PN decreased significantly in waterstressed plants. Dark respiration (RD) increased in an exponential manner as the leaf temperature changedfrom 18 to 38 to an extent about ten times higher under 38 than under 18 . Our data suggestedthat PN decrease under high temperature was attributed, st least in part, to the increased RD. RD in highEC- and/or water-stressed plants was higher than that in the plants of control under lower temperature butlower than that in the plants of control under high temperature. The analysis of stomatal and mesophyllconductance showed that low humidity effect was mainly through stomatal response while temperature effectwas mainly through biochemical functions. The result showed that environmental stresses affected PN in anadditive or synergistic manner.

Relationship between the Water Body Chlorophylla and Water Quality Factors of Wetlands Baiguishan Reservoir

[Objective] The aim was to explore the relationship between water body Chlorophyll-a and water quality factors of wetlands Baiguishan reservoir.[Method] Chlorophyll-a and water quality factors of water quality of Wetlands BaiGuishan Reservoir was studied,the analysis of the relationship on water quality of Wetlands Baiguishan Reservoir was made by use of trophic status indices and SPSS17.0 statistical analysis.[Result] Total phosphorus was an important factor of influence Chlorophyll-a in reservoir,water body had slight eutrophication phenomenon in reservoir of July to October in 2010.[Conclusion] Comprehensive management should be strengthened so as to improve the water quality of Baiguishan wetland.

Efficacy of Betel Leaf Extracts as Antioxidant in Moisturizing Cream

This work aims to study the appropriate method for extract Betel leaf as crude extracts to prepare as a natural antioxidant in moisturizing hand cream. Betel leaf was treated by 7 methods and the optimized method was selected for preparation of Betel leaf extract. The fresh Betel leaf and dried Betel leaf were used in this study. Betel leaf extracts were analysed for total phenolic content and essential oil as eugenol content. Then Betel leaf extracts were used as the one component for moisturizing hand cream. The lipid oxidation was evaluated by measurement on malondialdehyde content. The results revealed that an extracts solution from dried Betel leaf contained total phenolic content and eugenol content more than flesh Betel leaf. The ethanol extraction method was the optimum method since this method showed the maximum total phenolic content and eugenol content in dried Betel leaf as 5.26 g/100 g and 138.95 mg/100 g, respectively. The moisturizing creams were formulated by using crude Betel leaf extracts as the one composition compare with base cream （no addition of Betel leaf extracts）. The moisturizing cream samples were analysed for malondialdehyde. its showed that the cream that contained Betel leaf extract contained malondialdehyde content lower than in cream base. Thus, crude extracts from Betel leaf showed the efficacy to reduce lipid oxidation reaction in moisturizing hand cream.

Transpiration Rates of Carex Meyeriana in Relation to Micrometerological Factors in a Mountain Valley Wetland

In order to reveal transpiration rates of wetland plants and its relationships to micro-meterological factors in a mountain valley wetland, relative humidity, air temperature, leaf temperature, soil temperature, photo flux density and transpiration rates were measured once two hours in a Carex meyeriana wetland of the Changbai Mountain valley in dry (July) and wet (September) of 2003, respectively. Results showed that the tendency of "decreasing after increasing" was obvious in wet season. However, a relatively stable trend was observed for the transpiration in dry season.. Generally, the photon flux density of Carex meyeriana was higher in wet season than that in dry season. However, the variabilities of leaf temperature, air temperature and relative humidity were similar in both seasons. Higher transpiration rates of Carex meyeriana leaves were observed in July (varied from 40 to 150 mol·m-2·s-1) compared to those (varied from 7 to 14 mol·m-2·s-1) in September. Transpiration rates were significantly correlated with air temperature (P<0.01), leaf temperature (P<0.01), and wind speed (P<0.05), but correlationship between relative humidity and photo flux density was not significant (P<0.05).

Effect of Non-Equilibrium Condensation of Moist Air on Unsteady Behaviour of Shock Waves around a Circular Arc Blade

The unsteady phenomena in the transonic flow around airfoils are observed in the flow field of fan, compressor blades and butterfly valves, and this often causes serious problems such as the aeroacoustic noise, the vibration. In the transonic or supersonic flow where vapour is contained in the main flow, the rapid expansion of the flow may give rise to a non-equilibrium condensation. However, the effect of non-equilibrium condensation on the transonic internal flows around the airfoil has not yet been clarified satisfactorily. In the present study, the effect of non-equilibrium condensation of moist air on the self-excited shock wave oscillation on a circular arc blade was investigated numerically. The results showed that in the case with non-equilibrium condensation, frequencies of the flow oscillation became smaller than those without the non-equilibrium condensation.

Numerical Investigation on Wet Steam Non-equilibrium Condensation Flow in Turbine Cascade

Based on the two-phase wet steam flow with spontaneous condensation, experimental verification and flow analysis on nozzle and 2D cascade are carried out. The 3D Reynolds-Averaged gas-liquid two-phase flow control equation solver is explored with k-e-kp turbulence model. Furthermore, 3D flow numerical simulation on the last stage stator of the steam turbine is carried out. The results show that a sudden pressure rise on blade suction surface is mainly caused by the droplet growth in condensation flow. The more backward the condensation position is in cascade passage, the less the sudden pressure rise from condensation is, and the larger the nucleation rate is, the maximum under-cooling and the number of droplets per unit volume are. Interaction of condensation wave and shock wave has imposed greater influence on the parameters of the blade cascade outlet.