Design of Automatic Quasi-synchronizing Device in Rural Small Hydropower Station

Generator synchronization is an important and frequent operation in rural small hydropower station. In order to ensure that generator can be paralleled in the grid automatically, efficiently, and stably in the rural small hydropower station whose parallel in operation still needs to be accomplished manually. This paper described an automatic quasi-synchronizing device, based on 89C52 Single-chip Microcomputer （SCM）. Its hardware includes three modules and its software is structuralized. The device structure is simple, and its reliability is high and the maintenance is easy. Besides, convenient Human Machine Interface （HMI） makes the parameter setting simple and flexible     

低温胁迫下草坪草抗寒性的研究进展

通过介绍低温对草坪草的影响和作用机理,系统地综述了在低温胁迫下草坪草的光合特性、水分生理代谢、细胞质膜相对透性、保护酶系变化、碳水化合物贮藏、可溶性蛋白质含量、以及脂肪酸的变化在低温胁迫方面的研究进展,提出了今后进行草坪草抗寒性研究的趋势和建议。     

半地下带保温夹套发酵罐的应用

通过对半地下带保温夹套的发酵罐与普通发酵罐24 h的温度变化和6 d的产气量的对比试验分析,结果表明:采用半地下带保温夹套发酵罐发酵,24 h的温度变化缓慢,受外界温度变化影响小,高温持续的时间较长,利于微生物发酵;产气总量多,持续时间长。     

气候变化对秃尾河流域径流量的影响

为探讨秃尾河流域径流量对气候变化的关系,利用秃尾河流域1970～2005年36 a来的气温、降水和天然径流量数据,对该流域气温、降水和径流量年际和季节性的变化特征及趋势进行了分析,研究了气候因子与径流量的相关性.研究结果表明:秃尾河流域年平均气温呈现明显升高趋势,以冬季升温为主；年降水表现为缓慢减少趋势,降水减少主要表...     

低温胁迫对木薯腋芽部分生理指标的影响

以木薯品种南植199种茎为材料,以常温25℃为对照,研究在持续10℃与4℃低温胁迫以及卸除低温胁迫后木薯腋芽中丙二醛、可溶性淀粉、蛋白质、游离氨基酸含量以及保护酶活性等生理生化变化。结果表明:木薯腋芽中丙二醛含量随着处理时间延长逐渐增加,尤其对照均较之低温处理的高。在处理后120 h,低温处理与对照一样,其可溶性淀粉、可溶性蛋白质与游离氨基酸含量、POD总活性、SOD活性都有所下降。而在卸除低温处理后,低温处理的可溶性淀粉、蛋白质与游离氨基酸含量、POD总活性、SOD活性均升高,尤其是低温处理的可溶性蛋白质含量与POD总活性、SOD活性均比对照的高,达到极显著差异。表明适宜低温有利于木薯种茎的保存。     

The influence of temperature on the growth and sulfur uptake of oats (Avena sativa L.)

Abstract

Oats were grown in perlite and nutrient solution at temperatures varying from 10/5°C (day/night) to 36/31°C. The optimum temperature for growth of tops was found to be 27°C day/22°C night over an eight week period. Plant S content showed an inverse relationship with yield.

Uptake of S was low at low temperature (10/5, 15/10°C), but was balanced by retarded growth at this temperature. Hence, uptake did not restrict growth at low temperature.     

Single and Interactive Effects of Temperature and Light Quality on Four Canola Cultivars

Combined effects of temperature and light quality on plants have received little attention. We investigated the single and interactive effects of temperature and light quality on growth and physiological characteristics of four canola (Brassica napus) cultivars – Clearfield 46A76 (cv₁), Clearfield 45H72 (cv₂), Roundup Ready 45H24 (cv₃) and Roundup Ready 45H21 (cv₄). Plants were grown under lower (24°/20 °C) and higher (30°/26 °C) temperature regimes at low red/far‐red (R/FR), normal R/FR and high R/FR light ratios in environment‐controlled growth chambers (16 h light/8 h dark). Higher temperature reduced stem height and diameter; leaf number and area; dry matter of all plant parts; and specific leaf weight, but increased leaf area ratio; and chlorophyll (Chl) fluorescence (Y). Low R/FR increased stem height; Y; and ethylene, but decreased stem diameter; F_v/F_m; Chl a; Chl b; and carotenoids. Among cultivars, plants from cv₄ were tallest with thickest stems and greatest dry matter. None of the main factors affected gas exchange. Higher temperature at high R/FR caused cv₃ to be shortest, whereas lower temperature at low R/FR caused cv₄ to be tallest. We conclude that heat and other stress factors will adversely affect sensitive crops, but tolerant genotypes should perform well under future climate.     

从隐私权看中西文化差异

以透析中西方隐私权观念差异为视角，分析中西方文化差异，并探究缩小中西交流中的文化差异的有效途径。     

Effect of storage duration on egg quality,embryo mortality and hatchability in FUNAAB-ɑ chickens

Effect of extended storage on egg quality, embryo mortality and hatchability in FUNAAB-ɑ chickens was determined. Hatchable eggs (n = 288; weighing 53.2 ± 4.67 g) collected from a flock of FUNAAB-ɑ layer breeder hens aged 32 weeks were stored in egg tray with broad end up under 16 ± 1.5°C for either 0, 4, 8, 12, 16 or 20 d. Before incubation, eight eggs from each group were evaluated for internal and external quality traits. Remaining eggs were set in an incubator and transferred into hatcher on embryonic day 18. Data collected were subjected to one-way analysis of variance. Egg weight loss (EWL; p < .001), surface area (p < .001), yolk diameter (p < .001), inner and outer blastoderm diameters (p < .05) and dead in germ (DIG; p < .001) increased with storage duration while yolk height (p < .001), yolk index (p < .001), albumen weight (p < .05), albumen height (p < .05), albumen index (p < .01), Haugh's unit (HU; p < .05), fertility (p < .001), hatchability of set (HATCHS; p < .001) and fertile eggs (p < .05) decreased. Weight losses of 0, 1.2, 2.2, 3.4, 4.6 and 6.1% were recorded in egg stored for 0, 4, 8, 12, 16 and 20 days respectively. Eggs stored beyond 8 days exhibited higher DIG and lower HATCHS. Shell percentage in 4 days storage (11.4%) was lower (p < .05) than in 16 days storage (13.4%). Shell thickness was similar in eggs stored for 0 to 12 days, but 8 days storage (0.60 mm) had thinner (p < .01) shell than day 16 (0.71 mm) and day 20 (0.73 mm) storage. Internal quality unit (IQU) was higher (p < .05) in fresh eggs (180.4) than in 12 days (167.8) and 20 days (167.8) stored eggs. Extended storage of FUNAAB-ɑ eggs caused EWL, surface area shrinkage, lowered HU and IQU, loss of yolk and albumen quality, increased blastoderm diameters and DIG, and decreased egg fertility and HATCHS from day 8 forward. Storing FUNAAB-ɑ eggs beyond 8 days reduced quality parameters; therefore, other mitigating factors are recommended when storing beyond 8 days.     

三种荒漠植物叶绿素荧光参数日变化特征

利用Photosynq MultiseQ多功能植物测量仪测定塔克拉玛干沙漠腹地3种主要防护林植物头状沙拐枣、多枝柽柳和梭梭的叶绿素荧光参数日变化,探讨其与环境因子的关系,以揭示3种植物对极端环境的适应策略,为沙漠公路防护林的管护提供理论依据。结果表明：1）3种土壤都呈碱性;0~30 cm土层中的电导率（EC）远高于30 cm以下的土层。1 m内梭梭土层中的含水量高于多枝柽柳高于头状沙拐枣。2）3种植物的光合有效辐射（PAR）、叶片温度和线性电子传递（LEF）及植物周围的大气温度日变化均先升后降,且都在14：00达到最高;而大气湿度、实际光化学效率Y_（II）日变化均呈‘V’型。3）PAR基本上与3种植物的LEF、非光化学淬灭系数（NPQ）、调节性能量耗散量子产量Y_（NPQ）、非调节性能量耗散量子产量Y_（NO）呈显著正相关,与实际光化学效率Y_（II）呈显著负相关;3种植物的Y_（II）与Y_（NPQ）、Y_（NO） 均呈极显著负相关。3种植物的LEF、Y_（II）、Y_（NPQ）的日均值差异不显著,但梭梭与多枝柽柳的NPQ和Y_（NO）日均值差异显著。4）在3种植物的叶绿素荧光参数中,梭梭和头状沙拐枣的LEF、NPQ和Y_（II）要高于多枝柽柳;而多枝柽柳的Y_（NO）要显著高于头状沙拐枣和梭梭。因此,高温和高光均对3种植物造成了不同程度的影响,通过主成分分析表明,3种植物的抗逆性强弱顺序分别为梭梭>头状沙拐枣>多枝柽柳。