几种生长调节剂对四翅滨藜全光喷雾扦插效果的影响

四翅滨藜全光照喷雾嫩枝扦插试验结果表明:采用NAA、ABT 2号生根粉、IBA等3种外源植物生长调节剂处理插条2 h,对插条具有良好的促根作用,其中100 mg/L NAA为最好,生根率可达到93.6%;100 mg/LABT2号生根粉和100 mg/L IBA次之,生根率分别可以达到92.6%,92.3%.     

Spatiotemporal variation in snow cover and its effects on grassland phenology on the Mongolian Plateau

Snow cover is an important water source for vegetation growth in arid and semi-arid areas,and grassland phenology provides valuable information on the response of terrestrial ecosystems to climate change.The Mongolian Plateau features both abundant snow cover resources and typical grassland ecosystems.In recent years,with the intensification of global climate change,the snow cover on the Mongolian Plateau has changed correspondingly,with resulting effects on vegetation growth.In this study,using MOD10A1 snow cover data and MOD13A1 Normalized Difference Vegetation Index(NDVI)data combined with remote sensing(RS)and geographic information system(GIS)techniques,we analyzed the spatiotemporal changes in snow cover and grassland phenology on the Mongolian Plateau from 2001 to 2018.The correlation analysis and grey relation analysis were used to determine the influence of snow cover parameters(snow cover fraction(SCF),snow cover duration(SCD),snow cover onset date(SCOD),and snow cover end date(SCED))on different types of grassland vegetation.The results showed wide snow cover areas,an early start time,a late end time,and a long duration of snow cover over the northern Mongolian Plateau.Additionally,a late start,an early end,and a short duration were observed for grassland phenology,but the southern area showed the opposite trend.The SCF decreased at an annual rate of 0.33%.The SCD was shortened at an annual rate of 0.57 d.The SCOD and SCED in more than half of the study area advanced at annual rates of 5.33 and 5.74 DOY(day of year),respectively.For grassland phenology,the start of the growing season(SOS)advanced at an annual rate of 0.03 DOY,the end of the growing season(EOS)was delayed at an annual rate of 0.14 DOY,and the length of the growing season(LOS)was prolonged at an annual rate of 0.17 d.The SCF,SCD,and SCED in the snow season were significantly positively correlated with the SOS and negatively correlated with the EOS and LOS.The SCOD was significantly negatively correlated with the SOS and positively correlated with the EOS and LOS.The SCD and SCF can directly affect the SOS of grassland vegetation,while the EOS and LOS were obviously influenced by the SCOD and SCED.This study provides a scientific basis for exploring the response trends of alpine vegetation to global climate change.     

人工林UHF频段电波传播场强预测模型

人工林无线电波传播场强模型是合理设计人工林环境无线电遥测遥控等通信电路的理论依据.该文在分析无线电波传播机理的基础上确定了人工林UHF频段传播损耗的三大组成部分及相应的计算方法,提出了人工林中某接收点处电场强度的预测模型.经过对北京西山人工侧柏林中不同参数的场强测试数据进行分析,校验了所建模型具有很高的精度.      

城市微型公共空间景观设计

随着城市的发展,城市公共空间对城市生活的重要性不断凸显,城市微型公共空间作为其层次结构中不可或缺的一环,在世界范围内也得到了长足发展。但对于我国城市微型公共空间景观设计领域而言,却一直未能得到足够的重视。以深圳市罗湖区嘉宾公园为研究对象,阐述城市微型公共景观设计对于城市公共空间层次结构的重要意义,并展现其为城市所带来的独特魅力。深圳市罗胡区嘉实公园的建成为我国城市微型公共空间提供了一个极佳的参考样本。     

芦荟对肉仔鸡生长性能和免疫功能的影响

将360只1日龄雄性AA肉仔鸡随机分成6个组,每组设6个重复,每个重复10只.Ⅰ组为空白对照组,饲喂基础日粮,Ⅱ-Ⅵ组分别在基础日粮中添加600 mg.kg-1芦荟粉、600 mg.kg-1芦荟水提取物、600 mg.kg-1芦荟醇提取物、600mg.kg-1芦荟水提取物+600 mg.kg-1芦荟醇提取物和150 mg.kg-1金霉素.结果表明:Ⅲ组3、6周鸡的体增重均显著高于Ⅰ组(P<0.05);Ⅲ-Ⅳ组的料肉比与Ⅰ组比较均极显著降低(P<0.01),Ⅲ组与Ⅵ组比较显著降低(P<0.05);Ⅱ-Ⅴ组3周鸡的脾脏指数与Ⅰ组相比,差异均显著提高(P<0.05);Ⅲ组3周鸡的胸腺指数显著高于Ⅰ组(P<0.05);Ⅱ-Ⅴ组3周鸡的自然杀伤细胞的杀伤活性均极显著高于Ⅰ组(P<0.01),Ⅱ-Ⅴ组6周鸡均极显著高于Ⅰ、Ⅵ组(P<0.01).可见芦荟粉、水提取物、醇提取物和提取物混合组均能提高肉仔鸡的生产性能和免疫功能,其中水提取物组的效果最佳.     

Determination of reference intervals for metabolic profile of Hanwoo cows at early,middle and late gestation periods

Background: Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, there is little metabolic profile data available about Korean Hanwoo cows. Therefore, this study aimed to determine the reference intervals of metabolic profile for Korean Hanwoo cows.Methods: Healthy animals(2,205) were selected and divided into early(day 1 to 95), middle(day 96 to 190) and late(day 191 to 285) period according to their gestating period. Metabolic profile including total protein(TP), albumin(Alb), urea(UREA), glucose(Glu), total cholesterol(T-Cho), long-chain fatty acid(LCFA), aspartate aminotransferase(AST),gamma-glutamyl transpeptidase(GGT), creatinine(Crea), calcium(Ca), inorganic phosphorous(i P) and magnesium(Mg)were analyzed using a TBA-40 FR automatic biochemical analyzer. The data of Korean Hanwoo cows were then compared to those of the Japanese Wagyu cows.Results: Most of the data of the Korean Hanwoo cows were relatively higher than those of Japanese Wagyu cows, with the exception of Glu and GGT. This may indicate that the nutritional level of feed for the Korean Hanwoo cows was higher than that of the Japanese Wagyu cows because of the different feeding system. In particular, relatively higher levels of UREA and LCFA were observed in the Korean Hanwoo cows, and this may also contribute to the low reproduction efficiency.Conclusions: These findings may provide some theoretical basis for understanding the reproductive and feeding situation of Korean Hanwoo cows.     

盐碱土秸秆添加量对玉米种子萌发及幼苗生长特性的影响

探索盐碱土中添加最佳玉米秸秆量,以‘农华101’玉米种子、收获期玉米秸秆和通辽地区典型的盐碱土为材料,用盐碱土:蒸馏水(1:5)的土壤浸出液制备0、30、40、50、60 g/L秸秆粉培养液,作为5个处理,水培玉米种子;培养期间测定培养液pH、电导率、微生物数量及玉米幼苗根系内生菌数量,统计种子发芽率,4叶期测定幼苗农艺性状及其叶片和根系生理特性指标。结果表明：盐碱土添加玉米秸秆降低pH,降低玉米种子发芽率,但极显著增加幼苗根长、根数和株高;其中40 g/L处理对根长、根数的增加幅度最大,0 g/L处理2叶期死亡。添加秸秆极显著增加盐碱土细菌数量,除了30 g/L处理,其余处理极显著增加真菌和放线菌数量。根内生真菌和放线菌各处理无显著差异,30 g/L与40 g/L根内生细菌数显著大于50 g/L与60 g/L处理。40 g/L处理叶片POD活性极显著大于50、60 g/L处理,分别是它们的2.22倍和3.15倍;叶片MDA含量排序为60 g/L>50 g/L>30 g/L>40 g/L,处理间差异极显著;叶片SOD活性和根系活力为40 g/L>50 g/L>60 g/L>30 g/L,处理间差异极显著;根系MDA含量排序为60 g/L>30 g/L>50 g/L>40 g/L,处理间差异极显著;各处理根系POD活性规律与根系活力一致。盐碱土添加玉米秸秆可增加玉米幼苗抗盐碱胁迫能力,其中40 g/L处理最为显著。     

Determination of evapotranspiration from an alfalfa crop irrigated with saline waste water from an electrical power plant

Summary Investigations were carried out in 1989 to determine the evapotranspiration (ET) of alfalfa when irrigated with saline waste water coming from the evaporation of fresh water in the cooling towers of Utah Power and Light Company Electrical Power Plant at Huntington in central Utah, U.S.A. The primary goal is to dispose of the waste water from the power plant by irrigation and to maximize salt deposition in the soil, maximize crop ET, minimize runoff from the soil surface, and minimize leaching to the ground water. Using the Bowen ratio-energy balance method, alfalfa evapotranspiration was measured at an experimental site for each 20-minute period during the 1989 irrigation season. Using a simplified seasonal water balance, the results showed that cumulative irrigation plus rain was less than evapotranspiration for the 1989 irrigation season. This means that for the long term in addition to irrigation and precipitation some water was withdrawn from the soil for alfalfa crop water requirements (ET_a). Short term evaluations showed that because of unforeseen heavy rain (thunder showers) in this mountainous area between irrigations, ET_a was occasionally less than irrigation plus rain. This means the excess water was stored in the soil for later use. The average value for ET_a/ET_p (potential ET) for the 1989 irrigation season was 0.47 but occasionally the ratio was greater than unity. Short-term studies (Hanks et al. 1990 a) indicate that yield and ET_a are likely to decrease only slightly for the coming years if saline irrigation water is applied. This method of investigation can be applied to any industrial processes which produce waste water.     

Immunosuppressant Effect of Long Term and Subtherapeutic Chlortetracycline in Broiler

Experiments were conducted with 270 Abore Acre male broilers to study the influence of dietary chlortetracycline (CTC) on the bursal, thymus and spleen weight index and T, B cell proliferation and antibody responses of broilers. Results show that 50mg/kg CTC had no significant inhibitory effect on thymus and spleen weight index, and T, B cell proliferation of broilers at 21 days old. 150mg/kg CTC had significant inhibitory effect on bursal, thymus and spleen, and T, B cell proliferation (P＜0.05). Dietary CTC had a direct inhibitory effect on lymphocyte proliferation in vitro. 50mg/kg and 150mg/kg CTC had a significant inhibitory effect on the antibody responses to BSA (P＜0.01). Results demonstrated that subtherapeutic and long term CTC had significant inhibitory effects on immune organs and antibody response. The immunosuppressant effect became higher when the level of CTC increased. 150mg/kg CTC increased the growth rate of broilers significantly.