沼液在辣椒生产上的应用效果研究

研究施用沼液对辣椒生物学性状与品质的影响,结果表明:施用沼液可使辣椒初花期、座果期分别提前5～10、12～25 d;施用沼液也可使辣椒的株高更高,茎更粗;100%沼液氮处理与100%化学氮处理对比,辣椒素提高了22.08%,维生素C提高了26.44%,可溶性糖提高了22%,亚硝酸盐降低了26.44%。     

普安核桃优良单株选择初报

2010年以来,在普安县核桃重点产区开展了优良单株选择,按照丰产性状和坚果品质进行初选和复选,应用多性状综合评定开展决选。初选优株103株,复选优株43株,决选优株12株。优良单株的树冠投影产仁量为0.16～0.87 kg/m2,平均单果重为7.23～16.48 g,壳厚为0.85～1.80 mm,出仁率为51.4%～61.7%。优良单株无性繁殖材料在普安及周边区域可先行推广利用。     

不同防治措施对皖南春季马尾松林节肢动物和虫生真菌群落的影响

在皖南春季越冬代马尾松毛虫防治时期,于安徽长江以南采用不同治虫策略的5个林场,选立地条件和林分状况类似的马尾松纯林,对节肢动物和虫生真菌群落的调查表明,常年释放白僵菌的林场和长期监测虫情、准确挑治虫源地的林场害虫种数约占群落总种数的50%,个体数约占70%,益害物种数比(Ns/Ps)为0.72～0.83,个体数比(Nn/Pn)为0.44～0.45,多样性指数(H′)波动小,松毛虫虫口≤2.0条·株^-1.交替放菌和施药的林场,滥用农药、尤其不治虫的林场,害虫种数约占群落总种数的60%左右,个体数>74%,Ns/Ps0.46～0.54,Nn/Pn0.23～0.34,H′波动大,松毛虫虫口6.0～10.0条·株^-1,超过防治指标(5条·株^-1).长期的放菌或及时施药挑治利于优化群落结构,增大多样性指数,强化生态控制的力度     

Seasonal variations in radiation and energy balance in a deciduous broad-leaved forest

This study was conducted to document the effects of canopy change on radiation and energy balances in a deciduous broad-leaved forest. Global solar radiation was highly variable with a maximum close to 28.7 MJ m⁻² day⁻¹ and a minimum of about 0.7 MJ m⁻² day⁻¹. The high daily variation of net radiation was the result of the frequency and duration of rainfall. The mean annual albedo in this study site was 0.126. Seasonal variation of albedo was characterized by steadily decreasing values with leaf-fall, but at the time when new leaves sprouted the trend did turn upwards. The mean annual radiation efficiency at this study site was 0.564, and the seasonal variation of the radiation efficiency was dependent upon the net long-wave radiation rather than albedo. This study also illustrated the seasonal variation of the proportion of the actual evaporation to the equilibrium evaporation as a means for estimating the latent heat flux from forest using the equilibrium evaporation model. Seasonal variation of the proportion of the actual evaporation to the equilibrium evaporation reflected the physiological and productive activities of trees. Latent heat flux dominated the energy balance and, in particular, reached about 96% of net radiation in July.     

中国红壤丘陵区水土流失规律与土壤允许侵蚀量的研究

 在 8°～ 15°的红壤坡地上 ,对水土流失做了 14年的定位观察。结果表明 ,水土流失与土壤坡度和植被覆盖度密切相关。红壤坡地一经开发利用 ,径流量就成倍地减少 ;而侵蚀量在开始的头 2年成倍增加 ,第 3年后趋于稳定。土壤侵蚀量与坡度呈极显著的对数正相关 ,坡度每增加 1° ,年土壤侵蚀量递增约 12 0t·km-2 ;土壤侵蚀量与植被覆盖度呈显著的负指数相关 ,当植被覆盖度 >6 0 %时 ,每年土壤侵蚀量在 2 0 0t·km-2 以下 ;土壤侵蚀量与耕种方式密切相关 ,等高耕种的侵蚀量仅为顺坡耕种的 1/6。应用土壤肥力平衡观点 ,首次提出了Q2 红色粘土母质发育的红壤年土壤侵蚀允许指标为 <30 0t·km-2 。     

泵站主变压器运行效率分析

以提高泵站变压器的运行效率 ,降低泵站抽水能耗为目的 ,结合南上座泵站工程实例 ,对泵站变压器的运行工况从损耗与负载率、效率与负载率及效率与功率因数之间的关系进行了全面分析。结果表明 ,在泵站主变压器容量和机组功率一定的情况下 ,提高泵站的功率因数可以降低变压器的负载率 ,提高变压器的运行效率     

我国肉牛养殖风险及影响因素分析

为探讨肉牛养殖风险,基于1995—2013年河北等11个省区的非平衡面板数据,通过测算肉牛养殖利润、成本和产量的均值、方差和偏度,对肉牛养殖风险进行评估,并分析影响风险的相关因素。研究结果表明:我国肉牛养殖的利润和产量风险较大,利润和成本总体呈现左偏态,而产量则主要呈现右偏态,年际和区域间存在较大差异;利润风险大体呈现下降趋势,产量风险近年有所增加,成本风险较小且呈现下降趋势。养殖密度、疫病风险、产业优势、饲料结构、资本装备、养殖周期、技术进步和区域差异等因素,影响着肉牛养殖利润、成本和产量及其风险大小和发生概率。应警惕肉牛养殖左偏为常态的认识,建议合理调整载畜量,优化产业规模,调整饲料结构,加强资本装备水平,推进新型养殖模式,提升科技进步对肉牛产业贡献力度。     

Physicochemical properties and biological activities of DEAE-derivatized Sphingomonas gellan

Physicochemical characteristics and biological activities of Sphingomonas gellan (S-gellan) were investigated. The S-gellan weight fractions of Glc and GlcUA were 0.45 and 0.25, respectively, and the molar ratio of Glc:Rha:GlcUA was approximately 4:2:3. The S-gellan was chemically derivatized with diethylaminoethyl chloride-HCl (DEAE-HCl), and the resulting modified S-gellan contained both positive and negative charges. The elemental and IR analyses were conducted to confirm the successful incorporation of DEAE groups into S-gellan. A large increase in nitrogen fraction was observed from the derivatized S-gellan by elemental analysis. The IR absorption bands induced by C-H, C-N, and C-O-C stretching were noticeable at 2950, 1310-1380, and 1000-1150 cm(-1), respectively, resulting from the DEAE substitution. The characteristic CH3 and CH2 peaks originated from the DEAE group were detected in the 1H NMR spectrum of the derivatized S-gellan as well. The solubility of native S-gellan was improved almost twice from 40% to 75% after DEAE derivatization, while water holding capacity (WHC) drastically decreased from 10026% to 245%. Oil binding capacity (OBC) of S-gellan also significantly dropped from 1528% to 331% after the derivatization. The bile acid binding capacity of S-gellan was indirectly determined by measuring the holding capability of cholic acid inside the dialysis membrane (MWCO 12,000-14,000 Da). Once S-gellan was DEAE derivatized, there was substantial increase in the cholic acid retardation index (CRI). Up to 9 h of dialysis, the derivatized S-gellan released 29.3% less of cholic acid compared to the control group that did not contain S-gellan. From these results of the improved water solubility and stronger bile acid binding capacity, it would be suggested that the DEAE-derivatized S-gellan has more advantages than gellan itself for functional food applications.     

Bioremediation of a Crude Oil-Polluted Soil: Biodegradation,Leaching and Toxicity Assessments

The combined fate and effects of hydrocarbons (HC) on a soilecosystem affected by bioremediation were studied during 480days in a field experiment. The HC removal rates, the HC andmetabolites mobility and the potential toxicity were assessed.A clayey soil polluted by 18 000 mg HC kg^-1 dry soil, wastreated with either static-ventilated biopile or series of fivewindrows periodically tilled in order to determine the relativeinfluence of nutrients, bulking agents, aeration and soiltemperature. HC concentrations were determined by infraredspectrometry, gravimetry, gas chromatography andthermodesorption. Between 70 to 81% of the initial HC wereremoved through biological processes in fertilized soils,whereas natural attenuation without added nutrients was 56%.When adding fertilizers, residual HC were cyclic compoundspoorly biodegraded and strongly trapped on the organo-mineralmatter. Leaching of HC and water-soluble metabolites wasdemonstrated during the first stages of biodegradation. Lowlevels of the HC were detected in the leachates at day 480.Maximal toxicity was highest immediately after the introductionof oil then decreased as biodegradation proceeded. No toxiceffect was recorded on worms survival and on seeds germinationat day 480. However growth of plants was reduced in treatedsoils and a potential residual toxicity was observed on thebasis of photosynthesis inhibition and bacterial bioluminescence (Microtox) tests.     

Dynamic simulation of tuna longline gear using numerical methods

ABSTRACT:   The underwater shape and hook depth of tuna longline gear are important factors determining fishing performance. In this study, how the shape of tuna longline gear changes in response to sea conditions and gear rigging is explained. Physical models of underwater gear shape were made to simulate fishing gear and analyzed according to the direction and velocity of currents. Then experiments with small-scale models were conducted in a flume tank to confirm the accuracy of the simulation analysis. Finally, the simulation was examined relative to actual longline fishing gear. This approach provided an improvement over previous analytical methods that did not consider fishing gear shape in response to different sea conditions. A useful result is an improved understanding of the relationship between ocean currents and the configuration of longline gear (the shortening ratio, and number of hooks per basket). These factors affect hook depth which, in turn, affects selectivity. Application of these results could lead to more effective and efficient fishing under different sea conditions.