一种利用温湿图评价密闭式鸡舍通风系统性能的方法

从控制的角度考虑，可将鸡的适宜生存环境条件物化成由相应的干球温度和相对湿度构成的二维平面。在受控状态下，以满足鸡的生存需求为基本出发点、以追求鸡的最大生产量为优化指标，反推其可忍受的舍外天气条件，然后在温湿图上生成一个反映鸡的生存环境和高产环境能力的控制区域。上述方法可用于有效地评价鸡舍通风系统的性能。     

一种利用温湿图评价密闭式鸡舍通风系统性能的方法

从控制的角度考虑，可将鸡的适宜生存环境条件物化成由相应的干球温度和相对湿度构成的二维平面。在受控状态下，以满足鸡的生存需求为基本出发点、以追求鸡的最大生产量为优化指标，反推其可忍受的舍外天气条件，然后在温湿图上生成一个反映鸡的生存环境和高产环境能力的控制区域。上述方法可用于有效地评价鸡舍通风系统的性能。     

Spatial and Temporal Changes of Jet Fuel Contamination in an Unconfined Sandy Aquifer

Leakage of jet fuel from an oil skimmer has resulted in soil and groundwater contamination at the fire fighting training site of the Oslo international airport. The site is located on an unconfined sandy aquifer formed by the Gardermoen ice contact delta. A strong relationship between hydrogeological settings and spatial distribution of the hydrocarbons has been observed. Leaching hydrocarbons constitute a source of dissolved BTEX and naphthalene. Concentration of the dissolved hydrocarbons, electron acceptors and metabolic by-products has revealed concomitant changes in space and in time, in response to groundwater fluctuations. Correlation between high concentrations of hydrocarbons, elevated alkalinity and depleted electron acceptors supports the hypothesis that intrinsic bioremediation has been taking place at the site. Naphthalene, however, has been found persistent under anoxic conditions. Calculations of biodegradation potential indicates that Fe(III) reduction, methanogenesis, nitrate and sulphate reduction are the main factors controlling biodegradation.     

A Dynamic Mass-balance Model for Phosphorus in Lakes with a Focus on Criteria for Applicability and Boundary Conditions

This paper presents an improved version of a general, process-based mass-balance model (LakeMab/LEEDS) for phosphorus in entire lakes (the ecosystem scale). The focus in this work is set on the boundary conditions, i.e., the domain of the model, and critical tests to reveal those boundary conditions using data from a wide limnological range. The basic structure of the model, and many key equations have been presented and motivated before, but this work presents several new developments. The LakeMab-model is based on ordinary differential equations regulating inflow, outflow and internal fluxes and the temporal resolution is one month to reflect seasonal variations. The model consists of four compartments: surface water, deep water, sediment on accumulation areas and sediment on areas of erosion and transportation. The separation between the surface-water layer and the deep-water layer is not done from water temperature data, but from sedimentological criteria (from the theoretical wave base, which regulates where wind/wave-induced resuspension of fine sediments occurs). There are algorithms for processes regulating internal fluxes and internal loading, e.g., sedimentation, resuspension, diffusion, mixing and burial. Critical model tests were made using data from 41 lakes of very different character and the results show that the model could predict mean monthly TP-concentrations in water very well (generally within the uncertainty bands given by the empirical data). The model is even easier to apply than the well-known OECD and Vollenweider models due to more easily accessed driving variables.     

Criteria for measurement of microbial growth and activity in soil

Changes in CO₂ evolution, phosphatase and urease activity and ATP contents were related to bacterial and fungal biomass determined microscopically during glucose mineralization at different concentrations of mineral nutrients. Similar results were obtained in a sandy loam and a clay soil except that in the clay the increase in microbial and enzyme activities were delayed. Higher initial rates of CO₂ evolution were noted after the addition of P to a glucose and N amended soil at C:P ratios greater than 30:1. Increases in phosphatase activity coincided with increases in bacterial and fungal populations only in treatments without inorganic P. Peak rates of CO₂ evolution preceded biomass production by 18–24 h, therefore, CO₂ evolution rates did not show a correlation on normal regression analysis with biomass. Soil ATP content was influenced by P concentrations and soil type. ATP was therefore not a specific indicator of biomass in the detailed studies where P concentrations and sequential growth of bacteria and fungi were major factors. Soil urease increased with bacterial and fungal populations. It did not respond to P other than through microbial biomass and was highly correlated with microbial biomass. The results show that no one measurement of microbial biomass or activity is sufficient to interpret microbial growth in the soil system. Each of the criteria measured were sensitive to specific conditions affecting biomass and activity.     

皇甫川流域封育植被土壤保持功能及服务价值研究

以皇甫川流域五分地沟试验区为背景,运用相关手段和方法,对其土壤保持功能和服务价值进行了研究.(1)研究区土壤保持量已达到89.45 t/(hm2·a),总的土壤保持效率达到77.09%.按从高到低的排序依次为:草地>灌木林>乔木林>无植被地.(2)每年保持土壤价值为856 779.59元,其中保持土壤养分价值为822 925元,减少土地废弃价值为30 234元,减轻泥沙淤积价值为3 620元.植被类型的贡献顺序为:灌木林>无植被地>草地>乔木林.(3)研究区按单位面积的土壤保持价值量为2 049.71元/hm2,其中保持土壤养分价值为1 968.72元/hm2,减少土地废弃价值为72.23元/hm2,减轻泥沙淤积价值为8.66元/hm2,植被类型的贡献顺序是:灌木林>草地>无植被地>乔木林.     

Chemical,Physical and Biological Criteria for Maturity in Composts for Organic Farming

Properties of organic farming composts were examined during the composting process: pH, electrical conductivity, C/N ratio, total N content, NH₄₊ content, NO_3?content, ash content, and organic matter content. In addition to these properties the respiration rate, microbial population counts, hydrolysis of Fluorescein Diacetate (FDA) and the activity of the enzyme amidase were studied. Composts at several stages of maturity were incubated in soil, and their N mineralization rates were measured. The end of the thermophilic stage was characterized by irreversible decrease in pile temperature to under 55°C, followed by stabilization of the chemical properties. This stage in the composting process is also characterized by decrease in CO₂ evolution rate, changes in microbial populations and specific patterns in FDA hydrolysis and amidase activity. Based on this evidence, we suggest that biological parameters can be considered as indicators for compost maturity.     

猪蓝耳病病毒RT-LAMP快速可视化检测方法的建立

为建立能快速检测猪蓝耳病病毒（PRRSV）的检测方法,本研究根据基因库中PRRSV非结构蛋白NSP2基因的保守序列,设计了一套特异性环介导等温扩增（RT-LAMP）引物,建立了PRRSV的RT-LAMP可视化检测方法。该方法的敏感性可达10 copies RNA,高于常规PCR方法 10倍;全部反应可以在50 min内完成;可通过肉眼观察钙黄绿素（calcein）颜色变化直接判定结果;对其它常见病原体的检测结果均为阴性,同时应用实时浊度仪对反应体系浊度及浊度的变化速率进行实时测量,结果相一致。结果表明建立的RT-LAMP方法简便、快速、灵敏、特异,可用于PRRSV感染的快速检测。     

On the Use of Different Efficiency Criteria for the Validation of a Heavy Metal Balancing Tool

The validation of metal balancing tools is usually based on the comparison of simulated versus observed data. In our study, we applied a set of different relative and absolute criteria to evaluate the performance of the model Assessment Tool for Metals in Soils. In this process, the uncertainty of the model output and the sensitivity of model parameters were also assessed. The study includes data from 123 agricultural used top soils which are characterized by the application of different fertilizers (mineral and farmyard fertilizers, sewage sludge) resulting in diverse metal inputs into the soil. Although the most common validation criteria (coefficient of determination, error ratio between prediction and observation) indicated a good model performance in predicting the metal contents over a simulation period, the absolute measure (mean absolute difference between prediction and observation) showed that the informational value of the validation results was limited for several sites. Therefore sites with short simulation periods and/or low metal inputs are not suitable for validation, because the model uncertainty covers the metal concentration changes. Excluding such sites from the validation statistics led to evaluable and quite better validation results. Although the calculated output uncertainty was low, a further reduction can be realized by improving the database for the identified sensitive parameters (initial soil metal content and fertilizers metal concentration).     

Formal Criteria for the Humus Status of Mountainous Peat Soils in Altitudinal Zones

Eurasian Soil Science - Cryogenic oligotrophic (Hyperdystric Cryic Fibric Histosols), oligomesotrophic (Dystric Fibric Histosols), mesoeutrophic (Oligeoeutric Fibric Histosols), and eutrophic...     

中国土壤系统分类土族和土系划分标准

中国土壤系统分类建立了亚类以上高级单元分类标准和检索,但在基层分类标准方面尚待系统建立和完善.本文主要介绍了中国土壤系统分类土族与土系划分的标准,从标准建立的背景、原则与特点到标准本身进行了较为详尽的描述,并用实例演示了土族土系标准在具体土壤上的应用.     

金沙江干热河谷封禁管护坡面的产流产沙特征

运用坡面径流泥沙小区定位观测方法,2003年雨季对金沙江元谋干热河谷水土流失封禁管护措施的坡面产流产沙特征进行了对比研究。结果显示,封禁管护措施有较好的调节径流和减少土壤流失的作用,其产流量比干扰荒草地减少39.04%,产沙量减少50.26%;产流量与产沙量均与降雨量和最大10 min时段降雨强度呈显著幂函数关系,复相关系数分别在0.882和0.888以上;产沙量与产流量之间的线性关系显著,相关系数在0.929以上。     

梅花鹿鹿茸再生干细胞蛋白质组双向电泳条件优化

鹿茸是目前唯一可以完全再生的哺乳动物附属器官,这种再生基于鹿茸再生干细胞。本研究以梅花鹿(Cervus nippon)鹿茸再生干细胞为样品,在处理方法、染色方法、蛋白纯化和等电聚焦条件4个方面对蛋白质组双向电泳进行优化。结果显示,利用Bullet Blender细胞组织破碎仪处理细胞优于超声波破碎;双染法染色能够得到更多且更清晰的蛋白点;等电聚焦总volt-hours在15 000 volt-hours时竖条纹相对较少;通过比较6种不同的蛋白提取方法与纯化方法组合,发现采用自制裂解液与双向电泳纯化试剂盒纯化相结合的方式获得的电泳图谱较好。通过综合优化后的双向电泳技术所得到的蛋白图谱中蛋白点相对较多且圆滑,条纹现象较轻,重复性较好,满足后续软件分析以及数据处理的要求,本研究为不同发育期梅花鹿鹿茸再生干细胞比较蛋白质组学研究提供了基础实验数据。     

黄淮海平原粘土层在土系划分中的意义,分类指标和土系初建

通过整理分析有关粘土层对土壤水盐运动影响的研究资料和对黄淮海平原３０个有粘土层的 土壤剖面的归纳总结．研究确定了不同粘土层厚度和粘土层出现部位的土系划分指标，并将这３０个土壤剖面分类为９个土系．     

车厢壁面振动对其内部声场的影响度分析与阻尼降噪

减小车厢壁面振动是降低车厢内固体声最直接的方法。由于车厢壁面不同部位对其内部声场的影响不仅与该部位振动幅值有关,而且还与振动相位、振动部位与声场中观测点之间相对位置等有关,因此应选择和优先控制对内部声场影响较大部位的振动才能取得良好的降噪效果。根据Helmholz方程和Green定理建立了车厢内部声场与边界(即车厢壁面)条件的关系,将边界进行离散,提出了衡量边界单元对车厢内噪声影响程度的指标——影响度,并试用阻尼减振方法,对以正影响度为主的壁面粘贴阻尼材料,使耳旁噪声降低了2.2dB(A)     

Two-dimensional single strand conformation polymorphism (SSCP) of 16S rRNA gene fragments reveals highly dissimilar bacterial communities in an acidic fen

Genetic fingerprinting methods such as denaturing gradient gel electrophoresis (DGGE) and single strand conformation polymorphism (SSCP) are only able to separate about 20–40 well-distinguishable bands (signals) within each sample. As a result, the diversity of 16S rRNA genes within biological samples may be underestimated, because multiple sequences can migrate at the same rate to form a single band. This study reports a two-dimensional SSCP fingerprinting method that has the capability to resolve hundreds of signals in a single fingerprint by using different gel temperatures in the two dimensions of the separation (20 °C and 30 °C, respectively). Unlike previous two-dimensional approaches, the method presented in this study does not rely on DNA products of variable lengths but is able to separate 16S rRNA gene fragments of the same length. To demonstrate the effectiveness of this new method, DNA samples from oxic and anoxic zones of an acidic fen were examined. Whereas one-dimensional SSCP fingerprints indicated high similarity (>93%) between 16S rRNA gene fragments from oxic and anoxic zones of the fen, the two-dimensional SSCP approach virtually found no similarities.     

森林可持续经营标准与指标中水土保持指标的研究

水土保持指标是森林可持续经营标准与指标中的一项重要内容。介绍了森林可持续经营标准与指标的概况,水土保持与森林可持续经营的关系,国际和中国水土保持指标的研究现状,应用中存在的问题,为森林可持续经营实践和水土保持指标的完善提供借鉴。