敏感性分析在燃烧毒物和自由基生成机理研究中的作用

针对燃料氧化的详细/半详细化学反应动力学机理，采用定量研究模型与出现在模型中各种参量之间关系的系统化方法--敏感性分析法，研究各基元反应对燃料过程中毒物和自由基生成的影响系数随时间的变化关系，为反应设计提供理论指导。     

损伤固体推进剂冲击波作用危险性研究

利用轻气炮产生飞片直接撞击改性双基推进剂及丁羟复合团体推进剂。通过对不同加载条件下回收试件的微观观察，得到不同损伤程度的推进剂，利用锰铜压阻计研究损伤推进剂及未损伤推进剂的冲击起爆过程。结果表明，对已损伤的推进剂．其冲击波作用危险性大大增加。     

爆炸的破坏作用与伤害分区

讨论冲击波的各种破坏准则，即超压准则、冲量准则和超压～冲量准则；提出故爆炸伤害／破坏分区的概念，叙述了伤害／破坏区域划分的具体方法并进行了数值模拟计算。最后，还对中文有些问题作了简要说明。     

Impact of a shock wave on a structure on explosion at altitude

The number of explosive attacks on civilian buildings has recently increased and the pattern of damage inflicted on structures when an explosion takes place at altitude remains quite difficult to predict. The primary aim of the work reported here was to enhance the understanding of how blast waves from an explosion at altitude interact with the ground and with a structure. Small-scale experiments were conducted using a propane–oxygen stoichiometric mixture as explosive. This approach is original because it models high-explosive detonation in terms of gaseous charge explosion using TNT equivalents. Several non-dimensional laws are expressed and validated by experiments. These relationships allow determination of the propagation of a blast wave and its interaction with a structure as a function of the position of the explosive charge when the explosion occurs at altitude. Then, from knowledge of the blast loading, using Hopkinson's scaling law and TNT equivalents, we can predict the interaction of blast waves with the ground and a structure on a real scale. Simulations were performed using the Autodyn code, and good correlation with the experimental results was obtained.     

ROLE OF WATERSHED SUBDIVISION ON MODELING THE EFFECTIVENESS OF BEST MANAGEMENT PRACTICES WITH SWAT1

Distributed parameter watershed models are often used for evaluating the effectiveness of various best management practices (BMPs). Streamflow, sediment, and nutrient yield predictions of a watershed model can be affected by spatial resolution as dictated by watershed subdivision. The objectives of this paper are to show that evaluation of BMPs using a model is strongly linked to the level of watershed subdivision; to suggest a methodology for identifying an appropriate subdivision level; and to examine the efficacy of different BMPs at field and watershed scales. In this study, the Soil and Water Assessment Tool (SWAT) model was calibrated and validated for streamflow, sediment, and nutrient yields at the outlet of the Dreisbach (623 ha) and Smith Fry (730 ha) watersheds in Maumee River Basin, Indiana. Grassed waterways, grade stabilization structures, field borders, and parallel terraces are the BMPs that were installed in the study area in the 1970s. Sediment and nutrient outputs from the calibrated model were compared at various watershed subdivision levels, both with and without implementation of these BMPs. Results for the study watersheds indicated that evaluation of the impacts of these BMPs on sediment and nutrient yields was very sensitive to the level of subdivision that was implemented in SWAT. An optimal watershed subdivision level for representation of the BMPs was identified through numerical simulations. For the study watersheds, it would appear that the average subwatershed area corresponding to approximately 4 percent of total watershed area is needed to represent the influence of these BMPs when using the SWAT model.     

Computer-aided modeling of the protective effect of explosion relief vents in tunnel structures

This paper aims at contributing to the efficient design of explosion protection systems against confined explosions. The issue addressed concerns the quantitative estimation of the protective effect of explosion relief vents in the case of confined explosions inside tunnels. A series of virtual experiments performed by computer simulation, revealed how the number of vents, their diameter, as well as the angle between the vents and the tunnel, influences the blast wave attenuation. The computational study was performed considering a complicated large-scale tunnel configuration with branches on its half portion. The purpose was the calculation of the attenuation effect due to the presence of vents by comparing the total explosion-specific impulse developing at antidiametric positions inside the tunnel. Simulations were carried out via a three-dimensional numerical model built in the computational fluid dynamics code CFX 5.7.1, which has been validated in previous papers against experimental overpressure histories data demonstrating reasonable performance. Computer results showed that the use of branch vents provides an effective method for shock wave attenuation following an explosion, whereas their statistical elaboration revealed that the attenuation is mainly affected by the number of vents and their diameter. In contrast, the angle between the side vents and the main tunnel appeared to slightly affect the pressure wave weakening. Eventually, the quantitative influence of the above parameters was effectively illustrated in functional diagrams, so that the total attenuation effect may be promptly estimated, if the design variables are known. In addition, two statistical models with reasonable fitting to the calculated data are proposed, which express the attenuation effect as a dependent variable of the design variables including their interactions.     

活性污泥一号模型参数影响的分析研究

自从国际水质污染与控制协会（IAWQ）推出的活性污泥数学模型ASM系列以来,活性污泥工艺中的动力学过程得到了更精确的描述。通过对活性污泥一号模型（ASM1）的诸多参数文献值进行了分析研究,从中筛选出对模拟结果影响较大的部分,并做出灵敏度分析,为模拟研究和污水处理实际控制提供帮助。研究发现pH、Ks、bH、KH、Kx和YH对于出水中有机物影响较大,bH、YH、bA、μA、K0A、KNH和YA对氮组分的影响较大;bH和YH对硝酸盐氮降解影响较大。     

三亚市风景资源生态敏感性及保护初探

从可持续发展的角度,分析了三亚市海陆自然体系生态完整性和旅游资源单体的生态敏感性,根据区域所具有的承载力和风景资源的生态功能,对典型滨海型旅游景观资源的开发提出了具体保护建议。     

Discrimination of flicker frequency rates in the reptile tuatara (Sphenodon )

By investigating the mechanisms that underlie the perception of environmental cues, we may begin to understand how the sensory system governs behavioral responses. This is the first empirical study to examine learning and visual sensitivity in a reptile species, the tuatara (Sphenodon punctatus). We established a non-intrusive psychophysical method by employing an instrumental paradigm in order to examine discrimination learning and the ability to distinguish different flicker frequencies in the tuatara. Seventeen tuatara were trained under an operant conditioning task to respond to various discriminative stimuli flickering between 2.65 and 65.09 Hz. Tuatara were able to learn the operant task and discriminate between a constant light and flicker frequency rates between 2.65 and 45.61 Hz, but not at 65.09 Hz. We demonstrated a reliable psychophysical method where these reptiles could learn a basic operant task and discriminate visual stimuli in the form of flicker frequency rates. The tuatara’s ability to perceive flickering light is comparable to that of avian, mammalian, and other reptilian species. This method is thus suitable for more comprehensive examinations of vision and additional sensory abilities in other reptiles. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Influence of oxytetracycline on the structure and activity of microbial community in wheat rhizosphere soil

The microbial community composition in wheat rhizosphere was analyzed by detecting colony forming units (CFUs) in agar plates. The total CFUs in rhizosphere were 1.04 109/g soil with 9.0 108/g bacteria, 1.37 108/g actinomyces and 3.6 106/g fungi. The 10 dominant bacteria were isolated from wheat rhizosphere and were grouped into genus Bacillus according to their full length 16S rRNA gene sequences. Although belonging to the same genus, the isolated strains exhibited di erent sensitivities to oxytetracycline. When a series of the rhizosphere soil was exposed under various concentrations of oxytetracycline, the microbial community structure was highly a ected with significant decline of CFUs of bacteria and actinomyces (22.2% and 31.7% at 10 mg/kg antibiotic, respectively). This inhibition was clearly enhanced with the increase exposure dosage of antibiotic and could not be eliminated during 30 d incubation. There was no obvious influence of this treatment on fungi population. Among the four soil enzymes (alkaline phosphatase, acidic phosphatase, dehydrogenase and urease), only alkaline phosphatase was sensitive to oxytetracycline exposure with 41.3% decline of the enzyme activity at 10 mg/kg antibiotic and further decrease of 64.3%–80.8% when the dosage over 30 mg/kg.