我国热带地区燃料油植物资源的开发和利用

论述了我国热带地区燃料油植物资源的开发意义及燃料油植物的特点;介绍了热带地区种子或种仁含油率大于50 % 的15种燃料油植物的分布及生物学特性;提出了热带燃料油植物研究与开发利用需解决的问题和热带燃料油植物应用前景.     

基于气象大数据的台风强度预测统计模型研究

台风是一种破坏力极强的灾害性天气系统,做好台风路径和强度预报是防灾减灾的关键。除了气候性因子、台风持续性因子以及环境背景场因子,文章还考虑了在近海时,受陆地影响下,台风强度演变的情况,引入了新变量,即海陆比。将2000—2014年西北太平洋的所有台风样本分成海盆样本和近海样本,研究它们在12、24、36和48小时间隔的强度演变规律。本研究利用1°×1°美国国家环境预报中心/美国国家大气研究中心提供的 FNL全球再分析资料(Final Operational Global Analysis)数据,采用逐步回归和主成分分析法的多元统计回归模型预测台风强度,并比较了两种模型在台风强度预测上的表现。综合深海盆和近海台风强度的预测结果可以看出,文章提供的近海台风强度预报方法,比国内外的其他研究更具有防台减灾的实际应用价值。     

Influence of the Saharan Air Layer on Atlantic Tropical Cyclone Formation during the Period 1-12 September 2003

Atmospheric Infrared Sounder (AIRS) data show that the Saharan air layer (SAL) is a dry, warm, and well-mixed layer between 950 and 500 hPa over the tropical Atlantic, extending westward from the African coast to the Caribbean Sea. The formations of both Hurricane Isabel and Tropical Depression 14 (TD14)were accompanied with outbreaks of SAL air during the period 1-12 September 2003, although TD14 failed to develop into a named tropical cyclone. The influence of the SAL on their formations is investigated by examining data from satellite observations and numerical simulations, in which AIRS data are incorporated into the MM5 model through the nudging technique.Analyses of the AIRS and simulation data suggest that the SAL may have played two roles in the formation of tropical cyclones during the period 1-12 September 2003. First, the outbreaks of SAL air on 3and 8 September enhanced the transverse-vertical circulation with the rising motion along the southern edge of the SAL and the sinking motion inside the SAL, triggering the development of two tropical disturbances associated with Hurricane Isabel and TD14. Second, in addition to the reduced environmental humidity and enhanced static stability in the lower troposphere, the SAL dry air intruded into the inner region of these tropical disturbances as their cyclonic flows became strong. This effect may have slowed down the formation of Isabel and inhibited TD14 becoming a named tropical cyclone, while the enhanced vertical shear contributed little to tropical cyclone formation during this period. The 48-h trajectory calculations confirm that the parcels from the SAL can be transported into the inner region of an incipient tropical cyclone.     

Monitoring wind effects of a landfall typhoon on a 600 m high skyscraper

This article presents the observations of the atmospheric boundary layer (ABL) and wind effects on a 600 m high skyscraper during a landfall typhoon. Wind structure and characteristics throughout the entire ABL are presented and discussed based on records from a Doppler radar wind profiler and near-ground measurements at several meteorological stations. Wind speed profiles with the feature of low-level jets and radial-distance and exposure dependences of gradient height are stressed. Afterwards, wind-induced pressures on building surfaces of the skyscraper are investigated with highlights on non-Gaussian probability distributions of negative pressures and vortex shedding occurred alternately at two sides of the building. The structural responses measured by both accelerometers and strain gauges are analyzed subsequently. Modal parameters of the skyscraper and their dependence on response amplitude are presented and discussed. This study aims to provide useful information for the wind-resistant design of skyscrapers in tropic cyclone-prone regions.     

以热带废弃植物纤维为添加料的绿色建材的应用及发展

随着绿色建材市场日益凸显,国内外对绿色建材研究力度不断加大。以植物纤维作为建材的添加料不仅能够改善建材的性能,而且还具有降解性,符合绿色环保的特点。主要介绍海南热带植物纤维及其在绿色建材中的主要应用,指出海南热带植物纤维产量大,具有较大的发展空间。     

海南岛热带草地的数量分类研究

本文用一些数量分类和排序的方法对海南岛鹦歌岭热带草地进行了分类和排序。所用的方法包括两种多元等级聚合分类——最近邻体法(NN)和最远邻体法(FN),极点排序(PO)和主分量分析(PCA)排序,研究结果表明:可以把19个样地分为3大类型、9个群落,其分布格局与坡度、放牧强度和土壤肥力密切相关。所用的4种方法在热带草地的研究中均有一定的适用性。     

台风强度变化最快时涡度的解析解

利用旋转坐标系中的基本方程推导得到动能方程,通过动能的局地变化率定义刻画台风强度变化率的能量泛函,对泛函作变分得到Euler-Lagrange方程.分析方程可知,当台风强度变化率达到最大时,摩擦力、气压梯度力、重力和动能梯度满足四力平衡关系.因此,这四个力确定的向量可以作为台风强度的预报因子,更准确地确定台风系统强度变化率达到最大的时间点.进一步通过风场变分分解提取到有旋场中的最大涡旋,得到台风强度变化最快时涡度和流场的解析解,对研究台风发展过程中速度的变化趋势和台风的空间结构具有实用价值,为台风路径和强度预报提供了一定的理论指引.     

Synthesis,Inhibition Potency,Binding Mode,and Antiprotozoal Activities of Fluorescent Inhibitors of Trypanothione Reductase Based on Mepacrine‐Conjugated Diaryl Sulfide Scaffolds

Trypanothione reductase (TR) is a flavoenzyme unique to trypanosomatid parasites and a target for lead discovery programs. Various inhibitor scaffolds have emerged in the past, exhibiting moderate affinity for the parasite enzyme. Herein we show that the combination of two structural motifs of known TR inhibitors — diaryl sulfides and mepacrine — enables the simultaneous addressing of two hydrophobic patches in the active site. The binding efficacy of these conjugates is enhanced over that of the respective parent inhibitors. They show K_ic values for the parasite enzyme down to 0.9±0.1 μm and exhibit high selectivity for TR over human glutathione reductase (GR). Despite their considerable molecular mass and in some cases permanent positive charges, in vitro studies revealed IC₅₀ values in the low micromolar to sub‐micromolar range against Trypanosoma brucei rhodesiense and Trypanosoma cruzi, as well as the malaria parasite Plasmodium falciparum, which lack trypanothione metabolism. The inhibitors exhibit strong fluorescence due to their aminoacridine moiety. This feature allows visualization of the drugs in the parasite where high accumulation was observed by fluorescence microscopy even after short exposure times.     

Investigation on the nickel content design and the corrosion resistance of low alloy steel welded joint in tropical marine atmosphere environment

In this study, three kinds of welding materials (WMs) with different Ni contents were designed for low alloy steel welded joints made by CO₂ gas-shielded welding technique. The corrosion resistance of welded joint was studied through the atmosphere exposure test in Trat, Thailand. Results show that there was a hardening in the heat-affected zone after welding, and the average hardness slightly increased with the increase of Ni in WM. The electrochemical activity at the fusion line zone enhanced with the addition of Ni in WM, indicating a more obvious local galvanic corrosion effect there. Ni promoted the generation of NiFe₂O₄ and the transformation from γ-FeOOH to α-FeOOH, which increased the impedance modulus of the rust film on WM. More important, the corrosion performance assessment illustrated that the addition of Ni in WM hardly had an effect on the corrosion step values after half a year test, which confirmed that there is no need to add excessive content of Ni.     

Dynamics of photosynthetic pigments in an Andean lake in Colombia

Guatavita Lake is a small, sheltered tropical high mountain lake located in the Colombian Andes, with a closed watershed and a maximum depth of 25 m. It is the freshwater source for human consumption in nearby small towns, as well as being a site of cultural value for the country, as it was a sacred place to indigenous peoples until about five centuries ago. As the structure and function of this aquatic ecosystem is poorly understood, this study provides initial knowledge on its phytoplankton biomass dynamics, which should be useful in designing efficient management plans with environmental baseline information for similar lakes elsewhere. Physical and chemical data, and photosynthetic pigment concentrations, were measured for the period November 1999–November 2000 at the central vertical axis of Guatavita Lake. The vertical profile of the chlorophyll‐a concentration was closely related to the dissolved inorganic nitrogen concentrations and the thermal stratification characteristics. The maximum chlorophyll‐a concentration in the metalimnion was recorded for the thermal stratification period (November 1999–June 2000). Deepening of the maximum chlorophyll‐a concentration began in February, continuing to June, when it reached its lowest value at the 15 m depth. The phytoplankton biomass values showed an increment within the entire water column at the beginning of the mixing period (July). The relation between the metalimnetic peak of chlorophyll‐a and the dissolved inorganic nitrogen concentration suggests the growth of the phytoplankton community is limited mainly by the availability of nitrogen.