Study of Yield Combining Ability and Genetic Relationship Among Exotic Tropical,Subtropical Maize(Zea mays L.) Inbreds and Temperate Maize Inbreds in China

Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining ability and genetic relationship of 25 inbreds extracted from five tropical maize populations and a land race, with four temperate maize inbreds (Huangzaosi, Mol7, B73 and Dan 340). The 25 tropical inbreds were crossed with the four temperate inbreds and evaluated. Lines from Suwanl and POP28 had high general combining ability (GCA) for grain yield. The lines from POP32 (ETO) had the highest special combining ability (SCA) with B73; the average SCA value of the 5 lines was 879 kg/ha. The lines from Suwanl had the second-highest SCA (584 kg/ha) with Huangzaosi. The lines from Suwanl had the greatest relative heterosis (20%) with B73, followed by the lines from POP32 (ETO) with B73 (19%). Five heterotic patterns have been identified from this study: Suwanl × Reid, ETO × Reid, POP28× Reid, POP28× Ludahong-gu, and Suwan1× Lancaster.

Seasonal Prediction of Tropical Cyclones and Storms over the Southwestern Indian Ocean Region Using the Generalized Linear Models

Tropical cyclones (TCs) and storms (TSs) are among the devastating events in the world and southwestern Indian Ocean (SWIO) in particular. The seasonal forecasting TCs and TSs for December to March (DJFM) and November to May (NM) over SWIO were conducted. Dynamic parameters including vertical wind shear, mean zonal steering wind and vorticity at 850 mb were derived from NOAA (NCEP-NCAR) reanalysis 1 wind fields. Thermodynamic parameters including monthly and daily mean Sea Surface Temperature (SST), Outgoing Longwave Radiation (OLR) and equatorial Standard Oscillation Index (SOI) were used. Three types of Poison regression models (i.e. dynamic, thermodynamic and combined models) were developed and validated using the Leave One Out Cross Validation (LOOCV). Moreover, 2 × 2 square matrix contingency tables for model verification were used. The results revealed that, the observed and cross validated DJFM and NM TCs and TSs strongly correlated with each other (p ≤ 0.02) for all model types, with correlations (r) ranging from 0.62 - 0.86 for TCs and 0.52 - 0.87 for TSs, indicating great association between these variables. Assessment of the model skill for all model types of DJFM and NM TCs and TSs frequency revealed high skill scores ranging from 38% - 70% for TCs and 26% - 72% for TSs frequency, respectively. Moreover, results indicated that the dynamic and combined models had higher skill scores than the thermodynamic models. The DJFM and NM selected predictors explained the TCs and TSs variability by the range of 0.45 - 0.65 and 0.37 - 0.66, respectively. However, verification analysis revealed that all models were adequate for predicting the seasonal TCs and TSs, with high bias values ranging from 0.85 - 0.94. Conclusively, the study calls for more studies in TCs and TSs frequency and strengths for enhancing the performance of the March to May (MAM) and December to October (OND) seasonal rainfalls in the East African (EA) and Tanzania in particular.

The Genesis of Tropical Cyclone Bilis(2000) Associated with Cross-equatorial Surges

The purpose of this paper is to explore how a tropical cyclone forms from a pre-existing large-scale depression which has been observed and associated with cross-equatorial surges in the western North Pacific. Tropical cyclone Bilis(2000) was selected as the case to study.The research data used are from the results of the non-hydrostatic mesoscale model(MM5),which has successfully simulated the transformation of a pre-existing weak large-scale tropical depression into a strong tropical storm.The scale separation technique is used to separate the synoptic-scale and sub-synoptic-scale fields from the model output fields. The scale-separated fields show that the pre-existing synoptic-scale tropical depression and the subsynoptic scale tropical cyclone formed later were different scale systems from beginning to end.It is also shown that the pre-existing synoptic-scale tropical depression did not contract to become the tropical cyclone. A series of weak,sub-synoptic-scale low and high pressure systems appeared and disappeared in the synopticscale depression,with one of the low systems near the center of the synoptic-scale depression having deepened to become the tropical cyclone. The roles of the synoptic-scale flow and the sub-synoptic scale disturbances in the formation of the tropical cyclone are investigated by diagnoses of the scale-separated vertical vorticity equation.The results show that the early development of the sub-synoptic scale vortex was fundamentally dependent on the strengthening synoptic-scale environmental depression.The depression was strengthened by cross-equatorial surges,which increased the convergence of the synoptic-scale depression at low levels and triggered the formation of the tropical cyclone.

A NUMERICAL EXPERIMENTAL STUDY OF TROPICAL CYCLONE CROSSING SUBTROPICAL HIGH

The barotropic primitive equations model is used in a numerical study of a tropical cyclone crossing the Subtropical high. It is revealed that apart from its own characteristics, sensitive factors having immediate effects on the motion of the tropical cyclone also include its radial distance from the center of the subtropical high, the variation in latitudinal location and intensity. A complex mechanism for nonlinear interactions among the tropical,subtropical high and β effect is also shown in the experiment, and expected to serve for the diagnosis and prediction of abnormal motion.

Ecosystems Services of the Tropical Rain Forest Environment: Lessons from the Cross River National Park, Nigeria

This paper essayed to examine ecosystem functions with a case study of the tropical rainforest environment of the Cross River National Park, Nigeria. The paper highlighted the important functions of the ecosystems to include Purification of air and water mitigation of floods and droughts, detoxification and decomposition of wastes, generation and renewal of soil and natural vegetation, pollination of crops and natural vegetation, control of the vast majority of potential agricultural pests, dispersal of seeds and translocation of nutrients, maintenance of biodiversity, protection from the sun’s harmful ultraviolet rays among others. Problems associated with the rainforest ecosystems among which are logging, traditional methods of farming, poaching, excessive noise and encroachment were identified. The paper concluded by highlighting the way forward among others that, awareness creation should be stepped-up in Support Zone Communities;indigenes should be educated periodically on the benefits of the ecosystem services to not just humans but the forest resources and biodiversity themselves.

INFLUENCE OF THE INTERANNUAL VARIATION OF CROSSEQUATORIAL FLOW ON TROPICAL CYCLOGENESIS OVER THE WESTERN NORTH PACIFIC

The influence of the interannual variation of cross-equatorial flow(CEF) on tropical cyclogenesis over the western North Pacific(WNP) is examined in this paper by using the tropical cyclone(TC) best track data from the Joint Typhoon Warning Center and the JRA-25 reanalysis dataset. The results showed that the number of TCs forming to the east of 140°E over the southeastern part of the western North Pacific(WNP) is in highly positive correlation with the variation of the CEF near 125° E and 150° E, i.e., the number of tropical cyclogeneses increases when the cross-equatorial flows are strong. Composite analyses showed that during the years of strong CEF, the variations of OLR, vertical wind shear between 200-850 h Pa, 850 h Pa relative vorticity and 200 h Pa divergence are favorable for tropical cyclogenesis to the east of 140°E over the tropical WNP, and vice versa. Moreover, it is also discussed from the view of barotropic energy conversion that during the years of strong CEF, an eastward-extended monsoon trough leads to the rapid growth of eddy kinetic energy over the eastern part of WNP, which is favorable for tropical cyclogenesis;but during the years of weak CEF, the monsoon trough is located westward in the western part of the WNP, consistent with the growth area of eddy kinetic energy. As a result, there are fewer TC geneses over the eastern part of WNP.Besides, the abrupt strengthening of a close-by CEF 2-4 days before tropical cyclogenesis may be the one of its triggers.

A GCM-Based Forecasting Model for the Landfall of Tropical Cyclones in China

A statistical dynamic model for forecasting Chinese landfall of tropical cyclones （CLTCs） was developed based on the empirical relationship between the observed CLTC variability and the hindcast atmospheric circulations from the Pusan National University coupled general circulation model （PNU-CGCM）.In the last 31 years,CLTCs have shown strong year-to-year variability,with a maximum frequency in 1994 and a minimum frequency in 1987.Such features were well forecasted by the model.A cross-validation test showed that the correlation between the observed index and the forecasted CLTC index was high,with a coefficient of 0.71.The relative error percentage （16.3%） and root-mean-square error （1.07） were low.Therefore the coupled model performs well in terms of forecasting CLTCs;the model has potential for dynamic forecasting of landfall of tropical cyclones.

Land cover changes and fragmentation in mountain neotropical ecosystems of Oaxaca, Mexico under community forest management

Changes in land cover have a direct impact on forest ecosystem goods and services. In this study, changes in land cover in Sierra de Juarez–Oaxaca ecosystems were estimated using a consistent processing of Landsat images and OBIA methodology. Additionally, landscape analyses using FRAGSTAT were conducted. In 2014, Sierra de Juarez–Oaxaca was covered by approximately 84% of forests, mainly pine-oak and cloud forests. After extensive deforestation until 2001, this trend was reversed and the forest cover surface area in 2014 was slightly higher than in 1979. The comparison of the landscape structure of the forested and agricultural lands suggests an increase in habitat heterogeneity. However, interspersion and juxtaposition indices, showing the patch shape by patch area and perimeter, were similar throughout the study period(1979–2014). Social and economic drivers can explain this situation: namely, community organization, forest enterprises, payment for ecosystem services programs, and changes of agricultural activity. Communities in the Sierra of Oaxaca have reforested degraded lands, created community forest enterprises, and preserved the forest under conservation schemes like those proposed by the Mexican payment for ecosystem services programs. However, their sustainable management faces internal challenges and has become highly dependent on political and institutional decisions beyond their control.

Ethnic Differences in Thermal Responses between Thai and Japanese Females in Tropical Urban Climate

The outdoor thermal environment might become worse than at present. It causes health injuries through the deterioration of the outdoor thermal condition. It is necessary to study how humans stay outdoors and adjust to thermal conditions. The purpose of this study was to clarify the influence of the outdoor tropical urban thermal environment on a subject who has been acclimatized to the environment studied using the outdoor thermal environment evaluation index ETFe. In addition, the tendency of human impacts was clarified through comparison to subjects from a temperate thermal environment region. As a result, it was found that an ETFe of up to 35°C could be recognized as a temperate thermal environment. However, when the ETFe was greater than 40°C, the subject could not tolerate the environment. There was not a significant difference of psychological reaction between Thai people, who were acclimatized to the tropical climate, and Japanese people, who were acclimatized to the temperate climate.

A Diagnostic Study of Heavy Rainfall in Karachi Due to Merging of a Mesoscale Low and a Diffused Tropical Depression during South Asian Summer Monsoon

This paper presents the results of a diagnostic study of a typical case of very heavy rainfall during the South Asian summer monsoon when a mesoscale low in a desert climate merged with a diffused tropical depression. The former low was located over Pakistan's desert region and the latter depression originated over the Bay of Bengal. Surface and NCEP reanalysis data supported by satellite and radar images were incorporated in the diagnosis. The relationship between the heavy precipitation process and large-scale circulations such as monsoon trough, subtropical high, westerly jet, low level jet and water vapor transport were investigated to further understand the mechanism of this peculiar interaction. It was found that: (1) the mesoscale low developed as a result of cold air advection aloft from northern latitudes and strong convection over the region of humidity convergence on 24 July 2003 over the Indian Rajistan area. (2) On the same day, a low that formed over the Bay of Bengal was transformed into a monsoon depression and moved westward to the mesoscale low which existed over southwest India and the adjoining southeastern parts of Pakistan. (3) Initially, the mesoscale low received moisture supply from both the Bay of Bengal as well as the Arabian Sea, whereas the Bay of Bengal maintained the continuous supply of moisture to the monsoon depression. (4) After the depression crossed central India, the Bay's moisture supply was cut off and the Arabian Sea became the-only source of moisture to both the closely located systems. On 27 July, both of the systems merged together and the merger resulted in a heavy downpour in the Karachi metropolitan and in its surroundings. (5) With the intensification as well as the southeastward extension of the subtropical high and the shift of the monsoon trough axis from southwest-west to northeast-east, the monsoon depression moved southwestward. In this situation, there existed a very favourable condition for a merger of the two systems in the presence of cross-latitude influence. (6) A number of convective cloud clusters were developed and organized in the mesoscale low. Probably, interactions existed among the multi-scale systems.

Modulation of Low-Latitude West Wind on Abnormal Track and Intensity of Tropical Cyclone Nargis (2008) in the Bay of Bengal

Tropical cyclone （TC） Nargis （2008） made landfall in Myanmar on 02 May 2008, bringing a storm surge, major flooding, and resulting in a significant death toll. TC Nargis （2008） displayed abnormal features, including rare eastward motion in its late stage, rapid intensification before landing. Using reanalysis data and a numerical model, we investigated how a low-latitude westerly wind modulated TC Nargis’ （2008） track and provided favorable atmospheric conditions for its rapid intensification. More importantly, we found a possible counterbalance effect of flows from the two hemispheres on the TC track in the Bay of Bengal. Our analysis indicates that a strong westerly wind burst across the Bay of Bengal, resulting in TC Nargis’ （2008） eastward movement after its recurvature. This sudden enhancement of westerly wind was mainly due to the rapidly intensified mid-level cross-equatorial flow. Our results show that a high-pressure system in the Southern Hemisphere induced this strong, mid-level, cross-equatorial flow. During the rapid intensification period of TC Nargis （2008）, this strong and broad westerly wind also transported a large amount of water vapor to TC Nargis （2008）. Sufficient water vapor gave rise to continuously high and increased mid-level relative humidity, which was favorable to TC Nargis’ （2008） intensification. Condensation of water vapor increased the energy supply, which eventuated the intensification of TC Nargis （2008） to a category 4 on the Saffir-Simpson scale.

热带气候型家用燃气具技术要求探讨

介绍了中国具有热带气候特征的地区分布情况,指出对于家用燃气具设计,热带气候类型是环境条件参数,而非地理参数,具有热带气候特征的地区覆盖了中国主要的家用燃气具消费市场。由于现有家用燃气具标准基本以温带气候作为基本的环境条件要求,相关产品在热带气候地区长期使用会产生安全性、可靠性以及适用性等问题。参照国内外技术标准对热带气候条件的规定,归纳了适应热带气候条件的家用燃气具基本的技术要求,同时提出,中国家用燃气具设计应以热带气候作为基本环境条件。

热轧高强钢带卷板形质量控制

河钢集团唐钢公司所产热卷板形缺陷多以带卷双侧浪及板形翘曲为主,严重影响了下游用户开平质量、激光落料等质量控制的稳定及生产效率的提升。本文从带钢肋部(距带钢边部100 mm位置)与边部温差控制、热轧工艺参数设定及层冷工艺选用、带钢两侧侧喷开启等方面分析了热轧高强钢板卷DS侧边浪产生的原因,并给出了减小热轧带钢内应力的措施。发现,带钢边部温度较带钢肋部温度低约50~90℃不等,此区域带钢处于热传递最大区域,带钢向外传递出去的热量最多,故该区域温度呈急剧下降趋势,温度变化大,是带钢最终板形产生边浪的主因;热轧带钢肋部与边部温差与定宽机减宽量及终轧温度有关,200~250 mm的定宽量较50~100 mm的定宽量带钢边部温降可减少约20℃,终轧温度由895℃降到885℃,带钢的肋部与边部的温差可减小约10~20℃;而层冷工艺的选择应根据精轧出口带钢横断面温差,结合各钢种、规格在冷却过程中带中与带边组织及晶粒均匀性实施综合考虑,以更好地控制热轧带卷板形质量。

Pacific Tropics Are Warmer than Atlantic

Pacific tropics are warmer than Atlantic tropics. This can be seen immediately from a world’s sea surface temperature atlas, but readings from it of the latitudinal bandwidths between 80 F isotherms in the open waters of both oceans make this result very clear. Explanations are offered by introducing what has already been proposed for the large-scale surface circulations of the Pacific and incorporating conjectures for the circulation of the upper layer of the South Atlantic.

福建省顺昌县药用植物资源多样性分析

目的:全面了解顺昌县药用植物资源现状,为后续制定有效保护和合理开发药用植物资源的策略提供科学依据。方法:根据第四次全国中药资源普查规范要求,采用样地和样线相结合的方式,收集药用植物的分布信息,通过查阅文献和咨询专家进行物种鉴定,统计分析药用植物资源的分布特征。结果:顺昌县药用植物共计1065种,隶属于176科618属;物种构成以小型科(2~5种)和单种科(1种)为主;生活型以多年生草本和灌木居多;蕨类植物和种子植物的热带地理成分明显。重点调查的药材中,106种为2020年版中国药典收载品种,42种为福建省特色中药品种。结论:顺昌县药用植物资源类型多样性特征明显,重点和特色药用植物资源丰富,但储量差异较大,建议加大特色野生药用植物资源的保护力度,重点开展仿野生抚育和栽培技术的相关研究。

易贡藏布沿岸种子植物组成及其区系特征分析

通过野外植被实地调查和资料整理分析,以易贡藏布沿岸种子植物为研究对象,对区域内种子植物科、属组成特征及不同海拔种子植物物种丰富度进行分析。结果表明,该区域共记录到种子植物87科257属428种。其中,裸子植物3科7属13种,被子植物84科250属415种。科属的分布区类型中除世界广布外,热带科的比重略高于温带科,而温带属的比重占优势。SD值(植物区系种系分化度)和TSR(转换后的物种丰富度)与海拔变化不具明显相关性。与邻近区域的植物区系R/T值(热带成分/温带成分)比较,发现该研究区与色季拉山的植物区系最为接近。

不同来源玉米自交系籽粒性状比较分析

湖南省玉米种质资源较匮乏,为丰富湖南省的优良种质资源,在湖南省湘潭市采取随机排列的方式进行试验,对来自不同地区的345份玉米自交系籽粒的粒长、粒宽、粒厚、百粒质量和容重5个性状进行分类比较,发现各籽粒性状在各个亚群之间存在广泛遗传差异,总群及各亚群百粒质量变异系数最大、容重变异系数最小,其百粒质量可作为湖南省玉米选种的一个重要指标。通过相关数据筛选发现热带玉米各性状表现较好,是湖南省玉米种质资源选择较好的方向。

AN OBSERVATIONAL STUDY OF THE CHANGES IN THE INTENSITY AND MOTION OF TROPICAL CYCLONES CROSSING LUZON

Tropical cyclones(TCs) moving across Luzon from east to west are likely to affect Hong Kong. As such, it is important for forecasters take into account the likely changes in intensity and movement characteristics of TCs crossing Luzon. 50 TCs in the period 1980-2014 were examined to determine the effect of Luzon’s terrain on their intensity and movement.The results indicated that TCs generally weakened as they passed through the terrain of Luzon. The decrease in the maximum sustained winds(MSW) for TCs with intensity of severe tropical storms or below was normally < 10 knot. For typhoons, the decrease in the MSW was usually ≥10 knot. The study also showed that TCs moving across Luzon were likely to accelerate(decelerate) as they approached(moved away) from Luzon. Furthermore, while there was a slight bias for TCs to defl ect leftwards on leaving Luzon, a signifi cant negative correlation was found between the defl ection tendency before and after crossing Luzon. A TC defl ected to the right(left) before landfall was likely to defl ect to the left(right) after leaving Luzon. Also, defl ection upon/near landfalling is found to be related to the intensity, moving speed and the direction of motion of a TC.

外来热带、亚热带玉米自交系与温带玉米自交系产量配合力分析及其遗传关系的研究

以 4个分别代表我国北方温带玉米四大优势群的自交系 (黄早四、Mo17,B73和丹 340 )为测验种 ,采用NCⅡ设计 ,对来自 5个热带、亚热带玉米群体、地理族的 2 5个自交系进行产量配合力及杂种优势分析 ,根据配合力和杂种优势的表现 ,研究这些外来热带、亚热带玉米自交系与 4个测验种之间的遗传关系。研究结果表明 ,来自群体Suwan1、POP2 8的自交系的产量一般配合力 (GCA)效应值较高 ,5个自交系的平均产量GCA效应值分别为10 10 .6 4和 2 6 6 .5 7;来自群体POP32 (ETO)的自交系与B73及来自群体Suwan1的自交系与黄早四之间的平均产量特殊配合力 (SCA)效应值最高 ,分别为 879.2 9和 5 83.81;来自群体Suwan1的自交系与B73之间组合的杂种优势最大 ,平均产量对照优势值为 2 0 .36 % ,其次为来自群体POP32 (ETO)的自交系与B73的平均产量对照优势值(19.38% )。由此 ,Suwan1×瑞得、ETO×瑞得、POP2 8×瑞得、POP2 8×旅大红骨和Suwan1×兰卡斯特为

全球碳循环中的失汇及其形成原因

近 2 0多年来 ,大气碳收支不平衡 ,即碳失汇 ( Missing carbon sink) ,一直是全球碳循环研究的核心问题之一。在总结全球碳失汇的主要研究成果基础上 ,分析了碳失汇数量和可能分布地点 ,并对形成的主要原因 :CO2 施肥作用、氮沉降的变化、变暖促进氮矿化和早期破坏后的森林再生等 ,进行了综述和分析 ,指出了该问题的复杂性。