Reconstructing mean maximum temperatures of May-August from tree-ring maximum density in North Da Hinggan Mountains, China

Tree-ring samples from Dahurian Larch (Larix gmelinii (Rupr.) Rupr.) were collected at three sites in the northern Da Hinggan Mountains. Using samples measured by X-ray densitometry, measurements of tree-ring maximum latewood density chronologies of two sites were found to be significantly correlated with summer temperature. These two sites’ tree-ring series were combined to form a single standard regional chronology. This was used to reconstruct the May-August monthly mean maximum temperature for the period 1855-2008 AD, and it explained 39.5% of the total temperature variance. In the past 154 years, there were 4 cold periods (1874-1893, 1927-1948, 1951-1960 and 1992-2002) and 4 warm periods (1855-1873, 1894-1916, 1961-1991 and 2003-2008). The summer temperature rose more obviously than that of winter in this region. Having been validated by other temperature reconstructions from the surrounding area, the reconstruction could indicate the summer temperature changes of large-scale regions.     

The strengthening East Asia summer monsoon since the early 1990s

Previous studies have documented a weakening tendency of the East Asian summer monsoon (EASM) since the end of the 1970s. In this study, we report that the EASM has been recovering since the early 1990s, although its strength is still less than in previous decades (averaged over the period 1965-1980). Following the recovery of the EASM, there has been a tendency in the last decade toward northward-moving rainbands and excessive rainfall in the Huaihe River valley (110°-120°E, 30°-35°N). There is evidence suggesting that the strengthening EASM since the early 1990s is linked to interdecadal change of land-sea thermal contrast.     

上海郊区夏季鸟类群落特征及多样性研究

2001年和2002年夏季对上海郊区不同生境鸟类进行了调查，共记录到鸟类68种，隶属11目25科。上海郊区夏季鸟类平均密度为2.7237只/hm²,现存生物量为276.0663g/hm²。鸟类多样性指数为2.2815，均匀度指数为0.5407,优势指数为0.2254.农田居民区、滩涂湿地和丘陵林地三种典型生境中，湿地鸟类种类最多，多样性指数最高，但密度最低；农田生境多样性最低，但密度最高，林地生境种类最少。研究结果表明，上海郊区夏季不同生境鸟类群落特征差异显著，但群落结构稳定，改善环境的自然性、增加空间异质性、减少人为干扰等可使鸟类群落的多样性和密度增加。     

Interannual variability of Mascarene high and Australian high and their influences on summer rainfall over East Asia

Based on the reanalysis data from NCEP/NCAR and other observational data,interannual variability of Mascarene high(MH) and Australian high(AH) from 1970 to 1999 is examined.It is shown that interannual variability of MH is dominated by the Antarctic oscillation(AAO),when the circumpolar low in the high southern latitudes deepens,the intensity of MH will be intensified.On the other hand,AH is correlated by AAO as well as EI Nino and South Oscillation(ENSO),the intensity of AH will be intensified when EI Nino occurs.Both correlation analysis and case study demonstrate that summer rainfall over East Asia is closely related to MH and AH.When MH intensifies from boreal spring to summer (i.e.from austral autumn to winter),there is more rainfall over regions from the Yangtze River valley to Japan,in contrast,less rainfall is found over southern China and western Pacific to the east of Taiwan,and most of regions in mid-latitudes of East Asia.Compared with MH,the effect of AH on summer rainfall in East Asia is limited to localized regions,there is more rainfall over southern China with the intensification of AH.The results in this study show that AAO is a strong signal on interannual timescale,which plays an important role in summer rainfall over East Asia.This discovery is of real importance to revealingt the physical mechanism of interannual variability of East Asian summer monsoon and prediction of summer precipitation in China.     

夏热冬冷地区住宅能耗计算方法及程序实现

研究的主要目的是提出一种适合于建筑设计人员的，简便适用的住宅能耗的计算方法（特别是对于夏热冬冷地区的住宅设计），以便设计人员在住宅方案设计阶段即可对方安进行能耗分析和节能优化调整，通过理论分析和公式推导，我们发现：在一定的前提条件下，夏季住宅动态传热过程中热量传递计算的方法可以简化为类似于冬季稳态传热计算方法，另外，本文还详细介绍了影响住宅能耗的重要因素－太阳辐射得热量的计算方法，较之《民用建筑节能设计标准（采暖居住建筑部分）》中推荐的计算方法（修正系数法）更为准确，适用范围更广，本文还介绍了基于所提出的计算方法的建筑能耗分析与优化软件BeCaSoft.     

用78599和获白构建冀东夏玉米种质的初步研究

用获白改良的含有不同 785 99血缘比例的 3个自交系 ,作为构建冀东生态区夏玉米育种的核心种质 ,与生产上大面积应用的含有 785 99血缘的 3个骨干系进行比较 ,应用 6× 4不完全双列杂交模式进行遗传效应的初步分析。结果表明 :用获白改良 785 99选育的自交系 ,在抗病性、光合速率、叶向值、灌浆速度、散粉至成熟时间等农艺及光合性状的一般配合力显著提高 ;部分经济性状 ,如生物产量、单株产量、百粒重等一般配合力也十分显著。明确了导入 2 5 %获白种质改良 785 99是构建夏玉米核心种质的最佳比例     

独具魅力的夏季体育项目--沙滩排球

章从沙滩排球的起源、发展、传播的过程着手，向人们介绍了这项最具魅力的夏季体育运动项目的特点和比赛方法，其目的是使更多的人们了解、喜欢和热爱这项运动，并推动这项运动在我国的普及和开展。     

华南前汛期区域持续性暴雨的分布特征及分型

利用广东和广西两省共175个台站的日降水观测资料,采用计算机检索的方法,对1961-2005年间华南前汛期区域持续性暴雨进行了定义。对南海夏季风爆发前后区域持续性暴雨的气候分布特征的分析发现,季风爆发前持续性暴雨频数从60年代至今呈现出正态分布的年代际变化特征,而季风爆发后的区域持续性暴雨频数变化则几乎相反;广东省前汛期区域持续性暴雨降水明显比广西强。此外,通过EOF方法和相关分析得到了夏季风爆发前后出现频率较高的几种分布雨型,它们能较好地代表季风爆发前后华南降水分布的特点。     

Identifying the northernmost summer monsoon location in East Asia

An integrated index which can be used to indicate the advance of subtropical summer monsoon in East Asia has been proposed in this paper. The index was combined by three variables including precipitation, wind and pseudo-equivalent potential temperature. The northernmost summer monsoon location (NSML) was identified by using this index annually. It was found that the NSML experienced an interdecadal shift in the period 1977—1979 based on the annual index analysis from 1961 to 2001. A comparison of the NSML with other four summer monsoon indices has also been made. The result showed that the NSML could well represent the interannual and interdecadal variability of summer monsoon precipitation in North China (beyond 35°N), while other four indices could well indicate the precipitation anomalies of East Asian summer monsoon along the Yangtze River valley (around 30°N).     

Southern Hemisphere mean zonal wind in upper troposphere and East Asian summer monsoon circulation

1 Introduction Variability of the East Asian summer monsoon (EASM) has been detected by considering roles of El Nino and Southern Oscillation (ENSO) cycle, snow cover over Eurasia and Tibetan Plateau, and signals from the soil (namely, the soil temperatur…