烟草脱外壁花粉与完整花粉电激导入效果的比较研究

利用膜不通镜的荧光染料钙黄素作为指示剂,比较了烟草脱外壁花粉与完整的未萌发花粉和萌发花粉电激导入的效果。     

山丹湖环境水化学特征的主因子分析

用因子分析法和相关的统计方法研究了山丹湖的富营养化特征,从原始数据的相关矩阵出发,提取了占总方差８２％的两个主因子,并对主因子作出合理的解释,主因子分析的结果表明,由氮营养化引起的污染是控制山丹湖营养化学特征的主要因子。     

柑橘类植物染色体制片新技术

为获得清晰的染色体图像,对柑橘的体细胞染色体和花粉母细胞染色体制片方法进行了研究.开发了染色体制 片新技术:①体细胞染色体制片选取3～5mm长的幼叶,用体积分数为0.3%的纤维素酶和体积分数为0.2%的果胶 酶于37℃下进行2h酶解;②花粉母细胞的染色体制片则选取约开花3周前花蕾中的花药,酶解的适宜条件为3%纤 维素酶和2%果胶酶混合酶液于37℃下进行3h酶解.可得到背景干净、伸展分散良好、清晰可靠的染色体图像.     

中药菟丝子花粉形态的扫描电镜研究

利用扫描电子显微镜对山东菟丝子属(Cuscuta L.)3种植物的花粉形态进行了观察研究。结果显示该属花粉粒为长球形，具3～4沟。表明该属花粉粒大小、孔沟数量和外壁雕纹可以作为种间分类的依据。     

胡枝子属与米口袋属花粉亚显微形态特征的比较研究

报道了山东胡枝子属6种植物花粉与米口袋属4种植物花粉的亚显微形态特征，并对两属进行了比较分析．它们韵花粉从赤道面观均呈近长球形，极面观呈三裂圆形；具三条萌发沟；花粉粒的大小，极轴长27．2～19．5μm，赤道轴宽21．3～11．8μm．两属植物花粉的大小、表面纹饰、花粉粒萌发沟的沟裂宽度均有明显差别。研究结果表明，胡枝子属和米口袋属花粉的亚显微形态特征支持传统分类中的属、种级水平的分类。     

武汉市湖泊演变与合理开发利用

武汉市湖泊是江汉湖群的一部分，属于浅水型湖泊。近50年来，湖泊面积和生态环境在自然因素和人为活动影响下发生了深刻的变化。该通过分析，揭示了在自然条件下，湖泊环境变化主要受气候和河流水位的影响；在人为因素中，主要是受圈垦和城市化的影响，而主导因素是人类活动。在湖泊的开发利用方面，本考虑到武汉市所面临的环境问题，确定湖泊的主导功能应以生态服务为主，开发与保护相结合，以实现湖泊资源的可持续发展利用。     

Holocene lake deposits of Bosten Lake, southern Xinjiang, China

A 9.25-m-long sediment core from Bosten Lake,Xinjiang, provides detailed information about changes in the water budget and biological acticity over the last 8400 cal-endar years. The chronology is constructed from six AMS radiocarbon dates on the terrestrial plant remains. Based onanalyses of TOC, CO3, detrital compounds and biogenic SiO2,lake level fluctuations and periods of remarkably-negative water budget appeared at 8.4-8.2 cal ka, 7.38-7.25 cal ka,5.7-5.5 cal ka, 3.7-3.4 cal ka and 3.3-2.9 cal ka, respec-tively. As they are in-phase with low lake levels at Sumxl Co and Bangong Co in western Tibet Plateau and with paleo-lakes in Inner Mongolia, a climate-induced change to some-what drier and warmer conditions is inferred. A further drop in lake level after 1320 AD of about 200 yr duration may heattributed to a negative water balance prior to the main phase of the Little Ice Age. Deep and stable lake phases of 1500 yr and 1800 yr duration at 7.2-5.7 cal ka and 5.5-3.7cal ka coincide with maximum moisture during the Holocene Megathermai in China. The long term trend towards aridity since about 4.3 cal ka can dearly be recognised. The reduced water budget of Bosten Lake from 640-1200 AD may be attributed to local effects.     

Temperature variations on the Tibetan Plateau over the last two millennia

The paleoclimate data recovered from ice cores,tree rings and lake sediments indicate regional features of cfimatic change on the Tibeta n Plateau (TP) during the last 2000 years. The composite temperature reconstructions in-dicate that several main climatic episodes, such as the “LittleIce Age“ between 1400 and 1900, the “Medieval Warm Pe-riod“ in 1150-1400, a less warm period in 800-1100, and an earlier cold period between the 3rd and 5th centuries,occurred in the TP. In addition, temperature varied from region to region. The period from AD 800 to 1100, which waswarm in northeastern TP, was contemporaneous with cool-ing in the western and southern TP. The southern TP ex-perienced warming between 1150 and 1400. For western TP,the δ^18O records of the Guliya ice core indicate that the pe-Hod 1250-1500 witnessed a clear warming. Large-scaletrends in the temperature history from northeastern TP aremore similar to those in eastern China than are the trendsfrom the Guliya ice cap far to the west and southern TP. The most prominent similarities between the temperature varia-tions of the TP and eastern China are such cold phases as 1100-1150, 1500-1550, 1650-1700 and 1800-1850, andthe latter three cold events match with three widespreadg lacial advances which occurred on the TP during the Little Ice A2e.     

我国南方的生态特点及其保护措施

经济的飞速发展，带来的副作用是生态环境的破坏。章以湖北省为研究对象，指出我国南方生态环境的特点和由于追求经济发展而日益突出的四个主要生态问题，并且针对这些问题提出保护措施。     

湖泊沉积研究中一种定量估算陆源有机碳的方法

湖泊沉积研究中常把总有机质含量(TOM)或总有机碳含量(TOC)作为判识湖泊环境的一个重要指标.事实上,湖泊沉积物中的有机碳来源广泛,简单地可分出内源和陆源两部分.