Amplitudes, rates, periodicities and causes of temperature variations in the past 2485 years and future trends over the central-eastern Tibetan Plateau

Amplitudes, rates, periodicities, causes and future trends of temperature variations based on tree rings for the past 2485 years on the central-eastern Tibetan Plateau were analyzed. The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide. The largest amplitude and rate of temperature change occurred during the Eastern Jin Event (343-425 AD), and not in the late 20th century. There were significant cycles of 1324 a, 800 a, 199 a, 110 a and 2-3 a in the 2485-year temperature series. The 1324 a, 800 a, 199 a and 110 a cycles are associated with solar activity, which greatly affects the Earth surface temperature. The long-term trends (>1000 a) of temperature were controlled by the millennium-scale cycle, and amplitudes were dominated by multi-century cycles. Moreover, cold intervals corresponded to sunspot minimums. The prediction indicated that the temperature will decrease in the future until to 2068 AD and then increase again.     

Ancient DNA sequences of rice from the low Yangtze reveal significant genotypic divergence

Rice (Oryza sativa) was first domesticated in the lower and middle Yangtze regions of China, and rice remains have been found in many Chinese archaeological sites. Until now, only phenotypic archeobotanical evidence, such as the spikelet bases of ancient grains, has been used to speculate on the domestication process and domestication rate of rice. In this study, we sequenced 4 genomic segments from rice remains in Tianluoshan, a site of the local Hemudu Neolithic culture in the low Yangtze and two other archaeological sites (~2400 and 1200 BC, respectively). We compared our sequences with those of the current domesticated and wild rice (O. rufipogon) populations. At least two genotypes were found in the remains from each site, suggesting a heterozygotic state of the rice seeds. One ancient genotype was not found in the current domesticated population and might have been lost. The rice remains belonged to the japonica group, and most if not all were japonica-type, suggesting that the remains might be at an early stage of indica-japonica divergence or an indica-japonica mixture. We also identified sequences with significant similarity to those from species of Sapindales, Zygophyllales, and Brassicales, which is consistent with the identification of other plant remains in the Tianluoshan site and the common rice field weeds such as mustards in southern China.     

广东省民办高校图书馆虚拟参考咨询服务的实践与思考

对广东省31所民办高校图书馆的虚拟参考咨询进行了调查,总结了民办高校图书馆常用的虚拟参考咨询方式及虚拟参考咨询存在的问题,提出了民办高校图书馆改进参考咨询的策略。     

基于Gabor滤波的图像质量

基于Gabor滤波器的指纹图像质量分区方法，对指纹图像的各个分区进行了质量评价。然后对高质量分区直接进行脊线跟踪．提取细节特征点；对低质量分区先使用普遍使用的预处理方法，再进行特征提取。对著干幅低质量指纹进行了实验，得到了不错的实验效果，并且实验的效率和准确率也有所提高。     

平菇原种培养中木屑替代玉米芯的可行性研究

为寻找平菇原种制作中可用于替代玉米芯的材料,以减轻因玉米芯供应稀缺而造成的生产压力,进行了木屑替代玉米芯的试验。结果:平菇菌丝在木屑含量不同的培养基中长速和长势存在差异,与对照相比,木屑有促进平菇菌丝生长的作用,在木屑含量在25～30%时效果最好,木屑量达40～45%时,菌丝生长情况下降,但与对照持平,木屑量再增加,达到50～60%,即几乎全部替代原种培养基中的玉米芯时,菌丝早期长势差,后期长势向好,但满瓶时间稍长。结论:一定比例的木屑代替玉米芯是可行的,亦可通过培养基中不同比例的木屑来调整原种生理成熟时间,以方便实际应用。     

Z=116同位素链上原子核性质的研究

在宏观－微观模型的理论框架下，采用Nilsson势对Z=116同位素链上原子核基态的结合能、α衰变能和四极形变进行了计算，并把理论计算结果与实验数据和其他理论模型的结果进行了比较和讨论.研究发现，理论计算值和实验数据符合，也与其他模型的计算结果符合.此外，还讨论了Z=116同位素链上的位能曲面和可能出现的形状共存现象.     

环境友好合成褪黑素

褪黑素化学名3-N-乙酰基-5-甲氧基色胺,其生理和药理活性甚为广泛.研究和改进褪黑素（melatonin,MT）的合成方法,主要以4-氯丁醛和4-甲氧基苯肼盐酸盐缩合得5-甲氧基色胺,然后乙酰化得褪黑素,总收率达35.5%.制备的反应过程都在环境友好型原料和溶剂中进行,反应条件温和,对工业生产有积极的经济和社会价值.     

体检人群中乳腺增生症患者的危险因素调查

使用自制调查问卷对参加莆田学院附属医院体检的3809名女性体检者进行调查,找出与乳腺增生发生密切相关的危险因素。调查结果显示,乳腺增生症发病率为43.84%,乳腺增生症患者更关注疾病本身。多因素非条件Logistic分析显示影响其发生危险因素是年龄、职业、性格特点、母乳喂养、饮食方式和断乳行为。结果表明,提高妇女对乳腺增生的认识,提倡母乳喂养,科学断乳行为,健康饮食,劳逸结合,能预防乳腺增生症的发生。     

多金属氧酸盐结构研究的新进展

当前,一大批结构新颖的多金属氧酸盐被合成出来,这些化合物大致可分为以下四类:(1)高核轮簇状多金属氧酸盐;(2)充当模板剂的多金属氧酸盐;(3)以多金属氧酸盐为建筑块的高维孔状的有机-无机杂化材料;(4)仿生化的多金属氧酸盐。     

中药枳壳中柚皮苷和橙皮苷的提取方法研究

目的:采用正交设计法,对枳壳中的柚皮苷和新橙皮苷的提取方法和提取工艺参数进行优化。方法:通过水浴回流、索氏提取、超声辅助提取、微波炉辅助提取四种提取方法的比较,其中水浴回流提取法采用L9(33)正交实验以提取溶剂、时间、温度为因素,每个因素选3个水平,以枳壳中的柚皮苷和新橙皮苷的提取率来确定最优化的提取方法和提取条件。结果:水浴回流提取的优化条件是:溶剂为80%乙醇,温度为60℃,时间为40min.索氏提取优选95%乙醇,超声提取优选甲醇作溶剂。微波提取的最优化条件是,80%乙醇作溶剂,微波萃取仪功率400W,提取时间10min,温度40℃.结论:水浴回流提取法适用于作为生产制剂的提取,超声和微波提取法宜用于药物成分分析的提取。