Temperature variations evidenced by records on the latest spring snowing dates in Hangzhou of eastern China during 1131–1270AD

We collected and verified documentary records of the latest spring snowing dates(LSSD) in Hangzhou during Southern Song Dynasty. Furtherly, the statistical correlation between this proxy and February–April mean temperature in Hangzhou was examined, and samples later than the perennial mean of the LSSD during Southern Song Dynasty were transformed into the decadal mean of LSSD by means of Boltzmann function. General characteristics of this reconstructed LSSD series with a 10-year temporal resolution was analyzed, and it was also compared with other documentary evidences and reconstructed climate series in China for the period 1131–1270. The results and discussion suggested that:(1) Records of the LSSD in Hangzhou during Southern Song Dynasty did not refer to ice pellets and graupels, which had an explicit climate significance(–0.34℃/10 d, R2=0.37, p0.001). However, when this proxy is used to reconstruct temperature changes, all dates should be converted into proleptic Gregorian style and meet the same criterion of "true Qi" as the Chinese traditional calendar after 1929.(2) The decadal mean of LSSD can be effectively estimated by using the forefront of LSSD in the decade on the basis of Boltzmann function, whose extrapolation has a lesser uncertainty than those on the basis of linear models or polynomial models.(3) The spring climate in Hangzhou during 1131–1270 was almost as warm as the period 1951–1980. At the centennial scale, this period can be divided into two phases: the cold 1131–1170 and the warm 1171–1270. In the latter, 1181–1200 and 1221–1240 were two cold intervals at the multi-decadal scale.(4) The reconstructed LSSD series was consistent well with other documentary evidences and reconstructed climate series in China for 1131–1270, which may reflect the influence on the climate over most regions of China imposed by the Pacific Decadal Oscillation(PDO).     

深海生态学研究进展和几点建议

深海及其底部生物圈的探测和研究,是当前海洋大科学研究的焦点,是未来的海洋科学,具有重要的战略意义。深海及其底深部生态学的研究,是其中的一项重要内容。本文简要回顾了深海生态学发展的三个里程碑以及中国在该学科的研究进展,提出了大力发展深海探测和钻探设备、技术,建设深海生态站和大洋钻探船;以生态系统为中心开展深海生态研究;将深海生态研究纳入国家和有关部门的研究计划、支持多学科交叉和融合的建议。     

Specific oceanographic characteristics and phytoplankton responses influencing the primary production around the Ulleung Basin area in spring

The East Sea(Sea of Japan)is a marginal,semi-closed sea in the northwestern Pacific.The Ulleung Basin area,which is located near the subpolar front of the East Sea,is known to have high primary production and good fisheries in spring season.After episodic wind-driven events during the spring of 2017,horizontal and vertical profiles of physical chemical biological factors were investigated at 29 stations located in the Ulleung Basin area.In addition,growth responses of phytoplankton communities to nutrient additions were evaluated by bioassay experiments to understand the fluctuation of phytoplankton biomass.Because of strong northwestern wind,phytoplankton biomass was scattered and upwelling phenomenon might be suppressed in this season.The phytoplankton abundances in the coastal stations were significantly higher than offshore and island stations.In contrast,the nutrient and chlorophyll a(Chl a)concentrations and the phytoplankton biomass were quite low in all locations.Bacillariophyceae was dominated group(>75.1%for coastal,40.0%for offshore and 43.6%for island stations).In the algal bioassays,the phytoplankton production was stimulated by N availability.The in vivo Chl a values in the+N and+NP treatments were significantly higher than the values in the control and the+P treatments.Based on the field survey,the higher nutrients in coastal waters affected the growth of diatom assemblages,however,little prosperity of phytoplankton was observed in the offshore waters despite the injection of sufficient nutrients in bioassay experiments.The growth of phytoplankton depended on the initial cell density.All of results indicated that a dominant northwestern wind led to a limited nutrients condition at euphotic layers,and the low level of biomass supply from the coasts resulted in low primary production.Both supplying nutrients and introducing phytoplankton through the currents are critical to maintain the high productivity in the Ulleung Basin area of the East Sea.     

印尼热泉菌产热稳定褐藻胶裂解酶的酶学性质研究

以印尼热泉菌为材料,采用以褐藻酸钠为唯一碳源的培养基筛选产褐藻胶裂解酶的菌株,通过16S rDNA序列对产酶菌株进行种属鉴定,并通过硫酸铵沉淀、离子交换层析和凝胶过滤层析从高产酶菌株Aly-B5发酵液上清中纯化获得褐藻胶裂解酶,并对该酶的酶学性质进行了研究。结果表明:高产酶菌株经鉴定为Bacillus属;聚丙烯酰胺凝胶电泳(Sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)显示纯化的褐藻胶裂解酶Aly-B5分子量为45kDa,该酶最适作用温度为65°C,75°C时的半衰期为110min,最适pH为7.0;Zn~(2+)、Mg~(2+)、Fe~(2+)对酶活具有明显的抑制作用,但该酶对乙二胺四乙酸(ethylene diamine tetraacetic acid,EDTA)并不敏感;同时,底物特异性实验表明Aly-B5是一种偏好降解聚古罗糖醛酸(poly G)的双功能裂解酶,降解产物主要是二糖。该酶优良的耐热性使其在海藻高值化利用领域具有潜在的应用前景。     

气候变化对小油菜生长发育及产量的影响

以青海省门源县为例,分析小油菜生育期气候变化规律.观测资料表明,小油菜生育期气温升高,气候变暖,4～8月降水量以每10年1.64～20.70 mm的幅度下降,9月降水以每lO年20.16 mm的幅度增加;气候变暖使小油菜播种期提前,成熟期推迟,生育期延长,为提高气候资源利用率和单位面积产量提供了保证;增温对各发育阶段的影响差异明显,除出苗至现蕾间发育进程加快外,其余各发育期生长发育出现迟缓变化;气候产量主要受4、6月和年平均气温及6月降水的影响.     

青藏高原各拉丹冬冰芯记录的季节气温变化

A 70-year history of precipitation δ18O record has been retrieved using an ice core drilled from a plat portion of the firn area in the Guoqu Glacier (33o34′37.8″ N, 91o10′35.3″ E, 5720 m a.s.l.) on Mt. Geladaindong (the source region of Yangtze River) during October and November, 2005. Based on the seasonality of δ18O records and the significant positive relationships between monsoon/non-monsoon δ18O values and summer/spring air temperature from the nearby meteorological stations, the history of summer and spring air temperature have been reconstructed for the last 70 years. The results show that both summer and spring air temperature variations present similar trends during the last 70 years. Regression analysis indicates that the slope of the temperature-δ18O relationship is 1.3℃/‰ for non-monsoon δ18O values and spring air temperature, and 0.4℃/‰ for monsoon δ18O values and summer air temperature. Variation of air temperature recorded in the ice core is consistent with that in the Northern Hemisphere (NH), however, the warming trend in the Geladaindong region is more intense than that in the NH, reflecting a higher sensitivity to global warming in the high elevation regions. In addition, warming trend is greater in spring than in summer.     

近58年华北地区初、终霜日及无霜期变化特征分析

基于华北地区90个气象站点1961-2018年地面0 cm日最低温度和平均气温资料,采用线性倾向估计、反距离加权、Mann-Kendall检验、累积距平法,研究了近58年华北地区初、终霜日和无霜期的变化特征.结果表明:(1)在年际和年代际尺度上,华北地区初、终霜日和无霜期均分别呈显著推迟、提前和延长的趋势,从20世纪8...     

机器学习方法在预测泉水潜在出露位置中的应用

泉水出露受到多种因素影响,在传统地质勘查手段之外,各种模型方法及影响因子预测手段,也被越来越多地应用于泉水的研究中.本文尝试利用机器学习的方法进行泉水出露位置的预测研究.根据北京市野外调查,确定了1378个测试样本点,选取了高程、坡度、坡向、地形湿度指数、径流强度指数、距河流距离、距断裂距离、岩性、归一化植被指数及土地...     

贵州松桃大塘坡地区南华纪早期冷泉碳酸盐岩地质地球化学特征

贵州松桃大塘坡地区的南华系是研究古代天然气渗漏及冷泉碳酸盐岩的理想地区之一.该区冷泉碳酸盐岩由两类岩石组成: 一是两界河组含砾砂岩中(Sturtian冰期早期) 的白云岩丘或透镜体; 二是之上的大塘坡组第一段黑色含锰岩系中的似层状或透镜状菱锰矿矿体及少量白云岩透镜体.该地区冷泉碳酸盐岩的碳同位素具明显的负偏特征, 充填在菱锰矿矿石气孔中的沥青碳同位素为-30.98‰, 并具有异常高的硫同位素正值.结合冷泉碳酸盐岩的空间分布、古天然气渗漏构造、菱锰矿的沉积有机质等特征分析, 认为其与现代冷泉碳酸盐岩的特征十分相近.两界河组的白云岩丘是目前所发现的最古老的冷泉碳酸盐岩, 与在它之上的菱锰矿矿体是同一个古天然气渗漏系统中不同时期的冷泉碳酸盐沉积.天然气泄漏形成的冷泉与大塘坡组烃源岩的形成关系密切.      

北京地区春旱和春季第一场透雨指标的确定

利用北京地区１９５１－１９９５年降水和气温资料,探讨适用于春旱进行实时业务监测的春旱指标和春季第一场透雨的指标,并分析和讨论了指标的特点。