碳化对加填料氯氧镁胶凝材料力学性能的影响

以添加不同掺量填料的氯氧镁水泥(MOC)试件为基体,在空气和碳化箱中分别养护至规定龄期,研究碳化对掺加填料MOC力学性能的影响,并与空气环境进行对比,运用XRD和SEM分析碳化后水化产物和微观结构的变化规律。结果表明,28 d龄期内,随着填料掺量的增加MOC试件碳化后的抗折强度均有所增加,碳化后的抗压强度均有提升,碳化过程反应生成了MgCO_3,不同碳化龄期的主要物相均为5Mg(OH)_2·MgCl_2·8H_2O(5相),而掺加填料不影响MOC的水化产物的组成。     

New Cases of Superflares on Slowly Rotating Solar-type Stars and Large Amplitude Superflares in G-and M-type Main Sequence Stars

In our previous work, we searched for superflares on different types of stars while focusing on G-type dwarfs using entire Kepler data to study statistical properties of the occurrence rate of superflares. Using these new data, as a byproduct, we found 14 cases of superflare detection on 13 slowly rotating Sun-like stars with rotation periods of24.5–44 days. This result supports the earlier conclusion by others that the Sun may possibly undergo a surprise superflare. Moreover, we found 12 and se...     

大尺度海岸行为

大尺度海岸行为ＪｅｆｆｒｅｙＨ．Ｌｉｓｔ等该题目是指对海岸和近岸沉积系统的了解，以及对发生在该系统中的变化的预测。Ｌｉｓｔ（１９９３）定义大尺度海岸行为是几十年的时间尺度内、几至几十公里空间范围内的海岸物理演化．Ｔｅｒｗｉｎｄｔ和Ｗｉｊｎｂｅｒｇ（１...     

Distribution, use pattern and prospects for conservation of medicinal shrubs in Uttaranchal State, India

The present paper gives an insight into the distribution and use pattern of medicinal shrubs in Uttaranchal State. A total of 222 medicinal and aromatic shrub species have been appended based on secondary information. Euphorbiaceae, Rosaceae, Verbenaceae, and Fabaceae have the highest repre- sentatives of medicinal shrubs. Twenty one families had one species each in medicinal use. Verbenaceae and Euphorbiaceae in the sub-tropical region, Rosaceae in the temperate region, and Ericaceae and Rosaceae in the sub-alpine and alpine regions, respectively, had the highest representatives of medicinal shrubs. The distribution of medicinal shrubs was 42 % in sub-tropical, 29 % in warm temperate, 13 % in cool temperate, 9 % in sub-alpine and 7 % in the alpine region. Of the total species, 70 medicinal shrubs were native to the Himalayas and 22 native to Himalayan region including other Hima- layan countries. The most frequently used plant parts for various ailments were leaves (31 %) and roots (23 %). Most shrubs are being used for the diseases, viz. skin diseases, dysentery, cough, fever, wounds, and rheumatism. The present paper will help in the execution of strategies for promotion and cultivation of medicinal shrubs in Uttaranchal State.     

EFFECTS OF AGRICULTURE RECLAMATION ON THE HYDROLOGIC CHARACTERISTICS IN THE SANJIANG PLAIN, CHINA

1 THE NATURAL ENVIRONMENTAL CHARACTERISTICS The Sanjiang Plain is located in the northeast of Heilongjiang Province, China. Russia borders this region in the north and east. Its total area is 1.088×107ha. The area of plain occupies 61.21％of the total land area and that of hill and mountain amounts to 38.79％of the total land area. It is not only one of the most important regions with large area of fresh water wetlands and with varieties of rare migratory waterfowls, but a…     

LARGE-SCALE CIRCULATION CONDITIONS AFFECTINGTHE TYPHOON FORMATION OVER THENORTHWEST PACIFIC

A contrasting study of the large-scale circulation features responsible for months with many typhoons and months with tew typhoons has revealed that the frequency of typhoon formation over the Northwest Pacific is related to the following conditions:Over the Northwest Pacific, a well-defined ITCZ (Intertropical Convergence Zone) extending eastward to 160°E was displaced to 20°N. At 200 mb, an extensive anomalous anticyclonic circulation prevails over the western and central Pacific. The condition characteristic of a break in the monsoon prevailed in India. The monsoon trough at 500 mb and at the surface over the Indian Peninsula was relatively weak and was accompanied by higher-than-normal rainfall in the northern part of India and lower-than-normal rainfall over the peninsula. In addition, the polar vortex tends to be weak and move to the side of the Northern Hemisphere, opposite to the North Pacific. Finally, abnormally warm water was observed over the Central and Eastern Pacific and abnormally cold     

Foreword

Ocean circulation in the Yellow and East China Seas is very rich in mesoscale phenomena, such as eddies, fronts, upwellings, river plumes, etc. Among others, having drawn tremendous attention from oceanographic community in the past for nearly 50 years are mainly the Yellow Sea Cold Water Mass (YSCWM) and its related circulation, the Yellow Sea Warm Current (YSWC), the East China Sea     

在中国几个地区进行的大地电流法勘探工作

在中国,自从1957年起,与各种地球物理方法（解决石油地貭任务）广泛发展的同时,比較年輕的大地电流法也得到了很大的发展。大地中存在大地电流,这在一百多年前就知道了。以往的观測表明,大地电流具有脉动性貭,它的大小和方向随时間而变化,并在地球表面很多地区同时出現。大地电流的产生、它的变化以及与地磁場的关系,还沒有搞得相当清楚,这是一个需要进一步研究的問題。     

不同种植方式高油酸花生小气候特征研究

为研究不同种植方式下高油酸花生小气候特征,于2020年在商丘国家基准气候站内开展花生分期播种试验,试验设计5月6日、5月26日和6月15日3个播期,按垄作和平作两种方式种植。在5月6日播种的垄上、垄下和平作的花生田内安装温湿度自动记录仪,对比分析不同种植方式对农田气温、相对湿度及产量的影响,研究农田温湿度与基准站气象要素的定量关系。结果表明,种植方式不同,花生农田小气候特征存在差异。不同发育期,垄上和垄下气温均高于平作的,且二者之间的差异白天的大于夜间的。下针-饱果期和饱果-成熟期垄上平均气温分别比平作的高0.5℃和0.9℃,日较差分别比平作的高1.1℃和2.1℃;田间相对湿度平作的高于垄上和垄下的,下针-饱果期和饱果-成熟期垄上相对湿度日较差分别比平作的高11.2%和15.3%。典型晴天和多云天,基准站夜间气温高于垄上、垄下和平作的,白天的气温低于垄上、垄下和平作的;阴雨天垄上气温高于垄下、平作和基准站的。3种天气条件下,平作相对湿度高于垄上、垄下和基准站的。高油酸花生小气候与基准站温湿度之间存在显著的一元线性相关关系。3个播期的垄作花生单株荚果数、单株果重和产量均高于平作的,且呈极...     

内华达东中部安特勒前陆盆地演化与层序地层学

引言安特勒盆地的密西西比纪沉积岩出露于从爱达荷经东内华达至南内华达的连续区域内。这些岩石为硅质碎屑盆地充填序列,并超覆在晚古生代以碳酸盐沉积为主的北美西部边缘之上。在中内华达的研究区域内(图1),安特勒盆地的大部分地层已被划归为两个单位:(1)Chainman页岩(Spencer,1917;Easton等,1953);(2)Diamond Peak组的砾岩和砂岩(Easton等,1953;Nolan等,1956)。本区安特勒盆地从早密西西比世到早宾夕法尼亚