浅谈冬季混凝土施工技术与解决办法

结合实际,重点阐述了混凝土科季施工的一般原理及施工方法。

夜的季节

如果把一年比作一天,那么,早上是春季,中午是夏季,傍晚是秋季,晚上该是冬季了.科季,是寒冷而又漫长的夜的季节.太阳变得昏黄,天空是永远的灰蒙,朔风不时鼓起它的号角,搅动飞雪在空中乱舞.雪覆了山峦,冰断了大河,大地一片寂然.但是,黑夜并不是只有黑暗,冰雪覆盖下的大地,绝不是一片死寂.你看,积雪尽头,一枝红梅竞雪乍放,傲然独立,枝头间分明有暗香浮动;你看,冰雪险外,一行脚印深深浅浅,默默远去,弯曲在拔涉者前行的脚下;你听,渊冰深处,一道暗流悄然而成,愈唱愈响,裹着碎石,挟带裂冰,奔向浩荡;

LASIK的门诊保健指導

據资料统计我国每年需要接受LASIK手术的患者约为10万人,为他们提供正确的、科学的保健知识十分必要。準分子激光原位角膜磨镶术(LASIK)治疗近视的原理是通过激光改变角膜表面的曲率,将眼镜矫正的度数移到角膜上,以達到中和屈光不正的目的。它的手术方式是用自动板層角膜切削刀切出一個直径约8.5mm带蒂的角膜瓣,然后用凖分子激光切削角膜基質,再将角膜瓣復位。 1 適應症选择 1.1 年龄在18—50岁;近视屈光度-2.00至-20.

Morphological Characteristics Analysis of 11 Broom Sorghum Varieties

[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of broom sorghum were compared through the survey of some indicators, such as plant height, tillering, inflorescence, stem node, stem-leaf ratio, yield, and so on. [Result] The 11 kinds of broom sorghum were different in morphological characteristics with large amplitude of plant height; zygl-1, zygl-6, zygl-8 and zygl-9 were appropriate for fixed broom type; zygl-9 had the highest integrated production. [Condusion] The study laid the foundation for further exploring breeding, cultivation and promotion of broom sorghum.

A Multilayer Study of pCO2 in the Surface Waters of the Yellow and South China Seas in Spring and the Sea-Air Carbon Dioxide Flux

A multilayer study of pCO2 for the Yellow and South China Seas in the surface waters was conducted based on data from four cruises sponsored by the China SOLAS Project in 2005 and 2006,including data for the surface microlayer(SML) ,subsurface layer(SSL) and surface layer(SL) . The carbon fluxes across the air-sea interface were calculated. The results showed that the pCO2 values in the surface waters of the study area decreased in the following order:pCO2 SML> pCO2 SSL> pCO2 SL. The highest values were found in March for all SML,SSL and SL,followed by those in April,and the lowest were in May. The pCO2 values had a significant positive correlation with temperature or salinity. While there was no relationship between pCO2 and longitude,there was a significant negative correlation between it and latitude,i.e.,'high latitude low pCO2'. By using four calculation models,the carbon dioxide fluxes(FC O2) in spring in the Yellow and South China Seas,which were found to act as a 'sink' of atmospheric CO2,were preliminarily estimated on the basis of the pCO2 data in the SML to be -7.00×106 t C and -22.35×106 t C,respectively. It is suggested that the FC O2calculated on the basis of pCO2 data in the SML is more reliable than that calculated on the basis of those in the SL.

Properties of Solar Radiation over Chinese Arid and Semi-Arid Areas

Climatic characteristics of broadband solarradiation (Rs) in Chinese arid and semi-arid areas are reported in this study. The annual average daily Rs in thearid and semi-arid areas is 16.3 ± 5.77 and 15.3 ± 5.16 MJm-2 d-1, respectively. The highest value (17.2 ± 5.84 MJm-2 d-1) appears in an arid area at Linze. The lowest valueappears in the semi-arid area of Ansai. Pronounced seasonal variation of Rs is observed with the highest value insummer and the lowest in winter. The clearness indexshowed similar seasonal pattern at most sites, with theminimum observed in the summer and the highest valuesin winter at both arid and semi-arid areas. The seasonalvariation of the ratio of Rs to its extraterrestrial value Kt inthe arid area is more significant than that observed in thesemi-arid region, and it is caused by the different range ofvariation of water vapor between arid and semi-arid areasThe seasonal fluctuations in Rs and Kt are mainly controlled by the water vapor content in these areas. Theaerosol particles have significant influence on Rs and Kt atstations with higher aerosol burden.

Trends in Seasonal Precipitation over China during 1961-2007

Trends in six indices of precipitation in China for seasons during 1961-2007 were analyzed based on daily observations at 587 stations. The trends were estimated by using Sen's method with Mann-Kendall's test for quantifying the significance. The geographical patterns of trends in the seasonal indices of extremes were similar to those of total precipitation. For winter, both total and extreme precipitation increased over nearly all of China, except for a small part of northern China. Increasing trends in extreme precipitation also occurred at many stations in southwestern China for spring and the midlower reaches of the Yangtze River and southern China for summer. For autumn, precipitation decreased in eastern China, with an increasing length of maximum dry spell, implying a drying tendency for the post-rainy season. Wetting trends have prevailed in most of western China for all seasons. The well-known 'flood in the south and drought in the north' trend exists in eastern China for summer, while a nearly opposite trend pattern exist for spring.

Hydrological Processes in the Huaihe River Basin, China： Seasonal Variations, Causes and Implications

Understanding streamflow changes in terms of trends and periodicities and relevant causes is the first step into scientific management of water resources in a changing environment. In this study, monthly streamflow variations were analyzed using Modified Mann-Kendall(MM-K) trend test and Continuous Wavelet Transform(CWT) methods at 9 hydrological stations in the Huaihe River Basin. It was found that: 1) streamflow mainly occurs during May to September, accounting for 70.4% of the annual total streamflowamount with Cv values between 0.16–0.85 and extremum ratio values between 1.70–23.90; 2) decreased streamflow can be observed in the Huaihe River Basin and significant decreased streamflow can be detected during April and May, which should be the results of precipitation change and increased irrigation demand; 3) significant periods of 2–4 yr were detected during the 1960 s, the 1980 s and the 2000 s. Different periods were found at stations concentrated within certain regions implying periods of streamflow were caused by different influencing factors for specific regions; 4) Pacific Decadal Oscillation(PDO) has the most significant impacts on monthly streamflow mainly during June. Besides, Southern Oscillation Index(SOI), North Atlantic Oscillation(NAO) and the Ni?o3.4 Sea Surface Temperature(Ni?o3.4) have impacts on monthly streamflow with three months lags, and was less significant in time lag of six months. Identification of critical climatic factors having impacts on streamflow changes can help to predict monthly streamflow changes using climatic factors as explanatory variables. These findings were well corroborated by results concerning impacts of El Nino-Southern Oscillation(ENSO) regimes on precipitation events across the Huaihe River Basin. The results of this study can provide theoretical background for basin-scale management of water resources and agricultural irrigation.

Progress in Research on the Impacts of Global Climate Change on Winter Ski Tourism

The impacts of global climate change on ski tourism, which depends heavily on climate conditions, have increasingly gained concern overseas. This paper systematically summarized the relevant research ideas, the technical methods used, and the obtained achievements through an extensive synthesis of the previous studies. Moreover, the major shortcomings and the limitations in the recent studies are pointed in order to present a useful reference for our Chinese investigators. It indicates that the future climate warming would cause the loss of skiable areas, the shortening of skiing seasons and the sharp drop of ski visitors in many low altitude and low latitude ski resorts. The paper finally stressed that future research should pay particular attention to strengthening interdisciplinary cooperation and consider more factors about the impacts of climate-induced environmental changes on tourist flows. In the future ski resort planning and management, the possible impacts of global climate change should be taken into account.

Gametogenic Cycle, the Spawning Season, First Sexual Maturity, and the Biological Minimum Size in Male Ruditapes philippinarum （Bivalvia： Veneridae） in Western Korea

The male gametogenic cycle, spawning season, first sexual maturity, and the biological minimum size in male Ruditapes philippinarum were investigated by qualitative and quantitative reproductive analyses. In the study of the male gametogenic cycle by qualitative histological analysis, the gametogenic cycle in male individuals can be classified into five successive stages： （1） early active stage, （2） late active stage, （3） ripe stage, （4） partially spawned stage, and （5） spent and inactive stage. Monthly changes in the gonad index in males measured by qualitative analysis showed a similar pattern to the male gametogenic cycle. In the study of the male gametogenic cycle by quantitative statistical analysis, monthly changes in the portions （%） of areas occupied by the testis areas to total tissue areas showed a rapid increase in March, and reached the maximum in May-June. And also monthly changes in the portions （%） of areas occupied by the spermatogenic stages to the testis area showed a maximum in May and gradually decreased from June to October. Therefore, this species showed a unimodal gametogenic cycle during the year, and the number of spawning seasons occurred once per year, from June to October, with a peak spawning between July and August. The percentage at the first sexual maturity of male clams ranging from 15.1-20.0 mm in shell length was 64.7%, and that of all individuals ranging from over 25.1 mm in shell length was 100%. The biological minimum size （shell lengths at 50% of sexual maturity （RMs0）） of male mature clams that was fitted to an exponential equation was 17.16 mm （considered to be 1 year old）. Because harvesting clams less than 17.16 mm in shell length could potentially cause a drastic reduction in recruitment, a measure indicating a prohibitory fishing size should be enacted for adequate fisheries management.

Interannual and interdecadal variability of East Asian monsoon and its relation to oceanic processes: a review

A key component of the East Asian climate system is seasonally varying monsoon wind. Its interannual and interdecadal variability, as we1l as underlying oceanic processes, is the subject of a recent project completed by the Chinese Academy of Sciences. A series of research progress in the areas of monsoon winds, ocean responses, upwelling and productivity has been made and reviewed by this paper.

Scientists Use Palaeobotanical Evidence to Estimate Early Miocene Elevation in Northern Tibet

The area and elevation of the Tibetan Plateau over time has directly affected Asia’s topography,the characteristics of the Asian monsoon,and modified global climate—but in ways that are poorly understood.Charting the uplift history is crucial for understanding the mechanisms that link elevation and climate irrespective of time and place.While some palaeoelevation data are available for southern and central Tibet,clues to the uplift history of northern Tibet remain sparse and largely circumstantial.Lately,

发刊词

在全国蓬勃发展的社会主义建设高潮中,眼看着学术界也正在掀起一个空前未有的高潮。按照国家计划,我们将要在短短十几年内赶上世界科学的先进水平。这实在是一件了不起的大事。要达到这一目标,我们必须调动一切可以调动的力量。

冬季养生大膳——草木凋零最需被 天人合人温咸甘

冬季气候寒冷，草木凋零，万物蛰藏，人体在此时应该得到合理的营养补充。现代营养学认为，人们在科季户外活动减少，体内的自由基以及过氧化物等毒素不容易排出体外，所以在科季应该多食用一些富含维生素C、维生素E以及富含纤维素的食物。维生素C和维生素E有排除人体内自由基的作用，纤维素可加快人体肠道的蠕动，还可以在肠道的表面形成一屋保护膜，防止肠道对食物消化吸收后所产生的有害物质以及固醇的重吸收。这些营养素主要存在于一些黄绿色的蔬菜和水果当中，如蒜黄、白菜、芹菜、黄椒、猕猴桃等。祖国传统养生学根据“天人和一”的理论认为，冬季进补应用食用一些味甘、咸，性温热，具有温补牌肾、温通心阳功效的食物。发羊肉、鹿肉、鸡肉、海参、鲍鱼等。

SEASONAL PERFORMANCE AFFECTING POPULATION DYNAMICS OF CITRUS RED MITE, PANONYCHUS CITRI (MCGREGOR) (ACARI: TETRANYCHIDAE), ON PEAR

The population of the citrus red mite, Panonychus citri (McGregor), does not increase on pear from spring to mid summer but thereafter increases abruptly. To elucidate this phenomenon, we compared the performance of the mites on pear leaves with that on citrus leaves, at different time throughout the pear growing season. No significant difference was detected between the oviposition rate on pear and that on citrus throughout the season. However, the survival rate of ovipositing females that had fed on pear and the hatch rate of eggs laid by those females were significantly lower than those for females that had fed on citrus, until August. However, no significant difference was observed thereafter. The results showed that the decline of the population of citrus red mite before autumn is due to the high mortality of adult females that had fed on pear leaves and the low hatch rate of the eggs produced by those females.