甘肃大水式金矿床地质特征及与周边金矿对比浅析

大水式金矿床是近年来发现的一个新类型金矿,其矿化特征独特、埋藏浅、品位高、化学成分简单、易采选、具有很高的经济价值。本文通过对该矿床的地质特征、成因等和周边的金矿床进行了对比分析认为,大水式金矿是构造—岩浆—热液活动体系的系列演化产物。

Century-long variability and trends in daily precipitation characteristics at three Finnish stations

Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908e2008 from 3 meteorological stations in the south(Kaisaniemi),centre(Kajaani) and north(Sodankyl€a). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation(0 mm < daily precipitation long-term 50 th percentile of daily precipitation more than 0 mm) significantly( p < 0.05) decreased over time,with the highest rate in northern Finland. These decreasing trends might be the result of significant increases in frequency of days with very light precipitation at all the stations, with the highest and lowest rates in northern and southern Finland, respectively. Ratio of annual total precipitation to number of precipitation days also declined in Finland over 1908e2008, with a decreasing north to south gradient. However, annual duration indices of daily precipitation revealed no statistically significant trends at any station. Daily precipitation characteristics showed significant relationships with various well-known atmospheric circulation patterns(ACPs). In particular, the East Atlantic/West Russia(EA/WR)pattern in summer was the most influential ACP negatively associated with different daily precipitation intensity, frequency and duration indices at all three stations studied.

East China Summer Rainfall during ENSO Decaying Years Simulated by a Regional Climate Model

The performance of the Climate version of the Regional Eta-coordinate Model （CREM）, a regional climate model developed by State Key Laboratory of Numerical modeling for Atmospheric Science and Geophysical Fluid Dynamics/Institute of Atmospheric Physics （LASG/IAP）, in simulating rainfall anomalies during the ENSO decaying summers from 1982 to 2002 was evalu- ated. The added value of rainfall simulation relative to reanalysis data and the sources of model bias were studied. Results showed that the model simulated rainfall anomalies moderately well. The model did well at capturing the above-normal rainfall along the Yangtze River valley （YRV） during E1 Nifio decaying summers and the below and above-normal rainfall centers along the YRV and the Huaihe River valley （HRV）, respectively, during La Nifia decaying summers. These features were not evident in rainfall products derived from the reanalysis, indicating that rainfall simulation did add value. The main limitations of the model were that the simulated rainfall anomalies along the YRV were far stronger and weaker in magnitude than the observations during E1 Nifio decaying summers and La Nifia decaying summers, respectively. The stronger magnitude above-normal rainfall during E1 Nifio decaying summers was due to a stronger northward transport of water vapor in the lower troposphere, mostly from moisture advection. An artificial, above-normal rainfall center was seen in the region north to 35°N, which was associated with stronger northward water vapor transport. Both lower tropospheric circulation bias and a wetter model atmosphere contributed to the bias caused by water vapor transport. There was a stronger southward water vapor transport from the southern boundary of the model during La Nifia decaying summers; less remaining water vapor caused anomalously weaker rainfall in the model as compared to observations.

Morphology and ontogeny of dendritic cells in rats at different development periods

AIM： To study the morphology and ontogeny of dendritic cells of Peyer＇s patches in rats at different development periods. METHODS： The morphometric and flow cytometric analyses were performed to detect all the parameters of villous-crypts axis and the number of OX62＋DC, OX62＋CD4＋SIRP＋DC, and OX62＋CD4-SIRP-DC in the small intestine in different groups of rats. The relationship between the parameters of villous-axis and the number of DC and DC subtype were analyzed. RESULTS： All morphometric parameters changed significantly with the development of pups in the different age groups （F = 10.751, 12.374, 16.527, 5.291, 3.486; P = 0.000, 0.000, 0.000, 0.001, 0.015）. Villous height levels were unstable and increased from 115.24μm to 140.43 μm as early as 3 wk postpartum. Villous area increased significantly between 5 and 7 wk postpartum, peeked up to 13817.60 tam2 at 7 wk postpartum. Villous height and crypt depth ratios were relatively stable and increased significantly from 2.80 ＋ 1.01 to 4.54 =1= 1.56, 9-11 wk postpartum. The expression of OX62＋DC increased from 33.30%±5.80% to 80%± 17.30%, 3-11 wk postpartum （F =5.536, P = 0.0013）. OX62＋CD4＋SIRP＋DC subset levels detected in single-cell suspensions of rat total Peyer＇s patch dendritic cells （PP-DCs） increased significantly from 30.73% ± 5.16% to 35.50% ± 4.08%, 5-7 wk postpartum and from 34.20% ±1.35% to 43.60% ± 2.07% 9-11 wk postpartum （F = 7.216, P = 0.005）. CONCLUSION： This study confirms the agerelated changes in villous-crypt axis differentiation in the small intestine. Simultaneously, there are also development and maturation in rat PP-DCs phenotypic expression. Furthermore, the morphological changes of intestinal mucosa and the development of immune cells （especially DC） peaked at 9-11 wk postpartum, indicating that the intestinal mucosae reached a relatively mature state at 11 wk postpartum.

An Effective Approach for Improving the Real-Time Prediction of Summer Rainfall over China

This paper has two purposes. One is to evaluate the ability of an atmospheric general circulation model (IAP9L-AGCM) to predict summer rainfall over China one season in advance. The other is to propose a new approach to improve the predictions made by the model. First, a set of hindcast experiments for summer climate over China during 1982-2010 are performed from the perspective of real-time prediction with the IAP9L-AGCM model and the IAP ENSO prediction system. Then a new approach that effectively combines the hind-cast with its correction is proposed to further improve the model's predictive ability. A systematic evaluation reveals that the model's real-time predictions for 41 stations across China show significant improvement using this new approach, especially in the lower reaches between the Yellow River and Yangtze River valleys.

The Impacts of Climate Change on Fitzroy River Basin, Queensland, Australia

An analysis of historical data of Fitzroy River, which lies in the east coast of Australia, reveals that there is an increasing trend in extreme floods and droughts apparently attributable to increased variability of blue and green waters which could be due to climate change. In order to get a better understanding of the impacts of climate change on the water resources of the study area for near future as well as distant future, SWAT （soil and water assessment tool） model was applied. The model is first tested for its suitability in capturing the basin characteristics with available data, and then, forecasts from six GCMs （general circulation model） with about half-a-century lead time to 2046-2064 and about one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change under three marker emission scenarios： A2, A1B and B 1. The results showed worsening water resources regime into the future.

Delayed Seasonal Transition of Tropical Wave Activity in the CMIP3 Global Climate Models

This study evaluates the seasonal cycle of the activity of convectively coupled equatorial waves(CCEWs),including mixed Rossby-gravity(MRG) and tropical depression-type(TD-type) waves,based on the twentieth century experiments of 18 global climate models(GCMs) from the Coupled Model Intercomparison Project phase 3(CMIP3).The ensemble result of the 18 GCMs shows that the observed seasonal cycle of MRG and TD-type wave activity cannot be well reproduced.The seasonal transition of wave activity from the southern hemisphere to the northern hemisphere is delayed from April in the observations to May in the simulations,indicating that the simulated active season of tropical waves in the northern hemisphere is delayed and shortened.This delayed seasonal transition of tropical wave activity is associated with a delayed seasonal transition of simulated mean precipitation.The mean precipitation in April and May shows a double-ITCZ problem,and the horizontal resolution is important to the delayed seasonal transition of wave activity.Because of the coincident seasonal cycle of MRG and TD-type wave activity and tropical cyclone(TC) geneses,the delayed seasonal transition of wave activity may imply a similar problem of TC genesis in the GCMs,namely,a delayed and shortened TC season in the northern hemisphere.

Changes of Atmospheric Water Balance over China under the IPCC SRES A1B Scenario Based on RegCM3 Simulations

Simulations of the Regional Climate Model Version 3 (RegCM3) under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A1B scenario were employed to investigate possible decadal changes and long-term trends of annual mean atmospheric water balance components over China in the 21st century with reference to the period of 1981-2000. An evaluation showed that RegCM3 can reasonably reproduce annual evapotranspiration, precipitation, and water vapor transport over China, with a better performance for March-June. It was found that the water vapor exchange between the land surface and atmosphere would be significantly intensified in Northwest China by the mid-to late-21st century and that the region would possibly shift to a wetter or drought-mitigated state under global warming. Conversely, the water vapor exchange evidently weakened over the Tibetan Plateau and South-west China by the mid-to late-21st century. In addition, there appears to be a drier state for Northeast China and the middle and lower reaches of the Yangtze River valley by the mid-to late-21st century, with slight mitigation by the end compared with the mid-21st century. The westerly and southwesterly water vapor transport over China generally presents an increasing trend, with increasing diver-gence over the Tibetan Plateau and Northeast China, corresponding to a loss of atmospheric water vapor by water vapor transport.

Climate Change Impacts on Water Resources of Greater Zab River, Iraq

Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems. Contemporary studies have revealed that blue and green waters of the basin have been manifesting increasing variability contributing to more severe droughts and floods apparently due to climate change. In order to gain greater appreciation of the impacts of climate change on water resources in the study area in near and distant future, SWAT （Soil and Water Assessment Tool） has been used. The model is first tested for its suitability in capturing the basin characteristics, and then, forecasts from six GCMs （general circulation models） with about half-a-century lead time to 2046-2064 and one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change on water resources under three emission scenarios： A 1 B, A2 and BI. The results showed worsening water resources regime into the future.

Coupling methods of global climate models and regional climate models

The future climate dynamical downscaling method is that output of general circulation models( GCMs) is employed to provide initial conditions,lateral boundary conditions,sea surface temperatures,and initial land surface conditions to regional climate models( RCMs). There are two methods of downscaling: offline coupling and online coupling. The two kinds of coupling methods are described in detail by coupling the Weather Research and Forecasting model( WRF) with the Institute of Atmospheric Physics of Chinese Academy of Sciences Atmospheric General Circulation Model Version 4. 0( IAP AGCM4. 0) in the study. And the extreme precipitation event over Beijing on July 212012 is simulated by using the two coupling methods. Results show that online coupling method is of great value in improving the model simulation. Furthermore,the data exchange frequency of online coupling has some effect on simulation result.

Hydrologic Resource Sheds and the U.S.Great Lakes Applications

"水资源域"为在某一时段向河口或某一地点,传送水、水中营养物、泥沙或其它物质的空间范围。这一新概念与"流域"概念既相似又不同:1)流域边界以地貌特征来确定,相对稳定。而水资源域的边界以水文事件中的水和物质传播范围来确定,随时空而变化;2)流域强调给定空间范围内水和物质的时间分布,而水资源域强调水和物质随时间和空间二者相互变化的动态分布;3)水资源域综合考虑了不同尺度的时空即时变化对水资源及物质传播的影响。这一新概念应用遥感、空间分析、追踪及模拟技术分析流域空间模式与过程,为水资源探索、分析、模拟及预测提供了一种全新的方法与途径。该文以美国伊利湖茅密河为例,应用分布式大流域模型计算了水资源域的分布。

Variations in soil moisture over the ‘Huang-Huai-Hai Plain＇ in China due to temperature change using the CNOP-P method and outputs from CMIP5

In this study, the variations in surface soil liquid water(SSLW) due to future climate change are explored in the‘Huang-Huai-Hai Plain'(‘3H') region in China with the Common Land Model(CoLM). To evaluate the possible maximum response of SSLW to climate change, the combination of the conditional nonlinear optimal perturbation related to the parameter(CNOP-P) approach and projections from 10 general circulation models(GCMs) of the Coupled Model Intercomparison Project5(CMIP5) are used. The CNOP-P-type temperature change scenario, a new type of temperature change scenario, is determined by using the CNOP-P method and constrained by the temperature change projections from the 10 GCMs under a high-emission scenario(the Representative Concentration Pathway 8.5 scenario). Numerical results have shown that the response of SSLW to the CNOP-P-type temperature scenario is stronger than those to the 11 temperature scenarios derived from the 10 GCMs and from their ensemble average in the entire ‘3H' region. In the northern region, SSLW under the CNOP-P-type scenario increases to0.1773 m^3 m^(-3); however, SSLW in the scenarios from the GCMs fluctuates from 0.1671 to 0.1748 m^3 m^(-3). In the southern region,SSLW decreases, and its variation(–0.0070 m^3 m^(-3)) due to the CNOP-P-type scenario is higher than each of the variations(–0.0051 to –0.0026 m^3 m^(-3)) due to the scenarios from the GCMs.