碳酸盐岩地区水质和化学动力学模型研究

本文描述了在碳酸盐岩分布的水文地质系统内,怎样利用水质相对,绝对含量,运用化学热力学、化学动力学和水动力学的理论及方法,进行半定量或定量的确定研究区某些水文地质信息,具有重要的理论和实际意义。 文章就系统水文地球化学类型分带模型和成因;系绕水化学分带溶蚀特征的定量评价;以及定量评价水文地质条件的化学动力学法等三个方面展开讨论。理论和计算在山东、河北、山西等省区某些水文地层系统中运用时,获得与实际水文地质特点相吻合的效果。     

Projected Regional 1.50°C and 2.00°C Warming Threshold-crossing Time Worldwide Using the CMIP6 Models

The Paris Agreement aims to limit global warming to well below 2.00°C and pursue efforts to limit the temperature increase to 1.50°C. However, the response of climate change to unbalanced global warming is affected by spatial and temporal sensitivities. To better understand the regional warming response to global warming at 1.50°C and 2.00°C, we detected the 1.50°C and 2.00°C warming threshold-crossing time(WTT) above pre-industrial levels globally using the Coupled Model Intercomparison Project...     

The effect of three culture methods on intensive culture system of pacific white shrimp (Litopenaeus vannamei)

Different culture methods may affect the intensive culture system of Pacific white shrimp(Litopenaeus vannamei) regarding water quality and growth and economic performance.This study evaluated the potential effects of three culture methods through cultivation of juvenile shrimps under consistent tank management conditions for 84 d.The three methods involved shrimp cultivation in different tanks,i.e.,outdoor tanks with cement bottom(mode-C),greenhouse tanks with cement bottom(mode-G) and outdoor tanks with mud-substrate(mode-M).Results showed that water temperature was significantly higher in mode-G than that in mode-C(P < 0.05).In contrast to the other two treatments,mode-M had stable pH after 50 d cultivation of shrimps.In the mid-late period,the average concentrations of TAN,NO2-N,DIP and COD were significantly lower in mode-M and mode-G compared with those in mode-C(P < 0.05).Despite lack of differences in the final shrimp weight among different treatments(P > 0.05),mode-M had significantly higher shrimp yield,survival rate and feed conversion rate(P < 0.05) than other modes.There were significant differences in revenue and net return among different treatments(P < 0.05).These demonstrated that the treatments of mode-G and mode-M were conductive to the intensive culture system of L.vannamei.     

Characteristics of plant calcium fractions for 25 species in Tengger Desert

Little attention has been paid to plant calcium fractions in the desert.To address the characteristic of the calcium fractions of desert plants,we collected 25 plant species in Tengger Desert,observed the calcium crystals using an optical microscope and determined water soluble calcium,acetic acid soluble calcium,and hydrochloric acid soluble calcium.To do so,we used sequential fractionation procedures to probe the relationships among different functional groups,different growth forms,or different successional stages.The results showed that the psammophyte,the late successional plants,and the drought-resistant shrub and semi-shrub all held considerable calcium oxalate crystal compared to the grassland plants,the early successional plants,and the perennial herb.With the proceeding succession,the acetic acid soluble calcium decreased gradually,and the hydrochloric acid soluble calcium increased gradually.The perennial herb had more water soluble calcium,while shrub held greater hydrochloric acid soluble calcium.The grassland plants held more water soluble calcium,while psammophyte had greater hydrochloric acid soluble calcium.This implies that the plants that are relatively sensitive to drought hold more calcium ion,while the drought-resistance plants hold more calcium oxalate.Thus,the plant calcium components are in close relation to plant drought-resistance,and of important significance in plant physiology of the desert.     

Discrepancies in Simulated Ocean Net Surface Heat Fluxes over the North Atlantic

The change in ocean net surface heat flux plays an important role in the climate system. It is closely related to the ocean heat content change and ocean heat transport, particularly over the North Atlantic, where the ocean loses heat to the atmosphere, affecting the AMOC(Atlantic Meridional Overturning Circulation) variability and hence the global climate.However, the difference between simulated surface heat fluxes is still large due to poorly represented dynamical processes involving multisca...     

青藏高原调控区域能量过程和全球气候的机理

本文总结了中国国家自然科学基金委重点项目“青藏高原调控区域能量过程及其影响机理”的研究进展。着重阐明了春夏季伊朗高原和青藏高原(TIP)地表热通量特征及变化原因、TIP上空独特的水汽、云宏观和微观垂直结构,以及降水和云辐射效应;在夏季两个高原地区的感热加热存在相互影响和反馈,形成观测到的加热与大气垂直环流之间的准平衡耦合系统,由此提出了TIP系统(TIPS)的概念;项目还从天文和水文的角度佐证了TIPS对亚洲夏季风的影响,揭示TIPS导致上对流层暖、下平流层冷的南亚高压的形成机理及TIPS影响北半球环流和印度洋海气相互作用的物理过程;揭示TIPS系统对南亚高压年际变化的影响,提出高原位涡强迫激发中国东部激烈天气过程的一种新机制。此外还揭示了CMIP5模式对高原表面温度模拟存在冷偏差的原因和其中的物理过程,这是大气环流与冰雪反照率的动力耦合的结果。     

Effects of soil nitrate：ammonium ratio on plant carbon：nitrogen ratio and growth rate of Artemisia sphaerocephala seedlings

Can soil nitrate： ammonium ratios influence plant carbon： nitrogen ratios of the early succession plant？ Can plant carbon： nitrogen ratios limit the plant growth in early succession？ To address these two questions, we performed a two-factor （soil nitrate： ammonium ratio and plant density） randomized block design and a uniform-precision rotatable central composite design pot experiments to examine the relationships between soil nitrate： ammonium ratios, the carbon： nitrogen ratios and growth rate of Artemisia sphaerocephala seedlings. Under adequate nutrient status, both soil nitrate： ammonium ratios and plant density influenced the carbon： nitrogen ratios and growth rate of A. sphaerocephala seedlings. Under the lower soil nitrate： ammonium ratios, with the increase of soil nitrate： ammonium ratios, the growth rates of plant height and shoot biomass of A. sphaerocephala seedlings decreased significantly; with the increase of plant carbon： nitrogen ratios, the growth rates of shoot biomass of A. sphaerocephala seedlings decreased significantly. Soil nitrate： ammonium ratios affected the carbon： nitrogen ratios of A. sphaerocephala seedlings by plant nitrogen but not by plant carbon. Thus, soil nitrate： ammonium ratios influenced the carbon： nitrogen ratios of A. sphaerocephala seedlings, and hence influenced its growth rates. Our results suggest that under adequate nutrient environment, soil nitrate： ammonium ratios can be a limiting factor for the growth of the early succession plant.