Evaluation of a long-range lagrangian dispersion model with ETEX

Performance of a Lagrangian dispersion model was examined in connection with its dependency on the boundary layer modelling and the input data resolution. The European Tracer Experiment (ETEX) data were used as reference. According to the sensitivity analysis of the model performance, the long-range dispersion model with the sparse input data was not noticeably different from that with the finer resolution data. The assumption of the prescribed constant mixing depth did not largely degrade the prediction results as compared with the simulation results with the temporally changing boundary layer. It is, therefore, concluded that the model is practical, considering the limited input data in the operational mode. However, it was also pointed out that the parameterization for the horizontal and vertical diffusion processes used in the present model enhanced the growth of plume. The improvement of input data resolution in time and space caused further dispersion of tracer deterministically. These resulted in the underestimation of the maximum concentration and the unfocussed concentration distribution map although the mean concentration was predicted fairly well.     

铜尾矿对5种豆科植物根系生长的影响

针对铜陵市铜尾矿废弃地的复垦，选用了5种乡土豆科植物在5种不同的尾矿改良方式上进行盆栽试验。5种供试物种为：大豆(Glycine max)、赤豆(Phaseolus angularis)、赤小豆(P.calcaratus)、绿豆(P.radiatus)、山绿豆(P.mininus)。盆栽基质是以尾矿与正常土壤按体积100：0、75：25、50：50、25：75、0：100比例混合而成，分别标记为：TAl00、TA75、TA50、TA25、TA0005种豆科植物生长时间为70d。结果发现：随铜尾矿在混合基质中比例的增加，5种豆科植物根系的主根长逐渐变短、根系一级侧根的数目逐渐减少；铜尾矿对5种豆科植物根瘤的形成产生抑制作用，特别是山绿豆和绿豆在全尾矿的基质上，无根瘤生成；地下根部的生物量表现为随着尾矿含量比例的增加。地下部分的生物量逐渐下降，但根冠比表现为随尾矿含量比例的增加而增加；植物对铜尾矿中铜的积累，主要含集中根部，地上部分与地下部分差异明显。     

奥陶纪以来生物贝壳生长纹层与地月轨道参数的演化

通过显微镜、扫描电镜以及微量化学成分分析，对现代瓣鳃类粗饰蚶、花蛤和腹足类纺锤螺，第三纪美壳螺，三叠纪克氏蛤，石炭一二叠纪燕海扇，泥盆纪云南贝、颠石燕，奥陶纪震旦角石、赫南特贝等贝壳生长纹层进行了综合研究。结果表明，奥陶纪以来贝壳生长纹层具有年、半年、双周、日、半日生长周期的变化，年中所含双周生长纹层数、双周所含日生长纹数均呈递减的趋势。通过观测计算得出：奥陶纪每年的日数为415．69d，泥盆纪为407．1d，石炭一二叠纪为400．51d，三叠纪为393．98d，第三纪为374．13d，第四纪为367．4d，表明白奥陶纪以来有地球自转速度变慢、地月距离增大、月球后退速率减小等变化趋势，     

构建限制性条件下微生物群体生长模型时的问题

Logistic生长模型在表征营养限制性生长条件下微生物群体生长时,遇到了种种困难．该模型未能明确给出微生物群体生长的“延迟期”和“代时”两个重要生长动力学参数,也忽视了方程中参数“r”应为平均生长速率,且不具有内禀生长率性质等诸多生物学特点．采用E．coli ATCC31343,37℃液体摇瓶培养下获得的实验数据,证实了Logistic模型存在的上述局限性．通过对E．coli以葡萄糖和山梨醇共作碳源时,表现出的“二峰生长”曲线与用Logistic方程拟合结果的比较,表明适合度分析（goodness—fit test）不能作为模型是否适合的唯一判据．并对构建微生物群体生长模型的策略进行了讨论．图5参31     

高温和干旱对银杏光合作用、叶片中黄酮苷和萜类内酯含量的影响

为了探讨高温和干旱的相互作用对银杏(Ginkgobiloba)生长及叶内次生代谢物的影响,设干旱、高温(夜间30℃)和干旱+高温3个处理,测定了2年生银杏幼苗的生长指标、光合特性、叶片水势、气孔导度以及叶内黄酮苷和萜类内酯的含量。与对照(未经干旱或高温处理)相比,高温引起银杏叶片最大净光合速率降低,气孔导度和光补偿点增加;干旱处理后,银杏最大净光合速率、气孔导度和叶片水势均降低,但光补偿点以及叶片黄酮苷和萜类内酯含量增加,表观量子产量变化不明显。高温和干旱共同作用下,银杏光补偿点和呼吸速率增高,光饱和点显著降低,根冠干重比无统计学上显著变化,但总干重降低。上述结果说明干旱和高温降低了银杏对光的适应范围,银杏光能利用效率变低,气孔导度下降,最大净光合速率降低,呼吸作用增强,抑制了生长;干旱引起黄酮苷和萜类内酯含量增加的幅度大于高温。     

Maternal effects on post-weaning physical and social development in juvenile mountain goats (Oreamnos americanus)

Little is known about maternal effects on post-weaning development, yet they may be important because maternal care could have long-term consequences only evident when offspring approach adulthood. We have assessed the effects of maternal age, current reproduction (presence of a kid of the year) and social rank on the body mass, horn length and social rank of 1- and 2-year-old mountain goats (Oreamnos americanus). Maternal reproductive status and social rank did not affect the mass or horn length of either yearlings or 2-year-olds. Maternal age was positively correlated with yearling body mass for males but not females. We could not detect any maternal age effects on body mass of 2-year-olds. Maternal age and spring forage quality were positively correlated with horn length of yearlings of both sexes, but not of 2-year-olds. Juvenile females showed compensatory growth in mass between 1 and 2 years of age, but males did not. Neither sex showed compensatory growth in horn length. None of the maternal characteristics we examined directly affected the social rank of juveniles, which increased with body mass. Social rank in female mountain goats seems to be established early in life and maintained to adulthood. By affecting yearling development, maternal age could affect the reproductive success of males.     

Scarcity, growth and R&D

The limits to economic growth due to resource scarcity can be alleviated only by the development of backstop substitutes. This paper combines resource-based economic growth with R&D to reduce the cost of backstop technologies. Characterizing the entire dynamics of optimal growth and R&D processes, we find that an economy's growth prospects depend on its type, as determined by its production technology and learning ability, and by its knowledge–capital endowment. A wide variety of growth patterns emerges, ranging from cases in which an economy that without R&D eventually stagnates (converges to a steady state) is diverted by R&D onto a path of sustained growth, to cases in which R&D is not warranted. Resource scarcity is shown to encourage R&D due to the increased reliance on the backstop technology.     

对种群增长模型的改进

提出有限空间种群增长的Logistic新模型即ds(dt)^-1=rs(1-ds^0／k)，其中参数d描述环境对种群增长的影响，参数θ为种内竞争特性参数．该模型通过种群的竞争特性因子θ控制，将指数增长、线性制约、下凹增长和上凸增长非线性制约概括为一个统一的自适应的非线性制约模型．以格氏栲、红锥种群基面积增长为例，运用遗传算法对不同种群增长模型进行最优拟合与比较分析，表明新模型能较好地描述格氏栲、红锥种群增长规律，为种群增长动态变化的一个理想的机理描述式．表4参14     

Variations and drivers of aerosol vertical characterization after clean air policy in China based on 7-years consecutive observations

Understanding the aerosol vertical characterization is of great importance to both climate and atmospheric environment. This study investigated the variations of aerosol profiles over eight regions of interest in China after clean air policy (2013-2019) and discussed the drivers of the vertical aerosol structure, using observations from active satellite measurements (CALIPSO). From the annual variation, the amplitude of extinction coefficient profiles showed a decreasing trend with fluctuations, and the maximum was 0.21 km⁻¹ in Beijing-Tianjin-Hebei (JJJ). For regions suffered from air pollution, the variation was greatest below 0.45 km, while it was between 1-1.5 km for Sichuan Basin. The correlation coefficient between the relative humidity (RH) and the extinction coefficient indicated that the increase of RH inhibited the decrease of the extinction coefficient in the Yangtze River Delta. In most regions, the main aerosol subtypes were polluted dust and polluted continental, but they were coarser in JJJ and North West. The frequency of concurrency of dust and polluted dust aerosols decreased in JJJ, but polluted continental aerosols occurred more frequently. Further, the aerosol extinction coefficient profiles under different pollution conditions showed that it changed most during heavy pollution periods in JJJ, especially in 2017, with a significant aerosol loading between ∼700 and 1200 m. The atmospheric reanalysis data revealed that the weak convergence at low level and the divergence at high level supported the upward transport of aerosols in 2017. Overall, the differences in divergence allocation, RH, and wind filed were the main meteorological drivers.     

Phytoaccumulation of iron by callus tissue of Clerodendrum indicum (L)

Clerodendrum indicum (L.) is one of the important medicinal plants, originating in India. The plant is used as medicine for bronchitis, asthma and different immunological disease. Micro-propagation is a quick method, producing a huge number of plants. Apical leaf of Clerodendrum indicum (L.) was used as an explant for callogenesis. The combinations of different plant growth regulators (2,4-D, NAA, KN) in MS (Murashige and Skoog) medium produced two types of calli: one was friable and loose and the other was green, embryogenic and compact. Heavy metals cause pollution and health hazards. The plant absorbs heavy metals, which is very useful for controlling environmental pollution. Iron is a major nutrient for both plants and animals, but hyper accumulation of iron is injurious to health. Calli were used to study the optimum conditions of iron uptake in presence of different chemical environments. The different environments were created by using different chemical reagents such as (HCL, HNO₃, H₃PO₄ and KNO₃). Iron (III) was spiked with radioactive Fe-59 and dynamics of uptake was followed by measuring radioactivity by gamma-ray spectrometer. The best condition of iron uptake corresponded to 1 mol L^?1 KNO₃ after 4 hour of equilibration.