地震力作用下影响巨子型有控结构的动力参数研究

附加柱刚度与附加阻尼为影响巨子型有控结构抗震性能的两个重要参数。本文基于随机振动理论探讨水平地震作用下附加柱刚度及附加阻尼对巨、子结构动态特性的影响,分析附加阻尼与附加柱间的制约关系,并对比研究传统巨型框架结构、巨子型有控结构安装流体阻尼器前后的响应功率谱变化。结果表明:巨子型有控结构具有极好的抗震性能,安装合理的附加阻尼后,其抗震能力得到进一步提高;附加柱刚度变化不但影响巨、子结构动力响应,而且会导致最优附加阻尼区间迁移。因此,巨子型有控结构具有广阔的发展空间,实际设计中应充分考虑附加柱与附加阻尼的相互影响。     

Primary molecular basis of androgenic gland endocrine sex regulation revealed by transcriptome analysis in Eriocheir sinensis

In crustaceans, the male sexual differentiation and maintenance are specially regulated by androgenic gland (AG). However, little is known about the genes involved in the regulation process. RNA-Seq was performed on AG with ejaculatory duct (AG_ED) and ejaculatory duct (ED) as control in Eriocheir sinensis, one of the most important economic and fishery crabs with typically sex dimorphism. A total of 925 unigenes were identified as differentially expressed genes (DEGs) and the expression of nine genes randomly selected was confirmed by qRT-PCR. 667 unigenes were up-regulated in AG_ED, being supposed to be AG preferential genes. Among them, the full length of insulin-like androgenic gland factor (IAG) cDNA named as Es-IAG was obtained as a logo gene of AG, which together with the genes insulin-like receptor (INR), and single insulin binding domain protein (SIBD), might constitute the sex regulation pathway. Several sex related genes were identified, and their function will have to be investigated. Also, the identification of juvenile hormone epoxide hydrolase 1 (JHEH1), ecdysteroid 22-hydroxylase (DIB) and ecdysone receptor (ECR) preliminarily clarified the molecular regulation mechanism of eyestalk-AG-testis axis, which plays important roles in molting and reproduction. The results will enhance our understanding for the molecular basis of the AG involved in male sex regulation in crabs.

     

Evaluation and improvement of wastewater treatment plant performance using BioWin

In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.     

多源遥感揭示的郯庐断裂带江苏段及邻区特征

借助可见光、微波、GPS和重力等数据从多源遥感视角对郯庐断裂带江苏段的地表出露形态、断裂带周边形变场和块体重力等特征进行研究,并辅以实地调查和探槽验证。结果表明：1）有争议的F5断裂南部应位于泗洪县后陈村,地表出露长度约为9 km,走向约为NNE12°;2）Sentinel-1A数据反演的断裂区地表形变场与普遍认为的第四纪以来郯庐断裂带右旋特性一致,且宿迁、新沂、泗县表现为沉降,邳州、睢宁、泗洪表现为隆升,断裂两侧水平和垂直向形变速率差分别约为4 mm/a和3 mm/a;3）GPS形变场分析表明,断裂两侧相对滑动约为1.4 mm/a,与微波结果的形变差异体现出近年断裂走滑运动呈加速状态;4）布格重力异常分析表明,断裂两侧重力分异明显,表现出西低东高的特征分异状态。该成果可为郯庐断裂带江苏段周边地壳块体形变、潜在孕震、发震等级和震灾防御等研究提供借鉴。     

Numerical simulation of the relationship between electrification and microphysics in the prelightning stage of thunderstorms

To further investigate the influence of cloud base temperature, updraft velocity and precipitation particle constitution on cloud electrification, five thunderstorms in various regions of China were simulated by using the three-dimensional compressible hailstorm numerical model including inductive and non-inductive charging mechanisms. The results indicate that changes of cloud base temperature have an influence on the initial electrification. Comparison of the above cases shows that in the case of warm cloud base and moderate updraft velocity (< 20 m s^{−  1}), active electrification occurred below the − 10 °C level before moving upward to the − 20 °C level. In contrast, when cloud base is cold and updraft velocity is intensive, the main charging region is at the − 20 °C or even higher level. In that case, the vertical extent of the main negative charge region becomes larger with the increase of cloud base temperature. Apart from the main dipolar or tripolar charge structure, some smaller charge regions with relatively high values of charge density may also appear. Frozen drops, originating mainly from supercooled raindrops, mainly get electrified through charging interactions with snow at or below the − 20 °C level. They are responsible for the negative charge region near the melting level at the initial stage of precipitation if there is a large supercooled raindrop content. Non-inductive charging during hail-snow collisions is rather weak, resulting in the charge density on hail of no more than − 0.01 nC m^− 3.     

Numerical Simulations of a Florida Sea Breeze and Its Interactions with Associated Convection: Effects of Geophysical Representation and Model Resolution

The Florida peninsula in the USA has a frequent occurrence of sea breeze(SB)thunderstorms.In this study,the numerical simulation of a Florida SB and its associated convective initiation(CI)is simulated using the mesoscale community Weather Research and Forecasting(WRF)model in one-way nested domains at different horizontal resolutions.Results are compared with observations to examine the accuracy of model-simulated SB convection and factors that influence SB CI within the simulation.It is found that the WRF model can realistically reproduce the observed SB CI.Differences are found in the timing,location,and intensity of the convective cells at different domains with various spatial resolutions.With increasing spatial resolution,the simulation improvements are manifested mainly in the timing of CI and the orientation of the convection after the sea breeze front(SBF)merger into the squall line over the peninsula.Diagnoses indicate that accurate representation of geophysical variables(e.g.,coastline and bay shape,small lakes measuring 10-30 km2),better resolved by the high resolution,play a significant role in improving the simulations.The geophysical variables,together with the high resolution,impact the location and timing of SB CI due to changes in low-level atmospheric convergence and surface sensible heating.More importantly,they enable Florida lakes(30 km2 and larger)to produce noticeable lake breezes(LBs)that collide with the SBFs to produce CI.Furthermore,they also help the model reproduce a stronger convective squall line caused by merging SBs,leading to more accurate locations of postfrontal convective systems.     

Numerical Simulation of the Life Cycle of a Persistent Wintertime Inversion over Salt Lake City

An episode of persistent wintertime inversion over Salt Lake City, Utah and its vicinity from 1200 UTC 30 November to 0000 UTC 7 December 2010 is simulated using an advanced research version of the Weather Research and Forecasting model. The numerical simulations agree well with observed soundings in temperature, wind speed, and wind direction in the atmospheric boundary layer and above, although there are some differences near the surface due to the influence of complex terrain in the area. The characteristics of large-scale environmental conditions and their interactions with local-scale processes are analyzed to understand the factors that influence the onset and evolution of persistent inversions. It is found that the inversion formed mainly because of the interaction between the heating effect from a high-pressure ridge in the mid-troposphere and a near-surface cold pool due to the effects of radiation. During the following six to seven days, the high-pressure ridge was maintained and vertical motion very weak, allowing a persistent inversion to become established. Finally, the cold effect from a low-pressure trough in the mid-troposphere, combined with mixing due to vertical motion, led to extreme weakening of the persistent inversion.     

应用GIS制作《陕西省气候资源及专题气候区划图集》

通过《陕西省气候资源及专题气候区划图集》的编制，针对小网络资料推算和专题气候区划空间叠置分析所遇到的问题，提出实现分区域小网格推算和根据区划模型评判打分的叠置分析的技术方法，该方法的应用为利用GIS制作陕西省气候资源数字图像和专题气候区划数字图像，奠定了基础。     

Effects of Updated RegCM4 Land Use Data on Near-Surface Temperature Simulation in China

Biogeophysical effects of land use and land cover (LULC) changes play a significant role in modulating climate on various spatial scales. In this study, a set of recent LULC products with a spatial resolution of 500 m was developed in China for update in RegCM4 (regional climate model version 4). Two sets of comparative numerical experiments were conducted to study the effects of LULC changes on near-surface temperature simulation. The results show that after LULC changes, areas of crops and mixed woodlands as well as urban areas increase over entire China, accompanied with greatly expanded mixed farming and forests/field mosaics in southern China, and reduced areas of 1) irrigated crops and short grasses in northern China and the Tibetan Plateau, and 2) semi-desert and desert in northwestern China. Improvements in the LULC data clearly result in more accurate simulations of the near-surface temperature. Specifically, increasing latent heat and longwave albedo due to enhanced LULC in certain areas lead to reduction in land surface temperature (LST), while changes in shortwave albedo and sensible heat also exert a great influence on the LST. Overall, these parameter adjustments reduce the biases in near-surface temperature simulation.     

Evaluation of the Forecast Accuracy of Near-Surface Temperature and Wind in Northwest China Based on the WRF Model

This study investigated the performance of the mesoscale Weather Research and Forecasting (WRF) model in predicting near-surface atmospheric temperature and wind for a complex underlying surface in Northwest China in June and December 2015. The spatial distribution of the monthly average bias errors in the forecasts of 2-m temperature and 10-m wind speed is analyzed first. It is found that the forecast errors for 2-m temperature and 10-m wind speed in June are strongly correlated with the terrain distribution. However, this type of correlation is not apparent in December, perhaps due to the inaccurate specification of the surface albedo and freezing–thawing process of frozen soil in winter in Northwest China in the WRF model. In addition, the WRF model is able to reproduce the diurnal variation in 2-m temperature and 10-m wind speed, although with weakened magnitude. Elevations and land-use types have strong influences on the forecast of near-surface variables with seasonal variations. The overall results imply that accurate specification of the complex underlying surface and seasonal changes in land cover is necessary for improving near-surface forecasts over Northwest China.