枣庄市台儿庄区小龚庄岩溶地下水水源地允许开采量计算评价

科学有效的地下水资源评价是可持续开发地下水资源的关键,其中地下水资源可开采量的评价是地下水资源评价的核心内容。该文在对枣庄市台儿庄区小龚庄水源地水文地质条件、岩溶塌陷发育情况等进行详细分析的基础上,采用开采试验法对小龚庄水源地岩溶地下水允许开采量进行了计算,计算结果为11354m~3/d。根据已发生岩溶塌陷情况,设定岩溶塌陷预警水位,利用非稳定流Theis公式计算了安全开采量范围在11187～13150m~3/d之间,对开采试验法计算结果进一步进行评价。根据评价结果最终确定以11354m~3/d作为小龚庄水源地的允许开采量是可靠的,可以保证水源地最大限度的开采地下水资源,同时又保证水源地运行时不易引发岩溶塌陷的环境地质问题。该方法为同类型水源地地下水允许开采量的计算评价提供了一定的借鉴。     

Case Study of Fog Predictability for an Event with Cold-Front Synoptic Pattern

Fog has recently become a frequent high-impact weather phenomenon along the coastal regions of North China. Accurate fog forecasting remains challenging due to limited understanding of the predictability and mechanism of fog formation associated with synoptic-scale circulation. One frequent synoptic pattern of fog formation in this area is associated with cold front passage(cold-front synoptic pattern, CFSP). This paper explored the predictability of a typical CFSP fog event from the perspective of analyzing key characteristics of synoptic-scale circulation determining fog forecasting performance and the possible mechanism. The event was ensemble forecasted with the Weather Research and Forecasting model. Two groups of ensemble members with good and bad forecasting performance were selected and composited. Results showed that the predictability of this case was largely determined by the simulated strengths of the cold-front circulation(i.e., trough and ridge and the associated surface high). The bad-performing members tended to have a weaker ridge behind a stronger trough, and associated higher pressure over land and a weaker surface high over the sea, leading to an adverse impact on strength and direction of steering flows that inhibit warm moist advection and enhance cold dry advection transported to the focus region. Associated with this cold dry advection, adverse synoptic conditions of stratification and moisture for fog formation were produced, consequently causing failure of fog forecasting in the focus region. This study highlights the importance of accurate synoptic-scale information for improved CFSP fog forecasting, and enhances understanding of fog predictability from perspective of synoptic-scale circulation.     

Effects of Seawater Acidification on Early Development of Clam Cyclina sinensis

Anthropogenic emission of atmospheric carbon dioxide(CO_2) has led to a rapid increase in atmospheric CO_2 concentration. Increasing atmospheric CO_2 can reduce seawater pH and carbonate ions, which may adversely affect the survival of the larvae of calcareous animals. Cyclina sinensis is a commercially and ecologically important species in several Asian countries. Living in coast shallow waters, this species has experienced the coastal environmental changes frequently throughout its life cycle. In this study, we simulated possible future seawater pH values including 8.2, 7.8 and 7.4 and examined the effects of ocean acidification on the early development of C. sinensis. Clam embryos were incubated for 48 h(2 d) in control and high-CO_2 seawater to compare embryogenesis, larval growth and swimming behavior. Fertilization rate was quite sensitive to pH, and moderate acidification could induce a significant decrease in fertilization rate. However, only extreme acidification could bring significant negative effect to hatching rate, body size, and average path velocity of trochophora. Moreover, with seawater acidification, C. sinensis needs much more time to reach the same developmental stage, which increases the risk of larva survival. Together with recent studies demonstrating negative impacts of high CO_2 on fertilization and larva swimming behavior, the results imply a future decrease of C. sinensis populations in oceans if its acclimation to the predicted environmental alteration does not occur.     

Supplementation of Yeast Extract to Practical Diet Improves the Growth,Anti-Oxidative Capacity and Intestinal Morphology of Shrimp Litopenaeus vannamei

Two control diets based on the commercial formula were designed to contain high(27%, D1) and low(22%, D2) levels of fish meal, respectively. Into D2, 500, 1000 and 1500 mg kg~(-1) of yeast extract were added, respectively, yielding three experimental diets(YE1 through YE3). Shrimp(initial body weight 0.30 g ± 0.02 g) were fed with the experimental diets, five tanks each diet and 30 shrimp individuals each tank, for 8 weeks, and then challenged with Vibrio parahaemolyticus. The results showed that the specific growth rate(SGR) of shrimp in D2 was significantly lower than that of shrimp in D1(P 0.05). The SGR of shrimp in YE3 was similar to that of shrimp in D1. The feed intake of shrimp was similar between D1 and D2. The feed conversion ratio and protein efficiency ratio of shrimp were similar among all diets(P 0.05). YE significantly improved the activity of glutathione S-transferase. The concentration of glutathione(GSH) and the total serum anti-oxidative capacity(T-AOC) of D1 were significantly higher than those of shrimp feeding other diets(P 0.05). The content of serum malondialdehyde of shrimp feeding YE2 and YE3 was significantly lower than that of shrimp feeding D2(P 0.05). The thickness of intestine muscular layer of shrimp feeding YE1 and YE2 was similar to that of shrimp feeding D1. The shrimp feeding YE1 showed the highest villus height of intestine among all groups. The cumulative mortality after challenging was similar among all groups(70.00%–86.67%)(P 0.05). In conclusion, 1000–1500 mg kg~(-1) of YE was suggested to be supplemented into the practical diets to improve the growth, anti-oxidative capacity and intestinal morphology of shrimp L. vannamei.     

Characteristics of Sulfide Removal by Hydrogenovibrio thermophilus Strain TT in Mariculture System

To biologically inhibit the production of highly toxic sulfide in the aquaculture area, one bacterium, designated as Hydrogenovibrio thermophilus strain TT, was isolated from sediment in Jiaozhou Bay, China. The strain was found to be microaerobic mixtrophic, employing both carbon dioxide and organic carbons, e.g. citrate, lactate, glucose, and peptone as carbon sources. When it oxidized the sulfide and thiosulfate, oxygen was the optimal electron acceptor, followed by nitrite and nitrate, which benefited to removal of sulfide under low-oxygen mariculture environment. In addition, the strain TT exhibited remarkable tolerance of sulfide and thiosulfate in seawater, and it was able to oxidize 18.52 mmol L~(-1) S~(2-) in 12 h or 45 mmol L~(-1) S_2O_3~(2-) in 24 h at initial pH 7.0-9.0, 30-40℃. Therefore, this strain showed a quite promising application for biological remediation of sulfide-contaminated mariculture system.     

基于POI数据的西宁市零售业空间格局探究

零售业是城市商业结构中最有活力的组成部分,合理有序的零售空间结构对促进经济的发展、提高资源的配置、满足居民的生活需求至关重要。POI作为新的空间数据源,能够客观地、准确地对商业空间结构进行识别和探究。西宁市位于青藏高原东北部,是连接青藏高原与中国大陆的重要门户。西宁市集中大量的人口,且存在有潜力的消费市场。基于POI大数据,运用核密度、局域Getis-Ord G^*指数、Ripley’s K函数和区位熵的分析方法,以西宁市为研究案例探究零售网点的空间分布特征。零售业详细地分为以下8种类型,分别是食品、饮料及烟草制品,纺织、服装及日用品,文化、体育用品及器材,家用电器及电子产品,五金、家具室内装饰材料,医药及医疗器材,汽车、摩托车燃料及零配件,综合零售。结果表明:西宁市零售业集聚区空间分布特征显著,呈现"多集聚、多核心"商业空间形态。密度等级由中心区沿交通干线逐渐向外围递减;高密度集聚区分别分布在水井巷附近街区、商业巷附近街区、祁连路—北禅路交汇的附近街区(北山市场)和以万达广场为核心的海湖新区。行业属性不同使得零售点集聚和分布变化表现出较大的差异性,与人们日常生活密切相关的业态零售点呈现社区化、微型化和便利化的特征,且区位选择性较大,如:食品饮料及烟草制品、医药及医疗器材和综合零售行业,而家用电器及电子产品、文化体育用品和纺织服装等行业区位选择尺度小,集中在特定的区域;基于道路数据构建的街区单元冷热点区域分布特征显著,它受城市建设用地扩张,人口密度,交通可达性和城市规划等因素的影响,海湖新区将成为最有发展潜力的商业区;在街道尺度,各业态零售业专业化功能区块显著,发展成熟的街道表现出多优势行业集聚特征,西宁市多业态集聚区域较少,只有人民街街道。这项研究一方面有助于填补基于POI数据青藏高原河谷型城市商业空间结构研究的空白;另一方面,为政府战略制定,零售商选址和城市规划提供一些参考。     

中国近海棱梭群体形态学和耳石形态学研究

为研究棱梭不同地理群体间的形态差异,使用多元统计分析方法对采集自金门、厦门、虎门、湛江、北海和防城港6个地点邻近海域的棱梭群体样本的形态和矢耳石形态两方面进行比较研究。对棱梭样本的形态研究结合传统形态学和地标形态学开展,对矢耳石的形态研究则将传统耳石形态分析法和椭圆傅里叶分析法相结合,形态和耳石形态数据的分析结果相似。主成分分析结果表明从28个棱梭形态量度指标提取的前8个主成分累积贡献率为65. 868%,从85个耳石形态指标提取的前23个主成分的累积贡献率为79. 290%,根据临界值85. 000%可以推断这6个棱梭群体间形态和耳石形态上的差异不能够单独依靠少数指标来判断;聚类分析的结果总体显示出群体间差异与地理距离等因素相关联的分布规律;在判别分析中形态学量度指标的综合判别正确率为75. 9%,而耳石形态学指标的综合判别正确率略低,为69. 3%;对棱梭形态量度指标的单因子方差分析显示湛江棱梭群体与其他群体在形态上存在显著差异的量度指标较少。栖息地环境、饵料组成和海流等可能是导致形态学差异和耳石形态差异形成的主要因素。另一方面,理化因子的相似性和群体间的交流会减弱群体间形态和耳石形态的差异。     

高通量测序分析北仑河口红树林潮间带底栖真核生物分布

为了解红树林不同潮位沉积物中底栖真核生物群落分布,基于18S rRNA基因采用高通量测序方法分析了广西北仑河口陆缘、林中和海缘3个潮位红树林沉积物中底栖生物群落结构。结果表明,北仑河口潮间带红树林沉积物中底栖生物多样性丰富,Shannon-Wiener指数变化范围在6. 08～6. 73之间; PCA分析表明潮间带中底栖生物群落差异较大,陆缘红树林中扁形动物、节肢动物和软体动物相对丰度较高,林中区域中纤毛虫、环节动物和轮虫相对丰度较高,海缘红树林中硅藻相对丰度较高;红树林中主要OTUs有桡足类的太平洋纺锤水蚤(Acartia pacifica)、硅藻类的海链藻(Thalassiosira sp.)、纤毛虫类的前管虫(Prorodon teres)、多毛类的小头虫(Capitella sp.)。高通量测序方法能较全面反映红树林区微型/小型底栖生物群落,研究结果为丰富红树林底栖生物群落研究和解析底栖生物在红树林生态系统发挥的作用提供基础数据。     

Preparation and characterization of agar,agarose,and agaropectin from the red alga Ahnfeltia plicata

Agar,agarose,and agaropectin were extracted from the red alga Ahnfeltia plicata,and their properties and structures were characterized.Agar was extracted by a comparatively low alkaline consumption of 1.2%.It exhibited a gel strength of 1 152.50±74.25 g/cm^2 and a sulfate content of 0.55%±0.08%.The yield of agar from A.plicata was 24.53%,which is higher than those of other agarophytes commonly used in China.Three kinds of the method were compared for the purification of agarose,and the physicochemical properties of agarose that was prepared under the optimal condition were identical to those of commercially available agarose.Furthermore,agaropectin was purified from A.plicata and characterized by GC,HPLC,UV-spectrum,and FI-IR to understand its composition and structure.It was the first time to comprehensively study the agar and its fractions from the red alga of A.plicata.This research provided an eco-friendly agar extraction method from A.plicata and revealed its potential application for the production of agar,agarose,and agaropectin.