Physiological responses of macroalga Gracilaria lemaneiformis (Rhodophyta) to UV-B radiation exposure     

朱琳  肖慧  王影  菅潇扬  张智鹏  张焕新  唐学玺 《中国海洋湖沼学报》2015,33(2):389-399

This paper aims to evaluate the effects of ultraviolet-Bradiation(UVBR) on Gracilaria lemaneiformis,a commercial red macroalga and an important source of agar. To study the in-vitro effect of UVBR on G. lemaneiformis,this plant was cultivated and exposed to photosynthetically active radiation(PAR) at 40 μmol photons/(m2 ·s) and enhanced UVBR(0,0.36,0.72,1.08,1.44,and 1.80 k J/(m 2 ·d)) for 13 days. The samples were processed for histochemical analysis,and the growth rate,photosynthetic pigment contents,photosynthetic performance,reactive oxygen species levels,membrane permeability,malonyl dialdehyde contents and antioxidant capacity of G. lemaneiformis were investigated. After 13 days of exposure to PAR+UVBR,G. lemaneiformis showed photodamage and photoinhibition of photosynthetic pigments(chlorophylla and phycoerythrin),leading to a decreased photosynthetic efficiency. Further,there was a corresponding decrease in the relative growth rates and depigmentation and partial necrosis of the apical segments were noted after exposure to PAR+UVBR. Additionally,UVBR induced excess production of superoxide radicals and hydrogen peroxide,eliciting a marked cellular membrane damage and antioxidative response.  相似文献   

Sensitivity of Chinese Industrial Wastewater Discharge Reduction to Direct Input Coefficients in an Input-output Context   总被引：1，自引：0，他引：1  

TANG Zhipeng  GONG Peiping  LIU Weidong  LI Jiangsu 《中国地理科学(英文版)》2015,(1):85-97

Industrial wastewater discharge in China is increasing with the country′s economic development and it is worthy of concern. The discharge is primarily relevant to the direct discharge coefficient of each sector of the economy, its direct input coefficient and the final demand in input-output models. In this study, we calculated the sensitivity of the reduction in the Chinese industrial wastewater discharge using the direct input coefficients based on the theory of error-transmission in an input-output framework. Using input-output models, we calculated the direct and total industrial wastewater discharge coefficients. Analysis of 2007 input-output data of 30 sectors of the Chinese economy and of 30 provincial regions of China indicates that by lowering their direct input coefficients, the manufacturers of textiles, paper and paper products, chemical products, smelting and metal pressing, telecommunication equipment, computers and other electronic equipment will significantly reduce their amounts of industrial wastewater discharge. By lowering intra-provincial direct input coefficients to industrial sectors themselves of Jiangsu, Shandong and Zhejiang, there will be a significant reduction in industrial wastewater discharge for the country as a whole. Investment in production technology and improvement in organizational efficiency in these sectors and in these provinces can help lessen the direct input coefficients, thereby effectively achieving a reduction in industrial wastewater discharge in China via industrial restructuring.  相似文献   

PCBs and its coupling with eco-environments in Southern Yellow Sea surface sediments     

Zhang P  Song J  Liu Z  Zheng G  Zhang N  He Z 《Marine pollution bulletin》2007,54(8):1105-1115

In this paper, the spatial distribution and source of the PCBs in surface sediments of the Southern Yellow Sea (SYS) and influencing factors, such as the sediment characteristics (components, relative proportions and total organic carbon contents), and hydrodynamic conditions were analyzed. PCB concentrations in the surface sediments ranged from 518-5848 pg/g, with average values of 1715 pg/g decreasing sharply compared to last year. In the study area, the PCB pollution level in the middle area was the highest, followed by that of the east coast and the west coast, respectively. Although the PCB level in the coastal areas was lower than that in the middle areas, it was proven in our study that the Yellow Sea obtained PCBs by virtue of river inputs. There was a positive and pertinent correlation between the clay proportion and PCB concentrations, and the increase of the PCB concentrations was directly proportional to the increase of TOC contents, with r=0.61, but it was contrary to the sediment grain size. Consequently, the factors controlling PCB distribution had direct or indirect relationships with sediment grain size; moreover, the hydrodynamic conditions determined the sediment components and grain size. In conclusion, hydrodynamic conditions of the Yellow Sea were the most important influencing factors effecting the distribution of PCBs in the surface sediments of the SYS.  相似文献   

台湾海峡及其两岸的地球动力学环境     

陈园田  王志鹏  叶建辉  李光明  何丹明  谢志招 《大地测量与地球动力学》1999,19(2):38-45

本文根据断层的力学性质、活动习性、褶皱、断陷盆地、平原、海湾的形成机理,火山活动、水系分布格局,震源机制解、地壳形变场、ＧＰＳ观测成果和ＥＤＭ（光电测距）资料等,对比研究了台湾海峡及其两岸现今的地球动力学环境。结果表明：台湾海峡处在北西方向引张的应力环境;台湾地区受到来自太平洋菲律宾海板块向北西方向的挤压和因台湾海峡下降而产生的向南东方向的挤压;福建沿海则受到印度板块向北向东的挤压和太平洋菲律宾海板块向北西方向的挤压以及台湾海峡下降而产生的向北西方向的挤压。  相似文献   

垂直形变监测中引入重力观测值的可行性研究     

薄志鹏  刘国辉 《武汉大学学报(信息科学版)》1996,(3)

全面分析重力测量的各种误差和目前能达到的精度后，对垂直形变监测中引入重力观测值的可行性进行了具体研究。结果表明，若仅是为了测定点的垂直位移的高程速率，增加重力测量数据后对形变分析的精度增益十分有限。但是对于大跨度垂直形变监测和局部地区突发性垂直形变测定，重力测量方法可以及时掌握垂直形变的趋势  相似文献   

"流空间"视角的电子商务快递物流网络结构研究 ——以珠三角城市群为例     

李苑君  吴旗韬  吴康敏  王洋  张虹鸥  邹志鹏 《地域研究与开发》2021,40(2):20-26

基于“流空间”视角研究电子商务快递物流网络,以中国智能物流骨干网络大数据作为物流“流”数据,综合社会网络分析法和GIS空间分析,以珠三角城市群为案例探究电商快递物流网络空间结构特征,并利用QAP回归方法探究影响网络形成的因素。结果表明:珠三角电商快递物流网络结构存在空间非均衡特征,联系方向偏中心指向,中东部县区间联系更为密切,形成“穗莞深”物流轴线。东莞市,广州市增城区、荔湾区、白云区,深圳市南山区、龙岗区等为主要的快递物流对外辐射节点;江门市新会区、台山市,惠州市惠城区、惠东县等为主要的快递物流接收节点。珠三角城市群电商快递物流网络形成主要受人均可支配收入和社会消费品零售总额影响,人口因素已不构成其发展优势;网络形成在一定程度上克服了距离因素的负作用力。  相似文献   

互花米草入侵下福建漳江口红树林湿地土壤生态化学变化   总被引：1，自引：0，他引：1  

张祥霖  石盛莉  潘根兴  李恋卿  张旭辉  李志鹏 《地球科学进展》2008,23(9):974-981

采集了福建云霄漳江口米草入侵下红树林自然湿地保护区内红树林群落、米草群落、红树林—米草交互群落以及光滩的剖面土壤样品,分析了土壤的总养分库、有效养分库及微生物活性等指标。结果表明,不同植被群落下土壤理化性质均存在明显差异。土壤有机质、全氮、全磷、阳离子交换量和微生物生物量碳、氮在同一深度的含量变化为：红树林>红树林—米草混作>米草>光滩;土壤蔗糖酶、脲酶、磷酸酶、过氧化氢酶和多酚氧化酶等酶活性指标也表现出相似的变化趋势。从深度变化而言,上述各项土壤质量指标均随剖面深度而降低。米草入侵后土壤的各项养分指标均有明显下降,湿地土壤生态化学性质发生了明显的退化。土壤有机碳、土壤微生物生物量碳、氮含量以及土壤蔗糖酶与磷酸酶活性对滨海湿地土壤退化的反映最为强烈, 可以作为指示性指标。  相似文献   

中国省域资源环境的投入产出效率评价     

唐志鹏 《地理研究》2018,37(8):1515-1527

合理开发利用资源环境是实现中国未来人地关系和谐演进的关键。基于集对分析和熵值法对2000-2015年中国省域资源环境的投入产出效率作了综合评价。结果表明：① 全国农用地投入的经济效率一直相对最好,农药和化肥投入的利用率次之;其次是水资源投入,最后是能源投入,环境产出的效率优劣顺序依次为废水排放,SO₂排放和烟尘排放;② 从2000-2015年中国省域资源环境效率的同异反态势来看,东部沿海省份多为弱同势和准同势,序号等级较高,而中西部省份多为强反势和弱反势,序号等级较低,呈现出由东往西逐渐降低的格局分布;③ 资源环境的投入产出综合效率高的省域主要集中在京津鲁、苏浙沪以及闽粤琼等东部沿海地区,而综合效率低的省域主要集中在晋宁青新甘贵内蒙古等中西部地区。  相似文献   

海洋激光雷达反演水体光学参数   总被引：2，自引：2，他引：0  

刘志鹏  刘东  徐沛拓  吴兰  周雨迪  韩冰  刘群  宋庆君  毛志华  张与鹏  崔晓宇  陈鹏 《遥感学报》2019,23(5):944-951

研制了一套船载海洋激光雷达,用于探测海水光学参数垂直廓线。2017年8月,该系统在黄海海域进行了实验测量。在准单次散射模型中引入原位测量的光学参数,实现了理想激光雷达回波信号的模拟,并将该理想信号与系统响应函数卷积后精确复现了实验的激光雷达信号。采用Fernald后向迭代积分法(简称Fernald法),比较了不同水体悬浮物激光雷达比下反演的激光雷达衰减系数α与原位漫射衰减系数Kd的差别。基于停航时标定的水体悬浮物激光雷达比,采用Fernald法获得了走航时的激光雷达衰减系数。进一步地,提出一种基于米散射激光雷达数据和原位测量的后向散射数据的融合算法,模拟了高光谱分辨率激光雷达(HSRL)反演α的过程,并将其与Fernald法进行了比较。实验结果表明,自研的海洋激光雷达能够有效探测海水光学参数,基于合适的水体悬浮物激光雷达比的Fernald法可以有效应用于米散射激光雷达的反演,未来无需假设的HSRL在海水光学参数探测领域具有更大的优势。  相似文献   

高分辨率光学遥感几何与纹理约束的线段优化算法   总被引：1，自引：1，他引：0  

戴激光  谢诗哲  苗志鹏  宋伟东  王杨  朱婷婷 《测绘学报》2019,48(5):563-571

针对高分辨率光学遥感影像线段断裂问题,提出一种基于几何与纹理约束的线段优化算法。首先,将线段视为地物轮廓表达的一种方式,由此从同一地物边缘角度出发,提出线段断裂的几何与纹理规律;其次,提出线段优化算法,以提取线段结果为处理基元,依据线段长度确定初始优化线段,设定跟踪矩形,建立针对断裂线段的几何纹理约束模型,构建动态优化模型,并给出完整的线段优化流程。最后,通过多幅不同实际场景、不同类型高分辨率遥感影像的试验结果分析,表明本文算法不仅能够解决由地物遮挡、边缘模糊及边缘锯齿化造成的线段断裂问题,并且在优化线段长度以及抑制线段过提取问题方面,均表现出较大的优势。  相似文献