广州发展知识经济的有利条件制约因素与政策建议   总被引：1，自引：0，他引：1  

阎小培 《地域研究与开发》1999,18(2):4-8

文章在发达国家由工业经济向知识经济转换的大背景下,分析了产业结构处于急剧变化中的广州发展知识经济的有利条件和不利因素,并就广州加快发展知识经济提出了政策建议,以促进广州经济迈上新台阶。  相似文献   

数字滤波初始化对台风“烟花”数值模拟的影响          下载免费PDF全文

温晓培  李昌义  肖明静  朱文刚  刘诗军 《海洋气象学报》2024,(2):110-122

基于中尺度数值模式WRF（Weather Research and Forecasting）,分析在逐小时循环同化系统中,高频多次应用数字滤波初始化方案对台风“烟花”模拟结果的影响。结果表明：（1）数字滤波能够产生与天气现象相关的滤波增量。晴空区域由于向后积分过程中辐射等重要过程未开启,后向积分结束时近地面温度变化较小,在向前积分时白天到达地表的太阳短波辐射过度累积,夜间地表热辐射过度释放,造成晴空区白天2 m温度升高,夜间2 m温度降低。台风对流区域受后向积分为绝热过程的影响,原本上升运动中水汽凝结释放潜热脱离气块的降水无法在绝热下沉增温中吸收热量变为水汽,在后向积分时产生了热量的异常累积以及水汽的减少,导致强对流区域热力结构发生变化。（2）统计结果显示,随着数字滤波应用次数的增加,初始化过程对初始场和预报的影响逐渐积累,造成的预报差异持续整个模拟过程。（3）在循环同化的基础上多次应用数字滤波初始化,数字滤波初始化显示出较好的抑制高频噪声的作用。多次滤波后台风环流中心暖心增强引起台风强度增强,最低气压更加接近最佳路径资料;暖湿气流向鲁南地区输送的减弱造成鲁西南地区特大暴雨漏报;台风环流位置的偏南影响了后期与西风槽结合的时间导致后期移速偏慢。  相似文献   

Seasonal variation of the barrier layer in the PN section     

张媛  吴德星  林霄沛  山峰 《中国海洋湖沼学报》2009,27(2):192-201

In this paper, we use the conductivity-temperature-depth (CTD) observation data and a three-dimensional ocean model in a seasonally-varying forcing field to study the barrier layer (BL) in the PN section in the East China Sea (ECS). The BL can be found along the PN section with obviously seasonal variability. In winter, spring and autumn, the BL occurs around the slope where the cold shelf water meets with the warm Kuroshio water. In summer, the BL can also be found in the shelf area near salinity front of the Changjiang (Yangtze) River Dilution Water (YRDW). Seasonal variations of BL in the PN section are caused by local hydrological characteristics and seasonal variations of atmospheric forcing. Strong vertical convection caused by sea surface cooling thickens the BL in winter and spring in the slope area. Due to the large discharge of Changjiang River in summer, the BL occurs extensively in the shelf region where the fresh YRDW and the salty bottom water meet and form a strong halocline above the seasonal thermocline. The formation mechanism of BL in the PN section can be explained by the vertical shear of different water masses, which is called the advection mechanism. The interannual variation of BL in summer is greatly affected by the YRDW. In the larger YRDW year (such as 1998), a shallow but much thicker BL existed on the shelf area. Supported by National Basic Research Program of China (973 Program, No. 2005CB422303 and 2007CB411804), the Key Project of the International Science and Technology Cooperation Program of China (No. 2006DFB21250), the “111 Project” of the Ministry of Education (No. B07036), the Program for New Century Excellent Talents in University, China (No. NECT-07-0781)  相似文献   

台风“苏力”(2013)期间海洋上层温、盐及海平面异常变化特征     

牟平宇  林霄沛 《海洋湖沼通报》2018,(3):1-11

台风"苏力"是2013年最强的台风之一。本文利用再分析资料、卫星遥感资料及ARGO浮标数据等分析了台风过境所引起的海表面温度(SST)、海表面高度异常(SLA)以及海洋次表层温、盐的变化规律,给出了上层海洋对台风响应的基本特征。台风所经过的海域都存在着明显的降温,在冷涡区域引起了6~7℃的海表温度的冷却,降温区域集中在路径的右侧。台风造成SLA降低,最大为20cm左右。海表温度的变化滞后于海面高度的变化。ARGO浮标数据显示,台风引起了海面的显著降温,最大降温幅度为5℃,位于冷涡内,且位于路径的右侧。路径左侧的SST的降低相对较小,为1.5~2.5℃。台风的扰动导致次表层水涌升到表层,改变了表层的盐度和密度,引起混合层加深。  相似文献   

山东五莲七宝山多金属矿床勘查发现及启示          下载免费PDF全文

彭永和  王申  李小陪  李双飞 《山东国土资源》2018,34(10)

五莲七宝山多金属矿是目前山东省内最大的多金属矿床。矿床的发现,得益于转变传统找矿思路,从寻找隐爆角砾岩型金铜矿,转变为寻找受断裂控制的铅锌银铜多金属矿。通过分析矿床的发现和勘查历史得到重要启示有:要勇于突破传统的找矿思维,要充分利用物化探资料,要有效发挥"资金+技术"的作用,要勤于实践与思考,要因地制宜地对矿床进行综合评价。  相似文献   

巨型城市区域土地利用变化的人文因素分析--以珠江三角洲地区为例   总被引：65，自引：0，他引：65  

闫小培  毛蒋兴  普军 《地理学报》2006,61(6):613-623

在评述国内外相关研究的基础上,利用遥感土地利用数据和统计资料,应用定量分析和GIS空间分析技术从定性与定量的角度系统全面地开展了珠江三角洲巨型城市区域土地利用变化的人文因素研究。定性分析结果表明：珠江三角洲土地利用变化与人口、经济发展、城市化与工业化及政策因素密切相关,这些因素深刻影响着该区域的土地利用变化。定量分析是对定性分析的验证,定量分析结果表明：影响珠江三角洲巨型城市区域土地利用变化的因子可归纳为人口、经济发展水平、城市化与工业化、农业产业结构调整、区域产业结构调整和外资等6个因子,并且各因子的影响作用大小不同。  相似文献   

基于居民通勤行为分析的城市空间解读--以广州市典型街区为案例   总被引：24，自引：7，他引：17  

周素红  闫小培 《地理学报》2006,61(2):179-189

行为研究是近年来人文地理研究中颇受关注的领域之一,对微观行为进行宏观归纳,进而解释人地关系是提升其理论价值的重要方向之一。GIS的应用在很大程度上解决了研究手段上的瓶颈问题。本文将GIS与传统的研究方法相结合,构建基于智能图的微观行为调查方法体系,并利用GIS实现微观行为及空间感知的宏观空间模拟,探讨基于城市居民通勤行为分析的空间解读方法。同时,将该方法运用于广州市,选择具有典型意义的街区进行研究。通过调查,获取典型街区实体空间信息、被调查者社会属性、通勤行为空间和对通勤沿路相关实体要素的感知等信息,进行分析与模拟。一方面,分析认为,居民通勤行为空间在很大程度上反映实体空间的现状及其演化,同时,与社会空间有一定的关系;另一方面,以调查获取的数据为实验基础,利用GIS进行基于个体对实体空间感知的宏观效果模拟实验,该方法能较好地解读实体空间的特征和存在的主要问题,并具有一定的可拓展性。  相似文献   

Contributions of the Bering Strait throughflow to oceanic meridional heat transport under modern and Last Glacial Maximum climate conditions     

ZHANG Cunjie  LIN Xiaopei 《海洋湖沼学报（英文）》2019,(2):398-409

Paleo reconstructions and model simulations have suggested the Bering Strait plays a pivotal role in climate change. However, the contribution of the Bering Strait throughflow to oceanic meridional heat transport (OMHT) is about 100 times smaller than the OMHT at low latitudes in the modern climate and it is generally ignored. Based on model simulations under modern and Last Glacial Maximum (LGM,~21 ka;ka=thousand years ago) climate conditions, this study highlights the importance of the Bering Strait throughflow to OMHT. The interbasin OMHT induced by the Bering Strait throughflow is estimated by interbasin-intrabasin decomposition. Similar to barotropic-baroclinic-horizontal decomposition, we assume the nonzero net mass transport induced by interbasin throughflows is uniform across the entire section, and the interbasin term is separated to force zero net mass transport for the intrabasin term. Based on interbasinintrabasin decomposition, the contribution of the Bering Strait throughflow is determined as ~0.02 PW (1 PW=10 15 W) under the modern climate, and zero under the LGM climate because the closed Bering Strait blocked interbasin throughflows. The contribution of the Bering Strait throughflow to OMHT is rather small, consistent with previous studies. However, comparisons of OMHT under modern and LGM climate conditions indicate the mean absolute changes are typically 0.05 and 0.20 PWin the North Atlantic and North Pacific, respectively. Thus, the contribution of the Bering Strait throughflow should not be ignored when comparing OMHT under diff erent climate conditions.  相似文献   

西北太平洋黑潮延伸体观测回顾和展望     

陈朝晖  林霄沛  马昕  管延锋  周春  张岳奇  马克 《地学前缘》2022,29(5):13-22

西北太平洋黑潮延伸体是全球海洋动力过程最复杂、对全球气候变化最敏感和全球海洋渔业产量最大的区域之一,然而,目前对该海区物理、生态及生地化循环等过程的认识仍受限于长期连续海洋观测资料的缺乏。本文回顾了国际上针对黑潮延伸体海区的相关观测情况和取得的主要进展,介绍了近年来我国在该区域观测系统的构建工作及取得的初步成果,包括构建了全球首个西北太平洋黑潮延伸体定点观测系统;发现黑潮延伸体海区海洋涡旋的平流效应对该海区模态水的总潜沉率贡献超过一半,所携带当地的模态水只需要一年半的时间就可到达海盆的西边界;基于潜标首次展示了黑潮延伸体区域3种不同类型次温跃层涡旋流速的直接观测结果,为开展其生成消亡机制及其全球次表层物质能量输运提供了重要的现场观测基础。最后,本文展望了今后观测系统的发展方向,即在跨圈层和多学科交叉方面发展成为我国在西北太平洋重要的深远海综合观测网络。这将为揭示多尺度物理-生物过程耦合、深海能量串级及其气候效应与深海碳循环等领域实现突破提供重要的观测支撑。  相似文献   

The investigation of internal solitary waves over a continental shelf-slope   总被引：1，自引：0，他引：1  

Qian Ma  Chunxin Yuan  Xiaopei Lin  Xue&#;en Chen 《中国海洋湖沼学报》2020,38(3):695-706

Internal solitary waves (ISWs) always happen in marginal seas, where stable stratification exists. ISWs may carry large energy when they propagate and affect marine engineering constructions such as marine drilling platforms. Previous studies, including a large number of mooring observations and laboratory experiments, show the speed of ISWs will change when they pass by shelf slopes. Korteweg-de Vries (KdV) theory explain this phenomenon. In the paper, we use a laboratory experiment and a numerical model experiment to verify this theory. In the laboratory experiment, we injected two layers of water of different densities in a tank to simulate marine stratification and make ISWs. We use a CCD camera to record the whole process. The camera can take 16 photos per second. In the numerical experiment, we input the same original conditions as the laboratory one. The results of 18 different original conditions show the dimensionless factor d plays a key role in deciding the amplitudes and shapes of ISWs. The main conclusion also contains that small-amplitude waves match well with KdV theory while mKdV is better for largeamplitude waves. Whether the laboratory experiment or numerical experiment shows results with a high agreement. In future studies, we may use a numerical model with higher resolution to get analysis about phase speed and energy of ISWs.  相似文献