Hosts文件的作用与应用          下载免费PDF全文

赵晓丽 《山西气象》2005,(3):15-17

本文通过对临汾市气象部门办公信息网中多个站、多次出现的问题的分析,找出原因所在,并针对性的做了分析并提出了解决的方法。介绍了HOSTS文件的功能,并根据HOSTS文件的功能,对我们工作中出现的问题给予解决和指导,在保障网络畅通、网络安全中都起到重要作用。  相似文献   

内外网中转程序介绍          下载免费PDF全文

李定平  付东升  贺建中 《山西气象》2005,(3):22-23

为了防止计算机病毒的干扰,保证基础气象业务的正常运行,阳泉市气象局的局域网分为内网和外网,内网上的计算机用于基础气象业务,外网上的计算机都可以上互连网。为了方便内外网的信息交换,在内外网之间安装一台计算机,运行内外网中转程序,使内外网的文件基本达到同步更新。这样既保证了内网上的计算机运行稳定,又满足了外网上的计算机对内网上气象信息的需求。  相似文献   

基于宽带网的河南省太阳紫外线强度监测系统研究   总被引：2，自引：1，他引：2  

冶林茂  厉玉昇  杨海鹰  陈海波 《气象科技》2005,(Z1)

使用自主研发的Gstar-Ⅱ型太阳紫外线监测仪,建立基于宽带网的河南省城市紫外线强度监测系统。太阳紫外线强度自动监测站将从紫外线传感器获得的气象要素信息传给本地专用计算机,进行数据处理和编码,然后通过互联网把数据信息送到数据业务中心站,数据业务中心站具有对接收数据进行初步处理和进库的功能;各级气象台站可以很方便地通过宽带Internet网WinSock协议进入数据处理中心,按照自己的要求调用全省紫外线强度历史和实时资料,为本地紫外线预报提供有力的科学依据和手段。  相似文献   

The Terrestrial NPP Simulation in China since 6ka BP          下载免费PDF全文

HE Yong  DONG Wenjie  JI Jinjun  DAN Li 《Acta Meteorologica Sinica》2005,19(4):492-500

1. IntroductionAccording to the reconstruction of paleo-temperature based on δ18 O data of ice core in theGreenland (see Jouzel et al., 1987; Grootes et al.,1993; Blunier and Brook, 2001), the current inter-glacial epoch, the Holocene, began at ca. 11.5 thou-sand years before present (ka BP). Multiple sources(pollen data, macrofossils) reveal that the summer cli-mate in the Northern Hemisphere was warmer in theearly to middle Holocene (MH) (ca. 8-6ka BP) relativeto the present climate. …  相似文献   

Snow loads on wire mesh and cable net rockfall slope protection systems     

Shanzhi Shu  Thomas C. Badger 《Engineering Geology》2005,81(1):15-31

Snow load on mesh systems is complicated by many factors. This paper presents field instrumentation data on snow load variation with temperature, snowfall and snow depth on a mesh system. It was found that snow load pattern on mesh systems changed with temperature even without variation in snow depth. It reached its maximum value when the temperature rose just above freezing to melt the interface. The field data was used to formulate appropriate snow load models for the various conditions of temperature in the field. The snow load models were used to study the performance of a number of mesh systems in North America and estimate the interface friction that was prevalent for the different surface conditions.  相似文献   

中国陆地净初级生产力的季节变化研究   总被引：22，自引：1，他引：22  

崔林丽  史军  唐娉  高志强 《地理科学进展》2005,24(3):8-16

了解不同季节陆地净初级生产力(NPP)的变化及与气候的相互关系以及在不同地类的差异对深刻理解我国陆地生态系统对全球气候变化的响应和陆地碳循环研究具有重要意义。本文使用1981～2000年间GLO-PEM模型模拟的我国陆地NPP数据和同期气温、降水以及土地利用数据, 研究不同季节我国陆地植被NPP的变化。结果表明,在1981～2000年期间,四个季节的NPP都呈显著增加趋势,春季是NPP增加速率最快的季节,夏季是NPP增加量最大的季节。耕地在春、夏和秋季NPP增长和增长率最高,林地冬季NPP增长最多而水域冬季NPP增长率最高。夏季NPP增长最高的区域分布于我国东部的多数地区、内蒙古东部、四川盆地、贵州东部、藏南和新疆西部;夏季NPP降低最多的区域分布于在呼伦贝尔高原、鄂尔多斯高原、黄土高原、青藏高原东部和新疆西北部。  相似文献   

2000-2015年三江平原主要作物需水量征及影响因素分析          下载免费PDF全文

任修琳  李宏亮  张玉虎  蒲晓  张立林 《干旱区地理》2019,42(4):854-866

全生育期内作物需水量的研究是农业水资源有效利用和进行合理灌溉的重要依据。基于三江平原22个气象站点2000—2015年逐日气象观测资料及中国区域地面气象要素数据集，利用国际粮农组织 （FAO）Penman-Monteith模型和分段单值平均作物系数法，分别对三江平原水稻、玉米和大豆的作物需水量进行计算，分析作物需水量年际变化特征，采用通径分析法研究作物需水量的变化成因。结果表明：（1）三江平原16 a来年均参考作物蒸散量为537.4 mm，日均为 3.5 mm，呈波动减少趋势。（2）生长季内，水稻在分蘖期需水量最大，为177.1 mm，玉米在七叶期需水量最大，为99.7 mm，大豆在结荚期需水量最大，为96.1 mm；水稻、玉米和大豆的净灌溉需水量分别为195.4 mm、130.8 mm和72.2 mm，对灌溉的依赖程度水稻>玉米>大豆。（3）由通径分析结果可知，三江平原作物需水量的主要影响因素为净辐射、气温和日照时数。  相似文献   

海洋生态系统净生产力研究进展     

张异凡  王奎  王振波 《海洋通报》2019,38(1):1-7

海洋生态系统净生产力 （net ecosystem production，NEP） 表示总初级生产力 （gross primary production，GPP） 和呼吸作用 （respiration，R） 过程之间的差异，它对碳收支平衡、海洋生态系统营养状态乃至气候变化等研究具有十分重要的指示意义。影响海洋 NEP 的因素有细菌、浮游生物、温度、太阳辐射、海冰融化、水团迁移、富营养有机质排放以及海水酸化等。目前计算 NEP 的方法可分为实验培养测定及数据模型计算两种。溶解氧培养法及同位素标记法等是经典的培养测定方法，但存在误差较大且重现性较差等问题。数据模型计算即借助养分质量平衡、响应面模型、O2/Ar 示踪等方法，通过将现场实测数据和生物地球化学模型结合，进行高时间分辨率的连续性观测，这也是目前测算 NEP 的主流应用手段。然而，相较于发达国家，我国在 NEP 的研究设备、技术、测定方法等方面仍存在一定差距。今后的研究重点将是建立 NEP 指标与表征海洋环境、气候变化之间的耦合关系以及 NEP 测定方法的改进，这将有助于深入理解和探索全球变化背景下海洋生态系统响应机制及变化趋势。  相似文献   

Are peatlands in different states with respect to their thermodynamic behaviour? A simple test of peatland energy and entropy budgets     

Fred Worrall  Ross Morrison  Chris Evans  Joerg Kaduk  Susan Page  Alex Cumming  Mark Rayment  Nicholas Kettridge 《水文研究》2021,35(12):e14431

Whilst all ecosystems must obey the second law of thermodynamics, these physical bounds and controls on ecosystem evolution and development are largely ignored across the ecohydrological literature. To unravel the importance of these underlying restraints on ecosystem form and function, and their power to inform our scientific understanding, we have calculated the entropy budget of a range of peat ecosystems. We hypothesize that less disturbed peatlands are ‘near equilibrium’ with respect to the second law of thermodynamics and thus respond to change by minimizing entropy production. This ‘near equilibrium’ state is best achieved by limiting evaporative losses. Alternatively, peatlands ‘far-from-equilibrium’ respond to a change in energy inputs by maximizing entropy production which is best achieved by increasing evapotranspiration. To test these alternatives this study examined the energy balance time series from seven peatlands across a disturbance gradient. We estimate the entropy budgets for each and determine how a change in net radiation (ΔR_n) was transferred to a change in latent heat flux (ΔλE). The study showed that: (i) The transfer of net radiation to latent heat differed significantly between peatlands. One group transferred up to 64% of the change in net radiation to a change in latent heat flux, while the second transferred as little as 27%. (ii) Sites that transferred the most energy to latent heat flux were those that produced the greatest entropy. The study shows that an ecosystem could be ‘near equilibrium’ rather than ‘far from equilibrium’.  相似文献   

Flexible membranes anchored to the ground for slope stabilisation: Numerical modelling of soil slopes using SPH     

《Computers and Geotechnics》2016

An alternative modelling for flexible membranes anchored to the ground for soil slope stabilisation is presented using Smoothed-Particle Hydrodynamics to model the unstable ground mass in a soil slope, employing a dynamic solve engine. A regression model of pressure normal to the ground, q_sim, and also membrane deflection, f_sim, have been developed using Design of Experiment. Finally, a comparison between the pressure obtained from numerical simulation and from a limit equilibrium analysis considering infinite slope has been carried out, showing differences in the results, mainly due to the membrane stiffness.  相似文献