根据安全网络的要求,利用先进的网络安全技术与设备,针对大连市气象局局域网在网络结构、网络安全方面存在的问题及隐患,提出网络系统改造方案及加强网络安全的措施:网络改造方案中采用子网划分技术重新规划网络结构,实现子网划分;针对...根据安全网络的要求,利用先进的网络安全技术与设备,针对大连市气象局局域网在网络结构、网络安全方面存在的问题及隐患,提出网络系统改造方案及加强网络安全的措施:网络改造方案中采用子网划分技术重新规划网络结构,实现子网划分;针对可能存在的内、外部网络攻击,部署了多层次防线,对边界防毒和应用服务器防毒及客户端防毒均作了相应的部署。采用虚拟专用网络(virtual private network,VPN)技术、虚拟局域网(virtual local area network,VLAN)技术、网络版病毒防护软件、网关防毒产品、防火墙技术和物理隔离等多种专业网络安全产品,构建整体安全网络系统。实施后表明:网络安全得到保障,网络通信质量显著提高,达到了建设安全、畅通、高速局域网络的目的。展开更多
[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 195...[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 1951 to 2009,the annual,seasonal,and monthly variation of sunshine duration in recent 60 years were analyzed,as well as its relationship with meteorological factors,and sunshine duration was detected by means of climate mutation theory.[Result] Annual sunshine duration in Dalian in recent 60 years showed decrease trend on the whole,and its climatic variation rate was-3.31 h/a,with larger annual variation,namely the difference between maximum value(1978) and minimum value(2003) reached 681 h;there was obvious seasonal variation in sunshine duration,with the order of autumn>summer>winter>spring,and their climatic variation rate were-1.18,-1.15,-0.91 and-0.62 h/a;except for March,sunshine duration in each month went down,especially October,while there was slight increase in March;sunshine percentage had inverse correlation relationship with total cloudiness,relative humidity and heavy fog days;annual sunshine duration reduced abruptly around 1983.[Conclusion] Our study could provide scientific foundation for the development of agriculture and forestry in Dalian City.展开更多
阵风的预报误差检验对实际工作中的精细化预报订正具有一定的指导意义,同时对精细化预报中如何消除误差日变化的影响提供了借鉴。选取2017—2019年3~72 h逐日逐3 h欧洲中期天气预报中心(European Centre for Medium-Range Weather Forec...阵风的预报误差检验对实际工作中的精细化预报订正具有一定的指导意义,同时对精细化预报中如何消除误差日变化的影响提供了借鉴。选取2017—2019年3~72 h逐日逐3 h欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecast,ECMWF)细网格10 m阵风和10 m平均风预报资料,基于大连地区9个国家气象观测站实况逐3 h极大风资料进行预报误差检验分析。结果表明:按预报风级和实况风级分类的预报误差对比检验均表明ECMWF细网格预报整体偏大,平均误差为0.96 m·s-1,但具体到各风级时两种分类的预报误差统计结论并不一致,按预报风级分类的检验更符合基于模式预报开展的实际预报工作。以预报为基准统计,各风向、各风级、各站的预报误差均差异明显,风级越大预报偏大的程度越高,风向也表现出随风级增大误差增大的趋势。阵风预报的平均误差具有明显日变化,08:00(北京时,下同)前后误差最大,20:00前后误差最小,主要由10 m平均风的平均误差日变化所致。全部预报个例与实况各时效预报相关系数均在0.7以上,具体到各风级、风向时,各风向相关性均较好,而各风级的相关系数则明显降低,8级及以上风力预报的可信度大幅下降。展开更多
文摘根据安全网络的要求,利用先进的网络安全技术与设备,针对大连市气象局局域网在网络结构、网络安全方面存在的问题及隐患,提出网络系统改造方案及加强网络安全的措施:网络改造方案中采用子网划分技术重新规划网络结构,实现子网划分;针对可能存在的内、外部网络攻击,部署了多层次防线,对边界防毒和应用服务器防毒及客户端防毒均作了相应的部署。采用虚拟专用网络(virtual private network,VPN)技术、虚拟局域网(virtual local area network,VLAN)技术、网络版病毒防护软件、网关防毒产品、防火墙技术和物理隔离等多种专业网络安全产品,构建整体安全网络系统。实施后表明:网络安全得到保障,网络通信质量显著提高,达到了建设安全、畅通、高速局域网络的目的。
基金Supported by National Natural Science Foundation of China (40971294)Science and Technology Planning Project of Dalian Science and Technology Bureau(2009E11SF230)~~
文摘[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 1951 to 2009,the annual,seasonal,and monthly variation of sunshine duration in recent 60 years were analyzed,as well as its relationship with meteorological factors,and sunshine duration was detected by means of climate mutation theory.[Result] Annual sunshine duration in Dalian in recent 60 years showed decrease trend on the whole,and its climatic variation rate was-3.31 h/a,with larger annual variation,namely the difference between maximum value(1978) and minimum value(2003) reached 681 h;there was obvious seasonal variation in sunshine duration,with the order of autumn>summer>winter>spring,and their climatic variation rate were-1.18,-1.15,-0.91 and-0.62 h/a;except for March,sunshine duration in each month went down,especially October,while there was slight increase in March;sunshine percentage had inverse correlation relationship with total cloudiness,relative humidity and heavy fog days;annual sunshine duration reduced abruptly around 1983.[Conclusion] Our study could provide scientific foundation for the development of agriculture and forestry in Dalian City.