The Highest and Lowest Temperature Changes in Dongling in Shenyang from 1951 to 2008

[Objective] The aim was to study the characteristics of climate changes of highest and lowest temperature in Dongling District in Shenyang Province in recent 58 years.[Method] By dint of the highest temperature and lowest temperature in the meteorological observation station in Dongling District in Shenyang from 1951 to 2008,and through statistical method such as climate tendency rate and sequence relevance,the interannual trend changes of annual and seasonal average highest and lowest temperature were expounded.[Result] In recent 58 years,the annual and seasonal average highest and lowest temperature in Dongling District in Shenyang were increasing and the changes rate of average lowest temperatures (0.262 ℃/10 a) were larger than the rate of average highest temperature (0.187 ℃/10 a).The abrupt changes period was one era earlier than average highest temperature.The annual average highest temperature increased from 1980s and it reached historical new record in late 1990s;while annual lowest temperature stared from 1970s and reached historical new high in 1980s.The average highest temperature and lowest temperature increased most distinctly in winter,followed by spring and was weakest in summer.The differences of annual and seasonal average temperatures were declining and the significance level was low.[Conclusion] The study provided theoretical basis for the development and utilization of climate resources in Shenyang.

Climate Characters of Summer Drought in Mountain City and the Effect on Flowers and Trees

[Objective] The aim was to provide references for development of industries engaging in flowers and trees in Beipei area in Chongqing. [Method] The occurring trend, intensity trend of summer drought, relationship of intensity with rainfall and extremely highest temperature, occurring trend during initial period of summer drought and the effects in mountain cities were analyzed, based on information on lasting period, rainfall, average temperature, extremely highest temperature of sum- mer drought in Beipei area in mountain cities during 1981-2010 and, growth condi- tion and phenological phenomena of Michelia champaca during 2005-2007. [Result] The occurring probability of summer drought in mountain cities was 57% and the probabilities of light, moderate, heavy and extreme drought were 30%, 10%, 7% and 10%; intensity of summer drought was none of linear relation with rainfall and ex- tremely highest temperature. In summer drought, daily average rainfall was less than 0.9 ram; extremely highest temperature was 35.0-45.0 ℃ with probability at 30%; initial period of summer drought was from later June to middle August and of extreme drought was later June-later July; the ending period was early September. During drought, when the extremely highest temperature （〉35.0 ℃） occurred in three days within a Hou, flowers and trees were affected by the hot drought and when the extreme temperature （〉40.0 ℃） occurred in three days within a Hou, the plants were seriously affected. [Conclusion] Based on characters of summer drought, pre- cautions can be taken to reduce effects of summer drought on flowers and trees with the help of weather forecast.

Design of a cylindrical LED substrate without radiator

To reduce the weight and production costs of light-emitting diode （LED） lamps, we applied the principle of the chimney effect to design a cylindrical LED substrate without a radiator. We built a 3D model by using Solidworks software and applied the flow simulation plug-in to conduct model simulation, thereby optimizing the heat source distribution and substrate thickness. The results indicate that the design achieved optimal cooling with a substrate with an upper extension length of 35 mm, a lower extension length of 8 mm, and a thickness of 1 mm. For a substrate of those dimensions, the highest LED chip temperature was 64.78 ~C, the weight of the sub- strate was 35.09 g, and Rib = 7.00 K/W. If the substrate is powered at 8, 10, and 12 W, its temperature meets LED safety requirements. In physical tests, the highest temperature for a physical 8 W cylindrical LED substrate was 66 ℃, which differed by only 1.22 ℃ from the simulation results, verifying the validity of the simulation. The designed cylindrical LED substrate can be used in high-power LED lamps that do not require radiators. This design is not only excellent for heat dissipation, but also for its low weight, low cost, and simplicity of manufacture.