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In most cases, patients with Bowen disease lesions can be easily treated by surgical excision and direct closure; however, the ultrasonic surgical aspirator, an instrument in common use in many fields, offers a good treatment alternative with few drawbacks for patients with lesions that are large and/or located in joint areas, areas that are hard to heal, or areas that are surgically problematic such as the ears, nose, eyelids, and mucous membranes. The clinical application of the ultrasonic surgical aspirator in the treatment of Bowen disease promises considerable benefit in terms of patient comfort because removal of the lesion is easy, is noninvasive, and does not require hospitalization or result in restricted mobility. All of these factors, although benefiting patients, particularly the elderly, can also substantially lower the cost of treatment.  相似文献   

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Pitacco  A.  Gallinaro  N.  Giulivo  C. 《Plant Ecology》1992,99(1):163-168
Actual evapotranspiration from a closed-canopy Quercus ilex L. stand has been estimated by applying the Bowen Ratio-Energy Budget method. Daily water loss was 3.5 mm day–1, with a peak rate near 0.6 mm hour–1. The phenomenon of thermal inversion, quite common in mediterranean climates, seemed to play a significant role in reducing evapotranspiration, by promoting dew formation and delaying the establishment of fluxes of latent and sensible heat away from the canopy. Dew, which may form over many hours in the night, appears to be a major sink of available energy in the early morning and may represent a useful water source for stressed foliage. The alternating processes of condensation and evaporation may have a beneficial effect on the closed stand micro-environment.  相似文献   

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This paper documents the history of the introduction of the soybean (Glycine max), a domesticate of China, to North America. Henry Yonge, the Surveyor-General of Georgia, planted soybeans on his farm at the request of Samuel Bowen in 1765. Mr. Bowen, a former seaman employed by the East India Company, brought soybeans to Savannah, Georgia, from China via London. From 1766, Mr. Bowen planted soybeans on his plantation “Greenwich” located at Thunderbolt, Georgia. The soybeans were used to manufacture soy sauce and vermicelli (soybean noodles). In addition, he manufactured a sago powder substitute made from sweet potatoes. The 3 products were then exported to England. Samuel Bowen received a patent for his manufacturing inventions for producing these products. Another early introduction of soybeans to North America was by Benjamin Franklin. In 1770 he sent seeds from London to John Bartram in Philadelphia.  相似文献   

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波文比(β)是陆面过程中的重要参数, 影响着地表和大气间的能量交换, 明确β的空间变异规律和影响因素有助于对地表能量平衡和气候间反馈关系的预测。该研究收集了在中国不同生态系统类型开展的用涡度相关法(EC)测量地表能量平衡的公开发表文献, 构建了β和气象环境因子数据库, 分析了β在生态系统之间的差异、空间变异特征及影响因素。主要结果: (1)所有生态系统β平均值为0.95 ± 0.64, 变异系数67%, 偏度1.58, 峰度3.07, 整体服从对数正态分布, β平均值最高为灌木生态系统(1.26), 最低为湿地生态系统(0.49)。(2) β在生态系统类型间差异显著: 森林和湿地生态系统β无显著差异, 灌木生态系统β >草地生态系统 β >森林和湿地生态系统 β, 农田生态系统β介于草地生态系统与森林和湿地生态系统之间。(3) β随着纬度的增加而增加, 不随经度和海拔变化。纬度每增加1°,β增加0.038。(4) β随着年降水量(MAP)、年平均气温(MAT)、净辐射(Rn)、当年降水量(PPT)、当年平均气温(Ta)和叶面积指数(LAI)的增加而降低。(5)不同生态系统中β对生物和非生物因素的响应存在显著差异: 草地、森林和灌木生态系统的β对生物和非生物因素变化较为敏感, 而农田和湿地生态系统的β与所有生物和非生物因素均无显著相关关系。(6) MAPRnβ变化的直接影响因素, LAI通过影响Rn间接影响β。结果表明了植被类型与气候因素之间具有交互作用, 能量分配最主要的影响因素是降水, 叶面积对能量分配的调节作用并不显著。  相似文献   

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On the basis of measurements or stand transpiration and microclimate, the bulk stomatal or bulk leaf conductance (gL) of a beech forest in northern Germany was calculated for periods in which leaves were fully expanded and the canopy was dry. This conductance depends strongly on light and humidity conditions above the forest. During periods with photosynthetic photon flux densities Q > 1200 μmol m?2s?1, gL was reduced from 1500mmol m?2s?1 at a vapour pressure deficit D= 0.5kPa to 500 mmol m?2s?1 at D= 2kPa. Light saturation of gL was not reached until Q= 1200 μmol m?2s?1 at low D, or until even higher Q at higher D. The dependence of gL, on Q and D was described mathematically by a non-linear equation that requires two empirical parameters. Values for gL as simulated by this equation provided a satisfactory agreement with independent porometer data collected on single leaves and scaled up to the canopy. A comparison of stomatal and aerodynamic conductances showed a strong coupling between the forest canopy and the atmosphere, indicating that transpiration of the beech forest is controlled mainly by the stomata.  相似文献   

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