【摘 要】
:
近2年河北省高碑店地区杨树春尺蠖传播十分迅速,呈现加重趋势,给林业生产造成很大损失。通过调查,理清了高碑店地区春尺蠖传播规律特点,在分析春尺蠖在高碑店地区杨树大面积
论文部分内容阅读
近2年河北省高碑店地区杨树春尺蠖传播十分迅速,呈现加重趋势,给林业生产造成很大损失。通过调查,理清了高碑店地区春尺蠖传播规律特点,在分析春尺蠖在高碑店地区杨树大面积发生原因的基础上,提出了综合治理对策和防治措施。
Nearly two years in Gaobeidian area of Hebei Province poplar spring 蠖 spread very rapidly, showing an increasing trend, resulting in great loss of forestry production. Through investigating and clarifying the characteristics of the propagation rule of spring ridges in Gaobeidian, based on the analysis of the causes of large-area poplar trees in Gaobeidian, the paper proposes the comprehensive control measures and prevention measures.
其他文献
在对加碘食用盐进行碘含量检测时,各检验员对如何取"均匀"样品的认识和操作手法存在一定的差距.这一差距将直接导致同一样品不同的操作手法造成检验结果有很大偏差,严重时直
Packet losses usually result in frame losses in low bit rate video streaming over error prone networks.The whole frame error concealment (EC) algorithm is then
采用化学气相沉积法(chemical vapor deposition,简称CVD)不仅可以制备金属粉未,也可以制备氧化物、碳化物、氮化物等化合物粉体材料.该法是以挥发性的金属卤化物、氢化物或
Analytical method for the distributions of axial-load and stress is based on elastic assumption, but the threaded connections are often in plastic deformation s
The IEEE 802. 16 standard specifies the air interface of wireless metropolitan area network(WMAN),and aims to provide wireless broadband access for integrated v
It is widely used for the rotational parallel mechanism in the field of spatial orientation. While owing to the existence of coupling, the forward kinematic sol
~(56)Co and ~(66)Ga with γ-ray energies covering the range of 0.84-3.55 and 0.68-4.81MeV, respectively, are important radionuclides for Ge detector calibration
在国家新增200亿元加快水利基础设施建设的背景下,文成县小型水利工程建设将进入新一轮高速增长期,探索水利工程建设监理运行机制成为文成县水利工程管理亟待解决的问题。本