三个“镜头”透视思想改革助力长春经济振兴发展

???
Norwegian train plowing through drifted snow
Physical properties
Density (ρ)	0.1 – 0.8 g/cm3
Mechanical properties
Tensile strength (σt)	1.5 – 3.5 kPa
Compressive strength (σc)	3 – 7 MPa
Thermal properties
Melting temperature (Tm)	0 °C
Thermal conductivity (k) For densities 0.1 to 0.5 g/cm3	0.05 – 0.7 W K?1 m?1
Electrical properties
Dielectric constant (εr) For dry snow density 0.1 to 0.9 g/cm3	1 – 3.2
The physical properties of snow vary considerably from event to event, sample to sample, and over time.

百度 公共交通卡有效使用期不得低于3年。

??? ?? ?????? ??? ???????????? ??????? ??? ???????. ??? ???????? ???? ????????? ???? ??????? ?? ?????????? ???????? ???? ???????.

??? ???? ??????? ?????? ???? ???????????. ??? ???????? ??? ?????? ???????? ? ?? ?????? ?????? ??? ?????? ?????. ????????? ??????? ?? ??? ???? ?????? ? ????? ????? ??????? ? ??????? (????? ? ?????? ????????) ?????????.

?????????

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
  Snowflakes on handrail
• 
  Snowflake captured by a microscope
• 
  Snowflake captured by a scanning electron microscope