文章利用低温共烧陶瓷(Low temperature co-fired ceramic,LTCC)低插损,高集成,小温漂、易集成等优点,设计实现了一款小型化、高性能LTCC线性化器。根据电路原理,设计仿真了一个基于LTCC技术的C频段线性化器,该线性化器频率范围为3.7~4....文章利用低温共烧陶瓷(Low temperature co-fired ceramic,LTCC)低插损,高集成,小温漂、易集成等优点,设计实现了一款小型化、高性能LTCC线性化器。根据电路原理,设计仿真了一个基于LTCC技术的C频段线性化器,该线性化器频率范围为3.7~4.2 GHz,通过改变线性化器的二极管偏置电压可调整线性化器的增益扩张和相位扩张特性,从而匹配与之级联的功率放大器的增益和相位压缩,改善级联系统的非线性特性。仿真结果表明这种设计的线性化器具有体积小、重量轻、性能优、易于整机集成的特点。展开更多
According to the poor nutrient and soil salinization of Wuwei industrial park in Gansu in Northwest arid region,we collected a large number of samples in the region and measured the soil salinity and nutrient content ...According to the poor nutrient and soil salinization of Wuwei industrial park in Gansu in Northwest arid region,we collected a large number of samples in the region and measured the soil salinity and nutrient content in 020cm. By the statistical analysis and comparison the values of the water content, pH, salinity, organic matter andavailable nitrogen phosphorus and potassium (NPK) in Table 1, our results indicated that: (1) In the sample region,besides the low water content, the degree of soil salinization is predominant and the majority of soil belong to themoderate or severe saline-alkali land. (2) Due to the low nutrient content, the soil is relatively poor. There areobvious differences between the soil organic matter and the available NPK[1]. In short, the nitrogen contents ofthe soil in the region are seriously rare. The available phosphorus contents were at a moderate or deficient level,and the available potassium contents were at a sufficient level or an adequate level compared with the classificationstandard of the second general survey of soil (Table 2).展开更多
Sweet sorghum, the world's fifth most important cereal after rice, corn, wheat and barley, is a very attractivesource for biomass production. This raw material complements sugarcane production and is emerging as t...Sweet sorghum, the world's fifth most important cereal after rice, corn, wheat and barley, is a very attractivesource for biomass production. This raw material complements sugarcane production and is emerging as the idealfeed for animals and for the production of the first-generation of biofuels, such as ethanol and value-added chemicals.At present, most of the studies about sweet sorghum focus on utilization (such as ethanol production), and thestudy of suger accumulation in stem are rarely.展开更多
Leaf color mutants are ideal materials for studying physiological processes in plants.Here,a thermos-sensitive leaf-color mutant of Green wandering jew was isolated after carbon ions irradiation,which was designated a...Leaf color mutants are ideal materials for studying physiological processes in plants.Here,a thermos-sensitive leaf-color mutant of Green wandering jew was isolated after carbon ions irradiation,which was designated as mt.The color of young mutant leaves was more sensitive to variations of temperature,however,the young leaves of wild type remained green under low-temperature conditions(6℃-20℃).To elucidate the characteristics of pigmentation in mutant leaves under room temperature conditions(25℃)and low-temperature conditions(7℃),the ultra-structural,pigment composition,molecular mechanisms and anthocyanin accumulation involved in this phenomenon have been investigated in four independent experiments.展开更多
文摘文章利用低温共烧陶瓷(Low temperature co-fired ceramic,LTCC)低插损,高集成,小温漂、易集成等优点,设计实现了一款小型化、高性能LTCC线性化器。根据电路原理,设计仿真了一个基于LTCC技术的C频段线性化器,该线性化器频率范围为3.7~4.2 GHz,通过改变线性化器的二极管偏置电压可调整线性化器的增益扩张和相位扩张特性,从而匹配与之级联的功率放大器的增益和相位压缩,改善级联系统的非线性特性。仿真结果表明这种设计的线性化器具有体积小、重量轻、性能优、易于整机集成的特点。
文摘According to the poor nutrient and soil salinization of Wuwei industrial park in Gansu in Northwest arid region,we collected a large number of samples in the region and measured the soil salinity and nutrient content in 020cm. By the statistical analysis and comparison the values of the water content, pH, salinity, organic matter andavailable nitrogen phosphorus and potassium (NPK) in Table 1, our results indicated that: (1) In the sample region,besides the low water content, the degree of soil salinization is predominant and the majority of soil belong to themoderate or severe saline-alkali land. (2) Due to the low nutrient content, the soil is relatively poor. There areobvious differences between the soil organic matter and the available NPK[1]. In short, the nitrogen contents ofthe soil in the region are seriously rare. The available phosphorus contents were at a moderate or deficient level,and the available potassium contents were at a sufficient level or an adequate level compared with the classificationstandard of the second general survey of soil (Table 2).
文摘Sweet sorghum, the world's fifth most important cereal after rice, corn, wheat and barley, is a very attractivesource for biomass production. This raw material complements sugarcane production and is emerging as the idealfeed for animals and for the production of the first-generation of biofuels, such as ethanol and value-added chemicals.At present, most of the studies about sweet sorghum focus on utilization (such as ethanol production), and thestudy of suger accumulation in stem are rarely.
文摘Leaf color mutants are ideal materials for studying physiological processes in plants.Here,a thermos-sensitive leaf-color mutant of Green wandering jew was isolated after carbon ions irradiation,which was designated as mt.The color of young mutant leaves was more sensitive to variations of temperature,however,the young leaves of wild type remained green under low-temperature conditions(6℃-20℃).To elucidate the characteristics of pigmentation in mutant leaves under room temperature conditions(25℃)and low-temperature conditions(7℃),the ultra-structural,pigment composition,molecular mechanisms and anthocyanin accumulation involved in this phenomenon have been investigated in four independent experiments.
