杂交构树在兰州地区的生长动态及刈割期

本研究以兰州地区种植的杂交构树(Broussonetia papyrifera)为材料,对两种水肥条件下杂交构树的生长量和营养成分动态变化规律进行了研究,并采用灰色关联度分析和权重赋值法对两次刈割时的株高、产量、粗蛋白(crude protein, CP)、粗灰分(Ash)、中性洗涤纤维(neutral detergent fiber, NDF)、酸性洗涤纤维(acid detergent fiber, ADF)含量进行综合评价,以确定两次刈割最佳刈割期。结果表明:高肥力区杂交构树在第3个生长月进入株高与产量的快速生长期,低肥力区杂交构树进入快速生长期的时间要比高肥力区滞后1个月。两个肥力区的CP含量均在第3个生长月即植株进入快速生长期时含量最高,而后显著下降(P <0.05)的月份不同,低肥力区较高肥力区提前1个月。NDF、ADF含量在两个肥力区基本表现了相同的升高趋势,在第5个生长月均达到了最高。灰色关联度分析和权重赋值法结果显示,两种水肥条件下,两次刈割时间安排为第2个生长月和第4个生长月时综合评价值均最高,建议杂交构树在兰州地区两次刈割的适宜刈割期为第2个生长月和第4个生长月

非晶碳薄膜载流子输运和压阻行为研究

非晶碳(a-C)薄膜sp~2/sp~3比值、sp~2团簇大小等会显著影响薄膜的电子输运行为以及压阻特性,相关作用规律尚不明确。本研究采用磁控溅射技术,通过改变沉积过程中基体上施加的负偏压,制备了一系列sp~2/sp~3比值稳定、sp~2团簇大小不同的无氢非晶碳薄膜,并系统研究了其电学性能并探索了压阻特性。结果表明:当负偏压从0增加到300 V时,薄膜sp~2含量保持在52±1.5%,同时a-C中sp~2团簇尺寸在1.63～1.93 nm范围变化。在-50 V时,薄膜中sp~2团簇尺寸最大,同时薄膜电阻率最低0.32Ω·cm,这是由于sp~2团簇之间的平均跳跃距离减小所致。此外,对于-50 V和-100 V偏压下沉积的a-C薄膜,在100-350 K温度范围内,表现出变程跳跃传导(variable range hopping, VRH)导电行为。压阻测试表明a-C薄膜的压阻系数(GF)在1.4-12.1范围内,GF随薄膜sp~2含量和sp~2团簇尺寸变化。另外,集成了基于a-C的MEMS力传感器在0-1.16N范围内灵敏度为80.7μV/V/N,非线性度约1.3%,且可重复5000次试验循环

Preparation of Elastomers from Whole Ground Tire Rubber

［中文文摘］用硫化改性剂和废轮胎胶粉制备了全胶粉弹性体.讨论了改性剂用量、炭黑用量、加工工艺及加工助剂对全胶粉弹性体物理机械性能的影响.实验发现硫化改性剂用量为2份;炭黑用量15份;加工油用量小于2份,可以得到较好性能的全胶粉弹性体,拉伸强度达7.9 MPa,断裂伸长率为315%,超过了再生胶的国标(拉伸强度6 MPa).同时对全胶粉弹性体的微观形貌及断裂行为也进行了讨论.［英文文摘］Ground Tire Rubber(GTR) was reclaimed by using the strong shearing force and the reclaiming agent in less than ten minute.It was found that adding 2 phr reclaiming agent,15 phr carbon black,2 phr naphthenic oil,the obtained elastomer had the best mechanical properties.The tensile strength was 7.9 MPa,elongation at break was 315%,the tear strength was 28 N/m.The microstruture of elastomers were also been detected by SEM

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies