Water body and riparian buffer strip characteristics in a vineyard area to support aquatic pesticide exposure assessment

The implementation of a geodata-based probabilistic pesticide exposure assessment for surface waters in Germany offers the opportunity to base the exposure estimation on more differentiated assumptions including detailed landscape characteristics. Since these characteristics can only be estimated using field surveys, water body width and depth, hydrology, riparian buffer strip width, ground vegetation cover, existence of concentrated flow paths, and riparian vegetation were characterised at 104 water body segments in the vineyard region Palatinate (south-west Germany).Water body segments classified as permanent (n = 43) had median values of water body width and depth of 0.9 m and 0.06 m, respectively, and the determined median width:depth ratio was 15. Thus, the deterministic water body model (width = 1 m; depth = 0.3 m) assumed in regulatory exposure assessment seems unsuitable for small water bodies in the study area. Only 25% of investigated buffer strips had a dense vegetation cover (> 70%) and allow a laminar sheet flow as required to include them as an effective pesticide runoff reduction landscape characteristic. At 77 buffer strips, bordering field paths and erosion rills leading into the water body were present, concentrating pesticide runoff and consequently decreasing buffer strip efficiency. The vegetation type shrubbery (height > 1.5 m) was present at 57 (29%) investigated riparian buffer strips. According to their median optical vegetation density of 75%, shrubberies may provide a spray drift reduction of 72 ± 29%.Implementing detailed knowledge in an overall assessment revealed that exposure via drift might be 2.4 and via runoff up to 1.6 fold higher than assumed by the deterministic approach. Furthermore, considering vegetated buffer strips only by their width leads to an underestimation of exposure by a factor of as much as four. Our data highlight that the deterministic model assumptions neither represent worst-case nor median values and therefore cannot simply be adopted in a probabilistic approach.     

两种坡缕石基复合调湿材料的热湿性能测定与比较

鉴于调湿材料的热湿物性决定着其热湿传递行为,研制了2种新型坡缕石基复合调湿材料——坡缕石基亚麻纤维材料(FP)和坡缕石基木质纤维材料(WFP),全面测量了这2种复合调湿材料的水蒸气渗透系数、等温吸附曲线和湿扩散率等关系到其吸放湿能力和热湿传递特征的物性参数,探究了材料厚度和相对湿度上下限对复合调湿材料湿缓冲值的影响.结果表明：材料越厚,相对湿度区间越高,复合调湿材料的吸放湿能力就越强;厚度为2.5 cm的FP和WFP的湿缓冲值分别达到2.83、3.11 g/(m²·%).     

锻造操作机液压缓冲系统建模与仿真研究

根据锻造操作机高速、高精度和高可靠性的要求,进行了锻造操作机液压缓冲系统的设计,并在此基础上利用AMESim对液压系统进行了仿真研究,分析了不同溢流压力对缓冲系统的影响。同时利用MATLAB的Simulink模块对锻造操作机的缓冲系统进行了总体建模,分析了缓冲系统的动态响应情况。仿真结果表明:系统设计能满足操作机的工作要求,为锻造操作机液压系统设计提供了参考。     

多孔调湿材料湿缓冲特性的实验研究

利用NORDTEST实验方法对中国长江中下游地区(以南京为例)多孔调湿材料的湿缓冲值(Moisture Buffer Value)进行测定,同时,研究湿缓冲值对建筑能耗及室内湿度的影响。实验结果显示,高湿度区间内材料的湿缓冲测定值较大,且不同材料的湿缓冲值存在较大差异。分析表明在长江中下游地区,使用具有吸放湿特性的建筑内表面材料可有效降低建筑能耗10%以上,同时,室内环境湿度也会得到一定程度的调节。     

考虑项目网络特征的鲁棒性项目调度缓冲方法比较

对两种缓冲方法应用于具有不同网络特征的项目进行了比较分析。首先,生成具有不同网络特征的大量项目实例,分别用两种缓冲方法制定鲁棒性调度计划;然后,采用仿真实验方法模拟在不确定环境下执行所制定的调度计划;最后,通过分析实验结果比较两种缓冲方法所建计划的鲁棒性绩效指标,归纳出缓冲方法的适用性特征。研究表明,追求解鲁棒性的项目调度适用分散缓冲法,追求质量鲁棒性的项目调度要依据项目规模、网络复杂度及不确定性程度的具体情况选择缓冲方法。     

Performance analysis of two‐way MAC layer network coding under finite relay buffer and non‐negligible signalling overhead

Two‐way exclusive OR (XOR) relay can enable hidden nodes to exchange data with low delays and high data rate, while keeping signal processing simple. In this paper, we analyse practical two‐way XOR relaying systems, where finite relay buffer, non‐negligible signalling overhead, and lossy wireless channels are all captured. A two‐layer model is developed to characterise such practical two‐way relay systems, which is then reformulated into a Markov process after we project and combine inter‐layer state transitions of the two‐layer model. Using Markov techniques, we evaluate the steady state probabilities of the Markov process and, in turn, the key performance measures of two‐way XOR relaying, such as throughput, delay, and packet loss. The accuracy of our model is validated by simulations. Our model can also be used as an online tool to configure the buffer resources, adapting to wireless channel conditions and signalling requirements. Copyright © 2016 John Wiley & Sons, Ltd.     

酵母常规透射电镜样品制备方法的比较与改进

透射电镜技术中前期样品制备是获得最接近样品真实结构信息的关键。本文选择酵母为观察对象,运用常规样品制备技术,观察不同缓冲液、不同脱水时间和脱水温度对酵母超微结构的影响,优化了酵母常规透射电镜前期制样方案。     

缓冲气体及温度对DPAL输出性能的影响

为进一步提高半导体激光泵浦碱金属蒸汽激光器输出功率,基于三能级速率方程的理论模型,对DPAL的运行进行了模拟,考虑泵浦光带宽,在纵向泵浦的情况下,对缓冲气体气压、增益池长度、温度等参量对激光器输出光强及光光效率的影响进行了计算机模拟,结果表明,一定泵浦光下光光效率随着乙烷气压和温度增加而增大,对一定氦气气压有最大值,模拟结果为实验研究提供了有益的参考。     

缓冲装置不对称对自动机特性的影响

针对缓冲装置两侧不对称对自动机特性的影响,对其进行分析。运用键合空间理论建立自动机的键合空 间拓扑结构图,分析缓冲装置弹簧初力、弹簧刚度、后坐阻尼和复进阻尼的不对称对自动机的后坐动态特性和立靶 密集度的影响。计算分析结果表明：该分析得出了各因素对自动机最大后坐位移、最大后坐力和立靶密集度的影响 规律。     

基于MoO3和Re-Bphen修饰有机太阳能电池性能的研究

有机太阳能电池(OSCs)的性能与材料及器件结构密切相关。以MoO3为阳极缓冲层,有机金属配合物Re-Bphen为阴极缓冲层,制备了结构为ITO/MoO3/CuPc/C60/Re-Bphen/Al的OSCs。在标准太阳光照条件下,当MoO3和Re-Bphen的厚分别为5nm和8nm时实现了器件的最佳性能,能量转换效率(PCE)和器件寿命均显著提高。结合器件结构,分析了工作机制。