摘要：准确的滑坡易发性评价结果是山区滑坡灾害防治的关键,可有效规避潜在滑坡带来的风险。为获得准确、可靠的滑坡预防参考,笔者以云南芒市为研究对象,选取高程、地层岩性、年均降雨量等9项评价因子,通过多重共线性分析,构建研究区滑坡易发性评价指标体系。分别基于支持向量机(SVM)、BP神经网络和随机森林(rf)3种典型机器学习算法进行滑坡易发性评价。利用准确性(ACC)、ROC曲线下面积(AUC)、滑坡比(Sei)及野外实地考察对模型评价结果精度进行对比验证分析。结果显示rf模型的ACC、AUC和极高易发区的SeV值最高,分别为0.867、0.94、9.21;BP神经网络模型次之,其SeV值分别为0.829、0.90、9.14;SVM最低,其SeV值分别为0.794、0.88、6.85。此外,rf算法所得结果还与实地考察情况保持了较高的一致性。实验结果表明与其他两种算法相比,rf算法在芒市区域具有更高的准确性和可靠性,更适合用于该区域的滑坡易发性建模,且利用该模型获得的评价结果,能够为芒市区域的滑坡防治提供理论依据和科学参考。

摘要：选取1960−2017年汉江流域及附近24个气象站的逐日气象数据,构建16种基于粒子群算法优化随机森林(PSO-rf)的日尺度ET0计算模型,并与Hargreaves-Samani、Makkink和Irmark-Allen共3种模型进行比较,评价PSO-rf模型在汉江流域的适用性及可移植性。结果表明:(1)PSO-rf模型能很好地识别各输入参数与日尺度ET0的非线性关系;仅采用最高气温(Tmax)、最低气温(Tmin)和地球外辐射(Ra)建立的PSO-rf2模型具有足够精度,平均MAE为0.402mm·d^(−1),RMSE为0.575mm·d^(−1),R^(2)为0.863;随输入气象要素数量增加,模型计算精度不断升高,平均MAE减小了37.9%,RMSE减小了36.3%,R^(2)升高了6.78%。(2)PSO-rf模型的计算精度优于相同输入参数的Hargreaves-Samani、Makkink和Irmark-Allen模型,平均MAE减小了43.6%、RMSE减小了34.5%,R2升高了4.12%。(3)PSO-rf模型在汉江流域具有较强的泛化能力和可移植性,分区建立的PSO-rf模型相互移植时,平均MAE为0.159mm·d^(−1),RMSE为0.245mm·d^(−1),R^(2)为0.974。因此缺乏气象数据时,基于PSO-rf建立的日尺度ET0计算模型可作为汉江流域日尺度ET0计算的推荐模型。

摘要：An rf system for the CSRe （cooling storage experimental ring） is designed and manufactured domestically. The present paper mainly describes the rf system design in five main sections： ferrite ring, rf cavity, rf generator, low level system and cavity cooling. The cavity is based on a type of coaxial resonator which is shorted at the end with one gap and loaded with domestic ferrite rings. The rf generator is designed in the push-pull mode and the low level control system is based on a DSP＋FGPA＋DDS＋USB interface and has three feedback loops. Finally we give the results of the measurement on our system.

摘要：The Xi'an Proton Application Facility(XiPAF)is a facility dedicated to the experimental simulation of the space radiation *** facility uses a compact synchrotron as its final-stage *** synchrotron can accelerate a proton beam from 7 to 230 *** design results show that the radio frequency(rf) acceleration system should work in the frequency range of 1—6 MHz and provide a maximum voltage of >800 *** dilute the strong space charge effect during the injection period,we also aim to achieve multiharmonic acceleration.A compact rf acceleration system loaded with magnetic alloy cores has been designed and developed to fulfill these *** preliminary test results show that the system can work normally with a gap voltage of 800 *** a further rf power upgrade,the voltage can be improved to >1:2 kV.

摘要：A spoke cavity is a TEM-class superconducting resonator with particular advantages： compact structure and high shunt impedance. The 325 MHz β=0.40 （β=v/c, v is the velocity of particle and c is the velocity of light） single spoke cavity （Spoke040） is adopted for the Chinese ADS （Accelerator Driven Sub-critical System） project. The physics and mechanical design has been accomplished, and the fabrication of a prototype is currently in progress. In this paper, the optimization processes for the main radio frequency （rf） and mechanical parameters are analyzed in detail. Two kinds of cavity end-walls （flat and convex） are compared. The convex end-wall is preferred in order to improve mechanical performance of the cavity. Two and should be finished in early 2014. Vertical testing prototypes of the Spoke040 cavity are in the machining stage is also under preparation.

摘要：A multi-finger structure power SiGe HBT device （with an emitter area of about 166μm^2） is fabricated with very simple 2μm double-mesa technology. The DC current gain β is 144.25. The B-C junction breakdown voltage reaches 9V with a collector doping concentration of 1 × 10^17cm^-3 and a collector thickness of 400nm. Though our data are influenced by large additional rf probe pads, the device exhibits a maximum oscillation frequency fmax of 10.1GHz and a cut-off frequency fτ of 1.8GHz at a DC bias point of IC=10mA and VCE = 2.5V.

摘要：常规的无机水化学参数较难判别某些井田中成分相近的煤层顶板涌水水源,针对该问题,以榆横矿区某井田为研究区,在K^(+)+Na^(+)、Ca^(2+)、Mg^(2+)、Cl^(−)、SO_(4)^(2−)、HCO_(3)^(−)、TDS(总溶解固体)等无机指标的基础上加入TOC(总有机碳)、UV254(紫外吸光度)、DOM(溶解性有机质)等有机指标,探究无机-有机综合指标在煤层顶板涌水水源判别中的作用;利用荧光指纹技术和PARAFAC得到DOM主要组分及荧光强度,在对水样的无机、无机-有机数据集进行主成分分析(PCA)后,使用随机森林算法(rf)分别构建无机指标判别模型和无机-有机综合指标判别模型;并对8个待测水样的类型也进行了正确的判别。结果表明:综合判别模型的性能总是优于无机判别模型;在综合模型下,rf算法的平均精度、平均查准率、平均召回率和f1调和指数分别达到了93.14%、94.79%、95.08%、93.73%,较无机模型分别提高了9.71%、11.84%、12.25%、11.5%,回代准确率为98.63%;无机-有机综合指标能够显著提高煤层顶板涌水水源判别准确率。

摘要：The loss mechanisms of different passive devices （on-chip inductors and capacitors） on different substrates are analyzed and compared. OPS （oxidized porous silicon） and HR （high-resistivity） substrates are used as low-loss substrates for on-chip planar LPF （low pass filter） fabrication. For the study of substrate loss, a planar coil inductor is also designed. Simulation results show that Q （the quality factor） of the inductor on both substrates is over 20. Measurements of the LPF on OPS substrate give a - 3dB bandwidth of 2.9GHz and a midband insertion loss of 0.87dB at 500MHz. The LPF on HR substrate gives a - 3dB bandwidth of 2.3GHz and a midband insertion loss of 0.42dB at 500MHz.

摘要：对适用于DC～30GHz频率的并联接触式rf MEMS开关的设计与制造进行了研究。利用低应力电镀Au桥膜作为上电极,实现了接触电极之间的Au-Au接触。使用BorofloatTM玻璃作为衬底,并用隔离电阻对内置射频信号与驱动电极旁路进行隔离;通过对上电极桥膜与CPW间距的优化设计,使开关具有较低的插入损耗。所设计制造的并联接触式rf MEMS开关的下拉电压为60V,上下电极的接触电阻为0.1Ω。插入损耗为-0.03dB@1GH,-0.13dB@10GHz和-0.19dB@20GHz,在DC～30GHz的插入损耗都-23dB。测试结果表明,所设计的并联接触式rf MEMS开关适用频率为DC～30GHz,是一种应用频率范围较宽的rf MEMS开关。

摘要：分析了体硅 CMOS rf集成电路中电感的寄生效应 ,以及版图参数对电感品质因数 Q的影响 ,并通过Matlab程序模拟了在衬底电阻、金属条厚度、氧化层厚度改变时电感品质因数的变化 ,分析了不同应用频率时版图参数在寄生效应中所起的作用 ,得出了几条实用的设计原则并进行了实验验证 ,实验结果与模拟值符合得很好 ,表明此模拟方法与所得结论均可有效地用于指导射频 (rf)