基于LSTM神经网络的青藏高原月降水量预测

青藏高原的降水量预测不仅为该地区水资源合理规划利用提供依据,同时对中国及周边国家气候变化研究有着重要的意义。论文利用1990—2016年青藏高原降水量数据,采用长短期记忆神经网络（LSTM）对青藏高原月降水量进行预测,主要包括：① 使用青藏高原86个测站1990—2013年的月降水资料,预测各个测站2014—2016年的月降水量,并与传统的RNN、NAR、SSA和ARIMA预测模型相比,平均决定系数R²分别提高了0.07、0.15、0.13和0.36,均方根误差（RMSE）和平均绝对误差（MAE）表现更低;② 分析了降水量预测精度的空间分布特征,将各模型的R²在青藏高原地区内插值,分析R²的空间分布特征,发现所有模型降雨稀少的干旱地区和降雨多的湿润地区R²较低,在气候稳定、降水规律性明显的地区R²较高,且LSTM模型R²≥0.6的空间范围远大于传统模型;③ 分析了不同预测长度对各模型预测精度的影响,发现所有模型会随着预测长度增加而预测精度降低,但在不同的预测长度下LSTM预测的RMSE值都低于其他模型。     

Quantifying the effects of climate variability and human activities on runoff from the Laohahe basin in northern China using three different methods

Much attention has recently been focused on the effects that climate variability and human activities have had on runoff. In this study, these effects are quantified using three methods, namely, multi‐regression, hydrologic sensitivity analysis, and hydrologic model simulation. A conceptual framework is defined to separate the effects. As an example, the change in annual runoff from the semiarid Laohahe basin (18 112 km²) in northern China was investigated. Non‐parametric Mann‐Kendall test, Pettitt test, and precipitation‐runoff double cumulative curve method were adopted to identify the trends and change‐points in the annual runoff from 1964 to 2008 by first dividing the long‐term runoff series into a natural period (1964–1979) and a human‐induced period (1980–2008). Then the three quantifying methods were calibrated and calculated, and they provided consistent estimates of the percentage change in mean annual runoff for the human‐induced period. In 1980–2008, human activities were the main factors that reduced runoff with contributions of 89–93%, while the reduction percentages due to changes in precipitation and potential evapotranspiration only ranged from 7 to 11%. For the various effects at different durations, human activities were the main reasons runoff decreased during the two drier periods of 1980–1989 and 2000–2008. Increased runoff during the wetter period of 1990–1999 is mainly attributed to climate variability. This study quantitatively separates the effects of climate variability and human activities on runoff, which can serve as a reference for regional water resources assessment and management. Copyright © 2011 John Wiley & Sons, Ltd.     

用Atmega8L实现无线恒温控制燃气热水器

介绍了无线恒温控制系统的作用和组成、单片机Atmega8L、无线模块nRF905的特点和引脚、步进电机的控制和驱动，热敏电阻的连接以及整个系统的软硬件实现。     

Scattering of elastic wave by a partially sealed cylindrical shell embedded in poroelastic medium

Scattering of an elastic wave by a cylindrical shell embedded in poroelastic medium is investigated theoretically with the assumption that the shell material is also a porous elastic medium. The porous medium is modellized via Biot's theory and the scattering by cylindrical shell is expressed by the definition of scattering matrix. The normal mode expansion technique is employed for analysing the scattering field, and the asymptotic solutions of displacements, stresses and pore pressure are derived. Two limiting cases‐scattering by a poroelastic cylinder in Biot medium and a elastic cylindrical shell in elastic medium are obtained from the general solutions. The dispersion curves of displacement amplitude at the interface of shell and medium is compared with the case of elastic shell. The scattering amplitude associated with the fast, slow and transverse waves are identified by numerical simulation. Furthermore, the influence of the poroelastic property of shell material on scattering amplitude is analysed. Copyright © 2005 John Wiley & Sons, Ltd.     

倡导生态矿业,促进矿业可持续发展

展望 2 1世纪中国矿业的发展 ,认为大力倡导和发展生态矿业 ,走资源开发与环境保护相协调的矿业可持续发展之路 ,是实施可持续发展战略的必然要求。本文对生态矿业进行了探讨 ,同时提出了矿业可持续发展的对策措施     

1991年10月24日白光耀斑的高时间分辨率多波段光谱分析

本文分析了南京大学太阳塔1991年10月24日用多波段光谱仪观测到的高时间分辨率（5s）的一个2N／X2．1级白光耀斑光谱．对耀斑谱线轮廓、连续发射强度、X射线和射电爆发资料进行了综合对比，分析表明，该耀斑属Ⅰ类白光耀斑，具有如下特征：（1）在白光耀斑的脉冲相期间，各波段光谱线心强度、连续辐射、谱线半宽以及线翼红不对称性与硬X射线高能波段的爆发同时达到极大；（2）H_a谱线在连续发射极大时半宽达10A，且呈现强烈的线心反转，H_β和H_γ线心亦有反转；（3）所拍摄的5条谱线都有明显的红不对称性，持续时间约为1分钟，根据上述结果，本文用电子束轰击、色球蒸发和色球压缩区对该耀斑能量积聚和释放的动力学机制作了定性的分析和解释。     

THE CORRESPONDING ANALYSIS OF HEAVY-METAL POLLUTION OF SOIL IN ZHUZHOU CITY

ＴＨＥ ＣＯＲＲＥＳＰＯＮＤＩＮＧ ＡＮＡＬＹＳＩＳ ＯＦ ＨＥＡＶＹ－ＭＥＴＡＬ ＰＯＬＬＵＴＩＯＮ ＯＦ ＳＯＩＬ ＩＮ ＺＨＵＺＨＯＵ ＣＩＴＹ ＳｈａｎｇＪｉｎｃｈｅｎｇ（尚金城）；ＬｏｎｇＡｉｍｉｎ（龙爱民）ＬｉＢｉｎ（李斌）；ＪｉａｎｇＪ...     

成都花卉塑料薄膜大棚热量平衡初探

本文在测量的基础上,对热量平衡各分量在大棚内、外的差异,进行了比较与分析,对大棚生产管理有重要参考价值。     

相对论多方球的稳定性

本文从理论的角度，讨论了静态相对论多方球的稳定性问题，给出稳定性对球体物质的绝热指数的依赖关系．     

GNSS兼容接收机及其在CORS中的应用

随着近年来卫星定位技术的发展,世界上出现一场“GNSS”热。在介绍GNSS技术的发展概况、技术瓶颈、优势所在的基础上,着重分析GNSS兼容接收机在CORS系统中应用的现实必要性及可行性。