地产泡沫预警模型及实证分析

在短视的理性预期均衡(myopic REE)理论框架下,引入“负红利”的概念,证明土地价格在实际贴现率下是一个贴现鞅.利用1986年-1990年日本8个督道府剔除通货膨胀率之后的地价数据建立了一个地产泡沫预警模型,并对中国16个重点城市2003年和2004年地产市场的泡沫情况进行了实证分析.实证结果表明:2004年杭州、上海和沈阳存在着严重的地产泡沫;成都和重庆等地的地产市场有过热的迹象.地产泡沫预警模型对于防范地产泡沫的发生,促进中国房地产市场的健康发展具有重要意义.     

基于多普勒特性的飞机尾流回波提取方法

飞机尾流探测技术是航空安全领域的重要研究课题。使用一组均匀分布的粒子模拟尾流涡旋的运动特征,研究了潮湿大气中尾涡多普勒谱的视频回波仿真方法。尾流回波的信噪比很低,降低检测门限的方法导致产生大量虚警。为了克服这个缺点,基于尾涡多普勒特性,提出了一种利用多层前馈神经网络提取尾流回波的方法。仿真表明,尾流回波的多普勒谱谱宽较大,谱型不同于气象回波的高斯谱,通过对比分析验证了神经网络提取方法的有效性。研究结果有助于利用脉冲多普勒雷达对飞机尾流探测技术的研究。     

实时检验泡沫：基于严格局部鞅判别的泡沫检验方法

实时检验泡沫并对市场参与者和监管者进行预警,有利于防范和化解金融风险。基于检验泡沫的严格局部鞅判别原理,在RKSH方法的基础上拓展了一种倒向滚动检验方法（BSLM）,并通过蒙特卡洛仿真和实证分析验证了新方法的有效性。研究发现：相对于传统严格局部鞅判别方法,BSLM方法对距离当前时刻较近的泡沫具有更高的检验势,并且能更早地事前预警泡沫;在对中国股票市场主要指数2000~2015年的泡沫检验中,新方法能判断泡沫的生成时间和破灭时间,发现上证指数和深圳成指的泡沫具有较强的联动性。     

多段气液并流鼓泡塔流体流动性质研究

在塔径D_r=0.047m.塔高H_T=2.00 m的多段气液并流鼓泡塔内,于空气-自来水系统中考察了表观气速U_g=0.020～0.164m/s,表观液速u_L=0.010～0.050 m/s,多孔隔板孔径d_0=0.002、0.004、0.008 m及其开孔率(?)=5.61%、11.1%、23.4%和段数N=1、2、4、8对气含率、液相体积传质系数和液相返混系数的影响,并得到各自的经验关联式。     

热致液晶聚芳酯OHO-10条带织构的形成和发展

本文用偏光显微镜研究了主链带柔性间隔基的聚芳酯液晶OHO-10的条带织构的形成和发展。观察到两类不同的条带。第一类为普通条带,其寿命很短,只有通过淬火才能冻结结构进行观察。间接的观察表明这类条带是在停止剪切后形成的:刚开始形成时就有一个起始条带宽度约3μ多。第二类条带是在普通条带消失之后由气泡生长的压缩力推动形成的。在较低的剪切温度时可以直接观察到整个形成、发展和消失过程。     

硬磁畴稳定性与垂直布洛赫线间静磁相互作用的关系

研究石榴石磁泡膜在直流偏磁场作用下布洛赫线间的静磁作用对硬磁畴稳定性的影响.一方面实验研究了圆形硬磁畴的缩灭行为和条泡转变行为以及两种行为间的关系;另一方面通过引入相邻布洛赫线间的静磁作用能,改进了圆柱形硬磁畴的畴壁能公式,从而使一些多年来一直不能解释的硬磁畴在直流偏磁场下的行为得到了统一的解释,并在此基础上提出了估算硬磁畴畴壁中垂直布洛赫线数目的方法.最后还应用经该文改进了的畴壁能公式定性地解释了部分硬磁畴种类随温度而变化的现象.     

航海仿真虚拟环境的海浪视景生成技术

分析了海面浪花的生成条件，用粒子系统和图象合成相结合的方法，实现了动态海面及海面浪花的实时仿真。在模拟船舶周围浪花时，作者提出了椭圆模型，可方便行确定粒子的随机初始位置，通过调整粒子在椭圆上的限定范围，可用同一粒子系统，分别模拟出船体首部，尾部以及其它部位的兴波，并给出了粒子各属性的确定方法。     

丽斑麻蜥和草原沙蜥的种群调查

在兰州市郊区共捕获蜥蜴107只,其中丽斑麻蜥(Eremias argus)52只,草原沙蜥(Phrynocephalus frontalis)55只.其种群密度分别为丽斑麻蜥129只/hm2,草原沙蜥100只/hm2.2个种群划分为亚成体组和成体组后,平均吻肛长(SVL)丽斑麻蜥的亚成体组为34.2 mm,成体组为54.5 mm;草原沙蜥的亚成体组为35.4 mm,成体组为57.9 mm.种群性比(♀:♂)丽斑麻蜥为1∶1.07,草原沙蜥为1∶0.94,平均接近1∶1.调查结果表明:丽斑麻蜥和草原沙蜥2个种群的密度相差不大,二者的空间分布区域可以重叠,可以共处于同一生活环境中;丽斑麻蜥亚成体比草原沙蜥亚成体更生醒晚.蜥蜴体温主要受环境温度影响,通过行为调节来维持它们的正常生理机能.     

"气泡聚变"与冷聚变

论述了“气泡聚变”与冷聚变都属于新型聚变，指出中性粒子与核的聚变可在任何温度条件下进行，强调要用新观念与新思维来正确对待新奇核现象。     

Internal interactions within the human circadian system: the masking effect

Summary In the realm of human circadian rhythms, the masking effect is defined as the change in the course of deep body temperature induced by changes in the degree of physical activity, or by the alteration between sleep and wake. This effect is particularly obvious during internal desynchronization where the rhythms of deep body temperature, and the sleep-wake sleep-wake sleep cycle — i.e. one of the masking factors — run with different periods.Every sleep onset is accompanied by a rapid drop, and wake onset by a rapid rise in deep body temperature, each one with an overshoot of about 50% of the steady state variations. When rhythms are calculated, with the dominant temperature period as the screening period, exclusively from data obtained during sleep episodes, on the one hand, and from those obtained exclusively during wake, on the other, two average cycles emerge: the sleep temperature curve and the wake temperature curve. Both run in parallel but are separated by the masking effcct. As derived from many experiments, the mean masking effect amounts to 0.28±0.06°C. The masking effect also depends to some extent on the phase of the temperature rhtthm; it is larger than average around the temperature maximum and during the descending phase of the temperature cycle, where the alertness commonly is highest and the probability to sleep, in general, and the REM sleep propensity, in particular, are smaller than average. This also can be interpreted to indicate that the sleep temperature curve is phase advanced relative to the wake temperature curve; this, on the average, by 0.9±0.3 h.If the individually determined amount of masking is added to the temperature data obtained during sleep, or substracted from the temperature data obtained during wake, a temperature curve emerges that can be though of as being purified of the masking effect. Analyses of this artificial curve allow estimation of that part of the internal interactions uninfluenced by the masking effect. On the average, about half of the amount of interaction between the rhythm of sleep-wake and that of deep body temperature is explained by the masking effect, whereas the other half is oscillatory interaction. Both types of interaction are inherent and inseparable parts of the circadian clock mechanism, as can be deduced from model considerations.