长江经济带湖泊水下地形的热红外遥感反演——以武汉市东湖为例

针对长江经济带平原湖区的浅水湖泊,提出了一种基于热红外遥感的湖泊水深测量方法.首先根据湖泊水温的垂直分布规律,推导出浅水湖泊中表层水温与水深平方的倒数存在近似的正比关系.然后以武汉东湖为例,利用Landsat-8热红外(TIRS)遥感影像数据反演东湖水表温度.结合实测水深测量样本点对,利用半经验回归方法,确定水深与水温的关系式,根据此关系式由水温反演出整个湖泊的水深,最后再结合影像当日的水位数据得到水下地形.试验模型拟合的相关系数R2为0.657,在浅水湖泊水深反演中能取得平均相对误差8.93%的相对测深精度.试验表明, 利用热红外遥感可为长江经济带平原湖区浅水湖泊的水深测量和水下地形测量提供一个快捷的新方法.     

Stochastic DEA model with undesirable outputs: An application to the prediction of anti-HIV therapy efficiency

This paper proposes a stochastic prediction DEA model with undesirable outputs and simplifies the process using chance-constrained techniques in order to obtain an equivalent linear programming formulation. The existence and stability of the optimal solutions have been proved. And the model is used to describe and predict the efficiency of anti-HIV therapy in AIDS patients.     

(Bi3.15Nd0.85)(Ti2Fe0.5Co0.5)O11.5陶瓷的制备及多铁性能表征

采用改进的固相反应法制备(Bi3.15Nd0.85)(Ti2Fe0.5Co0.5)O11.5陶瓷.多铁性能测试结果表明,陶瓷样品具有室温多铁性.样品的剩余磁化为~77memu/g,剩余极化为~1.7μC/cm2,且磁场对介电频谱的影响证实该陶瓷样品的室温磁电耦合效应.     

Stability control of multi-parameter adaptive wireless communication systems based on multi-Lyapunov function

With the occurrence of burst interference, bit error rate ( BER) stability of the wireless commu-nication system ( WCS) always degrades significantly.To cope with it, a stability control algorithm is proposed, utilizing the stability theory of switched systems, which is specifically applicable for multi-parameter adaptive WCS with spectrum sensing ability, and it is capable of stabilizing BER within a reasonable range.Firstly, WCS is modeled as a switched system.Then, based on the multi-Lyapunov function, controlling rules are presented to enable the switched system to satisfy sta-ble condition asymptotically.Finally, analysis and numerical simulation results demonstrate that the switched WCS with the proposed controlling rules is superior to conventional power-controlled WCS with or without state feedback control in terms of stability performance.     

菊方翅网蝽在南京分布及其对中国的风险分析

【目的】了解菊方翅网蝽在南京的分布及危害情况,并确定其在中国的潜在适生分布区和风险大小,为菊方翅网蝽的防控提供参考。【方法】采用实地踏查的方式对南京市8个主城区的公园、广场、绿道等进行调查;采用MaxEnt生态位模型,结合地理信息系统(ArcGIS)预测菊方翅网蝽在中国的潜在适生区;采用多指标综合评价法,从传入的可能性、定殖的可能性、扩散的可能性、受害寄主的经济重要性和危险性管理难度方面,对菊方翅网蝽在中国的入侵风险进行定量和定性分析。【结果】在南京8个主城区均发现有菊方翅网蝽入侵,主要危害菊科杂草,在菊花上危害较轻;预测菊方翅网蝽在中国的潜在适生区约占中国国土面积的40%;菊方翅网蝽在外来入侵有害生物多指标综合评价体系中得分为2.05,属高度风险有害生物。【结论】菊方翅网蝽在南京市已普遍发生,中国潜在适生范围广、风险较大,应加强对该虫的监测,避免进一步扩散。     

Therapeutic angiogenesis induced by human hepatocyte growth factor gene in hindlimb ischemia of dogs

A preclinical study of treating peripheral srtery occlusive disease(PAD) was performed by using a hepatocyte growth factor(HGF) gene-expressing vector,plasmid pUDKH,in a dog model with complete ischemia of one hindlimb.After ligation of femoral artery of one hindlimb,pUDKH was transferred directly into the ischemic limb muscles.The angiogenic activity of the plasmid pUDKH was evaluated.On D 30 after injecting once of pUDKH at differ-ent doses into local muscles immediately after operation,the degree of augmentation of collateral vessel formation was significantly greater than that treated by blank vector.In addition,the blood flow rate of femoral artery in dogs treated with pUDKH was recovered on D90,while the folw rate was only 1/5 tp 1/3 in control dogs.The pulse amplitude of pUDKH-treated dogs was recovered on D90,but it was hardly detectable in most of the control dogs.The side effects of intramuscular transfection of pUDKH were also investi-gated,and no significant positive change was found.It is suggested that angiogenesis induced by HGF gene has the potential for clincal use in the treatment of peripheral arte-rial diseases.     

极值原理和有限元解的存在性

本文用浅湿直观的方法,在二维多边形压域,采用三角形剖分取一次元空间的条件下,证明了满足方程-△u+αu= f 的 u 在α≡0时,只要单元的最大角小于等于π/2就成立离散极值原理;当α≥0且α≠0时,如果存在ε>0使单元最大内角小于等于π/2-ε,则当 h≤(3(5)~(1/2)ctg(π/2-ε))/2‖α‖_0时成立离散极值原理。由于证明方法的直观性,对于理解和使用离散极值原理带来了方便。最后,作为例子在一个非线性问题的有限元解存在性的证明中阐明离散极值原理的应用。     

浅议城市水资源的概念及其特性

重点阐述了城市水资源的观念及特征,并提出了只有科学合理地开发利用城市水资源,才能促进城市水资源的经济发展。     

基于QR码构造的广义LDPC码

在低密度奇偶校验(low density parity check, LDPC)码的图形表示中,存在着一种陷阱集结构,其对性能的影响表现在,陷阱集中变量节点所对应的比特在迭代过程中如果发生错误,就不容易被纠正回来。因此,结合平方剩余(quadratic residue, QR)码来设计一种新颖的广义LDPC码的编译码方案。该方案利用QR码这一性能优良的码型,为LDPC码的某些变量节点提供额外的保护,在损失少许码率的情况下,以期消除某些陷阱集的影响,并获得比原始LDPC码更好的性能。在仿真模拟中,通过统计原始LDPC码的错误比特位置,发现某些比特位置的出错频率较高,为此,从陷阱集的角度分析了其中的原因,并根据这些变量节点,构造广义LDPC码。仿真结果表明,该方案能够有效地降低某些LDPC码的错误平层。     

Therapeutic angiogenesis induced by human hepatocyte growth factor (HGF) gene in rat myocardial ischemia models

Coronary arteriosclerotic cardiopathy is also named myocardial ischemia, which severely threatens humanhealth. Following the economic development and change of life style in China, population blood pressure, weight index and serum cholesterol level all rise. This prophesies incidence rate of coronary arteriosclerotic cardiopathy and stroke will increase year by year. Angioplasty and surgical bypass, the primary interventional therapies for these in-dividuals, are temporally limited by the prob…