三角形不全等的最大条件及其性质定理

三角形不全等的最大条件及其性质定理何宗光（浙江省嘉兴市南湖中学３１４０００）两个三角形全等的判定定理实际上都是判定两个三角形全等的最少条件或称为最小条件，那么这个问题的反面，三角形不全等的最大条件又是什么呢？全国统编教材（人民教育出版社）初中平面几何...

考虑父节点的贝叶斯网络故障路径追溯算法

基于概率图模型的故障诊断技术常被用于不确定信息的推理。其中贝叶斯网络作为一类具有强大实用性及适用性的概率图模型,得到了广泛应用。为有效识别大数据量工业系统中的故障传播路径,提出了一种考虑父节点影响的贝叶斯网络故障路径追溯算法。在建立贝叶斯网络后,给定父节点所有潜在取值组合,算法利用条件概率分解及二分法估计特定故障子节点的最大条件分布值,然后与真实观测值比较,得到导致此故障发生的最大可能原因。通过逐层推断,最终能够实现对网络中故障传播路径的有效追溯。实验结果表明,该算法具有准确追踪故障路径的能力,同时显示出较高的可用性及较快的追踪速度。

参数驱动实现两个非耦合神经元完全同步与相位同步

讨论了利用外部混沌信号或神经元膜电压实现两个初始条件不同的非耦合Hindmarsh Rose (HR)神经元的同步问题:利用外部混沌信号调制两个相同的非耦合HR神经元的某些参数,当刺激强度达到某一阈值时最大条件Lyapunov指数(LCLE)变负,两个系统可实现完全同步;利用混沌信号调制两个存在参数差的非耦合HR神经元的输入电流,当刺激强度达到某一阈值时两个系统的最大条件Lyapunov指数都变负,两个HR神经元将实现相位同步.此项研究从实验的角度为实现非耦合神经元同步提供了可行的方法,为今后研究更加复杂的神经元系统打下了一定的理论基础.

Effects of rearing temperature and density on growth,survival and development of sea cucumber larvae,Apostichopus japonicus(Selenka)

In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval length and density,metamorphic time,and survival rate of the larvae were recorded.Statistics showed that for A.japonicus,survival rate(from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature(P<0.05).At different temperatures SGR was statistically significant as well(P<0.05) from day 1,and maximal SGR was found on day 9 at 24℃(159.26±3.28).This study clearly indicated that at low temperature(<24℃),metamorphic rate was remarkably higher than at higher temperature(>26℃).Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups.Rearing larvae at the higher density had the smaller maximal-length,whereas needed longer time to complete metamorphosis.This study suggested that 21℃ and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large-scale artificial breeding of A.japonicus's larvae.

Underground mining of thick coal seams

This paper reviews underground mining methods for total thickness of a thick coal seam in single lift （TI＇rCSSL）. Review shows the required engineering for extraction of thick seams needs to be fitted with thickness of the seam, behavior of rock-mass and surrounding stress conditions for efficient mining. Variants of TI＇rCSSL are able to extract a maximum 10-12 m thickness only. An improvement in bending moment of the overlying coal band in longwall top coal caving （LTCC） provides better under-winning opportunity for the roof coal band. An acceptable limit of 25 MPa compressive strength of coal for the success of LTCC may be increased under favorable geo-technical conditions. Bord and pillar in India adopted induced caving of roof coal band for single lift depillaring of total thickness （SLDTr） of a compe- tent thick coal seam developed along floor. Case studies are given to arrest the adverse effects of extrac- tion height on pillars.

The characteristics of rill development and their effects on runoff and sediment yield under different slope gradients

Rill formation is the predominant erosion process in slope land in the Loess Plateau, China. This study was conducted to investigate rill erosion characteristics and their effects on runoff and sediment yielding processes under different slope gradients at a rate of 10°, 15°, 20° and 25° with rainfall intensity of 1.5 mm min-1 in a laboratory setting. Results revealed that mean rill depth and rill density has a positive interrelation to the slope gradient. To the contrary, width-depth ratio and distance of the longest rill to the top of the slope negatively related to slope gradient. All these suggested that increasing slope steepness could enhance rill headward erosion, vertical erosion and the fragmentation of the slope surface. Furthermore,total erosion tended to approach a stable maximum value with increasing slope, which implied that there is probably a threshold slope gradient where soil erosion begins to weaken. At the same time, the correlation analysis showed that there was a close connection between slope gradient and the variousindices of soil erosion: the correlation coefficients of slope gradient with maximal rill depth, number of rills and the distance of the longest rill from the top of the slope were 0.98, 0.97 and-0.98, respectively,indicating that slope gradient is the major factor of affecting the development of rills. Furthermore,runoff was not sensitive to slope gradient and rill formation in this study. Sediment concentration,however, is positively related to slope gradient and rill formation, the sediment concentrations increased rapidly after rill initiation, especially. These results may be essential for soil loss prediction.

Bridge Pressure Flow Scour at Clear Water Threshold Condition

Bridge pressure flow scour at clear water threshold condition is studied theoretically and experimentally.The flume experiments reveal that the measured scour profiles under a bridge are more or less 2-dimensional;all the measured scour profiles can be described by two similarity equations,where the horizontal distance is scaled by the deck width while the local scour by the maximum scour depth;the maximum scour position is located just under the bridge about 15% deck width from the downstream deck edge;the scour begins at about one deck width upstream the bridge while the deposition occurs at about 2.5 deck widths downstream the bridge;and the maximum scour depth decreases with increas-ing sediment size,but increases with deck inundation.The theoretical analysis shows that:bridge scour can be divided into three cases,i.e.downstream unsubmerged,partially submerged,and totally submerged.For downstream unsubmerged flows,the maximum bridge scour depth is an open-channel problem where the conventional methods in terms of critical velocity or bed shear stress can be applied;for partially and totally submerged flows,the equilibrium maximum scour depth can be described by a scour and an inundation similarity number,which has been confirmed by experiments with two decks and two sediment sizes.For application,a design and field evaluation procedure with examples is presented,including the maximum scour depth and scour profile.

Well-controlled column bioleaching of a low-grade copper ore by a novel equipment

For the low-grade copper sulfide ores with 0.99% of copper, of which 41.5% was primary copper sulfide, and 54.5% was secondary copper sulfide, well-controlled column bioleaching on a novel equipment was carried out to investigate the optimal conditions of pre-leaching, particle sizes of ores, temperature, spray intensity and strain consortium. Results show that copper extraction of 91.11% can be obtained after 90 d with the optimal p H value of pre-leaching of 0.8; the p H values of pre-leaching significantly affect the final copper extractions. Copper extractions of 93.11%, 91.04% and 80.45% can be obtained for the bioleaching of ores with particles size of 5-8 mm, 5-15 mm and 5-20 mm, respectively. Copper extractions are 83.77% and 91.02% for bioleaching under the conditions of room temperature and 35 oC. Copper extractions are 77.25%, 85.45% and 91.12% for the bioleaching when flow rate of spray was 5 L/（h·m2）, 10 L/（h·m2） and 15 L/（h·m2）, respectively. Additionally, the strain consortium C3 is the best among the four strain consortia in bioleaching. By considering the energy consumption, the optimal conditions of bioleaching in this work are determined as p H of pre-leaching of 0.8, particles size of 5-15 mm, temperature of 35 ℃, spray intensity of 15 L/（h·m2）, and strain consortium C3.

Monotone Iterative Technique for Duffie-Epstein Type Backward Stochastic Differential Equations

For Duffle-Epstein type Backward Stochastic Differential Equations, the comparison theorem is proved. Based on the comparison theorem, by monotone iterative technique, the existence of the minimal and maximal solutions of the equations are proved.

Spectrophotometric determination of heparin with safranine T and their interaction mechanism

In weak acidic medium the alkaline cationic Safranine T interacts with acidic biological rnacromolecule heparin intensively causing the change of the molecular conformation, the maximum absorption wavelength and the absorption value. The optimum experimental condition was given and a new method to determine the heparin was established. The linear range was 0.05-2.0 mg/L and the correlation coefficient was 0.9974. The method has been applied to analyze the samples and the results are satisfactory. Furthermore, the interaction mechanism was indicated.

Observed water current and transport through Qiongzhou Strait during August 2010

The velocity structure of the residual current across an entire section of the Qiongzhou Strait(QS) in summer is presented for the fi rst time. Shipboard Acoustic Doppler Current Profi le measurements, from the mid-region of the QS(110.18°E), were collected on 1–4 August 2010. The diurnal tidal currents had their maximum amplitudes between 4.24 and 20.24 m. Their amplitude along the major axis ranged from approximately 0.55 m/s in the middle part of the strait(20.15°N) to 0.84 m/s in the north part of the strait(20.20°N). Both anticlockwise and clockwise tidal current rotations exist in the QS. During the observation period(neap tide), a signifi cant westward residual current occupied almost the entire study section. Two velocity cores of westward current were observed at the northern part and near the deepest trough, although an eastward current appeared in the middle part of the transect. The deepest core was located near 62 m at 20.13°N, with a maximum velocity of-0.34 m/s. The shallower core was located at approximately 16 m at 20.20°N, with a maximum velocity of-0.33 m/s. The estimated total volume of water transported through the QS was-0.16 Sv. This value is an important boundary condition, applicable to numerical models studying coastal ocean circulation in the northwestern South China Sea.

Antibacterial Activity of Lyngbya and Chroococcus Species Isolated from Koya （Hizoop River）

In the study cyanobacterial strains were isolated from different sites of Hizoop rivers, Koya-Iraq and identified according to their morphological characters by using microscope, two genera which were in filamentous form identified as Chroococcus sp. and Lyngbya sp.. After identification of genera their optimum growth condition studied by using the effect of temperature and pH to their dry weight. In the result, the optimum temperature and pH for both filamentous cyanobacteria were 25 ℃ and pH 7.5. Both cyanobacterial strains were extracted with ethanol, methanol and diethyl ether at various concentrations （0.2 g/mL, 0.1 g/mL, 0.005 g/mL） which exhibited the antibacterial activities against Staphylococcus aureus, E. coli and B. subtilus. Inhibition activities of the two cyanobacterial extracts were more effective at high concentration against the tested pathogens at the low concentration, especially those ofLyngbya sp. The higher inhibition zone showed with extract by ethanol.

时空混沌的单向耦合同步

以耦合映象格子模型为例 ,提出利用单向耦合驱动时空混沌的同步方案 ,并进行了数值分析 .结果表明 ,适当地选择耦合驱动强度因子和均衡系数 ,两个时空混沌系统可以达到准确同步 .通过计算最大条件Lyapunov指数 ,给出了可实现时空混沌同步的最小耦合强度以及最小耦合强度与系统参数之间的关系曲线 .数值模拟还证明 ,此方法工作鲁棒 .

用单一驱动变量同步混沌与超混沌的一种方法

为减少混沌或超混沌同步过程中所需同步信号的个数以及提高同步的效率 ,提出了用线性可逆变换的方法重组系统 ,从而使原来不能同步的系统实现了只用单一信号就可同步的目的 .另外 ,也大大提高系统的同步速率 .

两个非耦合Hindmarsh-Rose神经元同步的非线性特征研究

利用Hindmarsh Rose(HR)神经元输出的膜电压作为刺激调整两个具有不同初始条件的非耦合HR神经元的电流输入,通过分析神经元放电峰峰间期(ISI)的分布揭示了两个神经元同步过程轨道演化的机理.在周期信号刺激下,两个具有相同参数原处于混沌状态的神经元可以实现完全同步,且可以同步到不同于刺激信号频率的周期响应上;两个具有不同参数的神经元可以实现相位同步,参数差别较小的两个神经元可以相位同步到与刺激信号不同频率的周期响应上,参数差别较大的两个神经元只可能相位同步到与刺激信号相同频率的周期响应上.混沌信号刺激两个神经元只可能同步到产生混沌信号神经元的放电模式上,可见混沌刺激更有利于神经元信息编码与解码.分析两个被调整神经元系统的最大条件Lyapunov指数(Lmc)与刺激强度k的关系表明当k达到某一阈值时两个系统的Lmc均为负值是两个系统实现同步的必要条件.平均发放率相同的混沌刺激和周期刺激相比较混沌刺激更容易使两个神经元实现同步,表明混沌刺激产生的效应更强,该结论与实验结果相符合.

BOUNDEDNESS OF MAXIMAL SINGULAR INTEGRALS

The authors study the singular integrals under the Hormander condition and the measure not satisfying the doubling condition. At first, if the corresponding singular integral is bounded from L^2 to itself, it is proved that the maximal singular integral is bounded from L^∞ to RBMO except that it is infinite μ-a.e. on R^d. A sufficient condition and a necessary condition such that the maximal singular integral is bounded from L^2 to itself are also obtained. There is a small gap between the two conditions.

MINIMAX PROGRAMMING UNDER GENERALIZED （p, r）-INVEXITY

Minimax programming problems involving generalized （p, r）-invex functions are consid- ered. Parametric sufficient optimality conditions and duality results are established under the aforesaid assumptions on the objective and constraint functions.

Some results on pointwise second-order necessary conditions for stochastic optimal controls

The purpose of this paper is to derive some pointwise second-order necessary conditions for stochastic optimal controls in the general case that the control variable enters into both the drift and the diffusion terms.When the control region is convex, a pointwise second-order necessary condition for stochastic singular optimal controls in the classical sense is established; while when the control region is allowed to be nonconvex, we obtain a pointwise second-order necessary condition for stochastic singular optimal controls in the sense of Pontryagin-type maximum principle. It is found that, quite different from the first-order necessary conditions,the correction part of the solution to the second-order adjoint equation appears in the pointwise second-order necessary conditions whenever the diffusion term depends on the control variable, even if the control region is convex.

Nonsmooth Semi-Infinite Minmax Programming Involving Generalized(Φ, ρ)-Invexity

This paper introduces some new generalizations of the concept of （~, p）-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the necessary and sufficient optimality conditions for a class of nonsmooth semi-infinite minmax programming problems, where set of restrictions are indexed in a compact set. Utilizing the sufficient optimality conditions, the authors formulate three types of dual models and establish weak and strong duality results. The results of the paper extend and unify naturally some earlier results from the literature.

A NECESSARY AND SUFFICIENT CONDITION FOR A POINT TO BE A GLOBAL MAXIMIZER OF ACONSTRAINED OPTIMIZATION

It is difficult to judge whether a given point is a global maximizer of an unconstrained optimization problem. This paper deals with this problem by considering global information via integral and gives a necessary and sufficient condition judging whether a given point is a global maximizer of an unconstrained optimization problem. An algorithm is offered under such a condition and finally two test problems are verified via the offered algorithm.