浅层水中沉底爆炸冲击波相互作用数值模拟

根据试验模型和试验结果，进行了浅层水中沉底爆炸冲击波相互作用数值模拟；研究了水底水面对沉底爆炸冲击波传播与相互作用的影响。结果表明，水底对冲击波压力峰值有较大的削弱作用，水面使冲击作用冲量明显减少，冲击波相互作用的压力叠加或多次冲击作用大大提高了爆炸威力。     

BP自适应网络在数值预报产品的释用

提出了动态指标库的概念，即不同时次采取不同的指标库，同时次在网络自适应时采取不断更新指标库的阈值，采取先建立消空指标库对样本进行消空，提高了降水样本在整体样本中的概率，然后利用BP(Back Propagation)网络作了大连短期的12h和24h降水有、无的预报，设计了网络的自适应算法，并在降水有、无预报中加以应用。结果表明，此方法比没有做消空样本和网络自适应的降水TS评分有所提高，在数值产品解释应用中更具有实际意义。     

Emergent Property in Macromolecular Motion

In this paper, the model of inverse cascade fractal super-blocks along one direction (in the positive or negative) in the 3-dimensional space is developed to describe the self-similar motion in macromolecular system. Microscopically the cohesive and dispersed states of the motion blocks are co- existent states with vastly different probability of occurrence. Experimental results and theoretical analysis show that the microscopic cohesive state energy and dispersed state energy of each motion block are respectively equal to the macroscopic glassy state energy kTg and molten state energy kTm of the system. This singularity unveils topologically the non-integrability, mathematically the anholonomy, and macroscopically the emergent property. This singularity also reveals that the glass, viscoelastic and melt states are three distinct emergent properties of macromolecular motion from a macroscopic viewpoint. The fractal concept of excluded volume is introduced to depict the random motion at various scales in     

Effect of Carboxymethyl Starch as Stabilizer for Increasing the Stability of Warp Sizing Pastes

The influences of carboxymethyl starch used as stabilizer upon the stability of native cornstarch-polyvinyl alcohol blend pastes for warp sizing have been investigated. The effect of the modified starch on the paste stability was evaluated in terms of the initial demixing time and the volume percentage of separated starch. The carboxymethyl starch with a series of different degrees of substitution was prepared in ethanol dispersion by varying the amount of monochloroacetic acid reacted with refined native cornstarch. The paste stability strongly depends on the modification extent and amount of carboxymethyl starch used, and on native starch content in the paste. Increase in the modification extent and/or the amount of the modified starch effectively retards the phase separation and reduces the separation extent of native cornstarch-polyvinyl alcohol blend pastes. Moreover, the mechanism and favorable modification extent of carboxymethyl starch for enhancing paste stability are also investigated and disc     

Genetic Diversity in Populations of Sepiella maindroni Using 16S rRNA Gene Sequence Analysis

Part of the 16S rRNA gene is amplified with PCR and sequenced for 5 populations of common Chinese cuttlefish Sepiella maindroni:three from the South China Sea,one from East China Sea and one from Japan.The result shows that a total of 5 nucleotide positions are found to have gaps or insertions of base pairs among these individuals,and 13 positions are examined to be variable in all the sequences,which range from 494 to 509 base pairs.All of the individuals are grouped into 7 haplotypes (h1-h7).No marked genetic difference is osberved among those populations.All of the individuals from Nagasaki belong to h1 and the h3 haplotype is found only in the coastal waters of China.A→←G transition in Nucleotide 255 is suggested to be taken as a kind of genetic marker to identify the populations distributed in East-South China Sea and the Nagasaki waters of Japan.     

C_0-半群的脉冲扰动与一类半线性脉冲发展方程(英文)

研究无限维Banach空间中一半群的脉冲扰动及一类非线性脉冲系统的温和解的存在性、唯一性、正则性和连续依赖性,最后给出例子加以说明。     

Multisymplectic five-point scheme for the nonlinear wave equation

In this paper, we introduce the multisymplectic structure of the nonlinear wave equation, and prove that the classical five-point scheme for the equation is multisymplectic. Numerical simulations of this multisymplectic scheme on highly oscillatory waves of the nonlinear Klein-Gordon equation and the collisions between kink and anti-kink solitons of the sine-Gordon equation are also provided. The multisymplectic schemes do not need to discrete PDEs in the space first as the symplectic schemes do and preserve not only the geometric structure of the PDEs accurately, but also their first integrals approximately such as the energy, the momentum and so on. Thus the multisymplectic schemes have better numerical stability and long-time numerical behavior than the energy-conserving scheme and the symplectic scheme.     

Land vehicle positioning using GPS and dead reckoning

To ensure reliable land vehicle positioning, the Global Positioning System (GPS) is one of the best techniques commonly used in present-day positioning systems. However, GPS signals are not available if line of sight with the satellites is lost. In this respect, the addition of the Dead Reckoning (DR) method to complement the GPS unit would enhance the reliability of land vehicle positioning system. For implementing the DR method, the magnetic sensor and accelerometer are used for obtaining heading and velocity or distance information. Calibration of two sensors' dynamic model and DR algorithm are also introduced in this paper. The test result utilizing the GPS and DR methods is analyzed in this paper. It utilize spositioning information from GPS receiver when GPSsignal is available, otherwise DR is started to compensate GPS outage with the GPS output as the original point. The results showed that the error in east and north produced by the DR algorithm for a short time interval can be limitedwithin an acceptable range.     

In-vehicle GPS/DR navigation system development and test results in Singapore

This paper introduces the in-car navigation system prototype development and test results under the context of Singapore. In the system, integrated GPS/DR is used for continuous vehicle positioning. A digital road network map database is built for the whole Singapore. The database is designed to support map matching, route determination, and route guidance functions. The prototype system demonstrates GPS positioning of the vehicle in real-time, tracking the vehicle onto a digital map with fix updates every one or two seconds.With the map matched vehicle location on the map, voice and/or text guidance is provide to the driver. The vehicle position can also be transferred to control centre through communication data link for the purpose of fleet management.     

A preliminary study of crassulacean acid metabolism (CAM) in the endangered aquatic quillwortIsoetes sinensis Palmer in China

Isoetes sinensis Palmer (Isoetaceae) is an aquatic or amphibious plant that is critically endangered in China. Previous studies have revealed the crassulacean acid metabolism (CAM)-like photosynthetic pathway occurs commonly in submerged leaves in genusIsoetes. Water chemistry parameters and the titratable acidity content of the plant extract were measured from samples obtained in the early morning (7∶00) and late afternoon (15∶00) from twoI. sinensis populations in China. One population occurs in the eulittoral zone of a freshwater tidal river at low elevation (134 m) and another occurs in a densely vegetated, high elevation (1 100 m) alpine shallow pool. Significant differences in pH and titratable acidity of the plant extract were detected between the morning and afternoon samples. These changes are associated with diurnal changes in water chemistry. Our results provide the first evidence for the existence of the CAM pathway in the East Asian endemicIsoetes sinensis Palmer. The magnitude of fluctuations in the titratable acidity of the plant extract may be correlated with the severe carbon limitation imposed on the plants by its aquatic habitat. Foundation item: Supported by the State Key Basic Research and Development Plan (G2000046805) Biography:Pang Xin-an (1974-), male, Master candidate, research direction: conservation biology.