Auto-parametric resonance of a continuous-beam-bridge model under two-point periodic excitation:an experimental investigation and stability analysis

The auto-parametric resonance of a continuous-beam bridge model subjected to a two-point periodic excitation is experimentally and numerically investigated in this study.An auto-parametric resonance experiment of the test model is conducted to observe and measure the auto-parametric resonance of a continuous beam under a two-point excitation on columns.The parametric vibration equation is established for the test model using the finite-element method.The auto-parametric resonance stability of the structure is analyzed by using Newmark's method and the energy-growth exponent method.The effects of the phase difference of the two-point excitation on the stability boundaries of auto-parametric resonance are studied for the test model.Compared with the experiment,the numerical instability predictions of auto-parametric resonance are consistent with the test phenomena,and the numerical stability boundaries of auto-parametric resonance agree with the experimental ones.For a continuous beam bridge,when the ratio of multipoint excitation frequency(applied to the columns)to natural frequency of the continuous girder is approximately equal to 2,the continuous beam may undergo a strong auto-parametric resonance.Combined with the present experiment and analysis,a hypothesis of Volgograd Bridge's serpentine vibration is discussed.

Investigation and Analysis of Main Diseases of Landscape Plants in the Main Urban Area of Lu'an City

To figure out the disease occurrence of landscape plants in the main urban area of Lu'an City,the author investigated the disease occurrence of landscape plants in park green space,residential green space,unit attached green space and main road in the area under administration.The survey results showed that there were 29 species of urban landscape plant diseases,mainly powdery mildew and spot diseases.According to the characteristics of the diseases,the causes and problems of the diseases were analyzed,and the corresponding prevention and control measures were put forward.

Comparative Analysis of Differences among Northern,Jiangnan,and Lingnan Classical Private Gardens Using Principal Component Cluster Method

This paper investigates the design essence of Chinese classical private gardens,integrating their design elements and fundamental principles.It systematically analyzes the unique characteristics and differences among classical private gardens in the Northern,Jiangnan,and Lingnan regions.The study examines nine classical private gardens from Northern China,Jiangnan,and Lingnan by utilizing the advanced tool of principal component cluster analysis.Based on literature analysis and field research,273 variables were selected for principal component analysis,from which four components with higher contribution rates were chosen for further study.Subsequently,we employed clustering analysis techniques to compare the differences among the three types of gardens.The results reveal that the first principal component effectively highlights the differences between Jiangnan and Lingnan private gardens.The second principal component serves as the key to defining the types of Northern private gardens and distinguishing them from the other two types,and the third principal component indicates that Lingnan private gardens can be categorized into two distinct types as well.

Investigation and Analysis on Agricultural Resources in the Main Living Areas of Pumi Nationality in Yunnan Province

[Objective] To fully grasp the living environment and the use of agricultural resources of Pumi nationality, a minority group specific in Yunnan. [Methods]Field investigation and analysis were conducted on the social economic conditions, living environment, types of agricultural resources and their use in the main inhabitances of Pumi people including Yulong, Ninglang, Lanping and Weixi County in Yunnan. [Result] There are certain differences in social and economic situations of the four counties, and the ecological environment is generally good. The main agricultural resources in villages under investigation include beans and coarse cereals, while there are certain differences among other agricultural resources due to their location. [Conclusion] The living environment of the main inhabitances of Pumi people in Yunnan is good and there are plenty and characteristic agricultural resources which have certain potentiality for development in the future.

A Study of E-C and C-E Translation in the Light of Lexical Contrastive Analysis and Cultural Differences

The essay briefly illustrates E-C and C-E Translation strategies in the light of lexical similarity and differences of Lexical Contrastive Analysis, and explores lexical translation skills under the theory of Cultural Differences.

An Analysis of the Difference between the Multiple Linear Regression Approach and the Multimodel Ensemble Mean

An investigation of the difference in seasonal precipitation forecast skills between the multiple linear regression （MLR） ensemble and the simple multimodel ensemble mean （EM） was based on the forecast quality of individual models. The possible causes of difference in previous studies were analyzed. In order to make the simulation capability of studied regions relatively uniform, three regions with different temporal correlation coefficients were chosen for this study. Results show the causes resulting in the incapability of the MLR approach vary among different regions. In the Nifio3.4 region, strong co-linearity within individual models is generally the main reason. However, in the high latitude region, no significant co-linearity can be found in individual models, but the abilities of single models are so poor that it makes the MLR approach inappropriate for superensemble forecasts in this region. In addition, it is important to note that the use of various score measurements could result in some discrepancies when we compare the results derived from different multimodel ensemble approaches.

Epidemiological Investigation and Genome Analysis of Duck Circovirus in Southern China

Duck circovirus （DuCV）, a potential immunosuppressive virus, was investigated in Southern China from March 2006 to December 2009 by using a polymerase chain reaction （PCR） based method. In this study, a total of 138 sick or dead duck samples from 18 different farms were examined with an average DuCV infection rate of-35%. It was found that ducks between the ages of 40~60 days were more susceptible to DuCV. There was no evidence showing that the DuCV virus was capable of vertical transmission. Farms with positive PCR results exhibited no regularly apparent clinical abnormalities such as feathering disorders, growth retardation or lower-than-average weight. The complete genomes of 91 strains from Fujian Province and 1 from Zhejiang Province were sequenced and analyzed. The 10 DuCV genomes, comlbared with others genomes downloaded from GenBank, ranged in size from 1988 to 1996 base pairs, with sequence identities ranging from 83.2% to 99.8%. Phylogenetic analysis based on genome sequences demonstrated that DuCVs can be divided into two distinct genetic genotypes, Group I （the Euro-USA lineage） and Group II（the Taiwan lineage）, with approximately 10.0% genetic difference between the two types. Molecular epidemiological data suggest there is no obvious difference among DuCV strains isolated from different geographic locations or different species, including Duck, Muscovy duck, Mule duck, Cheery duck, Mulard duck and Pekin duck.

Quantitative analysis of the dynamic change and spatial differences of the ecological security: a case study of Loess Plateau in northern Shaanxi Province

Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus/loss in 1986-2002 on the Loess Plateau in northern Shaanxi Province. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, and ecological security grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, and also has assessed the ecological footprint demands of 10,000 yuan GDE The results of this study are as follows： （1） the ecological carrying capacity in northern Shaanxi shows a decreasing trend, the difference of reducing range is the fastest; （2） the ecological footprint appears an increasing trend; （3） ecological pressure index rose to 0.91 from 0.44 during 1986-2002 on the Loess Plateau of northern Shaanxi with an increase of 47%; and （4） the ecological security in the study area is in a critical state, and the ecological oressure index has been increasing rapidlv.

Single channel source separation of radar fuze mixed signal based on phase difference analysis

A new method based on phase difference analysis is proposed for the single-channel mixed signal separation of single-channel radar fuze.This method is used to estimate the mixing coefficients of de-noised signals through the cumulants of mixed signals,solve the candidate data set by the mixing coefficients and signal analytical form,and resolve the problem of vector ambiguity by analyzing the phase differences.The signal separation is realized by exchanging data of the solutions.The waveform similarity coefficients are calculated,and the time鈥攆requency distributions of separated signals are analyzed.The results show that the proposed method is effective.

Investigation and Analysis of Natural Environment in Hainan International Tourism Island

Investigation and analysis of natural tourism environment is the foundation and premise of tourism planning,development and management.Through investigating,classifying and evaluating natural tourism resources in Hainan according to the Classification,Investigation and Evaluation of Tourism Resources(GB/T18972-2003),it was found that there are 4 principal categories,6 sub-categories and 61 basic types of natural tourism resources,accounting for 100%,94.1% and 85.9% of the national total respectively.There are 335 natural tourism resource units in Hainan,47 of them are superfine ones accounting for 14.0% of the total,225 excellent ones accounting for 67.2% of the total,48 common ones accounting for 14.3% of the total,62 of them without acquiring any grade,that is,18.5% of the total.Most of these resources are located in the mountainous areas in the central island,eastern coastal areas and Sanya City.Meanwhile,through collecting and sorting out the environmental quality bulletins and statistics of Hainan in recent 5 years,quality changes of its natural tourism environment have been analyzed,and it was found that the quality of water,air and sound on the whole in this island is fine,but a few study cities(towns) are suffering from serious noise pollution.Thus,besides enjoying its generally excellent ecological environment,Hainan Island is still faced with serious challenges.

ACCURACY ANALYSIS OF PASSIVE LOCATION SYSTEM WITH PHASE DIFFERENCE RATE MEASUREMENT

The conventional mono-station passive location techniques of direction finding are low in speed and accuracy, due to the little information available. In this paper, a novel measurement-rate (derivative) of phase difference from a two-element antenna array (interferometer) is introduced, accuracy of a passive location system with this measurement and directions of arrival (DOA) is analyzed, and the Cramer-Rao bound of location error of this system for 3D location is examined by simulations.

Investigation and Analysis of Understory Vegetation in Casuarina equisetifolia Forests in Northern Hainan Province

Understory vegetation in the Casuarina equisetifolia forests at different ages was sampled and analyzed fi rstly, and then the structural features, biomass, and distribution characteristics of carbon stock of the understory vegetation, as well as the quantity and thickness of the understory litter were studied. The results show that the understory vegetation in the C. equisetifolia forests is mainly composed of herbaceous plants, and there are nearly no shrubs in the study area. Moreover, the quantity of herbaceous plants rises obviously with the increase of forest age. There is a big difference between the woodlands at different ages in total biomass of herbaceous plants, and the maximum of total biomass can be found in 15-year-old woodland, reaching 1.68 t/hm^2; the biomass of overground parts of herbaceous plants is higher than that of underground parts. There is a big difference between the woodlands at different ages in thickness of the understory litter, and the thickness of understory litter in 10-yearold woodland is the highest, reaching 6.67 cm. The maximum quantity of the understory litter has reached 14.69 t/hm^2, and the thickness of the half decomposed litter is larger than that of the undercomposed litter in most woodlands.

Investigation and Analysis on the Present Situation of Indoor Formaldehyde Pollution in Residence of Binzhou City

As gradual improvement of living environment and indoor decoration form diversification, the indoor air pollution has become the ＂invisi- ble killer＂ harming human health, and has been listed as one of ten big threats to human health by the World Health Organization, which also be- came one of hot issues concerned by countries all over the world. In this paper, through the determination of formaldehyde in some houses of Binzhou, the release of formaldehyde with the increase of time was explored; change of formaldehyde in the same residence in different functional areas was analyzed; the influence of the temperature, humidity and plant to formaldehyde content was also analyzed.

Combination Use of PFGE and Drug-resistant Analysis in the Epidemiological Investigation of Listeria Monocytogenes

Listeria monocytogenes is the pathogen of listeriosis and it causes severe infections like septicemia, encephalitis, and meningitis, especially in immunocompromised individuals, newborns, and pregnant women. Its wide distribution in the environment and ability to survive or even grow under adverse conditions has made L. monocytogenes an important public health concern and in food industry.

Investigation and analysis of hazardous waste in the Three Gorges Area of Chongqing region

This article describes the investigation of hazardous waste (HW) in the Three Gorges Area of Chongqing region, which indicates that by May 2002, the dumped HW therein amounted to 14 600 t and was mainly distributed in five districts and counties with 11 000 t in Fuling, 1 650 t in Fengdu, 950 t in Wanzhou; 630 t in Wushan and 430 t in Yunyang. The total amount was composed of 9 670 t chromic residue, 2 310 t waste oil and residue, 410 t waste (false) fertilizer, 28 t waste chemical medicine, 26 t waste materials and 2 200 t other things including acid residue, waste asbestos, fluorine silicate, pigment, additive, waste acid, alkali, nitric acid, vitriol, lead mud, storage battery, calcium carbide, potassium cyanide, polluted soil, discard dynamite, waste packing barrel of cyanides, etc. In all of the HW, 578 t can be treated by chemical neutralization and stabilization technology such as redox, chemical precipitation, acid and alkali neutralization, etc., and the rest is temporarily untreatble and should be removed and piled at a temporary storage site above the 177 m water level of the dam with an aim to be transported to a future disposal site for innocuous treatment.

The difference analysis of physical-mechanical properties of sediments in the central South Yellow Sea and Zhe-Min coastal area in China

The difference analysis of physical-mechanical properties of muddy sediments is made in the central South Yellow Sea and the Zhe-Min（Zhejiang Province to Fujian Province of China） coastal area. The results show that sediments in the two regions are both dominated by mud. There are perfect negative power function correlations between the water content and the density, the compression coefficient and the compression modulus; a good positive power function correlation between the liquid limit and the plastic limit, a perfect positive linear correlation between the water content and the void ratio, and a perfect polynomial function correlation between the miniature vane shear strength and the pocket penetration resistance. In general, compared with sediments in the Zhe-Min coastal area, sediments in the central South Yellow Sea possess high water content, high void ratio,low density, high plasticity, high compressibility, low shear strength. The causes of the differences between physical-mechanical properties of sediments are analyzed from the topographic features, material sources,hydrodynamic conditions, deposition rate, and material composition. Compared with the Zhe-Min coastal area,the central South Yellow Sea is far from the Mainland and low-lying; has poor hydrodynamic condition; the materials diffused to the area are less and dominated by fine clay, have the high content of smectite and organic matters. These factors lead to sediments of the central South Yellow Sea has the higher water content, the higher plasticity, the lower density, and the lower strength than sediments in the Zhe-Min coastal area.

Investigation of Computerized Dynamic Oscillographic Analysis

A high speed data sampling system on dynamic Oscillographic analysis was established with a 80386DX40 computer, AD 674 and flow injection system. Programs were designed in Microsoft Windows 3.1, that can process E-t, dE/dt-t, i'(f)-t and other kinds of curve on oscillographic analysis. A satisfactory result on determination of Pb2+ and Cd2+ was obtained.

Analysis on Chinese Regional Differences in International Tourism Foreign Exchange Earnings with Method of One-way Variance Analysis

Based on data over 31 provinces and cities in China from2006 to 2013,this thesis first divides those 31 provinces and cities into four economic regions including northeastern region,central region,eastern region and western region.Based on data over 31 provinces and cities in China from 2006 to 2013,those 31 provinces and cities were devided into four economic regions in this thesis,including northeastern region,central region,eastern region and western region.Then,it takes international tourism foreign exchange earnings as the dependent variable,the four economic regions as the factor to measure the difference of international tourism foreign exchange earnings in different regions,and finds out the main reasons of it.Through the one-way variance analysis on international tourism foreign exchange earnings,we can know that international tourism foreign exchange earnings have differences in different regions apparently.Besides,significant differences can be found between northeastern and central regions as well as eastern and western regions,while it is not the same case between the central and western regions.

Key Technology Research and Exemplification Analysis on Investigation and Assessment of Geoheritages and Geopark Construction

In recent years,great efforts have been made on the geoparks’ application and construction,but there is a shortage of research on the theories and methodologies of geoheritage investigation and assessment. Based on the summaries of having finished geoheritage investtigation and assessment and geopark construction projects,some key technologic methods analyzed in this paper are as follows:(1)

Analysis of genotype differences of rice response to low Zn^(2+) activity and some morphological characteristics

Zinc deficiency is one of the most widespreadmicro-nutritional disorder for rice. To solve the problem, screening Zn-efficient cultivars isan available method and understanding geno-