非圆链(带)传动的速比函数计算方法研究

利用微分几何学中相伴曲线方法 ,建立了连续映射模型和离散映射模型 ,依据这一模型 ,可以方便地研究非圆链 (带 )轮副的传动特性、速比函数求解、多边形效应的影响等问题 ,探讨了非圆链传动的各类瞬心、节曲线、旋轮线等几何特征 ,研究发现两链轮节曲线同链条节曲线做纯滚动时 ,它们瞬时所滚过的弧长一般并不相等 ,给出了非圆带轮及非圆链轮速比函数求解的具体算例 ,从中可以看出多边形效应对速比的影响。

Effect of Cultivation on Spatial Distribution of Nematode Trophic Groups in Black Soil

Geostatistics combined with GIS was applied to assess the spatial distribution of nematode trophic groups following two contrasting soil uses in the black soil region of Northeast China. Two plots, one with fallow for 12 years and the other cultivated, were marked on regular square grids with 2-m spacing. Soil samples were collected from each sampling point, nematodes were extracted from these samples and classified into four trophic groups: bacterivores, fungivores, plant parasites, and omnivores/predators. The numbers of total nematodes and trophic groups analyzed had normal distributions on both fallow and cultivated plots. The absolute abundances of total nematodes and trophic groups were observed to be much more homogeneous on cultivated plot than on fallow one. Geostatistical analysis showed that the densities of total nematodes and trophic groups on both fallow and cultivated plots exhibited spatial dependence at the sampled scale and their experimental semivariograms were adjusted to a spherical or exponential model, except those of bacterivores and fungivores on cultivated plot. The spatial distribution of nematode trophic groups was found to be different for the two land uses, indicating that cultivation changed the native condition for soil nematode activities.

Design, Construction and Ocean Testing of Wave Energy Conversion System with Permanent Magnet Tubular Linear Generator

In this paper, the design, construction and ocean testing of a wave energy conversion system are studied. Based on the motion characteristics of double buoys in ocean waves, a wave energy conversion system with permanent magnet tubular linear generator （PMTLG） is proposed to convert ocean wave energy into electricity. The wave energy conversion system was installed in the Yellow Sea near Lianyungang, China. The ocean test re- suits indicate that it had dynamic and static performance, and obtained an expected amount of electricity. The calcu- lation result indicates the average output power was about 1 000 W, and the conversion efficiency from wave en- ergy into electricity was 1.4%. In addition, the wireless data communication, mechanics and oceanography were also discussed.

New Exact Travelling Wave and Periodic Solutions of Discrete Nonlinear Schroedinger Equation

Some new exact travelling wave and period solutions of discrete nonlinearSchroedinger equation are found by using a hyperbolic tangent function approach, which was usuallypresented to find exact travelling wave solutions of certain nonlinear partial differential models.Now we can further extend the new algorithm to other nonlinear differential-different models.

Multi-linear Variable Separation Approach to Solve a (2+1)-DimensionalGeneralization of Nonlinear Schroedinger System

By using a Baecklund transformation and the multi-linear variable separationapproach, we find a new general solution of a (2+1)-dimensional generalization of the nonlinearSchroedinger system. The new 'universal' formula is defined, and then, rich coherent structures canbe found by selecting corresponding functions appropriately.

Linear monitoring for cast-in-place reinforced concrete arch bridge construction

Linear monitoring is an important link of bridge construction control,which is conducted in key processes of construction to ensure the security of bridge in construction procedure. Combining with main arch construction monitoring program of No. 2 bridge in north district of Changbai international tourism resort,main content and key technologies are recommended. Considering the various influential factors during the construction process,linear adjustment is handled to ensure that the stress and linear of main arch meet design requirements.

Practical Application of Two-Way Multiple Overlapping Relationships in a BDM Network

Today, most construction projects in urban environments are complex high-rise buildings that present unique challenges, including local building ordinances and restrictions, adjoining public and residential areas, narrow sidewalks and streets, and underground utilities, all of which require extensive planning and tight schedules. A major problem facing such projects is to formulate realistic schedules that will make it possible to meet contractual completion dates with limited resources and budgets. The scheduling software products currently used in construction projects, which include Primavera P6, Microsoft Project, etc., are not actually applied as a scheduling tool in practical construction projects, which instead generally depend on Microsoft Excel or a bar-chart. This is because the existing scheduling programs cannot provide more user-oriented schedule format such as representing two-way multiple overlapping relationships. To overcome this deficiency, the BDM （beeline diagramming method） is proposed as a new networking technique in 2010. But two-way multiple overlapping relationships generate the loop in a conventional schedule computation process. This paper addresses the loop phenomenon of two-way multiple overlapping relationships in a BDM network as well as proposes the solutions of them, and then presents a practical application of two-way multiple overlapping relationships at a real project.

GIS-Based Simulation of Engineering Construction Schedule

For its complexity, engineering construction schedule design is limited by various factors.Simulation-based engineering construction schedule takes critical path method (CPM) network as frame and calls complex cyclic operation network (CYCLONE) simulation model enclosed in advance for its simulation nodes. CYCLONE simulation model takes charge of simulating stochastic duration of activity and efficiency of resources, while CPM model performs project scheduling. This combination avoids the shortcomings of both models. Furthermore, geographic information system (GIS) technique is utilized to visualize the construction processes which are otherwise difficult to be understood by static results described. Application in practical project verifies the feasibility and advantage of the technique.

Integrated Protection Scheme for Power Line

This paper presents an integrated relay and its associated protection scheme for power transmission lines.The concept of integrated protection is firstly introduced,in which a centralized protection system or relay provides the protection for multiple power plants or a substation.A novel integrated protection relay based on the combination of a number of protection principles is described.In the proposed scheme,the specially designed protection relays are installed at each substation of a network and are responsible for the protection of every line section connected to the substation busbar.The combined algorithms with multiple settings are implemented into the relay to cover all the protected line sections.Simulation studies show that the proposed protection scheme is able to produce desirable performance and may offer many advantages over the existing one and great potential for future applications.

Numerical analysis and field monitoring tests on shallow tunnels under weak surrounding rock

The Jianpudong No. 4 tunnel is a shallow tunnel, which belongs to Shaoshan County scenic highway in Hunan province, China and whose surrounding rock is weak. According to its characteristics, the field monitoring tests and numerical analysis were done. The mechanical characteristics of shallow tunnels under weak surrounding rock and the stress-strain rule of surrounding rock and support were analyzed. The numerical analysis results show that the settlement caused by upper bench excavating accounts for 44% of the total settlement, and the settlement caused by tunnel upper bench supporting accounts for 56% of the total settlement. The maximum axial force of shotcrete lining is 177.2 k N, which locates in hance under the secondary lining. The maximum moment of shotcrete lining is 5.08 k N·m, which locates in the arch foot. The stress curve of steel arch has three obvious stages during the tunnel construction. The maximum axial force of steel arch is 297.4 k N, which locates in tunnel vault. The axial forces of steel arch are respectively 23.5 k N and-21.8 k N, which is influenced by eccentric compression of shallow tunnel and locates in hance. The results show that there is larger earth pressure in tunnel vault which is most unfavorable position of steel arch. Therefore, the advance support should be strengthened in tunnel vault during construction process.

Minimum safe thickness of rock plug in karst tunnel according to upper bound theorem

High pressure and water-bearing caverns ahead of a karst tunnel face tend to cause geological disasters, such as water and mud bursts. So, the determination of safe thickness of the reserved rock plug is a key technical problem to be solved for karst tunnel construction. Based on the Hoek-Brown nonlinear failure criterion, the minimum safe thickness of rock plug was investigated in the light of the limit analysis theory. On the basis of the proposed failure mode, the expression of the minimum thickness for rock plug was obtained by means of upper bound theorem in combination with variational principle. The calculation results show the influence of each parameter on safe thickness and reveal the damage range of rock plug. The proposed method is verified by comparing the results with those of the drain cavern of Maluqing Tunnel. The research shows that with the increase of compressive strength and tensile strength as well as constant A of Hoek-Brown criterion, the safe thickness decreases, whereas with the increase of cavern pressure, tunnel diameter, and constant B from Hoek-Brown criterion, the safe thickness increases. Besides, the tensile strength, or constants A and B affect the shear failure angle of rock plug structure, but other parameters do not. In conclusion, the proposed method can predict the minimum safe thickness of rock plug, and is useful for water burst study and prevention measures of tunnels constructed in high-risk karst regions.

3D Finite Element Simulation of Tunnel Boring Machine Construction Processes in Deep Water Conveyance Tunnel

Applying stiffness migration method,a 3D finite element mechanical model is established to simulate the excavation and advance processes.By using 3D nonlinear finite element method,the tunnel boring machine(TBM) excavation process is dynamically simulated to analyze the stress and strain field status of surrounding rock and segment.The maximum tensile stress of segment ring caused by tunnel construction mainly lies in arch bottom and presents zonal distribution.The stress increases slightly and limitedly in the course of excavation.The maximum and minimum displacements of segment,manifesting as zonal distribution,distribute in arch bottom and vault respectively.The displacements slightly increase with the advance of TBM and gradually tend to stability.

Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and Its Influences on Cotton Yield in the Yangtze River Valley

[Objective] The historical evolution pattern of nitrogen （N）, phosphorus （P） and potassium （K） fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.

Platform Construction of Regional Energy Management Center

Based on the analysis of different requirements of energy management center construction and the data acquisition of various industries in wide area network, as well as the practices of real-lime online system, the paper puts forward the construction scheme of regional energy management center （REMC） which can achieve real time online monitoring of organizations＇ energy consumption via data collection, and also proposes the design idea of energy data acquisition based on national standards.

Speed Profile as a Tool to Estimate Traffic Calming Measures Efficiency

TCMs （traffic calming measures） are commonly installed in order to reduce speeds and volumes of traffic to acceptable levels and, thus, improve traffic safety as well as environmental impact when designed appropriately as a corridor or aerial implementation with proper spacing. Hence in many previous studies, their impact was mainly evaluated in scope of average and 85th percentile speed reduction. This paper presents and appraises the efficiency of calming measures of various types used in the city of Bialystok, Poland in terms of their influence zone. The assessment is based on speed profiles derived from individual test rides conducted with test vehicle equipped with GPS （global positioning system） data logger to obtain vehicle trajectory data. Speed measurements were conducted in vicinity of most commonly installed calming measures such as speed cameras, raised pedestrian crossing, raised intersection, speed bumps and speed cushion. The results reveal great differences within analysed devices and the usefulness of speed profiles in evaluation of their effectiveness. Speed bumps, most frequently used device in practice due to their low cost installation and speed reduction effectiveness, demonstrate lowest usefulness when influence zone is considered.

Potential Energy of Crops

This work consists of estimating the energy achieved from all land and water-based vegetations. This real potential is determined by identifying 10 biomass samples taken from vegetable resources which are favored by their aptitude of adaptation to the conditions of Iran. The net energy values of the 10 biomass samples change in the range of 13.65-18.00 MJ/kg using bomb calorimeter. By means of least squarere regression method all correlations were found. The results of 10 different biomass materials have been used to develop a linear equation correlation.

X-ray repair cross-complementing group 1 polymorphisms and hepatocellular carcinoma:A meta-analysis

AIM： To perform a systematic meta-analysis to in- vestigate the association between X-ray repair crosscomplementing group 1 （XRCC1） polymorphisms and hepatocellular carcinoma （HCC） risk. METHODS： Relevant studies extracted from PubMed, Embase, Wanfang, VIP and the Chinese National Knowledge Infrastructure databases up to March 2012 were included in the study. Stata software, version 11.0, was used for the statistical analysis. The odds ratios （ORs） and 95% confidence interval （CI） of the XRCC1 polymorphisms in HCC patients were analyzed and compared with healthy controls. The meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity. RESULTS： Eleven studies with 2075 HCC cases and 2604 controls met our eligibility criteria （four studies, 888 cases and 938 controls for Arg194Trp, four studies, 858 cases and 880 controls for Arg280His, and nine studies, 1845 cases and 2401 controls for Arg399Gln）. The meta-analysis revealed no associations between the Arg194Trp and Arg399GIn polymorphisms of the XRCC1 gene and HCC risk under all contrast models （codominant, dominant and recessive models） in the overall analysis and sensitivity analysis （the studies with controls not in the Hardy-Weinberg equilibrium were excluded）. For XRCC1 Arg280His polymorphism, the overall analysis revealed the significant associa- tion between the His/His genotype and the increased risk of HCC （His/His vs Arg/Arg model, OR： 1.96, 95% CI： 1.03-3.75, P = 0.04）. However, sensitivity analysis showed an altered pattern of result and non-significant association （OR： 2.06, 95% CI： 0.67-6.25, P = 0.20）. The heterogeneity hypothesis test did not reveal any heterogeneity, and Begg＇s and Egger＇s tests did not find any obvious publication bias. CONCLUSION： The XRCC1 Arg194Trp and Arg399GIn polymorphisms are not associated with HCC risk. More rigorous association studies are needed to verify the involvement ofXRCC1 Arg280His polymorphism in HCC susceptibility.

Research on Wireless Sensor Networks in Agriculture

This paper uses the hardware with ZigBee standard and communication protocol, it consists of wireless sensor network in the greenhouse that can timely sample temperature, humidity, collection of environmental parameters. At the same time, this design uses the GPRS module, the data will be collected through the Internet and send to the PC server, and can receive control instructions from the host computer, through the adjustment of agricultural facilities valve to reverse control environment parameters.

Analytical Architectural Study on Nuclear Power Plants

This paper aims to study the architectural design and components of Nuclear Power Plants （NPPs）. It is also focusing on the simulation system. Its main objective is to set general guidelines for architects. They should be aware of the basics of nuclear facilities designs and components. A traditional nuclear power plant consists of a nuclear reactor, a control building, a turbines building, cooling towers, service buildings （an office building ＆ a medical research center） and a nuclear ＆ radiation waste storage building. Bushehr nuclear power plant in Iran and Angra nuclear power plant in Brazil have been chosen as examples. Furthermore, this paper presents design analyses for Bushehr nuclear power plant and Angra nuclear power plant that include design theory （linear design and radial design） and positive ＆ negative aspects of these designs. At the end of this paper, results and recommendations on the architectural and urban aspects of nuclear power plants are revealed.

Determination of construction art and parameters for passenger dedicated line grouting test within karst area

There are many karst areas within Wuhan-Guangzhou route. Karst grouting is one of the main construction procedures of the sub-grade construction. Through construction art tests,construction principles,water and cementation ratio,grouting construction key points and quality check requirements were determined. Grouting quantity and pressure can be determined according to different geology conditions. Recommendations for quality problems such as bad practicability of grouting,unexpected dissipation of slurry,slurry belching,and overfeeding of slurry going to non-grouting area were proposed.