Ascertainment Corrected Prevalence Rate (ACPR) of Leukopenia in Workers Exposed to Benzene in Small-Scale Industries Calculated With Capture-Recapture Methods

ACPRs of leukopenia in peripheral blood of workers exposed to benzene in small-scale industries are calculated using capture-recapture methods. The results from two figures with 6-month apart demonstrate that the ACPR in workers exposed to benzene is 36.81(29. 14-44.48)%, significantly higher than that of control 12.71(7.20-18.22)% (P<0.05),with a relative risk of 2.9. The prevalences of 4 cross-sectional investigations in exposure group calculated with routine method are 18.73%, 26.37%, 27.93%, and 36.76% respectively;in controls, 8.38%, 6.85%, 7.94%, and 15.00% respectively and all fall in the range of 95% CI of ACPR. It is suggested that the methods of calculating ACPR by capture-recapture methods is simple, feasible and efficient, with the results more precise than with traditional methods.

航空发动机旋转盘腔内部流动换热特性研究进展综述

The rotating disk cavity is an important part of the cooling-air system of the aero engine,and it has obviously significance to study the internal flow and heat transfer characteristics of the disc cavity,which will be helpful to improve the efficiency of the aero engine.This paper summarizes the existing research results of domestic and overseas.The present work considers the test methods and calculation methods of the flow and heat transfer characteristics of the rotating disc cavity of the aircraft engine.It points out that,the main factors which affect the heat transfer characteristics are the disc chamber speed,the intake volume,the design of the disc cavity pre-rotation/despin structure,and the type of disc cavity system.The influence of these factors on the characteristics of flow heat transfer is summarized.Based on these factors,the disc cavity structure can be optimized and designed,which provides suggestions for reducing the weight of the turbine,improving the thrust-to-weight ratio of the aero engine,and improving the cooling efficiency.

Seismic Design Strategy of High Pier Bridge

China’s infrastructure construction has been continuously improving in recent years,especially its highway construction,which spans from north to south and connects east to west.Some special areas are also interconnected through bridges,but constructing highway bridges through complex terrains or across valleys and mountain gullies presents significant challenges,requiring an increase in the height of bridge piers.These bridge piers generally reach tens or even hundreds of meters in height.Furthermore,the construction of these high-pier bridges is becoming increasingly widespread.Not only do they pose greater construction challenges,but they also have higher requirements for seismic resistance.This article primarily analyzes the characteristics of high-pier bridges and proposes seismic design schemes,calculation methods,and design strategies to enhance the construction quality of high-pier bridges.

RESEARCH ON METHOD TO CALCULATE VELOCITIES OF SOLID PHASE AND LIQUID PHASE IN DEBRIS FLOW

Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction, then general equations of velocities of solid phase and liquid phase were founded in two-phase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham＇s rheology equation of liquid phase and Bagnold＇s testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.

Simplified Calculation Methods for All-Vertical-Piled Wharf in Offshore Deep Water

All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static or dynamic calculation methods. In this paper, the finite element method （FEM） and theoretical analysis method are combined to analyze the structural property, bearing behavior and failure mode of the all-vertical-piled wharf in offshore deep water, and to establish simplified calculation methods determining the horizontal static ultimate bearing capacity and the dynamic response for the all-vertical-piled wharf. Firstly, the bearing capability and failure mechanism for all-vertical-piled wharf are studied by use of FEM, and the failure criterion is put forward for all-vertical-piled wharf based on the ＇plastic hinge＇. According to the failure criterion and P-Y curve method, the simplified calculation method of the horizontal static ultimate bearing capacity for all-vertical-piled wharf is proposed, and it is verified that the simplified method is reasonable by comparison with the FEM. Secondly, the displacement dynamic magnification factor for the all-vertical-piled wharf under wave cyclic loads and ship impact loads is calculated by the FEM and the theory formula based on the single degree of freedom （SDOF） system. The results obtained by the two methods are in good agreement with each other, and the simplified calculation method of the displacement dynamic magnification factor for all-vertical-piled wharf under dynamic loads is proposed. Then the simplified calculation method determining the dynamic response for the all-vertical-piled wharf is proposed in combination with P-Y curve method. That is, the dynamic response of the structure can be obtained through the static calculation results of P-Y curve method multiplied by the displacement dynamic magnification factor. The feasibility of the simplified dynamic response method is verified by comparison with the FEM under different conditions.

Dynamic Characteristics and Simplified Numerical Methods of An All-Vertical-Piled Wharf in Offshore Deep Water

There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly affected by wave action. Currently, no systematic studies or simplified numerical methods are available for deriving the dynamic characteristics and dynamic responses of all-vertical-piled wharves under wave cyclic loads. In this article, we compare the dynamic characteristics of an all-vertical-piled wharf with those of a traditional inshore high-piled wharf through numerical analysis; our research reveals that the vibration period of an all-vertical-piled wharf under cyclic loading is longer than that of an inshore high-piled wharf and is much closer to the period of the loading wave. Therefore, dynamic calculation and analysis should be conducted when designing and calculating the characteristics of an all-vertical-piled wharf. We establish a dynamic finite element model to examine the dynamic response of an all-vertical-piled wharf under wave cyclic loads and compare the results with those under wave equivalent static load; the comparison indicates that dynamic amplification of the structure is evident when the wave dynamic load effect is taken into account. Furthermore, a simplified dynamic numerical method for calculating the dynamic response of an all-vertical-piled wharf is established based on the P-Y curve. Compared with finite element analysis, the simplified method is more convenient to use and applicable to large structural deformation while considering the soil non-linearity. We confirmed that the simplified method has acceptable accuracy and can be used in engineering applications.

A Review of the Calculation Methods of Lifting Capacity in Wind Loads on Ocean Platforms

Wind load is a control load that affects the safety of structures in the design of ocean platforms. It has not only direct and powerful effects that may cause structure resonance but also has indirect effects causing waves or currents in the ocean. By analyzing the domestic and international norms, this study presents a review of calculation methods of wind load on ocean platforms, which belongs to large-scale non-entity structure used in the open sea while surrounding wind has no fixed direction. Current computations according to the norms are not accurate, which even not takes the force of the wind against the surface perpendicular to the structure into consideration. Additionally, this study also introduces and compares the lift model of platforms based on different theories, such as vortex-excitation and vibration, engineering structure dynamics, gas flow pressure theory, analyzing their applicability, advantages, and disadvantages. This paper analyzes the limitations and applicable conditions of the existing calculation method itself, such as the lift model is suitable for the existence of stable vortex wake;the calculation method of the structural dynamics of marine engineering must be combined with the wind tunnel test and consider the mistakes caused by the position relationship;the numerical simulation method is accurate but tedious. This study provides an insight into the calculation methods of lift in designing ocean platforms, including the finite element method for simulating fluid force and updating formulas in Chinese norms.

Comparison of Calculation Methods for Potential Reference Crop Evapotranspiration ET_0 in North Xinjiang

Reference crop evapotranspiration (ET_0) is a critical part in water cycle and water balance of ecosystem, which is greatly important to effective utilization of agricultural water resources and for making reasonable irrigation system. In order to propose a suitable method for computing ET_0 in North Xinjiang, based on daily meteorological data from May 1 to September30, 2010 provided by Weather Station of Fuhai County, we used FAO56 Penman-Monteith as the standard formula to compute ET_0, compared the differences and relations between such the method and other 4 calculation formulas, and analyzed the cause of the deviation, finally evaluated the applicability of computational method in North Xinjiang. The results showed that the calculation results by FA056 PM Method was approximate to that by FAO Penman method and IA method, of which the relative error was 9.26% and 13.51% respectively, the ET_0 results calculated by PT method and HS method were generally greater than the results by FAO56 PM, and their deviation was very obvious.

A SIMPLE METHOD TO CALCULATE RESONANCE ENERGY

A very simple method to calculate resonance energies of conjugated hydrocarbons by counting carbon numbers was introduced.

Electronic States of Difluorocarbene Calculated by Multireference Configuration Interaction Method

We investigate the geometries and energies of seven electronic states X-1A1, A1B1, a-3B1, B-1A2,b-3A2, C1B2 and c-3B2 of CF2 carbene using internally contracted multireference configuration interaction methods including Davidson correction （icMRCIq-Q） with different basis sets aug-cc-pVXZ （X=T, Q, 5）. For the first time, the potential energy curves of electronic states of CF2 related icMRCI＋Q/aug-cc-pVTZ level. The ab initio results will and dynamics of electronic states of CF2 radical. to the lowest dissociation limit are calculated at the further increase our understanding of the structures

Optimization of the Algorithm for Increasing Injection Rate in Water Injection Wells for Pressure Optimization in P Oilfield

In today’s society, with the continuous growth of energy demand, Bohai Oilfield, as an important offshore oil resource base in China, is facing increasingly severe challenges while contributing to national energy security. In order to improve the quality of water injection in the oilfield and gradually achieve efficient and stable production, Bohai Oilfield has launched a water injection well pressure optimization project, focusing on improving the efficiency and quality of water injection in the water injection wells, in order to achieve the optimal water injection plan. In practical work, P Oilfield continues to promote the development of water injection well pressure optimization projects, emphasizing practical exploration and continuous optimization of work plans. However, during the project implementation process, there were some problems, one of which was that the statistics of cumulative injection volume were not scientific enough, resulting in a more comprehensive and accurate presentation of the actual results of pressure optimization work. In the context of continuous improvement work, after careful analysis and research, P Oilfield has decided to optimize the cumulative injection rate algorithm to guide the oilfield’s water injection work in a more refined way, ensuring sufficient and good water injection, and enhancing the oilfield’s production efficiency and comprehensive competitiveness.

Standardized Distance from the Mean to the Median as a Measure of Skewness

The normal distribution, which has a symmetric and middle-tailed profile, is one of the most important distributions in probability theory, parametric inference, and description of quantitative variables. However, there are many non-normal distributions and knowledge of a non-zero bias allows their identification and decision making regarding the use of techniques and corrections. Pearson’s skewness coefficient defined as the standardized signed distance from the arithmetic mean to the median is very simple to calculate and clear to interpret from the normal distribution model, making it an excellent measure to evaluate this assumption, complemented with the visual inspection by means of a histogram and a box-and-whisker plot. From its variant without tripling the numerator or Yule’s skewness coefficient, the objective of this methodological article is to facilitate the use of this latter measure, presenting how to obtain asymptotic and bootstrap confidence intervals for its interpretation. Not only are the formulas shown, but they are applied with an example using R program. A general rule of interpretation of ∓0.1 has been suggested, but this can only become relevant when contextualized in relation to sample size and a measure of skewness with a population or parametric value of zero. For this purpose, intervals with confidence levels of 90%, 95% and 99% were estimated with 10,000 draws at random with replacement from 57 normally distributed samples-population with different sample sizes. The article closes with suggestions for the use of this measure of skewness.

我国三级公立医院绩效考核指标评分方法分析

基于某市三级公立医院绩效考核实践,指出用加权逼近理想解排序法及全国三级公立医院绩效考核评分办法参考说明中推荐的评分方法进行考核存在的问题与不足,并提出改进和优化评分方法的思路,为构建更加科学公正的绩效考核体系提供新的思路和方法。

Calculating Method for Influence of Material Flow on Energy Consumption in Steel Manufacturing Process

From the viewpoint of systems energy conservation, the influences of material flow on its energy consumption in a steel manufacturing process is an important subject. The quantitative analysis of the relationship between material flow and the energy intensity is useful to save energy in steel industry. Based on the concept of standard material flow diagram, all possible situations of ferric material flow in steel manufacturing process are analyzed. The expressions of the influence of material flow deviated from standard material flow diagram on energy consumption are put forward.

A MODEL FOR NUMERICAL CALCULATION OF UNSTEADYTEMPERATURE FIELD

The model established in this paper for calculating the unsteady temperature field, in which physical parameters varies with temperatures, is simplified as compared with the classical one by defining the heat conductivity as function of temperature and dealing with the latent heat of phase transformation and boundary conditions. The results show that the probability of absolute error less 2℃ between the calculated and measured values in temperature field calculation reaches above 80%.

A Fast Approach for Predicting Aerodynamic Noise Sources of High-Speed Train Running in Tunnel

The aerodynamic noise of high-speed trains passing through a tunnel has gradually become an important issue.Numerical approaches for predicting the aerodynamic noise sources of high-speed trains running in tunnels are the key to alleviating aerodynamic noise issues.In this paper,two typical numerical methods are used to calculate the aerodynamic noise of high-speed trains.These are the static method combined with non-reflective boundary conditions and the dynamic mesh method combined with adaptive mesh.The fluctuating pressure,flow field and aerodynamic noise source are numerically simulated using the abovemethods.The results showthat the fluctuating pressure,flow field structure and noise source characteristics obtained using different methods,are basically consistent.Compared to the dynamic mesh method,the pressure,vortex size and noise source radiation intensity,obtained by the static method,are larger.The differences are in the tail car and its wake.The two calculation methods show that the spectral characteristics of the surface noise source are consistent.The maximum difference in the sound pressure level is 1.9 dBA.The static method is more efficient and more suitable for engineering applications.

Simulation Research on Dynamic Characteristics of Hydraulic Mount

At present,research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle.Compared to the traditional finite element analysis method,the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss angle.The aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount,and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters,so as to use suitable parameters as the basis for vibration analysis.A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid dynamics.The dynamic stiffness and loss angle of the dimensionless expression were proposed.A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived.A one-to-one correspondence was established between the structural parameters and peak frequency of the evaluation index.The accuracy and applicability of the mechanical model were verified by the test results.The results demonstrated the accuracy of the nonlinear mechanical model of the hydraulic mount,and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.

Ranking Method for Complementary Judgment Matrixes with Fuzzy Numbers Based on Hausdorff Metric Distance

A method for ranking complementary judgment matrixes with traspezoidal fuzzy numbers based on Hausdorff metric distance and fuzzy compromise decision approach is proposed. With regard to fuzzy number complementary judgment matrixes given by a decider group whose members have various weights, the expert＇s information was aggregated first by means of simple weight average（SWA） method and Bonissone calculational method. Hence a matrix including all the experts＇ preference information was got. Then the matrix＇ column members were added up and the fuzzy evaluation values of the alternatives were got. Lastly, the Hausdorff metric distance and fuzzy compromise decision approach were used to rank the fuzzy evaluation values and then the ranking values of all the alternatives were got. Because exact numbers and triangular fuzzy numbers could all be transformed into trapezoidal fuzzy numbers, the method developed can rank complementary judgment matrixes with trapezoidal fuzzy numbers, triangular fuzzy numbers and exact numbers as well. An illustrative example is also given to verify the developed method and to demonstrate its feasibility and practicality.

Electronic structure and optical properties of Ge-and F-doped α-Ga2O3:First-principles investigations

The prospect ofα-Ga2O3 in optical and electrical devices application is fascinating.In order to obtain better performance,Ge and F elements with similar electronegativity and atomic size are selected as dopants.Based on density functional theory(DFT),we systematically research the electronic structure and optical properties of dopedα-Ga2O3 by GGA+U calculation method.The results show that Ge atoms and F atoms are effective n-type dopants.For Ge-dopedα-Ga2O3,it is probably obtained under O-poor conditions.However,for F-dopedα-Ga2O3,it is probably obtained under O-rich conditions.The doping system of F element is more stable due to the lower formation energy.In this investigation,it is found that two kinds of doping can reduce theα-Ga2O3 band gap and improve the conductivity.What is more,it is observed that the absorption edge after doping has a blue shift and causes certain absorption effect on the visible region.Through the whole scale of comparison,Ge doping is more suitable for the application of transmittance materials,yet F doping is more appropriate for the application of deep ultraviolet devices.We expect that our research can provide guidance and reference for preparation ofα-Ga2O3 thin films and photoelectric devices.

Maximum Overlap Symmetry Molecular Orbital Calculation under CNDO／2 Approximation

A basic calculation procedure for the MOSMO method under CNDO/2 approximation is presented in this paper,and performed by using the same parameters as those used in the ordinary CNDO/2 LCAO-MO calculation.The calculated results on the whole are close to those obtained by use of the ordinary CNDO/2 LCAO-MO calculation,illustrating that the presented procedure is reasonable.Due to its simplicity,the presented calculation procedure may be feasible even in very large molecular s ystems.