Basic Problems in Design and Inverse Engineering Solution for Outer Characteristic of Vehicle Suspension Shock Absorbers

Based on the theory and the practical experiences of linearity design of feasible design area and inverse solution of non linear outer characteristic of suspension shock absorber, in accordance with non linearity outer characteristic formed by open up damping coefficient, full open damping coefficient and smoothness to safety ratio of suspension shock absorber, a method and a research conclusion of the feasible design and inverse solution for the basic problems of designing and inverse solution of non linear outer characteristic of suspension damping components are provided.

A New Proposal of Inverse-Time Characteristics for Overcurrent Relay Based on Microcomputer

The conventional time function of electromechanical relays is hard to coordinate with other relays. In order to promote the application of inverse-time overcurrent relays, a new time function for microprocessor-type relay is proposed. The setting of the trip time for this relay is performed by determining the shortest trip time and the longest trip time, respectively. The results of analysis show that with the new time function, the inverse-time overcurrent relay is easy to coordinate with other relays and has a comparatively shorter trip time, and that the fault happens in the protective zone.

Prestack seismic stochastic inversion based on statistical characteristic parameters

In the conventional stochastic inversion method,the spatial structure information of underground strata is usually characterized by variograms.However,effectively characterizing the heterogeneity of complex strata is difficult.In this paper,multiple parameters are used to fully explore the underground formation information in the known seismic reflection and well log data.The spatial structure characteristics of complex underground reservoirs are described more comprehensively using multiple statistical characteristic parameters.We propose a prestack seismic stochastic inversion method based on prior information on statistical characteristic parameters.According to the random medium theory,this method obtains several statistical characteristic parameters from known seismic and logging data,constructs a prior information model that meets the spatial structure characteristics of the underground strata,and integrates multiparameter constraints into the likelihood function to construct the objective function.The very fast quantum annealing algorithm is used to optimize and update the objective function to obtain the fi nal inversion result.The model test shows that compared with the traditional prior information model construction method,the prior information model based on multiple parameters in this paper contains more detailed stratigraphic information,which can better describe complex underground reservoirs.A real data analysis shows that the stochastic inversion method proposed in this paper can effectively predict the geophysical characteristics of complex underground reservoirs and has a high resolution.

Study on optical constants inversion and infrared transmission characteristics of aerosol particles

Based on the experimental infrared spectral transmittances,an inverse model has been developed to determine the optical constants of the aerosol particles (SiO2 and Al2O3).Combined with the Mie theory and Kramers-Kronig (K-K) relations,the complex refractive indices of the SiO2 and Al2O3 particles are retrieved.The effects of the measurement errors on the inverse results are also investigated.With the optical constants inversed from the experiment,the discrete ordinate method (DOM) is used to calculate the infrared transmission characteristics of the aerosol particle cloud.Considering the multi-scattering and self-emission of the particles,the equivalent transmittance ratio (ETR) is suggested to evaluate the infrared transmission characteristics of the aerosol particles.Particular attention is given to analyze the effects of the volume fraction and diameters on infrared transmission characteristics.When the volume fraction is larger than 0.001,the particle diameter has little effect on the infrared transmission characteristics.For the uniform monodisperse particles in the detection waveband range of 3-5 μm and 8-12 μm,there exists a critical diameter where the ETR reaches the minimum value.In addition,the ETR of 3-5 μm is smaller than that of 8-12 μm with the same volume fraction and particle diameter.

Graded and Quantitative Technology and Application of Coal-Bearing Reservoir Based on Seismic Reflection Characteristics

Taiyuan formation is the main exploration strata in Ordos Basin, and coals are widely developed. Due to the interference of strong reflection of coals, we cannot completely identify the effective reservoir information of coal-bearing reservoir on seismic data. Previous researchers have studied the reservoir by stripping or weakening the strong reflection, but it is difficult to determine the effectiveness of the remaining reflection seismic data. In this paper, through the establishment of 2D forward model of coal-bearing strata, the corresponding geophysical characteristics of different reflection types of coal-bearing strata are analyzed, and then the favorable sedimentary facies zones for reservoir development are predicted. On this basis, combined with seismic properties, the coal-bearing reservoir is quantitatively characterized by seismic inversion. The above research shows that the Taiyuan formation in LS block of Ordos Basin is affected by coals and forms three or two peaks in different locations. The reservoir plane sedimentary facies zone is effectively characterized by seismic reflection structure. Based on the characteristics of sedimentary facies belt and petrophysical analysis, the reservoir is semi quantitatively characterized by attribute analysis and waveform indication, and quantitatively characterized by pre stack geostatistical inversion. Based on the forward analysis of coal measure strata, this technology characterizes the reservoir facies belt through seismic reflection characteristics, and describes coal measure reservoirs step by step. It effectively guides the exploration of LS block in Ordos Basin, and has achieved good practical application effect.

Boundary Layer Characteristics and Numerical Simulation Analysis of Winter Dense Fog in Nanjing

Based on the boundary layer data of winter dense fog in 2007 from Nanjing University of Information Science & Technology,the profile characteristics of temperature,wind direction,wind speed and humidity in a dense fog weather on December 13-14 in 2007 were analyzed,as well as their evolution laws in the formation and dispersion of fog,and the boundary layer characteristics of winter dense fog in Nanjing were revealed,while the development of fog was simulated by means of mesoscale numerical model.The results showed that the formation and dispersion of fog was greatly affected by inversion and humidity in the surface layer,and the wind direction in the surface layer also had effect on the formation and dispersion of advection fog.Mesoscale numerical model could preferably simulate the evolution of temperature,humidity,vertical speed in the development of fog,and the simulation of water vapor content in the fog could forecast the formation and dispersion of fog.

The seismic reflecting characteristics of gas hydrate bearing strata and its possible distribution in the South China Sea

The research on gas hydrate is one of the topics of general interest in the field of energy resource and environment. The South China Sea has favorable conditions for the occurrence and formation of gas hydrate. The presence of gas hydrate changes acoustic properties of the sedimentary strata and results in the occurrence of bottom simulating reflectors, which makes the multi-channel seismic investigation an important method to identify gas hydrates. First, the paper, based on results of seismic reflection imaging, analyzes the qualitative seismic reflection characteristics of sedimentary strata containing gas hydrate. Some key seismic imaging techniques are also discussed. Next, a pseudo-well is constructed to perform an impedance inversion to get the quantitative velocity structure of the strata since there is no well in the study area. Finally, the velocity field from geophysical inversion is integrated with the geochemical and geophysical data acquired on the Ocean Drilling Program 184 cruise. All information confirms the presence of gas hydrate and shows its spatial distribution.

Inverse Eigenvalue Problem for Generalized Arrow-Like Matrices

This paper researches the following inverse eigenvalue problem for arrow-like matrices. Give two characteristic pairs, get a generalized arrow-like matrix, let the two characteristic pairs are the characteristic pairs of this generalized arrow-like matrix. The expression and an algorithm of the solution of the problem is given, and a numerical example is provided.

Generalized Cayley-Hamilton theorem for core-EP inverse matrix and DMP inverse matrix

By using the classical Cayley-Hamilton theorem,the polynomial equations of the core-EP inverse matrix and Drazin-Moore-Penrose(DMP)inverse matrix are given,respectively.If the characteristic polynomial of the singular matrix A,p A(s)=det(s E n-A)=s n+a n-1 s n-1+…+a 1 s,is given,then f A(A)=0 and f A(A d,+)=0 in which f A(A)=a 1 x n+a 2 x n-1+…+a n-1 x 2+x,and A and A d,+are the core-EP inverse and the DMP inverse of A,respectively.Furthermore,some properties of the characteristic polynomials of A D∈C n,n and A∈C n,n are derived.

Analysis of Weather Element Characteristics and Air Pollution Status during Continuous Fog Days in Liaoning

[Objective] The aim was to discuss the formation, duration and disappearance of fog. [Method] Based on the weather data and physics of Liaoning Province, and considering the continuous 4 foggy days in 11 places in Liaoning from November 29 to December 2, 2009, detailed analysis of this consecutive foggy days was given proceeding from the weather situation, element characteristics, especially the occurrence, duration and disappearance of dense fog. [Result] This dense fog was because that Liaoning was in the saddle pressure field. The weak cold air divergence set the ground in many weak mild scale convergence areas. The high temperature in the early time resulted in melting snow and long duration of dense fog days, along with radiation low temperature and southwest convergence transmission. In the meantime, because of the existence of small wind speed and existence of upper inversion temperature layer, it was inconvenient for the divergence of wet air; in addition, there was dense fog in north China. The upper southwest airstream transmitted wet air in the north China to the air of Liaoning, increasing the intensity of dense fog in Liaoning. [Conclusion] The study offered reference for the further forecast of air pollution.

Spatial interfacial heat transfer and surface characteristics during gravity casting of A356 alloy

As one of the key boundary conditions during casting solidification process, the interfacial heat transfer coefficient (IHTC) affects the temperature variation and distribution. Based on the improved nonlinear estimation method (NEM), thermal measurements near both bottom and lateral metal-mold interfaces throughout A356 gravity casting process were carried out and applied to solving the inverse heat conduction problem (IHCP). Finite element method (FEM) is employed for modeling transient thermal fields implementing a developed NEM interface program to quantify transient IHTCs. It is found that IHTCs at the lateral interface become stable after the volumetric shrinkage of casting while those of the bottom interface reach the steady period once a surface layer has solidified. The stable value of bottom IHTCs is 750 W/(m^2·℃), which is approximately 3 times that at the lateral interface. Further analysis of the interplay between spatial IHTCs and observed surface morphology reveals that spatial heat transfer across casting-mold interfaces is the direct result of different interface evolution during solidification process.

Quantitative description of infrared radiation characteristics of preflawed sandstone during fracturing process

Previous studies show that infrared radiation temperature(IRT)abnormalities are always accompanied by the crack development in rocks under external loads.In this context,experiments were conducted on preflawed sandstone to investigate the infrared radiation characteristics during failure process.Two indicators were defined herein,i.e.coefficient of variation of IRT(CVIRT)and skewness of IRT(SIRT).The regression analysis shows that the IRT probability distributions during loading process fit the Gaussian model.The variations in the CVIRT are characterized by four stages:primary stage,steady stage,accelerating stage and post-peak stage.Besides,the variations in the SIRT are divided into three stages:primary stage,steady stage and failure and post-peak stage.The precursor point for preflawed rock failure is identified based on the CVIRTetime curve,with average precursor point of 83%of the peak stress.Compared with other IRT indicators,the proposed two IRT indicators have higher sensitivity to IRT abnormalities during failure process.Furthermore,the connection between the IRT indicators and the rock fracturing was investigated to interpret the IRT indicator abnormalities.Based on the Verhulst inverse function,a new quantitative model was presented to describe the primary stage,steady stage and accelerating stage of the CVIRTetime curve.The results obtained in this study can provide early-warning information for rock failure prediction.

Integrative method in lithofacies characteristics and 3D velocity volume of the Permian igneous rocks in H area, Tarim Basin

This paper introduces horizon control, seismic control, logging control and facies control methods through the application of the least squares fitting of logging curves, seismic inversion and facies-controlled techniques. Based on the microgeology and thin section analyses, the lithology, lithofacies and periods of the Permian igneous rocks are described in detail. The seismic inversion and facies-controlled techniques were used to find the distribution characteristics of the igneous rocks and the 3D velocity volume. The least squares fitting of the logging curves overcome the problem that the work area is short of density logging data. Through analysis of thin sections, the lithofacies can be classified into eruption airfall subfacies, eruption pyroclastic flow subfacies and eruption facies.

Experimental Studies on High-Frequency Performance of the Inverse Control Magneto-Rheological Damper

Severe vibration of underground structures may be induced under blast loads. According to the characteristics of the explosion-induced ground shock wave, a new-type damper, inverse control magneto-rheological（MR） damper was designed to control the vibration, The high-frequency performance test of the MR damper was carried out on the small shaking table. It is shown that the performance can be modeled by use of the modified Bouc-Wen model, and the Parameters of the model keep stable in the range of 15--50 Hz.

Comparison of Surface Characteristics of Mesoporous Titania Prepared in Matrix-Free Solutions and Using Triton X Reverse Micelles

Titania nanoparticles have been prepared from the precursor compound Ti(OiPr)4 using Triton X reverse micelles with varying surfactant tail, in a matrix-free aqueous (pH 2) and in non-aqueous phase (benzyl alcohol and glacial acetic acid, solvothermal method). The importance of this work lies in the further elucidation in the synthetic methodology of preparing well-characterized nanoporous solids. Comparison of the texture characteristics and surface properties of the samples prepared from each technique, was carried out using physicochemical techniques: pXRD, ΒΕΤ/DFT/BJH, FTIR, DRUV-Vis and SEM. The results show that the use of Triton X reverse micelles with varying surfactant size results in TiO2 solids with adjustable surface characteristics in contrast to matrix-free. Specifically, samples of the latter methods present higher surface area values at lower calcination temperatures but present reduced thermal stability and control of their surface properties.

Some Equations for the External Space and Their Implications on the Inverse Cone Concept and the Geometry of the Physical Universe

In previous works, they were proposed a photonic model of the Big Bang [1] and several parameters derived from the Hubble-Lemaitre equation [2]. Since these parameters result higher than the classical ones and, otherwise, the General Theory of Relativity does not apply far away the Physical Universe, in this paper, it will be revised the adequacy of such parameters in the external Space and their influence on the relativistic concept of the cone of time. As well, it will be intended to define the Physical Universe geometry accordingly to a thermo-dynamical analysis of the Big Bang.

Extraction of gravel characteristics and spatial inversion for ecological restoration monitoring in the Northern Tibetan Plateau

Previous studies have often focused on monitoring grassland growth as the primary target of remote sensing investigations on grassland ecological restoration in the northern Tibetan Plateau,overlooking the crucial role played by gravel in the ecological restoration of these grasslands.This study utilizes supervised classification and segmentation techniques based on machine learning to extract gravel morphology profiles from field-sampled plot images and calculate their characteristic parameters.Employing a multivariate linear approach combined with Principal Component Analysis(PCA),a model for inferring gravel characteristic parameters is constructed.Statistical features,particle size characteristics,and spatial distribution patterns of gravel are analyzed.Results reveal that gravel predominantly exhibit sub-rounded shapes,with 80%classified as fine gravel.The coefficients of determination(R2)between gravel particle size and coverage,perimeter,and area are 0.444,0.724,and 0.557,respectively,indicating linear relationships.The cumulative contribution rate of the top five remote sensing factors is 95.44%,with the first geological factor contributing 77.64%,collectively reflecting the primary information of the 20 factors used.Modeling shows that areas with larger gravel particle sizes correspond to increased perimeter and coverage.Gravels in the Nagqu Prefecture of northern Tibet have a particle size range of 4-8 mm,primarily comprising fine gravel which accounts for 94.61%.These findings provide a scientific basis for extracting gravel characteristic parameters and understanding their spatial distribution variations in the northern Tibetan Plateau.

河南省典型农区近地表大气氨时空分布特征及主要影响因素

【目的】农田氨挥发是大气颗粒物中铵盐的主要来源之一,对城市和农村空气质量有密切影响。对河南省典型农区近地表大气氨浓度时空变化特征及关键影响因素进行系统研究,为农田区域大气颗粒污染物的针对性治理提供科学依据。【方法】选取河南省10个代表性农田区域(小麦-玉米轮作区),利用被动法,开展为期两年的近地表大气氨浓度监测与驱动因素研究。【结果】从时间上(季节性)来看,不同季节近地表大气氨浓度差异较大,其中夏季近地表大气氨平均浓度最高,为12.0μg N·m^(-3),其次为春季和秋季,均值分别为10.8和8.9μg N·m^(-3),冬季最低,均值仅为6.7μg N·m^(-3)。从空间上来看,豫东开封农田区域氨浓度最高,其年平均氨浓度可达14.7μg N·m^(-3),其次为豫北新乡和安阳,其年均大气氨浓度分别为12.5和11.0μg N·m^(-3),再次为豫中郑州和豫北的焦作,其近地表大气氨浓度分别为10.9和10.6μg N·m^(-3),而豫西的洛阳、平顶山、豫南许昌、漯河和黄泛区(周口)的近地表大气氨浓度较低,其数值介于7.9—9.6μg N·m^(-3)之间。从土壤类型来看,不同土壤类型近地表大气氨浓度存在明显不同,其中潮土近地表大气氨浓度最高,为11.0—14.7μg N·m^(-3),褐土和黄褐土区其氨浓度介于9.0—9.6μg N·m^(-3)之间,砂姜黑土和黄棕壤农田区域氨浓度较低,为8.06—8.11μg N·m^(-3)。不同区域的近地表大气氨浓度高低是多重因素共同作用的结果,其中氮肥施用量和土壤pH与近地表大气氨浓度存在显著的正相关关系,降雨量与近地表大气氨浓度存在显著的负相关关系,几种因素的交互作用导致河南省农田系统近地表大气氨浓度差异较大。【结论】基于以上研究结果,降低施氮量有助于系统性降低河南省农田区域近地表氨浓度;豫北和豫东农田区是重点关注区域。

基于逆温层基差风险的浙江茶叶低温气象指数保险

利用2008−2019年浙江省杭州市春季(2−4月)逐日探空资料和欧洲中期天气预报中心第五代再分析数据集(ERA5),分析逆温层的时空分布特征、量化垂直空间基差风险,为优化茶叶气象指数保险方案设计、约定测站选择及向茶农宣导逆温层现象提供理论依据。结果表明:(1)现有气象站在垂直方向的分布密度尚不能覆盖参保区域的整体风险性,即使约定测站与参保标的距离相近,也会因海拔差、逆温层等原因导致垂直基差风险。(2)杭州地区2月逆温层厚度和强度高于3月、4月,2月开采的早生茶树品种需谨慎选择约定测站以降低基差风险。(3)气象指数厘定灾损和实际灾损存在差异,处于逆温层的参保户可能面临较大垂直空间基差风险,需建立基于海拔的精细化理赔产品,依海拔进行投保及理赔,从而降低垂直空间基差风险。

Low-Level Temperature Inversions and Their Effect on Aerosol Condensation Nuclei Concentrations under Different Large-Scale Synoptic Circulations

Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results gen- erated using the self-organizing map （SOM） weather classification method, this study compares the statistical characteristics of surface-based inversions （SBIs） and elevated inversions （EIs）, and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei （CN） concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains （SGP） site during 2001-10. Large-scale synoptic patterns strongly influ- ence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The verti- cal distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN con- centrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground.