A consecutive joint shear strength model considering the 3D roughness of real contact joint surface

A consecutive joint shear strength model for soft rock joints is proposed in this paper,which takes into account the degradation law of the actual contact three-dimensional(3D)roughness.The essence of the degradation of the maximum possible dilation angle is the degradation of the 3D average equivalent dip angle of the actual contact joint asperities.Firstly,models for calculating the maximum possible dilation angle at the initial and residual shear stress stages are proposed by analyzing the 3D joint morphology characteristics of the corresponding shear stages.Secondly,the variation law of the maximum possible dilation angle is quantified by studying the degradation law of the joint micro convex body.Based on the variation law of the maximum possible dilation angle,the maximum possible shear strength model is proposed.Furthermore,a method to calculate the shear stiffness degradation in the plastic stage is proposed.According to the maximum possible shear strength of rock joints,the shear stress-shear displacement prediction model of rock joints is obtained.The new model reveals that there is a close relationship between joint shear strength and actual contact joint roughness,and the degradation of shear strength after the peak is due to the degradation of actual contact joint roughness.

A rigid-flexible coupling finite element model of coupler for analyzing train instability behavior during collision

Rail vehicles generate huge longitudinal impact loads in collisions.If unreasonable matching exists between the compressive strength of the intermediate coupler and the structural strength of the car body,the risk of car body structure damage and train derailment will increase.Herein,a four-stage rigid-flexible coupling finite element model of the coupler is established considering the coupler buckling load.The influence of the coupler buckling load on the train longitudinal-vertical-hori-zontal buckling behavior was studied,and the mechanism of the train horizontal buckling instability in train collisions was revealed.Analysis results show that an intermediate coupler should be designed to ensure that the actual buckling load is less than the compressive load when the car body structure begins to deform plastically.The actual buckling load of the coupler and the asymmetry of the structural strength of the car body in the lateral direction are two important influencing factors for the lateral buckling of a train collision.If the strength of the two sides of the car body structure in the lateral direction is asymmetrical,the deformation on the weaker side will be larger,and the end of the car body will begin to deflect under the action of the coupler force,which in turn causes the train to undergo sawtooth buckling.

Changing the Air Parameters in the Cotton Pneumatic Transport Pipe

This scientific article examines the issue of changes in the density and speed of the airflow in the pipeline pneumatic conveying equipment used in ginneries, analyzes the causes of changes in the density and speed of air.

Evaluation of Actual Evapotranspiration and Crop Coefficient in Carrot by Remote Sensing Methodology Using Drainage and River Water to Overcome Reduced Water Availability

Searching for alternative methods for traditional irrigation is World trend at days due to a reduction in water and increased of drought due to climate changes therefore farmers need use modern methods of scheduling water and minimizing water losses while also increasing yield. To meet the future increasing demands water and food there is a need to utilize alternative methods to reduce evaporation, transpiration and deep percolation of water. Any countries use recycled water (drain and sewage) and desalination water from the sea or drains to irrigate crops plus computing actual crop evapotranspiration (ETc) so as to calculate the amount of water to apply to a crop. The paper aims to assess the actual evaporation and evaporation coefficient of carrots, by planting carrots in a field and the crop was exposed to several sources of water (DW and RW) and comparing ETc, Kc and production among plots of three sites (A, B and C). The study used two types of irrigation water (drain water (DW) and river water (RW)). The results were to monthly rate and accumulated actual evapotranspiration to C (irrigation by RW only) more than A (67% RW and 33% DW) and B (17% RW and 83% DW) via 7% and 58%, respectively. The yield to C more than A and B by 17% and 75%, respectively. In conclusion the use of DW can cause a reduction in crop consumptive of carrot crops also causes a reduction in yield, crop length, root length, root size, canopy of crop, number of leaves and biomass of the plant therefore, the drainage water needs to treated before irrigating crops And making use of it to irrigate the fields and fill the shortfall in the amount of water from the river. The drain water helped on filling the water shortage due to climate changes and giving production of carrot crop but less than river water.

西安市东大温泉度假区游客满意度评价

西安市东大温泉度假区位于陕西省西安市长安区西部东大镇的行政辖区内,距西安市中心32km,其南倚秦岭北麓,北俯关中平原。度假区占地面积约15km2,区内地热资源丰富,具有埋藏浅、水温高、出水量大、承压自喷等特点。

生态公园营建中农耕文化主题的运用——以重庆白云寨生态示范园为例(英文)

Definitions and features of eco-park and theme park were introduced as well as their differences, it was proposed that by applying cultural themes suited to regional ecological resources in the construction of eco-park, the eco-park could achieve not only desired ecological benefits, but also social and economic benefits, and the optimal comprehensive benefits. Design of Baiyunzhai Demonstration Eco-park was taken for an example, integration of eco-park and farming culture was confirmed as the nature, principles of "adaptation to actual conditions, amended protection and construction of plant system" proposed, three functional areas of "Colorful Forest Belt, Yiyun Health Maintenance Zone, Lakefront Meditation Zone" are given on the basis of actual terrains, planning highlights and desired landscape effects expounded to promote the value of regional cultures in Chongqing by building Baiyunzhai Eco-park.

高考英语模拟练习(中)

第三部分:阅读理解(共20小题) 阅读下列短文,从每题所给的四个选项中,选出最佳选项。 A Fatigue(疲劳)can actually be considered akind of poisoning.When a muscle(肌肉)in ourbody works,it produces lactic acid(乳酸).If weremove the lactic acid from a tired muscle,it willbe able to start working again at once.

《英美文学选读》辅导(13)

Ⅰ.文学常识1.Calvinism (加尔文主义) -It is the theological system of John Calvin. Its key principle is that God, not man, is central and supreme. Hence scripture is the source of doctrine.2. original sin (原罪)-In Christian theology, it is the state of sinfulness in which all mankind

四、六级难句攻关(46)

1.Is the belief that marriage is between a man and a woman—until recently common even in liberal circles—now presumed so bigoted as to deserve no consideration,even when the exercise of this belief does not actually keep gays from marrying？（Washington News,Feb.24,2014）翻译：婚姻是男女之间的结合,这种观念直到最近就算在思想开明的圈子里都很常见。即便这种观念并不妨碍同性恋者结婚,如今难道也被认为古板而不值得考虑吗？

考研翻译能力训练(85) 脱欧的悲剧

从难以想象到覆水难收,这一切的发展是多么迅速。一年前几乎没有人能想到,众多喜欢抱怨欧盟（规章制度愚蠢、预算庞大、充斥浮夸官僚主义）的英国人,竟然真的会投票退出这个购买其近一半出口物的国家俱乐部。然而,到了6月24日凌晨,选民们显然不顾经济学家、盟友和本国政府的警告,在作为欧盟成员40多年后，即将大胆迈入未卜的前程。

应对英语四级听力选择题的10大原则

对于非英语专业的大学生而言,大学英语四级考试的阅读和写作部分不难过关,能否顺利通过英语四级往往取决于听力是否及格。英语四级听力部分的分值占总分的35%,其中英语听力选择题所占比例为25%。下面笔者将从听前预读选项、听时把握重点和听后答题要点三个方面来介绍解答听力选择题的10大原则,希望对考生答题有所帮助。听前预读选项由于英语四级考试的命题人是在知道正确答案的基础上来编写其他干扰项的,所以这些干扰项或多或少会和正确答案有关联。因此,考生在听前预读选项时。

《电大英语》第三册模拟试题

Ⅲ.每道题下有A,B,C和D四个选项。根据句子的意思,其中只有一个是正确的。将正确的选项选出,并将答案写在答题纸的相应题号旁。

Selective extraction and conversion of lignin in actual biomass to monophenols: A review

Our over dependency on the fossil resource for industrial chemicals and fuels faces great challenges.Recently, the production of monophenols from lignin in lignocellulosic biomass is regarded as a promising process for sustainable biofuels. This article discusses the conversion of lignin in actual biomass directly to monophenols. The two step way including extraction of lignin from biomass and further degradation of the lignin oligomers to monophenols is especially discussed. The obtained monophenols can also be converted to chemicals with low-oxygen content via hydrodeoxygenation process. For extraction of lignin,co-solvent system is the most adopted for hydrolysis or solvolysis of lignin assisted by acid or alkaline catalysts. The structure of the obtained oligomers derived from lignin is discussed in detail. For lignin depolymerization, hydrogenolysis is an efficient method with the use of gaseous hydrogen or alcohols as hydrogen source. At the meantime, depolymerization mechanism and the route for repolymerization of the reaction intermediates are presented here. In hydrodeoxygenation process, metal catalysts, especially noble metal catalysts are required. The precise effects of the reaction solvents and catalysts on extraction and degradation of lignin need to be further investigated, and this will benefit to design more efficient strategies for lignin utilization.

Actual evapotranspiration of subalpine meadows in the Qilian Mountains, Northwest China

As a main component in water balance,evapotranspiration(ET)is of great importance for water saving,especially in arid and semi-arid areas.In this study,the FAO(Food and Agriculture Organization)Penman-Monteith model was used to estimate the magnitude and temporal dynamics of reference evapotranspiration(ET0)in 2014 in subalpine meadows of the Qilian Mountains,Northwest China.Meanwhile,actual ET(ETc)was also investigated by the eddy covariance(EC)system.Results indicated that ETc estimated by the EC System was 583 mm,lower than ET0(923 mm)estimated by the FAO Penman-Monteith model in 2014.Moreover,ET0 began to increase in March and reached the peak value in August and then declined in September,however,ETc began to increase from April and reached the peak value in July,and then declined in August.Total ETc and ET0 values during the growing season(from May to September)were 441 and 666 mm,respectively,which accounted for 75.73%of annual cumulative ETc and 72.34%of annual cumulative ET0,respectively.A crop coefficient(kc)was also estimated for calculating the ETc,and average value of kc during the growing season was 0.81(ranging from 0.45 to 1.16).Air temperature(Ta),wind speed(u),net radiation(Rn)and soil temperature(Ts)at the depth of 5 cm and aboveground biomass were critical factors for affecting kc,furthermore,a daily empirical kc equation including these main driving factors was developed.Our result demonstrated that the ETc value estimated by the data of kc and ET0 was validated and consistent with the growing season data in 2015 and 2016.

Status quo and development trend of lost foam casting technology

Lost foam casting(LFC)technology has been widely applied to cast iron and cast steel.However,the development of LFC for Al and Mg alloys was relatively slower than that for cast iron and cast steel.The application of LFC to Al and Mg alloys needs more effort,especially in China.In this paper,the development history of LFC is reviewed,and the application situations of LFC to Al and Mg alloys are mainly discussed.Meanwhile,the key problems of LFC for Al and Mg alloys are also pointed out.Finally,the prospects for LFC technology are discussed,and some special new LFC technologies are introduced for casting Al and Mg alloys.In future,the development trends of green LFC technology mainly focus on the special new LFC methods,metal material,coating,heat treatment,new foam materials as well as purification technology of tail gas,etc.

Experimental study on dynamic gas adsorption

In order to predict the actual adsorption amount as gas adsorption reaches the equilibrium,this research designed a dynamic gas adsorption experiment under constant temperature and pressure,and also studied the isopiestic adsorption characteristics of coal samples with same quality but different sizes.Through the experiment,the study found the adsorption-time changing relationships under different pressures of four different size samples.After regression analysis,we obtained the functional relationship between adsorption and time.According to this,the research resulted in the actual adsorption amount when gas adsorption reaches the equilibrium.In addition,the current study obtained the relationship between adsorption and pressure as well as the effect of the coal size to the adsorption rate.These results have great theoretical and practical significance for the prediction of gas amount in coal seam and gas adsorption process.

A Case Study of Warm Sector Rainbands in North China

This article investigates in detail the structure, genesis and development of parallel-type warm sector rainbands from radar observations. By comparing these observations with diagnostic results from temperature, pressure, moisture and wind data, which are both actually observed and numerically generated by a mesoscale model, and the theory of symmetric instability, it is found that the conditional symmetric instability might be responsible for the formation and development of these rainbands.

Simulation and projection of climate change using CMIP6 Muti-models in the Belt and Road Region

Climate condition over a region is mostly determined by the changes in precipitation,temperature and evaporation as the key climate variables.The countries belong to the Belt and Road region are subjected to face strong changes in future climate.In this paper,we used five global climate models from the latest Sixth Phase of Coupled Model Intercomparison Project(CMIP6)to evaluate future climate changes under seven combined scenarios of the Shared Socioeconomic Pathways and the Representative Concentration Pathways(SSP1-1.9,SSP1-2.6,SSP2-4.5,SSP3-7.0,SSP4-3.4,SSP4-6.0 and SSP5-8.5)across the Belt and Road region.This study focuses on undertaking a climate change assessment in terms of future changes in precipitation,air temperature and actual evaporation for the three distinct periods as near-term period(2021−2040),mid-term period(2041−2060)and long-term period(2081−2100).To discern spatial structure,Köppen−Geiger Climate Classification method has been used in this study.In relative terms,the results indicate an evidence of increasing tendency in all the studied variables,where significant changes are anticipated mostly in the long-term period.In addition to,though it is projected to increase under all the SSP-RCP scenarios,greater increases will be happened under higher emission scenarios(SSP5-8.5 and SSP3-7.0).For temperature,robust increases in annual mean temperature is found to be 5.2°C under SSP3-7.0,and highest 7.0°C under SSP5-8.5 scenario relative to present day.The northern part especially Cold and Polar region will be even more warmer(+6.1°C)in the long-term(2081−2100)period under SSP5-8.5.Similarly,at the end of the twenty-first century,annual mean precipitation is inclined to increase largely with a rate of 2.1%and 2.8%per decade under SSP3-7.0 and SSP5-8.5 respectively.Spatial distribution demonstrates that the largest precipitation increases are to be pronounced in the Polar and Arid regions.Precipitation is projected to increase with response to increasing warming most of the regions.Finally,the actual evaporation is projected to increase significantly with rate of 20.3%under SSP3-7.0 and greatest 27.0%for SSP5-8.5 by the end of the century.It is important to note that the changes in evaporation respond to global mean temperature rise consistently in terms of similar spatial pattern for all the scenarios where stronger increase found in the Cold and Polar regions.The increase in precipitation is overruled by enhanced evaporation over the region.However,this study reveals that the CMIP6 models can simulate temperature better than precipitation over the Belt and Road region.Findings of this study could be the reliable basis for initiating policies against further climate induced impacts in the regional scale.

Incident prevention tools-incident investigations and pre-job safety analyses

Careful and thorough incident investigations and pre-job safety analyses completed by knowledgeable and competent individuals can significantly reduce workplace incidents. Working parties must act together to make these safety tools effective. To get the staff units to work together in a co-ordinated manner, they must be shown the value of their work in preventing accidents. Examples of actual accidents investigated during the author's 18 years as a mine inspector in Saskatchewan are discussed within the context of pre-job safety analyses. The causes of the accidents are explored with close reference to how pre-job safety analyses could have prevented their occurrence.

An Analytical Study of Leibniz’s Secant and Tangent on the Logical Basis of Mathematical Infinity

Refs 1 and 2 provide the definition of the concepts of‘potential infinity’(poi)and actual infinity(aci);Ref 3 discusses and verifies that poi and aci are a pair of contradictory opposites without intermediate(p,-p).The second part of this paper,i.e.,§2,further discusses the manners in which a variable x approaches infinitely to its limit x0 using the poi and aci methods and concludes that,in any system compatible with both poi and aci, the two approaching manners are also a pair of contradictory opposites without intermediate (A,-A).Finally,on the basis of this conclusion,we reexamine the fundamental question of Leibniz’s Secant and Tangent Lines in calculus and the limit theory and offer our analysis and raise new questions.