The effective smoke preventing installation should have the functions such as absolute smoke insulation, going into and coming off the smoke preventing place freely, no confinement of sight. The smoke preventing ai...The effective smoke preventing installation should have the functions such as absolute smoke insulation, going into and coming off the smoke preventing place freely, no confinement of sight. The smoke preventing air curtain is the most effective. Based on the previous researches done by others, the flow field is theoretically analyzed and the calculating method for the smoke preventing air curtain of high rise buildings is inferred by means of mathematics in this paper.展开更多
Soybean (Glycine max. (L.) Merr.) sap flow during the growth stages in relation to soil moisture, nutrition, and weather conditions determine the plant development. Modeling this process helps to better understand the...Soybean (Glycine max. (L.) Merr.) sap flow during the growth stages in relation to soil moisture, nutrition, and weather conditions determine the plant development. Modeling this process helps to better understand the plant water-nutrition uptake and improve the decisions of efficient irrigation management and other inputs for effective soybean production. Field studies of soybean sap flow took place in 2017-2021 at Marianna, Arkansas using heat balance stem flow gauges to measure the sap flow during the reproductive growth stages R3-R7. Plant water uptake was measured using the lysimeter-container method. The uniform sap flow-based hydraulic system in the soil-root-stem-leaf pathway created negative water tensions with osmotic processes and water surface tensions in stomata cells as water evaporation layers increase are the mechanism of the plant water uptake. Any changes the factors like soil water tension, solar radiation, or air relative humidity immediately, within a few seconds, affect the system’s balance and cause simultaneously appropriate reactions in different parts of the system. The plant water use model was created from plant emergence, vegetative to final reproductive growth stages depending on soil-weather conditions, plant morphology, and biomass. The main factors of the model include solar radiation, air temperature, and air relative humidity. The effective sap flow uptake occurs around 0.8 KPa VPD. Further research is needed to optimize the model’s factors to increase the plant growth dynamics and yield productivity.展开更多
For some special flows, especially the potential flow in a plane, using the hodograph method has obvious advantages. Realistic flows have a stream surface, namely, a two-dimensional manifold, on which the velocity vec...For some special flows, especially the potential flow in a plane, using the hodograph method has obvious advantages. Realistic flows have a stream surface, namely, a two-dimensional manifold, on which the velocity vector of the flow lies on its tangent space. By introducing a stream function and a potential function, we establish the hodo- graph method for potential flows on a surface using the tensor analysis. For the derived hodograph equation, we obtain a characteristic equation and its characteristic roots, from which we can classify the type of the second-order hodograph equation. Moreover, we give some examples for special surfaces.展开更多
Stress-dilatancy relationship or plastic potential function are crucial components of every elastoplastic constitutive model developed for sand or cemented sand.This is because the associated flow rule usually does no...Stress-dilatancy relationship or plastic potential function are crucial components of every elastoplastic constitutive model developed for sand or cemented sand.This is because the associated flow rule usually does not produce acceptable outcomes for sand or cemented sand.Many formulas have been introduced based on the experimental observations in conventional and advanced plasticity models in order to capture ratio of plastic volumetric strain increment to plastic deviatoric strain increment(i.e.dilatancy rate).Lack of an article that gathers these formulas is clear in the literature.Thus,this paper is an attempt to summarize plastic potentials and specially stress-dilatancy relations so far proposed for constitutive modelling of cohesionless and cemented sands.Stress-dilatancy relation is usually not the same under compression and extension conditions.Furthermore,it may also be different under loading and unloading conditions.Therefore,the focus in this paper mainly places on the proposed stress-dilatancy relations for compressive monotonic loading.Moreover because plastic potential function can be calculated by integration of stress-dilatancy relationship,more weight is allocated to stress-dilatancy relationship in this research.展开更多
The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric an...The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric and Magnetic fields. Also, every moving particle has a De Broglie wavelength determined by its mass and velocity. This paper shows that all of these properties of a particle can be derived from a single wave function equation for that particle. Wave functions for the Electron and the Positron are presented and principles are provided that can be used to calculate the wave functions of all the fundamental particles in Physics. Fundamental particles such as electrons and positrons are considered to be point particles in the Standard Model of Physics and are not considered to have a structure. This paper demonstrates that they do indeed have structure and that this structure extends into the space around the particle’s center (in fact, they have infinite extent), but with rapidly diminishing energy density with the distance from that center. The particles are formed from Electromagnetic standing waves, which are stable solutions to the Schrödinger and Classical wave equations. This stable structure therefore accounts for both the wave and particle nature of these particles. In fact, all of their properties such as mass, spin and electric charge, can be accounted for from this structure. These particle properties appear to originate from a single point at the center of the wave function structure, in the same sort of way that the Shell theorem of gravity causes the gravity of a body to appear to all originate from a central point. This paper represents the first two fully characterized fundamental particles, with a complete description of their structure and properties, built up from the underlying Electromagnetic waves that comprise these and all fundamental particles.展开更多
BACKGROUND： Studies have shown that latency changes of some elements in a somatosensory evoked potential （SEP） and motor evoked potential （MEP） can reflect electrical activity of cerebral cortical neurons and con...BACKGROUND： Studies have shown that latency changes of some elements in a somatosensory evoked potential （SEP） and motor evoked potential （MEP） can reflect electrical activity of cerebral cortical neurons and conduction of white matter nerve fibers. However, there is a paucity of information regarding the dynamic observation of SEP and MEP following cerebral ischemic injury. OBJECTIVE： To explore SEP and MEP changes following acute ischemic stroke, and investigate the role of evoked potentials in monitoring brain function in stroke. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Chongqing Key Laboratory of Neurology, Affiliated Hospital of Chongqing Medical University from September 2007 to August 2008. MATERIALS＂ Hydrogen blood flow detector was purchased from Soochow University Medical Instrument Co., China, and Power lab system was purchased from AD Instruments, Inc., USA. METHODS A total of 36 healthy, adult, male, Sprague Dawley rats were randomly assigned to four groups （n = 9）, including three ischemia groups （12, 24 and 72 hours of ischemia） and a sham-surgery group. The rat model of acute ischemic stroke was established by middle cerebral artery occlusion （MCAO） in the left hemisphere. MAIN OUTCOME MEASURES＂ SEP and MEP of the left limbs were detected, and cerebral blood flow was measured by the hydrogen cleaning method. RESULTS： The latency of positive wave 1 （P1）, negative wave 1 （N1） and positive wave 2 （P2） waves in SEP, and latency of negative wave 1,2 （N1, N2） waves in MEP were significantly prolonged with increasing ischemic duration following MCAO （P 〈 0.01）, but cerebral blood flow was significantly decreased （P 〈 0.05, or P 〈 0.01）. CONLUSION： Ischemic stroke prolongs the latency of SEP waves （P1, N1, P2） and MEP waves （N1, N2）, and cerebral cortical evoked potential may correlate with cerebral blood flow changes. This indicates that SEP and MEP can be used to evaluate brain function following acute ischemic stroke.展开更多
目的探讨呼吸困难指数气流受限程度指数(dyspnea index air flow restriction degree,ADO)在慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者近期预后评估中的价值。方法选取新疆医科大学第二附属医院呼吸内科自2021...目的探讨呼吸困难指数气流受限程度指数(dyspnea index air flow restriction degree,ADO)在慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者近期预后评估中的价值。方法选取新疆医科大学第二附属医院呼吸内科自2021年3月—2023年3月的COPD患者120例,并依照患者最终转归情况将其分为存活组(n=95)与死亡组(n=25)。观察2组患者的基础病情况及患者性别、年龄、第1秒用力呼气容积(first second forced expiratory volume,FEV1)占预计值的百分比和ADO指数等相关指标。比较ADO指数不同分数患者病死率。比较ADO指数预测180 d死亡的受试者工作特征(receiver operating characteristic,ROC)曲线面积。结果2组患者的高血压、冠心病、心律失常、糖尿病、慢性肝病、慢性肾病、亚临床甲减发生情况对比,差异无统计学意义(P>0.05)。死亡组患者的FEV1占预计值的百分比、FEV1占预计值的百分比评分、呼吸困难分[英国医学研究委员会(the Medical Research Council,MRC)]评分以及ADO指数均高于存活组患者(P<0.05)。ADO指数<5分者的死亡率高于ADO指数≥5分者(P<0.05)。ADO指数预测180 d死亡的ROC曲线面积为0.851(95%CI:0.767~0.928,P<0.001),ADO指数为5.5时,约登指数最大,为0.565。结论ADO可有效反映COPD病情严重程度,对于患者而言可准确反映其病情进展情况,帮助其获得良好的疾病治疗效果,对于患者近期预后而言也具有积极意义,临床应用效果良好。展开更多
文摘The effective smoke preventing installation should have the functions such as absolute smoke insulation, going into and coming off the smoke preventing place freely, no confinement of sight. The smoke preventing air curtain is the most effective. Based on the previous researches done by others, the flow field is theoretically analyzed and the calculating method for the smoke preventing air curtain of high rise buildings is inferred by means of mathematics in this paper.
文摘Soybean (Glycine max. (L.) Merr.) sap flow during the growth stages in relation to soil moisture, nutrition, and weather conditions determine the plant development. Modeling this process helps to better understand the plant water-nutrition uptake and improve the decisions of efficient irrigation management and other inputs for effective soybean production. Field studies of soybean sap flow took place in 2017-2021 at Marianna, Arkansas using heat balance stem flow gauges to measure the sap flow during the reproductive growth stages R3-R7. Plant water uptake was measured using the lysimeter-container method. The uniform sap flow-based hydraulic system in the soil-root-stem-leaf pathway created negative water tensions with osmotic processes and water surface tensions in stomata cells as water evaporation layers increase are the mechanism of the plant water uptake. Any changes the factors like soil water tension, solar radiation, or air relative humidity immediately, within a few seconds, affect the system’s balance and cause simultaneously appropriate reactions in different parts of the system. The plant water use model was created from plant emergence, vegetative to final reproductive growth stages depending on soil-weather conditions, plant morphology, and biomass. The main factors of the model include solar radiation, air temperature, and air relative humidity. The effective sap flow uptake occurs around 0.8 KPa VPD. Further research is needed to optimize the model’s factors to increase the plant growth dynamics and yield productivity.
基金Project supported by the National Natural Science Foundation of China (Nos. 10971165, 10771167,and 10926080)
文摘For some special flows, especially the potential flow in a plane, using the hodograph method has obvious advantages. Realistic flows have a stream surface, namely, a two-dimensional manifold, on which the velocity vector of the flow lies on its tangent space. By introducing a stream function and a potential function, we establish the hodo- graph method for potential flows on a surface using the tensor analysis. For the derived hodograph equation, we obtain a characteristic equation and its characteristic roots, from which we can classify the type of the second-order hodograph equation. Moreover, we give some examples for special surfaces.
文摘Stress-dilatancy relationship or plastic potential function are crucial components of every elastoplastic constitutive model developed for sand or cemented sand.This is because the associated flow rule usually does not produce acceptable outcomes for sand or cemented sand.Many formulas have been introduced based on the experimental observations in conventional and advanced plasticity models in order to capture ratio of plastic volumetric strain increment to plastic deviatoric strain increment(i.e.dilatancy rate).Lack of an article that gathers these formulas is clear in the literature.Thus,this paper is an attempt to summarize plastic potentials and specially stress-dilatancy relations so far proposed for constitutive modelling of cohesionless and cemented sands.Stress-dilatancy relation is usually not the same under compression and extension conditions.Furthermore,it may also be different under loading and unloading conditions.Therefore,the focus in this paper mainly places on the proposed stress-dilatancy relations for compressive monotonic loading.Moreover because plastic potential function can be calculated by integration of stress-dilatancy relationship,more weight is allocated to stress-dilatancy relationship in this research.
文摘The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric and Magnetic fields. Also, every moving particle has a De Broglie wavelength determined by its mass and velocity. This paper shows that all of these properties of a particle can be derived from a single wave function equation for that particle. Wave functions for the Electron and the Positron are presented and principles are provided that can be used to calculate the wave functions of all the fundamental particles in Physics. Fundamental particles such as electrons and positrons are considered to be point particles in the Standard Model of Physics and are not considered to have a structure. This paper demonstrates that they do indeed have structure and that this structure extends into the space around the particle’s center (in fact, they have infinite extent), but with rapidly diminishing energy density with the distance from that center. The particles are formed from Electromagnetic standing waves, which are stable solutions to the Schrödinger and Classical wave equations. This stable structure therefore accounts for both the wave and particle nature of these particles. In fact, all of their properties such as mass, spin and electric charge, can be accounted for from this structure. These particle properties appear to originate from a single point at the center of the wave function structure, in the same sort of way that the Shell theorem of gravity causes the gravity of a body to appear to all originate from a central point. This paper represents the first two fully characterized fundamental particles, with a complete description of their structure and properties, built up from the underlying Electromagnetic waves that comprise these and all fundamental particles.
基金the National Natural Science Foundation of China, No. 30300075China Postdoctoral Science Foundation, No. 20080440995Sichuan Science Fund for Out-standing Youths, No. 05ZQ026-020
文摘BACKGROUND： Studies have shown that latency changes of some elements in a somatosensory evoked potential （SEP） and motor evoked potential （MEP） can reflect electrical activity of cerebral cortical neurons and conduction of white matter nerve fibers. However, there is a paucity of information regarding the dynamic observation of SEP and MEP following cerebral ischemic injury. OBJECTIVE： To explore SEP and MEP changes following acute ischemic stroke, and investigate the role of evoked potentials in monitoring brain function in stroke. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Chongqing Key Laboratory of Neurology, Affiliated Hospital of Chongqing Medical University from September 2007 to August 2008. MATERIALS＂ Hydrogen blood flow detector was purchased from Soochow University Medical Instrument Co., China, and Power lab system was purchased from AD Instruments, Inc., USA. METHODS A total of 36 healthy, adult, male, Sprague Dawley rats were randomly assigned to four groups （n = 9）, including three ischemia groups （12, 24 and 72 hours of ischemia） and a sham-surgery group. The rat model of acute ischemic stroke was established by middle cerebral artery occlusion （MCAO） in the left hemisphere. MAIN OUTCOME MEASURES＂ SEP and MEP of the left limbs were detected, and cerebral blood flow was measured by the hydrogen cleaning method. RESULTS： The latency of positive wave 1 （P1）, negative wave 1 （N1） and positive wave 2 （P2） waves in SEP, and latency of negative wave 1,2 （N1, N2） waves in MEP were significantly prolonged with increasing ischemic duration following MCAO （P 〈 0.01）, but cerebral blood flow was significantly decreased （P 〈 0.05, or P 〈 0.01）. CONLUSION： Ischemic stroke prolongs the latency of SEP waves （P1, N1, P2） and MEP waves （N1, N2）, and cerebral cortical evoked potential may correlate with cerebral blood flow changes. This indicates that SEP and MEP can be used to evaluate brain function following acute ischemic stroke.
文摘目的探讨呼吸困难指数气流受限程度指数(dyspnea index air flow restriction degree,ADO)在慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者近期预后评估中的价值。方法选取新疆医科大学第二附属医院呼吸内科自2021年3月—2023年3月的COPD患者120例,并依照患者最终转归情况将其分为存活组(n=95)与死亡组(n=25)。观察2组患者的基础病情况及患者性别、年龄、第1秒用力呼气容积(first second forced expiratory volume,FEV1)占预计值的百分比和ADO指数等相关指标。比较ADO指数不同分数患者病死率。比较ADO指数预测180 d死亡的受试者工作特征(receiver operating characteristic,ROC)曲线面积。结果2组患者的高血压、冠心病、心律失常、糖尿病、慢性肝病、慢性肾病、亚临床甲减发生情况对比,差异无统计学意义(P>0.05)。死亡组患者的FEV1占预计值的百分比、FEV1占预计值的百分比评分、呼吸困难分[英国医学研究委员会(the Medical Research Council,MRC)]评分以及ADO指数均高于存活组患者(P<0.05)。ADO指数<5分者的死亡率高于ADO指数≥5分者(P<0.05)。ADO指数预测180 d死亡的ROC曲线面积为0.851(95%CI:0.767~0.928,P<0.001),ADO指数为5.5时,约登指数最大,为0.565。结论ADO可有效反映COPD病情严重程度,对于患者而言可准确反映其病情进展情况,帮助其获得良好的疾病治疗效果,对于患者近期预后而言也具有积极意义,临床应用效果良好。
