The Chern-Simons theory in two-space one-time dimensions is quantized on the light-front under appropriate gauge-fixing conditions using the Hamiltonian, path integral and BRST formulations.
In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Unde...In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Underground Storage Facility in Los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas production.In our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and magnitude.Ignoring depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir pressure.Moreover,this irreversible compaction may bring the nearby faults closer to reactivation.However,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.展开更多
A effective approximate scheme which is combined by cluster with the discrelized path-integral representation (DPIR) is used in the study on the random-bond Ising model in a transverse field (RTIM). The critical therm...A effective approximate scheme which is combined by cluster with the discrelized path-integral representation (DPIR) is used in the study on the random-bond Ising model in a transverse field (RTIM). The critical thermodynamical properties, such as the critical temperature, the critical transverse field, the average magnetization ,the susceptibility and the special heat atc.. are calculated, And some results have been improved.展开更多
为了确定通用性园艺作物发育期和采收期模拟模型的最优模拟路径,该研究获取了9 a 58茬分期播种试验观测数据,分别以黄瓜(‘津优35’和‘津盛206’)、番茄(‘瑞粉882’和‘普罗旺斯’)、芹菜(‘尤文图斯’)、菠菜(‘大叶’)、香芹(‘四季...为了确定通用性园艺作物发育期和采收期模拟模型的最优模拟路径,该研究获取了9 a 58茬分期播种试验观测数据,分别以黄瓜(‘津优35’和‘津盛206’)、番茄(‘瑞粉882’和‘普罗旺斯’)、芹菜(‘尤文图斯’)、菠菜(‘大叶’)、香芹(‘四季’)、郁金香(‘粉色印象’、‘白日梦’、‘艾斯米’和‘夜皇后’)、茶叶(‘龙井’)为供试材料,依据作物生长发育与关键气象因子(辐射和温度)的关系,基于4类建模方法(温差法、积温法、生理发育时间法和辐热积法)构建了园艺作物发育期和采收期模拟模型,确定了模型关键参数,并以4种方式(平均值、最值均值、中值和逐步回归)集成模拟结果,最终确定模型最优模拟路径。结果表明:1)不同时间尺度发育期和采收期模拟模型的均方根误差(root mean square error,RMSE)为4.85~17.01 d,归一化均方根误差(normalized root mean square error,NRMSE)为10.65%~16.31%;不同作物发育期和采收期模拟模型的RMSE为0.50~17.08 d,NRMSE为4.33%~20.24%,郁金香发育期模拟模型最优,黄瓜采收期模拟模型最优;不同模拟方法发育期和采收期模拟模型的RMSE为0.08~24.37 d,NRMSE为0.18%~54.81%。2)通过比较不同模拟方法的模拟精度,得出逐时优于逐日时间尺度,集成方法优于单一方法模拟,正弦优于线性温度响应模式,叶温优于气温温度形式,温度响应模拟需要考虑下限和上限温度。3)最优模拟路径为先选择逐时尺度、考虑生物学下限和上限温度的正弦温度响应模式和叶温温度形式构建模型,再选择集成法优化发育期(中值集成)和采收期(逐步回归集成)模型。研究结果为指导园艺作物智慧生产管理和高效利用农业资源方面提供理论基础和技术支撑。展开更多
With the development of advanced high strength steel,especially for dual-phase steel,the model algorithm for cooling control after hot rolling has to achieve the targeted coiling temperature control at the location of...With the development of advanced high strength steel,especially for dual-phase steel,the model algorithm for cooling control after hot rolling has to achieve the targeted coiling temperature control at the location of downcoiler whilst maintaining the cooling path control based on strip microstructure along the whole cooling section.A cooling path control algorithm was proposed for the laminar cooling process as a solution to practical difficulties associated with the realization of the thermal cycle during cooling process.The heat conduction equation coupled with the carbon diffusion equation with moving boundary was employed in order to simulate temperature change and phase transformation kinetics,making it possible to observe the temperature field and the phase fraction of the strip in real time.On this basis,an optimization method was utilized for valve settings to ensure the minimum deviations between the predicted and actual cooling path of the strip,taking into account the constraints of the cooling equipment′s specific capacity,cooling line length,etc.Results showed that the model algorithm was able to achieve the online cooling path control for dual-phase steel.展开更多
为使交互式水域环卫机器人(Interactive Water Sanitation Vehicle,IWSV)在进行垃圾收集时成功捕获水中浮动垃圾并顺利规避水域障碍物,提出一种将基于采样的快速搜索随机树(Rapidly-exploring Random Tree,RRT)算法与速度障碍模型相结...为使交互式水域环卫机器人(Interactive Water Sanitation Vehicle,IWSV)在进行垃圾收集时成功捕获水中浮动垃圾并顺利规避水域障碍物,提出一种将基于采样的快速搜索随机树(Rapidly-exploring Random Tree,RRT)算法与速度障碍模型相结合的路径规划算法。利用双目摄像头基于视差定位法获取水域动态障碍物的位置坐标,利用IWSV搭载的感应元件获取其自身与障碍物的相对方位角,基于速度障碍法计算可成功避开障碍物的移动角度调整范围,对更优的RRT算法中的随机采样过程进行进一步优化,得到改进的避障路径规划算法。考虑实际应用场景,引入抗积分饱和比例积分微分控制(Proportional Integral Differentiational Control,PID Control)法使航向控制器的控制效果更为精准有效。在实景测试时避障路径规划算法存在稳健性,基于到达时间(Time of Arrival,TOA)定位法进行仿真分析。仿真试验结果表明,该路径规划算法比RRT算法和改进前的RRT算法路径规划效果更优,可靠性更好,可在较短时间内避障并得到较优移动路径。在实景测试时基于TOA的Chan算法更加符合定位估计需求,且IWSV本体感应装置的噪声测算宜在10 m以内。展开更多
文摘The Chern-Simons theory in two-space one-time dimensions is quantized on the light-front under appropriate gauge-fixing conditions using the Hamiltonian, path integral and BRST formulations.
基金conducted with funding provided by the California Energy Commission under the contract PIR-16-027 for Research on Risk Management Framework for Underground Natural Gas infrastructure in California。
文摘In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Underground Storage Facility in Los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas production.In our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and magnitude.Ignoring depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir pressure.Moreover,this irreversible compaction may bring the nearby faults closer to reactivation.However,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.
文摘A effective approximate scheme which is combined by cluster with the discrelized path-integral representation (DPIR) is used in the study on the random-bond Ising model in a transverse field (RTIM). The critical thermodynamical properties, such as the critical temperature, the critical transverse field, the average magnetization ,the susceptibility and the special heat atc.. are calculated, And some results have been improved.
文摘为了确定通用性园艺作物发育期和采收期模拟模型的最优模拟路径,该研究获取了9 a 58茬分期播种试验观测数据,分别以黄瓜(‘津优35’和‘津盛206’)、番茄(‘瑞粉882’和‘普罗旺斯’)、芹菜(‘尤文图斯’)、菠菜(‘大叶’)、香芹(‘四季’)、郁金香(‘粉色印象’、‘白日梦’、‘艾斯米’和‘夜皇后’)、茶叶(‘龙井’)为供试材料,依据作物生长发育与关键气象因子(辐射和温度)的关系,基于4类建模方法(温差法、积温法、生理发育时间法和辐热积法)构建了园艺作物发育期和采收期模拟模型,确定了模型关键参数,并以4种方式(平均值、最值均值、中值和逐步回归)集成模拟结果,最终确定模型最优模拟路径。结果表明:1)不同时间尺度发育期和采收期模拟模型的均方根误差(root mean square error,RMSE)为4.85~17.01 d,归一化均方根误差(normalized root mean square error,NRMSE)为10.65%~16.31%;不同作物发育期和采收期模拟模型的RMSE为0.50~17.08 d,NRMSE为4.33%~20.24%,郁金香发育期模拟模型最优,黄瓜采收期模拟模型最优;不同模拟方法发育期和采收期模拟模型的RMSE为0.08~24.37 d,NRMSE为0.18%~54.81%。2)通过比较不同模拟方法的模拟精度,得出逐时优于逐日时间尺度,集成方法优于单一方法模拟,正弦优于线性温度响应模式,叶温优于气温温度形式,温度响应模拟需要考虑下限和上限温度。3)最优模拟路径为先选择逐时尺度、考虑生物学下限和上限温度的正弦温度响应模式和叶温温度形式构建模型,再选择集成法优化发育期(中值集成)和采收期(逐步回归集成)模型。研究结果为指导园艺作物智慧生产管理和高效利用农业资源方面提供理论基础和技术支撑。
文摘With the development of advanced high strength steel,especially for dual-phase steel,the model algorithm for cooling control after hot rolling has to achieve the targeted coiling temperature control at the location of downcoiler whilst maintaining the cooling path control based on strip microstructure along the whole cooling section.A cooling path control algorithm was proposed for the laminar cooling process as a solution to practical difficulties associated with the realization of the thermal cycle during cooling process.The heat conduction equation coupled with the carbon diffusion equation with moving boundary was employed in order to simulate temperature change and phase transformation kinetics,making it possible to observe the temperature field and the phase fraction of the strip in real time.On this basis,an optimization method was utilized for valve settings to ensure the minimum deviations between the predicted and actual cooling path of the strip,taking into account the constraints of the cooling equipment′s specific capacity,cooling line length,etc.Results showed that the model algorithm was able to achieve the online cooling path control for dual-phase steel.
文摘为使交互式水域环卫机器人(Interactive Water Sanitation Vehicle,IWSV)在进行垃圾收集时成功捕获水中浮动垃圾并顺利规避水域障碍物,提出一种将基于采样的快速搜索随机树(Rapidly-exploring Random Tree,RRT)算法与速度障碍模型相结合的路径规划算法。利用双目摄像头基于视差定位法获取水域动态障碍物的位置坐标,利用IWSV搭载的感应元件获取其自身与障碍物的相对方位角,基于速度障碍法计算可成功避开障碍物的移动角度调整范围,对更优的RRT算法中的随机采样过程进行进一步优化,得到改进的避障路径规划算法。考虑实际应用场景,引入抗积分饱和比例积分微分控制(Proportional Integral Differentiational Control,PID Control)法使航向控制器的控制效果更为精准有效。在实景测试时避障路径规划算法存在稳健性,基于到达时间(Time of Arrival,TOA)定位法进行仿真分析。仿真试验结果表明,该路径规划算法比RRT算法和改进前的RRT算法路径规划效果更优,可靠性更好,可在较短时间内避障并得到较优移动路径。在实景测试时基于TOA的Chan算法更加符合定位估计需求,且IWSV本体感应装置的噪声测算宜在10 m以内。
