There are a large number of Mesozoic intrusive and volcanic rocks in western Liaoning of China,which is an ideal place to study the Mesozoic Paleo-Pacific subduction processes,and lithospheric destruc-tion of North Ch...There are a large number of Mesozoic intrusive and volcanic rocks in western Liaoning of China,which is an ideal place to study the Mesozoic Paleo-Pacific subduction processes,and lithospheric destruc-tion of North China Craton.Detailed petrographic,zircon U-Pb dating and geochemical studies of the Early Jurassic granites in Huashan pluton,Xingcheng,western Liaoning,indicate that the Early Jurassic granites were formed at 184-174 Ma,mainly composed of syenite and monzogranite.The geochemical characteristics show high contents of SiO_(2),Al_(2)O_(3)and Na_(2)O+K_(2)O,low contents of Fe_(2)O_(3)and MgO,enrichment in LREEs and LILEs,and depletion in HREEs and HFSEs,and have a high content of Sr and low contents of Y and Yb,with weak negative Eu anomalies and slightly negative anomalies of Ce,indicating that they are a set of intermediate-acidic adakitic granites in high-K calc-alkaline series.All the facts significantly suggest that the Early Jurassic adakitic granites were formed at the active continental margin in the context of Paleo-Pacific plate subduction.展开更多
目的分析西安市某三甲医院药字号肠内营养制剂的使用情况,为临床合理使用药字号肠内营养制剂提供参考。方法从该院信息管理系统(hospital information system,HIS)中提取2019年至2021年药字号肠内营养制剂的用药数据,对全院药字号营养...目的分析西安市某三甲医院药字号肠内营养制剂的使用情况,为临床合理使用药字号肠内营养制剂提供参考。方法从该院信息管理系统(hospital information system,HIS)中提取2019年至2021年药字号肠内营养制剂的用药数据,对全院药字号营养制剂的销售情况及构成比、用药频度(defined daily doses,DDDs)、限定日费用(defined daily cost,DDC)等药物经济学指标以及各科室使用量进行回顾性统计分析。结果该院肠内营养制剂使用量2019年至2020年呈增长趋势,但2021年度有所下降。DDDs排名前3的制剂分别是百普力、能全素和瑞素。DDC排序前3的制剂是瑞先、百普素和百普力。肝胆外科3年间短肽类制剂使用量位居第1,整蛋白制剂使用量前3的科室分别是神经内科、重症医学科和康复科。结论该院肠内营养制剂平均年使用量偏低,肠内营养与肠外营养治疗比例不均衡。整蛋白制剂瑞先价格较高,患者经济负担重,肠内营养制剂应保质保效,同时应降低价格。临床肠内营养治疗率远低于实际营养不良反应发生率,营养科需进一步加强与临床科室的沟通协作,提高住院患者肠内营养治疗比例。展开更多
Improvements in hybrid electric vehicle (HEV) fuel economy and emissions heavily depend on an efficient energy management strategy (EMS).However,the uncertainty of future driving conditions generally cannot be easily ...Improvements in hybrid electric vehicle (HEV) fuel economy and emissions heavily depend on an efficient energy management strategy (EMS).However,the uncertainty of future driving conditions generally cannot be easily tackled in EMS design.Most existing EMSs act upon fixed parameters and cannot adapt to varying driving conditions.Therefore,they usually fail to fully explore the potential of these advanced vehicles.In this paper,a novel EMS design procedure based on neural dynamic programming (NDP) is proposed.The NDP is a generic online learning algorithm,which combines stochastic dynamic programming (SDP) and the temporal difference (TD) method.Instead of computing the utility function and optimal control actions through Bellman equations,the NDP algorithm uses two neural networks to approximate them.The weights of these neural networks are updated online by the TD method.It avoids the high computational cost that SDP suffers from and is suitable for real-time implementation.The main advantages of NDP EMS is that it does not rely on prior information related to future driving conditions,and can self-tune with a wide variance in operating conditions.The NDP EMS has been applied to "Qianghua-I",a prototype of a parallel HEV,using a revolving drum test bench for verification.Experiment results illustrate the potential of the proposed EMS in terms of fuel economy and in keeping state of charge (SOC) deviations at a low level.The proposed research ensures the optimality of NDP EMS,as well as real-time applicability.展开更多
A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the t...A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy.展开更多
The Jiutai area is tectonically situated at the eastern segment of the Central Asian Orogenic Belt(CAOB) and is close to the North China Craton(NCC) to the south, serving as an ideal place to investigations of the clo...The Jiutai area is tectonically situated at the eastern segment of the Central Asian Orogenic Belt(CAOB) and is close to the North China Craton(NCC) to the south, serving as an ideal place to investigations of the closure of the PaleoAsian Ocean(PAO). Sandstone samples collected from the Yangjiagou Formation and the Lujiatun Formation in this area have been studied in detail in terms of petrology, geochronology and geochemistry. The maximum depositional time of the Yangjiagou and Lujiatun formations has been constrained to early Middle Triassic(ca. 245 Ma) and middle Late Triassic(ca. 219 Ma), respectively. The Yangjiagou Formation, with a major provenance of dissected island arcs, is dominantly composed of Phanerozoic sediments from Northeastern China(NE China) massifs. The Lujiatun Formation, with major sediments from active continental margins, has a relatively larger proportion of Precambrian sediments, in which the ~1.85 Ga and ~2.5 Ga sediments are typical of the crystalline basements of the NCC and NE China massifs, which were uplifted and eroded during the closure of the PAO. Besides, both formations show the enrichment in LREEs and the depletion in HREEs, the common Eu negative anomalies, and trace element contents similar to that of the upper continental crust. Based on the provenance analysis of these two formations, the final closure time of the PAO in this area is constrained as from the early Middle Triassic(ca. 245 Ma) to the middle Late Triassic(ca. 219 Ma).展开更多
基金Supported by the National Key R&D Program of China(No.2016YFC0666108-02).
文摘There are a large number of Mesozoic intrusive and volcanic rocks in western Liaoning of China,which is an ideal place to study the Mesozoic Paleo-Pacific subduction processes,and lithospheric destruc-tion of North China Craton.Detailed petrographic,zircon U-Pb dating and geochemical studies of the Early Jurassic granites in Huashan pluton,Xingcheng,western Liaoning,indicate that the Early Jurassic granites were formed at 184-174 Ma,mainly composed of syenite and monzogranite.The geochemical characteristics show high contents of SiO_(2),Al_(2)O_(3)and Na_(2)O+K_(2)O,low contents of Fe_(2)O_(3)and MgO,enrichment in LREEs and LILEs,and depletion in HREEs and HFSEs,and have a high content of Sr and low contents of Y and Yb,with weak negative Eu anomalies and slightly negative anomalies of Ce,indicating that they are a set of intermediate-acidic adakitic granites in high-K calc-alkaline series.All the facts significantly suggest that the Early Jurassic adakitic granites were formed at the active continental margin in the context of Paleo-Pacific plate subduction.
基金supported by Innovation Technology Fund of the Hong Kong Special Administrative Region of China (Grant No. GHP/011/05)
文摘Improvements in hybrid electric vehicle (HEV) fuel economy and emissions heavily depend on an efficient energy management strategy (EMS).However,the uncertainty of future driving conditions generally cannot be easily tackled in EMS design.Most existing EMSs act upon fixed parameters and cannot adapt to varying driving conditions.Therefore,they usually fail to fully explore the potential of these advanced vehicles.In this paper,a novel EMS design procedure based on neural dynamic programming (NDP) is proposed.The NDP is a generic online learning algorithm,which combines stochastic dynamic programming (SDP) and the temporal difference (TD) method.Instead of computing the utility function and optimal control actions through Bellman equations,the NDP algorithm uses two neural networks to approximate them.The weights of these neural networks are updated online by the TD method.It avoids the high computational cost that SDP suffers from and is suitable for real-time implementation.The main advantages of NDP EMS is that it does not rely on prior information related to future driving conditions,and can self-tune with a wide variance in operating conditions.The NDP EMS has been applied to "Qianghua-I",a prototype of a parallel HEV,using a revolving drum test bench for verification.Experiment results illustrate the potential of the proposed EMS in terms of fuel economy and in keeping state of charge (SOC) deviations at a low level.The proposed research ensures the optimality of NDP EMS,as well as real-time applicability.
基金supported by the National Natural Science Foundation of China(61773398 61703421)
文摘A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy.
基金financially co-supported by the National Key R&D Program of China (Grant No. 2017YFC0601401 and 2017YFC0601300-01)Self-determined Foundation of Key Laboratory of Mineral Resources Evaluation in Northeast Asia, Ministry of Natural Resources, China (Grant No. DBY–ZZ–18–09)
文摘The Jiutai area is tectonically situated at the eastern segment of the Central Asian Orogenic Belt(CAOB) and is close to the North China Craton(NCC) to the south, serving as an ideal place to investigations of the closure of the PaleoAsian Ocean(PAO). Sandstone samples collected from the Yangjiagou Formation and the Lujiatun Formation in this area have been studied in detail in terms of petrology, geochronology and geochemistry. The maximum depositional time of the Yangjiagou and Lujiatun formations has been constrained to early Middle Triassic(ca. 245 Ma) and middle Late Triassic(ca. 219 Ma), respectively. The Yangjiagou Formation, with a major provenance of dissected island arcs, is dominantly composed of Phanerozoic sediments from Northeastern China(NE China) massifs. The Lujiatun Formation, with major sediments from active continental margins, has a relatively larger proportion of Precambrian sediments, in which the ~1.85 Ga and ~2.5 Ga sediments are typical of the crystalline basements of the NCC and NE China massifs, which were uplifted and eroded during the closure of the PAO. Besides, both formations show the enrichment in LREEs and the depletion in HREEs, the common Eu negative anomalies, and trace element contents similar to that of the upper continental crust. Based on the provenance analysis of these two formations, the final closure time of the PAO in this area is constrained as from the early Middle Triassic(ca. 245 Ma) to the middle Late Triassic(ca. 219 Ma).
