Predictive cruise control(PCC)is an intelligence-assisted control technology that can significantly improve the overall performance of a vehicle by using road and traffic information in advance.With the continuous dev...Predictive cruise control(PCC)is an intelligence-assisted control technology that can significantly improve the overall performance of a vehicle by using road and traffic information in advance.With the continuous development of cloud control platforms(CCPs)and telematics boxes(T-boxes),cloud-based predictive cruise control(CPCC)systems are considered an effective solution to the problems of map update difficulties and insufficient computing power on the vehicle side.In this study,a vehicle-cloud hierarchical control architecture for PCC is designed based on a CCP and T-box.This architecture utilizes waypoint structures for hierarchical and dynamic cooperative inter-triggering,enabling rolling optimization of the system and commending parsing at the vehicle end.This approach significantly improves the anti-interference capability and resolution efficiency of the system.On the CCP side,a predictive fuel-saving speed-planning(PFSP)algorithm that considers the throttle input,speed variations,and time efficiency based on the waypoint structure is proposed.It features a forward optimization search without requiring weight adjustments,demonstrating robust applicability to various road conditions and vehicles equiped with constant cruise(CC)system.On the vehicle-side T-box,based on the reference control sequence with the global navigation satellite system position,the recommended speed is analyzed and controlled using the acute angle principle.Through analyzing the differences of the PFSP algorithm compared to dynamic programming(DP)and Model predictive control(MPC)algorithms under uphill and downhill conditions,the results show that the PFSP achieves good energy-saving performance compared to CC without exhibiting significant speed fluctuations,demonstrating strong adaptability to the CC system.Finally,by building an experimental platform and running field tests over a total of 2000 km,we verified the effectiveness and stability of the CPCC system and proved the fuel-saving performance of the proposed PFSP algorithm.The results showed that the CPCC system equipped with the PFSP algorithm achieved an average fuel-saving rate of 2.05%-4.39%compared to CC.展开更多
The East Kunlun Orogenic Belt(EKOB) provides an important link to reconstruct the evolution of the Proto-Tethys and Paleo-Tethys realm. The EKOB is marked by widespread Early Paleozoic magmatism.Here we report the pet...The East Kunlun Orogenic Belt(EKOB) provides an important link to reconstruct the evolution of the Proto-Tethys and Paleo-Tethys realm. The EKOB is marked by widespread Early Paleozoic magmatism.Here we report the petrology, bulk geochemistry, zircon Ue Pb dating and, Lue Hf and SreN d isotopic data of the Early Paleozoic granitic rocks in Zhiyu area of the southern EKOB. Based on the zircon U-Pb dating, these granitoids, consisting of diorite, granodiorite and monzogranite, were formed during 450 -430 Ma the Late Ordovician to Middle Silurian. The diorite and granodiorite are high Sr/Y ratio as adakitic affinities, and the monzogranite belongs to highly fractionated I-type. Their(^(87)Sr/^(86)Sr)ivalues range from 0.7059 to 0.7085, εNd(t) values from -1.6 to -6.0 and the zircon εHf(t) values show large variations from +9.1 to -8.6 with Hf model ages(T_(DM2)) about 848 Ma and 1970 Ma. The large variations of whole-rock Nd and zircon Hf isotopes demonstrate strong isotopic heterogeneity of the source regions which probably resulted from multi-phase underplating of mantle-derived magmas. Geochemical and isotopic studies proved that the diorite and granodiorite had been derived from partial melting of heterogeneous crustal source with variable contributions from ancient continental crust and juvenile components, and the monzogranites were representing fractional crystallization and crustal contamination for arc magma. The Early Paleozoic adakitic rocks and high-K calc-alkaline granitoids in the southern EKOB were likely emplaced in a continental marginal arc setting possibly linked to the southwards subduction of the Paleo Kunlun Ocean and the magma generation is linked to partial melting of thickened continental crust induced by underplating of mantle-derived magmas.展开更多
An integrated approach that considers the performance limitations of tracking control systems for air-breathing hypersonic vehicles is proposed. First, a set of ascent trajectories is obtained as candidates for tracki...An integrated approach that considers the performance limitations of tracking control systems for air-breathing hypersonic vehicles is proposed. First, a set of ascent trajectories is obtained as candidates for tracking control through a trajectory design method that considers the available acceleration. Second, the basic theory of performance limitations, which is adopted to calculate the limits on control performance through the trajectory, is integrated. The openloop dynamics of air-breathing hypersonic vehicles is responsible for these limits on the control system. Comprehensive specifications on stability, tracking accuracy, and robustness are derived, and the flight envelope with constraints and control specifications is identified. Simulation results suggest that trajectory design should consider restrictions on control performance to obtain reliable solutions.展开更多
To reduce the design burden of Aerospace Vehicles(ASVs)control systems,this paper proposes a multi-constrained robust trajectory optimization method,which provides a good front-end input for the control system.Differ ...To reduce the design burden of Aerospace Vehicles(ASVs)control systems,this paper proposes a multi-constrained robust trajectory optimization method,which provides a good front-end input for the control system.Differ from the conventional aircraft,some control performance of ASVs is not only related to the model parameters,but also affected by the flight status.Therefore,the robust optimization method combines this characteristic of ASVs,sets the control performance as one of the optimization objectives,and considers the influence of parameter uncertainty.In this method,the polynomial chaos expansion algorithm is used to transform the trajectory optimization problem with uncertain parameters into the equivalent deterministic robust trajectory optimization problem.Finally,compared with traditional deterministic trajectory optimization methods to illustrate the effectiveness of proposed control optimization method.展开更多
The Gejiu-Bozushan-Laojunshan W-Sn polymetallic metallogenic belt(GBLB)in southeast Yunnan Province is an important part of the southwestern Yangtze Block in South China.Tin polymetallic mineralization in this belt in...The Gejiu-Bozushan-Laojunshan W-Sn polymetallic metallogenic belt(GBLB)in southeast Yunnan Province is an important part of the southwestern Yangtze Block in South China.Tin polymetallic mineralization in this belt includes the Niusipo,Malage,Songshujiao,Laochang and Kafang ore fields in the Gejiu area which are spatially and temporally associated with the Kafang-Laochang and Songshujiao granite plutons.These granites are characterized by variable A/CNK values(mostly>1.1,except for two samples with 1.09),high contents of SiO2(74.38-76.84 wt.%)and Al2 O3(12.46-14.05 wt.%)and variable CaO/Na2 O ratios(0.2-0.65)as well as high zirconδ18O values(7.74‰-9.86‰),indicative of S-type affinities.These rocks are depleted in Rb,Th,U,Ti,LREE[(La/Yb)N=1.4-20.51],Ba,Nb,Sr,and Ti and display strong negative Eu and Ba anomalies.The rocks possess high Rb/Sr and Rb/Ba ratios,relatively low initial 87Sr/86Sr ratios(0.6917-0.7101),and less radiogenicεNd(t)values(-8.0 to-9.1).The zircon grains from these rocks show negativeεHf(t)values in the range of-3.7 to-9.9 with mean TDM2(Nd)and TDM2(Hf)values of 1.57 Ga and 1.55 Ga.They show initial 207Pb/204Pb ranging from15.69 to 15.71 and 206Pb/204Pb from 18.36 to 18.70.Monazite from Songshujiao granites exhibits higher U and lower Th/U ratios,lowerδ18O values and higherεHf(t)values than those of the zircon grains in the KafangLaochang granites.The geochemical and isotopic features indicate that the Laochang-Kafang granites originated by partial melting of Mesoproterozoic crustal components including biotite-rich metapelite and metagraywacke,whereas the Songshujiao granites were derived from Mesoproterozoic muscovite-rich metapelite crustal source.Most zircon grains from the Songshujiao,Laochang and Kafang granites have high-U concentrations and their SIMS U-Pb ages show age scatter from 81.6 Ma to 88.6 Ma,80.7 Ma to 86.1 Ma and 82.3 Ma to 87.0 Ma,suggesting formation earlier than the monazite and cassiterite.Monazite SIMS U-Pb ages and Th-Pb ages of three same granite samples are consistent and show yielded 206 Pb/238U ages of 83.7±0.6 Ma,83.7±0.6 Ma,and 83.4±0.6 Ma,and 208Pb/232Th ages of 83.2±0.5 Ma,83.8±0.4 Ma,and 83.5±0.9 Ma,which are within the range of the SIMS zircon U-Pb ages from these rocks.The data constrain the crystallization of the granites at ca.83 Ma.In situ U-Pb dating of two cassiterite samples from the cassiterite-sulfide ore in the Songshujiao ore field and Kafang ore field,and two from the cassiterite-oxide+cassiterite bearing dolomite in the Laochang ore field yielded weighted mean 206 Pb/238U ages of 83.5±0.4 Ma(MSWD=0.6),83.5±0.4 Ma(MSWD=0.5),83.6±0.4 Ma(MSWD=0.6)and 83.2±0.7 Ma(MSWD=0.6),respectively.Combined with geological characteristics,the new geochronological data indicate that the formation of the granites and Sn polymetallic deposits are coeval.We correlate the magmatic and metallogenic event with lithospheric thinning and asthenosphere upwelling in continental extension setting in relation to the eastward subduction of the Neo-Tethys beneath the Sanjiang tectonic domain during Late Cretaceous.展开更多
Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so on.To deeply their struc...Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so on.To deeply their structure and function in ecosystems,we investigated the spatial patterns and nitrogen(N)transfer of EM networks usingN labelling technique in a Mongolian scotch pine(Pinus sylvestris var.mongolica Litv.)plantation in Northeastern China.In August 2011,four plots(20 × 20 m)were set up in the plantation.125 ml 5 at.%0.15 mol/LNHNOsolution was injected into soil at the center of each plot.Before and 2,6,30 and 215 days after theN application,needles(current year)of each pine were sampled along four 12 m sampling lines.Needle total N andN concentrations were analyzed.We observed needle N andN concentrations increased significantly over time afterN application,up to 31 and0.42%,respectively.There was no correlation between needle N concentration andN/N ratio(R2=0.40,n=5,P=0.156),while excess needle N concentration and excess needleN/N ratio were positively correlated across different time intervals(R~2=0.89,n=4,P\0.05),but deceased with time interval lengthening.NeedleN/N ratio increased with time,but it was not correlated with distance.NeedleN/N ratio was negative with distance before and 6th day and 30th day,positive with distance at 2nd day,but the trend was considerably weaker,their slop were close to zero.These results demonstrated that EM networks were ubiquitous and uniformly distributed in the Mongolian scotch pine plantation and a random network.We found N transfer efficiency was very high,absorbed N by EM network was transferred as wide as possible,we observed N uptake of plant had strong bias forN andN,namely N fractionation.Understanding the structure and function of EM networks in ecosystems may lead to a deeper understanding of ecological stability and evolution,and thus provide new theoretical approaches to improve conservation practices for the management of the Earth’s ecosystems.展开更多
To speedily regulate and precisely control a hydraulic power system in a unmanned walking platform(UWP),based on the brief analysis of digital PID and its shortcomings,dual control parameters in a hydraulic power syst...To speedily regulate and precisely control a hydraulic power system in a unmanned walking platform(UWP),based on the brief analysis of digital PID and its shortcomings,dual control parameters in a hydraulic power system are given for the precision requirement,and a control strategy for dual relative control parameters in the dual loop PID is put forward,a load and throttle rotation-speed response model for variable pump and gasoline engine is provided according to a physical process,a simplified neural network structure PID is introduced,and formed mixed neural network PID(MNN PID)to control rotation speed of engine and pressure of variable pump,calculation using the back propagation(BP)algorithm and a self-adapted learning step is made,including a mathematic principle and a calculation flow scheme,the BP algorithm of neural network PID is trained and the control effect of system is simulated in Matlab environment,real control effects of engine rotation speed and variable pump pressure are verified in the experimental bench.Results show that algorithm effect of MNN PID is stable and MNN PID can meet the adjusting requirement of control parameters.展开更多
In order to explore the spatial and temporal changes of runoff and sediment in the Taohe River and its driving mechanism,Spearman correlation coefficient method,Mann-Kendell mutation test method and ordered clustering...In order to explore the spatial and temporal changes of runoff and sediment in the Taohe River and its driving mechanism,Spearman correlation coefficient method,Mann-Kendell mutation test method and ordered clustering method were used to analyze the changes of runoff and sediment discharge and their driving factors in four hydrological stations along the Taohe River from 1957 to 2016.The results showed that the correlation between runoff and sediment of the four hydrological stations along the Taohe River was significant,and the correlation coefficient was 0.728-0.984.The runoff and sediment transport in the interval showed an increasing and decreasing trend.The decrease rate of runoff was 133.82%-216.17%higher than that of Xiabagou station,and the decrease rate of sediment transport was 250.49%-4766.33%higher than that of Xiabagou station.The mutation year of the Taohe River runoff occurred in 1986,and the maximum decrease was 35%.The water-sediment relationship curves of different periods showed that the sediment discharge of the four stations changed abruptly around 1990,and the maximum reduction before and after the mutation was up to 73%,and the sediment discharge in the river channel decreased significantly.The research showed that human activities were the main driving factors for the change of water-sediment relationship in the Taohe River.展开更多
Vehicle-Road-Cloud Integration system(VRCIS)requires high-precision vehicle positioning and tracking,with very low system latency,which is a difficult task given the quantity and quality of data.To this end,a distribu...Vehicle-Road-Cloud Integration system(VRCIS)requires high-precision vehicle positioning and tracking,with very low system latency,which is a difficult task given the quantity and quality of data.To this end,a distributed computing framework using multi-access edge computing(MEC)devices is proposed in this paper.To process trajectory data(including preprocessing,calibration,multi-sensor trajectory matching,and trajectory prediction),as well as integrate machine learning algorithms to improve the accuracy of trajectory prediction,especially for complex and diverse driving scenarios environmental conditions,a framework is designed.In addition,to conduct a comprehensive evaluation of the overall performance of trajectory tracking,factors such as trajectory smoothness and velocity consistency—components of our novel evaluation metrics—are considered.Experiments show that the framework can continuously track tens of thousands of vehicles on highway,with average longitudinal and lateral errors of 2.14 and 0.84 m respectively,with average speed error of 1.91 kph.The experiments on large-scale road networks with 1,777 sensors are implemented,with continuous multi-vehicle tracking over 157 km of highway,and establishing superior performance compared to existing methods.Furthermore,processing latency remained below 340 ms,demonstrating the potential of this framework to enhance driver experience,improve road safety and efficiency.展开更多
Cancer vaccine efficacy relies on T cells eliciting tumor-specific adaptive immunity,with antigen-presenting cells,particularly dendritic cells(DCs),playing a crucial role.After capturing antigens,DCs migrate to lymph...Cancer vaccine efficacy relies on T cells eliciting tumor-specific adaptive immunity,with antigen-presenting cells,particularly dendritic cells(DCs),playing a crucial role.After capturing antigens,DCs migrate to lymph nodes,where they present antigens to naïve T cells and activate B and natural killer(NK)cells,thereby strengthening anti-tumor immune responses.However,limitations in immune adjuvants and insufficient antigen presentation hinder DCs migration,reducing vaccine effectiveness.This study introduces an outer membrane vesicle(OMV)-based platform engineered to express Vibrio vulnificus flagellin B(FlaB),a Toll-like receptor 5(TLR5)agonist.FlaB effectively activates DCs,enhances interactions with T cells,provides robust costimulatory signals,and promotes cytotoxic CD8^(+)T cell differentiation.Compared to unmodified OMV-Ag,the antigen-loaded OMV-FlaB-Ag nanovaccine significantly enhances DC function,eliciting potent antitumor responses and delaying tumor progression across multiple models.When combined with immune checkpoint inhibitors,it further amplifies antitumor immunity,markedly suppressing tumor growth and improving therapeutic outcomes.展开更多
The South China Block(SCB)is among the large-scale W-Sn mineralized regions of the globe.The Laojunshan W-Sn-dominant ore area(LOA)in the western part of the SCB preserves the records of the tectonic history of the Te...The South China Block(SCB)is among the large-scale W-Sn mineralized regions of the globe.The Laojunshan W-Sn-dominant ore area(LOA)in the western part of the SCB preserves the records of the tectonic history of the Tethys realm extending through North Vietnam,and Yangtze to Cathaysia blocks,with coeval formation of giant metallic deposits.The prolonged tectonic activities and their control on the genesis and spatio-temporal distribution of giant metallic deposits in the LOA provide a window for a holistic understanding of the tectono-metallogenesis of the SCB.In this study,we present results from a multi-chronologic study to determine the timing of formation of the cassiterite-wolframite-schee lite mineralization.The results suggest three distinct tectono-metallogenic periods in the LOA during the geodynamic evolution of the surrounding tectonic units.The opening of the Proto-Tethys Ocean between the Yangtze-Indochina blocks and the westward Paleo-Pacific subduction beneath the Cathaysia block(420–380 Ma)jointly contributed to the Silurian to early Devonian intracontinental orogeny in the middle of the SCB that involved top-to-the-north thrusting along NE-striking shear zones.This event generated the Dulong-Song Chay granitoids,together with the formation of Xinzhai Sn deposit related to sheared mylonitic granites(ca.419 Ma)and pegmatites(ca.389 Ma),which include the early-stage Sn-sulfide skarn(ca.418 Ma)and the late-stage Sn-bearing schist(ca.389 Ma).During the Late Permian to Late Triassic(260–220 Ma),with the closure of the Proto-Tethys oceans in the west and ongoing Paleo-Pacific westward subduction in the east,the SCB and Indochina Block(IB)were amalgamated which also marks the time of formation of the Nanwenhe scheelite skarn deposit.The subducted PaleoTethys oceanic crust was likely entrained by the nearby rising Emeishan mantle plume(270–259 Ma),which formed the Maguan diabase(ca.260 Ma)that shows significantly older Re-Os model age of ca.268 Ma,suggesting that the Nanwenhe mineralization is potentially derived from ca.260 Ma source.Furthermore,the intraplate shortening induced thin skinned crustal deformation and low grade metamorphism(ca.230 Ma),with the main stage of scheelite-Sn-Mo mineralization(229.9,229.8 and 219 Ma)and contemporary formation of the pegmatite(230.7 Ma).The Late Cretaceous involved two episodes of alternate extension and shortening,driven by the subduction polarity change from northwestward subduction of the Okhotomorsk block to northward subduction of the NeoTethys seafloor.The evolution of the LOA consists of the NW–SE transpression ending ca.100 Ma,the WNW–ESE extension in the earlier episode lasting from 100 Ma to 86 Ma,the WNW–ESE transpression beginning at ca.85 Ma and the NAS extension in the later episode during the latest Cretaceous,which produced the extension-related three periods of Laojunshan granitic magmatism and coeval Sn-W mineralization,with ages in the range of 90–89 Ma,87–85 Ma and 83–79 Ma.We also evaluate the implications of magmaticmetamorphic-metallogenic degassing on the regional paleoclimatic history.展开更多
This paper models the Mars UAV formation exploring the surface of Mars,and then the formation obstacle avoidance is brought up with the assumptions of the Mars circumstance and the UAVs.Based on their specialty,constr...This paper models the Mars UAV formation exploring the surface of Mars,and then the formation obstacle avoidance is brought up with the assumptions of the Mars circumstance and the UAVs.Based on their specialty,constrained Delaunay triangulation,Yen-K shortest path algorithm,the collaborative function,and the improved pigeon-inspired optimization(PIO)algorithm are integrated to solve the obstacle avoidance for the formation.Since the steering maneuver costs much energy and increases instabilities vulnerable in extraterrestrial exploration,the paper focuses on the route smoothness problem.The PIO is improved to be suitable for smooth routes and is compatible with other PIO variants.The simulation results show that the sum of the steering angle,namely the performance index,is e®ectively reduced and satises the obstacle avoidance requirements for Mars UAV formation.展开更多
Hypersonic vehicles(HSVs)exhibit significant advantages over other vehicles,including the wide range of velocity and large airspace types,and these features have contributed to the rapid development of HSVs in the las...Hypersonic vehicles(HSVs)exhibit significant advantages over other vehicles,including the wide range of velocity and large airspace types,and these features have contributed to the rapid development of HSVs in the last 20 years.Moreover,hypersonic technologies have become a multidisciplinary research topic in the fields of aerodynamics,propulsion,structure,material,and control.Different types of re-entry gliding,air-breathing cruise,and aerospace vehicles have been designed to realize ambitious tasks,which in turn influenced the technological advancements and process change in the military.This paper summarizes the control-oriented integrated design of HSVs.First,the status of current research on the distinct characteristics and technique issues of HSVs is introduced.Then,the progresses made on complex modeling,guidance and control,and trajectory optimization are elaborated to exhibit the significant research interest in hypersonic technologies.The control-integrated design of HSVs is emphasized to solve the multidisciplinary design problems associated with the model and its control and trajectory.Various strategies regarding the multidisciplinary optimization design are also proposed to solve the integrated design problem.Finally,suggestions are provided for the control-oriented integrated design of HSVs.展开更多
Photoacoustic Doppler flow measurement based on continuous wave laser excitation owns the merit of clearly presenting the Doppler power spectra.Extending this technique to dual wavelengths can gain the spectral inform...Photoacoustic Doppler flow measurement based on continuous wave laser excitation owns the merit of clearly presenting the Doppler power spectra.Extending this technique to dual wavelengths can gain the spectral information of the flow sample extra to the flow speed information.An experimental system with two laser diodes respectively operated at 405 nm and 660 nm wavelengths is built and the flow measurement with black and red dyed polystyrene beads is performed.The measured Doppler power spectra can vividly reflect the flow speed,the flow direction,as well as the bead color.Since it is straightforward to further apply the same principle to multiple wavelengths,we can expect this type of spectroscopic photoacoustic Doppler flow measurement will be developed in the near future which will be very useful for studying the metabolism of the slowly moving red blood cell inside microvessels.展开更多
Diterpenes,or diterpenoids,are the most abundant and diverse subgroup of terpenoids,the largest family of sec-ondary metabolites.Most diterpenes possess broad biological activities including anti-inflammatory,antivira...Diterpenes,or diterpenoids,are the most abundant and diverse subgroup of terpenoids,the largest family of sec-ondary metabolites.Most diterpenes possess broad biological activities including anti-inflammatory,antiviral,anti-tumoral,antimicrobial,anticancer,antifungal,antidiabetic,cardiovascular protective,and phytohormone activities.As such,diterpenes have wide applications in medicine(e.g.,the anticancer drug Taxol and the antibiotic pleuromutilin),agriculture(especially as phytohormones such as gibberellins),personal care(e.g.,the fragrance sclareol)and food(e.g.,steviol glucosides as low-calorie sweeteners)industries.Diterpenes are biosyn-thesized in a common route with various diterpene synthases and decoration enzymes like cytochrome P450 oxidases,glycosidases,and acyltransferases.Recent advances in DNA sequencing and synthesis,omics analysis,synthetic biology,and metabolic engineering have enabled efficient production of diterpenes in several chassis hosts like Escherichia coli,Saccharomyces cerevisiae,Yarrowia lipolytica,Rhodosporidium toruloides,and Fusarium fujikuroi.This review summarizes the recently discovered diterpenes,their related enzymes and biosynthetic pathways,particularly highlighting the microbial synthesis of high-value diterpenes directly from inexpensive carbon sources(e.g.,sugars).The high titers(>4 g/L)achieved mean that some of these endeavors are reaching or close to commercialization.As such,we envisage a bright future in translating microbial synthesis of diterpenes into commercialization.展开更多
基金Supported by National Key Research and Development Program of China(Grant No.2021YFB2501000).
文摘Predictive cruise control(PCC)is an intelligence-assisted control technology that can significantly improve the overall performance of a vehicle by using road and traffic information in advance.With the continuous development of cloud control platforms(CCPs)and telematics boxes(T-boxes),cloud-based predictive cruise control(CPCC)systems are considered an effective solution to the problems of map update difficulties and insufficient computing power on the vehicle side.In this study,a vehicle-cloud hierarchical control architecture for PCC is designed based on a CCP and T-box.This architecture utilizes waypoint structures for hierarchical and dynamic cooperative inter-triggering,enabling rolling optimization of the system and commending parsing at the vehicle end.This approach significantly improves the anti-interference capability and resolution efficiency of the system.On the CCP side,a predictive fuel-saving speed-planning(PFSP)algorithm that considers the throttle input,speed variations,and time efficiency based on the waypoint structure is proposed.It features a forward optimization search without requiring weight adjustments,demonstrating robust applicability to various road conditions and vehicles equiped with constant cruise(CC)system.On the vehicle-side T-box,based on the reference control sequence with the global navigation satellite system position,the recommended speed is analyzed and controlled using the acute angle principle.Through analyzing the differences of the PFSP algorithm compared to dynamic programming(DP)and Model predictive control(MPC)algorithms under uphill and downhill conditions,the results show that the PFSP achieves good energy-saving performance compared to CC without exhibiting significant speed fluctuations,demonstrating strong adaptability to the CC system.Finally,by building an experimental platform and running field tests over a total of 2000 km,we verified the effectiveness and stability of the CPCC system and proved the fuel-saving performance of the proposed PFSP algorithm.The results showed that the CPCC system equipped with the PFSP algorithm achieved an average fuel-saving rate of 2.05%-4.39%compared to CC.
基金financially sponsored by The National Key Research and Development Program of China (Grant No. 2016YFC0600502)the Program of the China Geological Survey (Grant Nos. 1212011121260, 1212011220920)111 Project (B07011)
文摘The East Kunlun Orogenic Belt(EKOB) provides an important link to reconstruct the evolution of the Proto-Tethys and Paleo-Tethys realm. The EKOB is marked by widespread Early Paleozoic magmatism.Here we report the petrology, bulk geochemistry, zircon Ue Pb dating and, Lue Hf and SreN d isotopic data of the Early Paleozoic granitic rocks in Zhiyu area of the southern EKOB. Based on the zircon U-Pb dating, these granitoids, consisting of diorite, granodiorite and monzogranite, were formed during 450 -430 Ma the Late Ordovician to Middle Silurian. The diorite and granodiorite are high Sr/Y ratio as adakitic affinities, and the monzogranite belongs to highly fractionated I-type. Their(^(87)Sr/^(86)Sr)ivalues range from 0.7059 to 0.7085, εNd(t) values from -1.6 to -6.0 and the zircon εHf(t) values show large variations from +9.1 to -8.6 with Hf model ages(T_(DM2)) about 848 Ma and 1970 Ma. The large variations of whole-rock Nd and zircon Hf isotopes demonstrate strong isotopic heterogeneity of the source regions which probably resulted from multi-phase underplating of mantle-derived magmas. Geochemical and isotopic studies proved that the diorite and granodiorite had been derived from partial melting of heterogeneous crustal source with variable contributions from ancient continental crust and juvenile components, and the monzogranites were representing fractional crystallization and crustal contamination for arc magma. The Early Paleozoic adakitic rocks and high-K calc-alkaline granitoids in the southern EKOB were likely emplaced in a continental marginal arc setting possibly linked to the southwards subduction of the Paleo Kunlun Ocean and the magma generation is linked to partial melting of thickened continental crust induced by underplating of mantle-derived magmas.
基金supported by Aerospace Science and Technology Innovation Fund of China (No. CASC2016)Six Talent Peaks Project in Jiangsu Province of China (KTHY025)+3 种基金Funding of Jiangsu Innovation Program for Graduate Educationthe National Natural Science Foundation of China (Nos. 61403191, 11572149)the Funding of Jiangsu Innovation Program for Graduate Education of China (Nos. KYLX_0281, KYLX15_0318 and NZ2015205)the Fundamental Research Funds for the Central Universities of China
文摘An integrated approach that considers the performance limitations of tracking control systems for air-breathing hypersonic vehicles is proposed. First, a set of ascent trajectories is obtained as candidates for tracking control through a trajectory design method that considers the available acceleration. Second, the basic theory of performance limitations, which is adopted to calculate the limits on control performance through the trajectory, is integrated. The openloop dynamics of air-breathing hypersonic vehicles is responsible for these limits on the control system. Comprehensive specifications on stability, tracking accuracy, and robustness are derived, and the flight envelope with constraints and control specifications is identified. Simulation results suggest that trajectory design should consider restrictions on control performance to obtain reliable solutions.
基金co-supported by the Fundamental Research Funds for the Central Universities,China(No.NS2021061)the Six Talent Peaks Project in Jiangsu Province,China(No.KTHY-025)+2 种基金the China Postdoctoral Science Foundation No.2020M681586)the Natural Science Foundation of Jiangsu Province(No.BK20200437)the Interdisciplinary Innovation Foundation for doctoral students of Nanjing University of Aeronautics and Astronautics(No.KXKCXJJ202008).
文摘To reduce the design burden of Aerospace Vehicles(ASVs)control systems,this paper proposes a multi-constrained robust trajectory optimization method,which provides a good front-end input for the control system.Differ from the conventional aircraft,some control performance of ASVs is not only related to the model parameters,but also affected by the flight status.Therefore,the robust optimization method combines this characteristic of ASVs,sets the control performance as one of the optimization objectives,and considers the influence of parameter uncertainty.In this method,the polynomial chaos expansion algorithm is used to transform the trajectory optimization problem with uncertain parameters into the equivalent deterministic robust trajectory optimization problem.Finally,compared with traditional deterministic trajectory optimization methods to illustrate the effectiveness of proposed control optimization method.
基金financially supported by the China Geological Survey Program(Grant Nos.1212011121260,1212011220928)the National Natural Science Foundation of China(Project No.491755206)。
文摘The Gejiu-Bozushan-Laojunshan W-Sn polymetallic metallogenic belt(GBLB)in southeast Yunnan Province is an important part of the southwestern Yangtze Block in South China.Tin polymetallic mineralization in this belt includes the Niusipo,Malage,Songshujiao,Laochang and Kafang ore fields in the Gejiu area which are spatially and temporally associated with the Kafang-Laochang and Songshujiao granite plutons.These granites are characterized by variable A/CNK values(mostly>1.1,except for two samples with 1.09),high contents of SiO2(74.38-76.84 wt.%)and Al2 O3(12.46-14.05 wt.%)and variable CaO/Na2 O ratios(0.2-0.65)as well as high zirconδ18O values(7.74‰-9.86‰),indicative of S-type affinities.These rocks are depleted in Rb,Th,U,Ti,LREE[(La/Yb)N=1.4-20.51],Ba,Nb,Sr,and Ti and display strong negative Eu and Ba anomalies.The rocks possess high Rb/Sr and Rb/Ba ratios,relatively low initial 87Sr/86Sr ratios(0.6917-0.7101),and less radiogenicεNd(t)values(-8.0 to-9.1).The zircon grains from these rocks show negativeεHf(t)values in the range of-3.7 to-9.9 with mean TDM2(Nd)and TDM2(Hf)values of 1.57 Ga and 1.55 Ga.They show initial 207Pb/204Pb ranging from15.69 to 15.71 and 206Pb/204Pb from 18.36 to 18.70.Monazite from Songshujiao granites exhibits higher U and lower Th/U ratios,lowerδ18O values and higherεHf(t)values than those of the zircon grains in the KafangLaochang granites.The geochemical and isotopic features indicate that the Laochang-Kafang granites originated by partial melting of Mesoproterozoic crustal components including biotite-rich metapelite and metagraywacke,whereas the Songshujiao granites were derived from Mesoproterozoic muscovite-rich metapelite crustal source.Most zircon grains from the Songshujiao,Laochang and Kafang granites have high-U concentrations and their SIMS U-Pb ages show age scatter from 81.6 Ma to 88.6 Ma,80.7 Ma to 86.1 Ma and 82.3 Ma to 87.0 Ma,suggesting formation earlier than the monazite and cassiterite.Monazite SIMS U-Pb ages and Th-Pb ages of three same granite samples are consistent and show yielded 206 Pb/238U ages of 83.7±0.6 Ma,83.7±0.6 Ma,and 83.4±0.6 Ma,and 208Pb/232Th ages of 83.2±0.5 Ma,83.8±0.4 Ma,and 83.5±0.9 Ma,which are within the range of the SIMS zircon U-Pb ages from these rocks.The data constrain the crystallization of the granites at ca.83 Ma.In situ U-Pb dating of two cassiterite samples from the cassiterite-sulfide ore in the Songshujiao ore field and Kafang ore field,and two from the cassiterite-oxide+cassiterite bearing dolomite in the Laochang ore field yielded weighted mean 206 Pb/238U ages of 83.5±0.4 Ma(MSWD=0.6),83.5±0.4 Ma(MSWD=0.5),83.6±0.4 Ma(MSWD=0.6)and 83.2±0.7 Ma(MSWD=0.6),respectively.Combined with geological characteristics,the new geochronological data indicate that the formation of the granites and Sn polymetallic deposits are coeval.We correlate the magmatic and metallogenic event with lithospheric thinning and asthenosphere upwelling in continental extension setting in relation to the eastward subduction of the Neo-Tethys beneath the Sanjiang tectonic domain during Late Cretaceous.
基金supported by National Natural Science Foundation of China(30830024)
文摘Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so on.To deeply their structure and function in ecosystems,we investigated the spatial patterns and nitrogen(N)transfer of EM networks usingN labelling technique in a Mongolian scotch pine(Pinus sylvestris var.mongolica Litv.)plantation in Northeastern China.In August 2011,four plots(20 × 20 m)were set up in the plantation.125 ml 5 at.%0.15 mol/LNHNOsolution was injected into soil at the center of each plot.Before and 2,6,30 and 215 days after theN application,needles(current year)of each pine were sampled along four 12 m sampling lines.Needle total N andN concentrations were analyzed.We observed needle N andN concentrations increased significantly over time afterN application,up to 31 and0.42%,respectively.There was no correlation between needle N concentration andN/N ratio(R2=0.40,n=5,P=0.156),while excess needle N concentration and excess needleN/N ratio were positively correlated across different time intervals(R~2=0.89,n=4,P\0.05),but deceased with time interval lengthening.NeedleN/N ratio increased with time,but it was not correlated with distance.NeedleN/N ratio was negative with distance before and 6th day and 30th day,positive with distance at 2nd day,but the trend was considerably weaker,their slop were close to zero.These results demonstrated that EM networks were ubiquitous and uniformly distributed in the Mongolian scotch pine plantation and a random network.We found N transfer efficiency was very high,absorbed N by EM network was transferred as wide as possible,we observed N uptake of plant had strong bias forN andN,namely N fractionation.Understanding the structure and function of EM networks in ecosystems may lead to a deeper understanding of ecological stability and evolution,and thus provide new theoretical approaches to improve conservation practices for the management of the Earth’s ecosystems.
基金Supported by the National Natural Science Foundation of China(51305457)。
文摘To speedily regulate and precisely control a hydraulic power system in a unmanned walking platform(UWP),based on the brief analysis of digital PID and its shortcomings,dual control parameters in a hydraulic power system are given for the precision requirement,and a control strategy for dual relative control parameters in the dual loop PID is put forward,a load and throttle rotation-speed response model for variable pump and gasoline engine is provided according to a physical process,a simplified neural network structure PID is introduced,and formed mixed neural network PID(MNN PID)to control rotation speed of engine and pressure of variable pump,calculation using the back propagation(BP)algorithm and a self-adapted learning step is made,including a mathematic principle and a calculation flow scheme,the BP algorithm of neural network PID is trained and the control effect of system is simulated in Matlab environment,real control effects of engine rotation speed and variable pump pressure are verified in the experimental bench.Results show that algorithm effect of MNN PID is stable and MNN PID can meet the adjusting requirement of control parameters.
基金Supported by Gansu Youth Science and Technology Fund Program(21JR7RA778)Innovation Fund Project of Gansu Provincial Universities(2020A-186)。
文摘In order to explore the spatial and temporal changes of runoff and sediment in the Taohe River and its driving mechanism,Spearman correlation coefficient method,Mann-Kendell mutation test method and ordered clustering method were used to analyze the changes of runoff and sediment discharge and their driving factors in four hydrological stations along the Taohe River from 1957 to 2016.The results showed that the correlation between runoff and sediment of the four hydrological stations along the Taohe River was significant,and the correlation coefficient was 0.728-0.984.The runoff and sediment transport in the interval showed an increasing and decreasing trend.The decrease rate of runoff was 133.82%-216.17%higher than that of Xiabagou station,and the decrease rate of sediment transport was 250.49%-4766.33%higher than that of Xiabagou station.The mutation year of the Taohe River runoff occurred in 1986,and the maximum decrease was 35%.The water-sediment relationship curves of different periods showed that the sediment discharge of the four stations changed abruptly around 1990,and the maximum reduction before and after the mutation was up to 73%,and the sediment discharge in the river channel decreased significantly.The research showed that human activities were the main driving factors for the change of water-sediment relationship in the Taohe River.
基金National Natural Science Foundation of China(Grant Number:52172389)National Key Research and Development Program of China(Grant Number:2022YFB2503202)Alibaba Innovative Research Program.
文摘Vehicle-Road-Cloud Integration system(VRCIS)requires high-precision vehicle positioning and tracking,with very low system latency,which is a difficult task given the quantity and quality of data.To this end,a distributed computing framework using multi-access edge computing(MEC)devices is proposed in this paper.To process trajectory data(including preprocessing,calibration,multi-sensor trajectory matching,and trajectory prediction),as well as integrate machine learning algorithms to improve the accuracy of trajectory prediction,especially for complex and diverse driving scenarios environmental conditions,a framework is designed.In addition,to conduct a comprehensive evaluation of the overall performance of trajectory tracking,factors such as trajectory smoothness and velocity consistency—components of our novel evaluation metrics—are considered.Experiments show that the framework can continuously track tens of thousands of vehicles on highway,with average longitudinal and lateral errors of 2.14 and 0.84 m respectively,with average speed error of 1.91 kph.The experiments on large-scale road networks with 1,777 sensors are implemented,with continuous multi-vehicle tracking over 157 km of highway,and establishing superior performance compared to existing methods.Furthermore,processing latency remained below 340 ms,demonstrating the potential of this framework to enhance driver experience,improve road safety and efficiency.
基金supported by the National Natural Science Foundation of China(Nos.U24A20765 and T2321005)Jiangsu Provincial Science and Technology Plan Special Fund(No.BM2023003)+1 种基金Jiangsu Provincial Medical Key Discipline(No.ZDXK202247)the Priority Academic Program Development of the Jiangsu Higher Education Institutes.
文摘Cancer vaccine efficacy relies on T cells eliciting tumor-specific adaptive immunity,with antigen-presenting cells,particularly dendritic cells(DCs),playing a crucial role.After capturing antigens,DCs migrate to lymph nodes,where they present antigens to naïve T cells and activate B and natural killer(NK)cells,thereby strengthening anti-tumor immune responses.However,limitations in immune adjuvants and insufficient antigen presentation hinder DCs migration,reducing vaccine effectiveness.This study introduces an outer membrane vesicle(OMV)-based platform engineered to express Vibrio vulnificus flagellin B(FlaB),a Toll-like receptor 5(TLR5)agonist.FlaB effectively activates DCs,enhances interactions with T cells,provides robust costimulatory signals,and promotes cytotoxic CD8^(+)T cell differentiation.Compared to unmodified OMV-Ag,the antigen-loaded OMV-FlaB-Ag nanovaccine significantly enhances DC function,eliciting potent antitumor responses and delaying tumor progression across multiple models.When combined with immune checkpoint inhibitors,it further amplifies antitumor immunity,markedly suppressing tumor growth and improving therapeutic outcomes.
基金supported by the China Geological Survey Program(Grant Nos.1212011121260,1212011220928)the National Natural Science Foundation of China(Gant No.91755206)。
文摘The South China Block(SCB)is among the large-scale W-Sn mineralized regions of the globe.The Laojunshan W-Sn-dominant ore area(LOA)in the western part of the SCB preserves the records of the tectonic history of the Tethys realm extending through North Vietnam,and Yangtze to Cathaysia blocks,with coeval formation of giant metallic deposits.The prolonged tectonic activities and their control on the genesis and spatio-temporal distribution of giant metallic deposits in the LOA provide a window for a holistic understanding of the tectono-metallogenesis of the SCB.In this study,we present results from a multi-chronologic study to determine the timing of formation of the cassiterite-wolframite-schee lite mineralization.The results suggest three distinct tectono-metallogenic periods in the LOA during the geodynamic evolution of the surrounding tectonic units.The opening of the Proto-Tethys Ocean between the Yangtze-Indochina blocks and the westward Paleo-Pacific subduction beneath the Cathaysia block(420–380 Ma)jointly contributed to the Silurian to early Devonian intracontinental orogeny in the middle of the SCB that involved top-to-the-north thrusting along NE-striking shear zones.This event generated the Dulong-Song Chay granitoids,together with the formation of Xinzhai Sn deposit related to sheared mylonitic granites(ca.419 Ma)and pegmatites(ca.389 Ma),which include the early-stage Sn-sulfide skarn(ca.418 Ma)and the late-stage Sn-bearing schist(ca.389 Ma).During the Late Permian to Late Triassic(260–220 Ma),with the closure of the Proto-Tethys oceans in the west and ongoing Paleo-Pacific westward subduction in the east,the SCB and Indochina Block(IB)were amalgamated which also marks the time of formation of the Nanwenhe scheelite skarn deposit.The subducted PaleoTethys oceanic crust was likely entrained by the nearby rising Emeishan mantle plume(270–259 Ma),which formed the Maguan diabase(ca.260 Ma)that shows significantly older Re-Os model age of ca.268 Ma,suggesting that the Nanwenhe mineralization is potentially derived from ca.260 Ma source.Furthermore,the intraplate shortening induced thin skinned crustal deformation and low grade metamorphism(ca.230 Ma),with the main stage of scheelite-Sn-Mo mineralization(229.9,229.8 and 219 Ma)and contemporary formation of the pegmatite(230.7 Ma).The Late Cretaceous involved two episodes of alternate extension and shortening,driven by the subduction polarity change from northwestward subduction of the Okhotomorsk block to northward subduction of the NeoTethys seafloor.The evolution of the LOA consists of the NW–SE transpression ending ca.100 Ma,the WNW–ESE extension in the earlier episode lasting from 100 Ma to 86 Ma,the WNW–ESE transpression beginning at ca.85 Ma and the NAS extension in the later episode during the latest Cretaceous,which produced the extension-related three periods of Laojunshan granitic magmatism and coeval Sn-W mineralization,with ages in the range of 90–89 Ma,87–85 Ma and 83–79 Ma.We also evaluate the implications of magmaticmetamorphic-metallogenic degassing on the regional paleoclimatic history.
文摘This paper models the Mars UAV formation exploring the surface of Mars,and then the formation obstacle avoidance is brought up with the assumptions of the Mars circumstance and the UAVs.Based on their specialty,constrained Delaunay triangulation,Yen-K shortest path algorithm,the collaborative function,and the improved pigeon-inspired optimization(PIO)algorithm are integrated to solve the obstacle avoidance for the formation.Since the steering maneuver costs much energy and increases instabilities vulnerable in extraterrestrial exploration,the paper focuses on the route smoothness problem.The PIO is improved to be suitable for smooth routes and is compatible with other PIO variants.The simulation results show that the sum of the steering angle,namely the performance index,is e®ectively reduced and satises the obstacle avoidance requirements for Mars UAV formation.
基金Aerospace Science and Technology Innovation Fund(CASC2016)Six Talent Peaks Project in Jiangsu Province(KTHY-025).
文摘Hypersonic vehicles(HSVs)exhibit significant advantages over other vehicles,including the wide range of velocity and large airspace types,and these features have contributed to the rapid development of HSVs in the last 20 years.Moreover,hypersonic technologies have become a multidisciplinary research topic in the fields of aerodynamics,propulsion,structure,material,and control.Different types of re-entry gliding,air-breathing cruise,and aerospace vehicles have been designed to realize ambitious tasks,which in turn influenced the technological advancements and process change in the military.This paper summarizes the control-oriented integrated design of HSVs.First,the status of current research on the distinct characteristics and technique issues of HSVs is introduced.Then,the progresses made on complex modeling,guidance and control,and trajectory optimization are elaborated to exhibit the significant research interest in hypersonic technologies.The control-integrated design of HSVs is emphasized to solve the multidisciplinary design problems associated with the model and its control and trajectory.Various strategies regarding the multidisciplinary optimization design are also proposed to solve the integrated design problem.Finally,suggestions are provided for the control-oriented integrated design of HSVs.
基金This work is supported by the National Natural Science Foundation of China(Grant No.11774256)the Natural Science Foundation of Guangdong Province(Grant No.2018B03031104).
文摘Photoacoustic Doppler flow measurement based on continuous wave laser excitation owns the merit of clearly presenting the Doppler power spectra.Extending this technique to dual wavelengths can gain the spectral information of the flow sample extra to the flow speed information.An experimental system with two laser diodes respectively operated at 405 nm and 660 nm wavelengths is built and the flow measurement with black and red dyed polystyrene beads is performed.The measured Doppler power spectra can vividly reflect the flow speed,the flow direction,as well as the bead color.Since it is straightforward to further apply the same principle to multiple wavelengths,we can expect this type of spectroscopic photoacoustic Doppler flow measurement will be developed in the near future which will be very useful for studying the metabolism of the slowly moving red blood cell inside microvessels.
基金supported by the Agency for Science,Technology and Research(A∗STAR),Singapore:AME Young Individual Research Grant(YIRG)A2084c0064(Dr.Congqiang Zhang)and A1984c0040(Dr.Xixian Chen)A∗STAR Central Strategic Fund for the Singa-pore Integrative Biosystems and Engineering Research(SIBER)Program C211917009.
文摘Diterpenes,or diterpenoids,are the most abundant and diverse subgroup of terpenoids,the largest family of sec-ondary metabolites.Most diterpenes possess broad biological activities including anti-inflammatory,antiviral,anti-tumoral,antimicrobial,anticancer,antifungal,antidiabetic,cardiovascular protective,and phytohormone activities.As such,diterpenes have wide applications in medicine(e.g.,the anticancer drug Taxol and the antibiotic pleuromutilin),agriculture(especially as phytohormones such as gibberellins),personal care(e.g.,the fragrance sclareol)and food(e.g.,steviol glucosides as low-calorie sweeteners)industries.Diterpenes are biosyn-thesized in a common route with various diterpene synthases and decoration enzymes like cytochrome P450 oxidases,glycosidases,and acyltransferases.Recent advances in DNA sequencing and synthesis,omics analysis,synthetic biology,and metabolic engineering have enabled efficient production of diterpenes in several chassis hosts like Escherichia coli,Saccharomyces cerevisiae,Yarrowia lipolytica,Rhodosporidium toruloides,and Fusarium fujikuroi.This review summarizes the recently discovered diterpenes,their related enzymes and biosynthetic pathways,particularly highlighting the microbial synthesis of high-value diterpenes directly from inexpensive carbon sources(e.g.,sugars).The high titers(>4 g/L)achieved mean that some of these endeavors are reaching or close to commercialization.As such,we envisage a bright future in translating microbial synthesis of diterpenes into commercialization.
