期刊文献+
共找到914篇文章
< 1 2 46 >
每页显示 20 50 100
An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion
1
作者 Kai-Xuan Qiu Jia Li +2 位作者 Dong Feng Shi-Ming Wei Gang Lei 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期352-365,共14页
In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture network.It has been proven to cause inaccurate pro... In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture network.It has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture communication.In addition,most of the existing models are solved analytically based on Laplace transform and numerical inversion.Hence,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix depletion.To simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the microfractures.Then,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by integration.Finally,a relationship between oil rate and production time in real-time space is obtained.The new model is verified against classical analytical models.When the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,respectively.Certainly,the new model also has an excellent agreement with the numerical model.The model is then applied to two actual tight oil wells completed in western Canada sedimentary basin.After identifying the flow regime,the solution suitably matches the field production data,and the model parameters are determined.Through these output parameters,we can accurately forecast the production and even estimate the petrophysical properties. 展开更多
关键词 Analytical solution Unconventional reservoir Variable matrix simultaneous flow
下载PDF
Extended finite element-based cohesive zone method for modeling simultaneous hydraulic fracture height growth in layered reservoirs
2
作者 Lei Yang Baixi Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2960-2981,共22页
In this study,a fully coupled hydromechanical model within the extended finite element method(XFEM)-based cohesive zone method(CZM)is employed to investigate the simultaneous height growth behavior of multi-cluster hy... In this study,a fully coupled hydromechanical model within the extended finite element method(XFEM)-based cohesive zone method(CZM)is employed to investigate the simultaneous height growth behavior of multi-cluster hydraulic fractures in layered porous reservoirs with modulus contrast.The coupled hydromechanical model is first verified against an analytical solution and a laboratory experiment.Then,the fracture geometry(e.g.height,aperture,and area)and fluid pressure evolutions of multiple hydraulic fractures placed in a porous reservoir interbedded with alternating stiff and soft layers are investigated using the model.The stress and pore pressure distributions within the layered reservoir during fluid injection are also presented.The simulation results reveal that stress umbrellas are easily to form among multiple hydraulic fractures’tips when propagating in soft layers,which impedes the simultaneous height growth.It is also observed that the impediment effect of soft layer is much more significant in the fractures suppressed by the preferential growth of adjoining fractures.After that,the combined effect of in situ stress ratio and fracturing spacing on the multi-fracture height growth is presented,and the results elucidate the influence of in situ stress ratio on the height growth behavior depending on the fracture spacing.Finally,it is found that the inclusion of soft layers changes the aperture distribution of outmost and interior hydraulic fractures.The results obtained from this study may provide some insights on the understanding of hydraulic fracture height containment observed in filed. 展开更多
关键词 Hydraulic fracturing Layered reservoir simultaneous height growth In situ stress Fracture spacing Extended finite element method(XFEM) Cohesive zone method(CZM)
下载PDF
Simultaneous Identification of Thermophysical Properties of Semitransparent Media Using a Hybrid Model Based on Artificial Neural Network and Evolutionary Algorithm
3
作者 LIU Yang HU Shaochuang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第4期458-475,共18页
A hybrid identification model based on multilayer artificial neural networks(ANNs) and particle swarm optimization(PSO) algorithm is developed to improve the simultaneous identification efficiency of thermal conductiv... A hybrid identification model based on multilayer artificial neural networks(ANNs) and particle swarm optimization(PSO) algorithm is developed to improve the simultaneous identification efficiency of thermal conductivity and effective absorption coefficient of semitransparent materials.For the direct model,the spherical harmonic method and the finite volume method are used to solve the coupled conduction-radiation heat transfer problem in an absorbing,emitting,and non-scattering 2D axisymmetric gray medium in the background of laser flash method.For the identification part,firstly,the temperature field and the incident radiation field in different positions are chosen as observables.Then,a traditional identification model based on PSO algorithm is established.Finally,multilayer ANNs are built to fit and replace the direct model in the traditional identification model to speed up the identification process.The results show that compared with the traditional identification model,the time cost of the hybrid identification model is reduced by about 1 000 times.Besides,the hybrid identification model remains a high level of accuracy even with measurement errors. 展开更多
关键词 semitransparent medium coupled conduction-radiation heat transfer thermophysical properties simultaneous identification multilayer artificial neural networks(ANNs) evolutionary algorithm hybrid identification model
下载PDF
Sci-tech Simultaneous Interpreter Education Based on Translation Universals Research
4
作者 JI Mengqi JI Xiaowen 《Sino-US English Teaching》 2024年第9期443-448,共6页
The rapid evolution of scientific and technological advancements and industrial changes has profoundly interconnected countries and regions in the digital information era,creating a globalized environment where effect... The rapid evolution of scientific and technological advancements and industrial changes has profoundly interconnected countries and regions in the digital information era,creating a globalized environment where effective communication is paramount.Consequently,the demand for proficient interpreting skills within the scientific and technology sectors has surged,making effective language communication increasingly crucial.This paper explores the potential impact of translation universals on enhancing sci-tech simultaneous interpreter education.By examining the selection of teaching materials,methods,and activities through the lens of translation universals,this study aims to improve the quality of teaching content,innovate instructional approaches,and ultimately,enhance the effectiveness of interpreter education.The findings of this research are expected to provide valuable insights for curriculum development and pedagogical strategies in interpreter education. 展开更多
关键词 simultaneous interpreting translation universals interpreter education sci-tech interpreting
下载PDF
Simultaneous Waveform Inverse Modelling for Litho-Fluid Prediction in an Old Marginal, “Agbbo”Field, Onshore Niger Delta, Nigeria
5
作者 Charles Chibueze Ugbor Peter Ogobi Odong Chukwuemeka Austine Okonkwo 《Journal of Geoscience and Environment Protection》 2024年第5期40-59,共20页
Simultaneous waveform inversion was used to predict lithofacies and fluid type across the field. Very often, characterizing reservoirs in terms of lithology and fluid type using conventional methods is replete with un... Simultaneous waveform inversion was used to predict lithofacies and fluid type across the field. Very often, characterizing reservoirs in terms of lithology and fluid type using conventional methods is replete with uncertainties, especially in marginal fields. An approach is employed in this study that integrated rock physics and waveform inverse modelling for lithology and fluid-type characterization to appropriately identify potential hydrocarbon saturated zones and their corresponding lithology. Seismic and well-log data were analyzed using Hampson Russel software. The method adopted includes lithofacies and fluid content analysis using rock physics parameters and seismic simultaneous inverse modelling. Rock physics analysis identified 2 broad reservoirs namely: HDZ1 and HDZ2 reservoirs. Results from the inverse modelling showed that low values of acoustic impedance from 19,743 to 20,487 (ft/s)(g/cc) reflect hydrocarbon-bearing reservoirs while medium to high values shows brine and shale respectively, with brine zone ranging from 20,487 to 22,531 (ft/s)(g/cc) and shale above 22,531 (ft/s)(g/cc). Two lithofacies were identified from inversion analysis of Vp/Vs and Mu-Rho, namely: sand and shale with VpVs 1.95 values respectively. Mu-Rho > 12.29 (GPa)(g/cc) and <12.29 (GPa) (g/cc) represent sand and shale respectively. From 3D volume, it was observed that a high accumulation of hydrocarbon was observed to be saturated at the north to the eastern part of the field forming a meandering channel. Sands were mainly distributed around the northeastern to the southwestern part of the field, that tends to be away from Well 029. This was also validated by the volume of rigidity modulus (Mu-Rho) showing high values indicating sands fall within the northeastern part of the field. 展开更多
关键词 simultaneous Waveform Inversion Lithofacies Fluid Type Rock Physics HYDROCARBON Acoustic Impedance Mu-Rho Reservoir
下载PDF
A universal probe for simultaneous detection of six pospiviroids and natural infection of potato spindle tuber viroid(PSTVd) in tomato in China 被引量:1
6
作者 ZHANG Yu-hong LI Zhi-xin +2 位作者 DU Ya-jie LI Shi-fang ZHANG Zhi-xiang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第3期790-798,共9页
Several viroids in the genus Pospiviroid can infect tomato(Solanum lycopersicum)and cause severe diseases,posing a serious threat to tomato production.For simultaneous detection of six tomato-infecting pospiviroids-co... Several viroids in the genus Pospiviroid can infect tomato(Solanum lycopersicum)and cause severe diseases,posing a serious threat to tomato production.For simultaneous detection of six tomato-infecting pospiviroids-columnea latent viroid(CLVd),pepper chat fruit viroid(PCFVd),potato spindle tuber viroid(PSTVd),tomato apical stunt viroid(TASVd),tomato chlorotic dwarf viroid(TCDVd),and tomato planta macho viroid(TPMVd),we developed a universal probe based on a highly conserved 61 nt long sequence shared among them.Compared with their specific probes,the universal probe has a similar,though slightly reduced,detection sensitivity and has the advantages of simple and cost-effective preparation and simultaneous detection of the six pospiviroids.In addition,the universal probe was used in dot-blot hybridization assays for a large-scale survey of viroid(s)in tomato plantings in China.Only PSTVd was detected in a few greenhouse-planted tomato plants.Sequence analysis revealed that these tomato PSTVd isolates may have been introduced from tomato seeds imported from abroad. 展开更多
关键词 TOMATO VIROID simultaneous detection molecular hybridization pospiviroids
下载PDF
Simultaneous nitrification and autotrophic denitrification in fluidized bed reactors using pyrite and elemental sulfur as electron donors 被引量:1
7
作者 Maria F.Carboni Sonia Arriaga Piet N.L.Lens 《Water Science and Engineering》 EI CAS CSCD 2023年第2期143-153,共11页
In this study, simultaneous nitrification and autotrophic denitrification (SNAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was... In this study, simultaneous nitrification and autotrophic denitrification (SNAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was evaluated at different ammonium (12-40 mg/L of NH4+-N), nitrate (35-45 mg/L of NO3--N), and dissolved oxygen (DO) (0.1-1.5 mg/L) concentrations, with a hydraulic retention time of 12 h. The pyrite reactor supported the SNAD process with a maximum nitrogen removal efficiency of 139.5 mg/(L·d) when the DO concentration was in the range of 0.8-1.5 mg/L. This range, however, limited the denitrification efficiency of the reactor, which decreased from 90.0% ± 5.3% in phases II-V to 67.9% ± 7.2% in phases VI and VII. Sulfate precipitated as iron sulfate (FeSO4/Fe2(SO4)3) and sodium sulfate (Na2SO4) minerals during the experiment. The sulfur reactor did not respond well to nitrification with a low and unstable ammonium removal efficiency, while denitrification occurred with a nitrate removal efficiency of 97.8%. In the pyrite system, the nitrifying bacterium Nitrosomonas sp. was present, and its relative abundance increased from 0.1% to 1.1%, while the autotrophic denitrifying genera Terrimonas, Ferruginibacter, and Denitratimonas dominated the community. Thiobacillus, Sulfurovum, and Trichlorobacter were the most abundant genera in the sulfur reactor during the entire experiment. 展开更多
关键词 PYRITE Elemental sulfur simultaneous nitrification and denitrification Nitrogen removal 16S rRNA
下载PDF
Simultaneous resonance of an axially moving ferromagnetic thin plate under a line load in a time-varying magnetic field 被引量:1
8
作者 Xie Mengxue Hu Yuda Xu Haoran 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第4期951-963,共13页
In this paper,the simultaneous resonance of a ferromagnetic thin plate in a time-varying magnetic field,having axial speed and being subjected to a periodic line load,is studied.Based on the large deflection theory of... In this paper,the simultaneous resonance of a ferromagnetic thin plate in a time-varying magnetic field,having axial speed and being subjected to a periodic line load,is studied.Based on the large deflection theory of thin plates and electromagnetic field theory,the nonlinear vibration differential equation of the plate is obtained by using the Hamilton′s principle and the Galerkin method.Then the boundary condition in which the longer opposite sides are clamped and hinged is considered.The dimensionless nonlinear differential equations are solved by using the method of multiple scales,and the analytical solution is given.In addition,the stability analysis is also carried out by using Lyapunov stability theory.Through numerical analysis,the variation curves of system resonance amplitude with frequency tuning parameter,magnetic field strength and external excitation amplitude are obtained.Different parameters that have significant effects on the response of the system,such as the thickness,the axial velocity,the magnetic field intensity,the position,and the frequency of external excitation,are considered and analyzed.The results show that the system has multiple solution regions and obvious nonlinear coupled characteristics. 展开更多
关键词 ferromagnetic thin plate time-varying magnetic field simultaneous resonance axially moving line load
下载PDF
Simultaneous denoising and resolution enhancement of seismic data based on elastic convolution dictionary learning 被引量:1
9
作者 Nan-Ying Lan Fan-Chang Zhang +1 位作者 Kai-Heng Sang Xing-Yao Yin 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2127-2140,共14页
Enhancing seismic resolution is a key component in seismic data processing, which plays a valuable role in raising the prospecting accuracy of oil reservoirs. However, in noisy situations, existing resolution enhancem... Enhancing seismic resolution is a key component in seismic data processing, which plays a valuable role in raising the prospecting accuracy of oil reservoirs. However, in noisy situations, existing resolution enhancement methods are difficult to yield satisfactory processing outcomes for reservoir characterization. To solve this problem, we develop a new approach for simultaneous denoising and resolution enhancement of seismic data based on convolution dictionary learning. First, an elastic convolution dictionary learning algorithm is presented to efficiently learn a convolution dictionary with stronger representation capability from the noisy data to be processed. Specifically, the algorithm introduces the elastic L1/2 norm as a sparsity constraint and employs a steepest gradient descent strategy to efficiently solve the frequency-domain linear system with substantial computational cost in a half-quadratic splitting framework. Then, based on the learned convolution dictionary, a weighted convolutional sparse representation paradigm is designed to encode the noisy data to acquire an optimal sparse approximation of the effective signal. Subsequently, a high-resolution dictionary with a broadband spectrum is constructed by the proposed parameter scaling strategy and matched filtering technique on the basis of atomic spectrum modeling. Finally, the optimal sparse approximation of the effective signal and the constructed high-resolution dictionary are used for data reconstruction to obtain the seismic signal with high resolution and high signal-to-noise ratio. Synthetic and field dataset examples are executed to check the effectiveness and reliability of the developed method. The results indicate that this method has a more competitive performance in seismic applications compared with the conventional deconvolution and spectral whitening methods. 展开更多
关键词 simultaneous denoising and resolution enhancement Elastic convolution dictionary learning Weighted convolutional sparse representation Matched filtering
下载PDF
ON BEST SIMULTANEOUS APPROXIMATION IN QUOTIENT SPACES 被引量:1
10
作者 M. Iranmanesh H. Mohebi 《Analysis in Theory and Applications》 2007年第1期35-49,共15页
We assume that X is a normed linear space, W and M are subspaces of X. We develop a theory of best simultaneous approximation in quotient spaces and introduce equivalent assertions between the subspaces W and W + M a... We assume that X is a normed linear space, W and M are subspaces of X. We develop a theory of best simultaneous approximation in quotient spaces and introduce equivalent assertions between the subspaces W and W + M and the quotient space W/M. 展开更多
关键词 quotient space best simultaneous approximation simultaneous pseudo-Chebyshev simultaneous quasi-Chebyshev simultaneous weakly-Chebyshev
下载PDF
A Fiber Optic Sensor for the Simultaneous Measurement of Dual-parameter Based on Hydrogel-immobilized Enzyme Complex
11
作者 TONG Yilin ZHANG Yu +2 位作者 HAN Xuecai YU Kan BAO Jiaqi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第6期1311-1318,共8页
A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic s... A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved.By controlling the temperature from high to low,the function of fiber sulfide sensor and fiber DCP sensor can be realized,so as to realize the continuous detection of dual-parameter.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions,the response curves,linear detection ranges,detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing sulfide and DCP concentration of practical water samples. 展开更多
关键词 hydrogel-immobilized enzyme complex dual-parameter simultaneous measurement fiber optic sensor
下载PDF
Repeat peroral endoscopic myotomy with simultaneous submucosal and muscle dissection as a salvage option for recurrent achalasia
12
作者 Yun-Juan Lin Sheng-Zhen Liu +4 位作者 Long-Song Li Ke Han Bo-Zong Shao En-Qiang Linghu Ning-Li Chai 《World Journal of Gastroenterology》 SCIE CAS 2023年第15期2349-2358,共10页
BACKGROUND For recurrent achalasia after initial peroral endoscopic myotomy(POEM)failure,repeat POEM(Re-POEM)has been reported as a treatment option.However,severe esophageal interlayer adhesions caused by previous pr... BACKGROUND For recurrent achalasia after initial peroral endoscopic myotomy(POEM)failure,repeat POEM(Re-POEM)has been reported as a treatment option.However,severe esophageal interlayer adhesions caused by previous procedures impede the successful establishment of a submucosal tunnel and lead to aborted Re-POEM procedures.Our team previously described POEM with simultaneous submucosal and muscle dissection(POEM-SSMD)as a feasible solution for achalasia with severe interlayer adhesions.AIM To investigate the effectiveness and safety of Re-POEM with simultaneous submucosal and muscle dissection(Re-POEM-SSMD).METHODS A total of 1049 patients with achalasia who underwent successful endoscopic myotomy at the Digestive Endoscopic Center of Chinese PLA General Hospital from December 2014 to May 2022 were reviewed.Patients with recurrent achalasia who experienced initial POEM clinical failure were retrospectively included in this study.The primary endpoint was retreatment clinical success,defined as an Eckardt score≤3 during the postretreatment follow-up and no need for additional treatment.Procedure-related adverse events,changes in manometric lower esophageal sphincter(LES)pressure and reflux complications,as well as procedure-related parameters,were recorded.RESULTS Sixteen patients underwent Re-POEM(9 patients)or Re-POEM-SSMD(7 patients)successfully at a median of 45.5 mo(range,4-95 mo)after initial POEM.During a median followup period of 31 mo(range,7-96 mo),clinical success(Eckardt score≤3)was achieved in 8(88.9%)and 6(85.7%)patients after Re-POEM and Re-POEM-SSMD,respectively(P=0.849).The median Eckardt score dropped from 4(range,3-8)at preretreatment to 1(range,0-5)at postretreatment in the Re-POEM group(P=0.025)and from 5(range,2-8)to 2(range,0-4)in the Re-POEM-SSMD group(P<0.001).The mean manometric LES pressure decreased from 23.78±9.04 mmHg to 11.45±5.37 mmHg after Re-POEM(P<0.001)and from 26.80±7.48 mmHg to 11.05±4.38 mmHg after Re-POEM-SSMD(P<0.001).No serious adverse events were recorded in both groups.CONCLUSION In conclusion,Re-POEM-SSMD appears to be a safe and effective salvage therapy for recurrent achalasia with severe interlayer adhesions. 展开更多
关键词 Esophageal achalasia Recurrence Peroral endoscopic myotomy simultaneous submucosal and muscle dissection Interlayer adhesion Salvage therapy
下载PDF
Cooperative Sampling Path Planning of Underwater Glider Fleet with Simultaneous Launch and Recovery
13
作者 ZANG Wenchuan SONG Dalei YAO Peng 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第4期975-982,共8页
As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative ... As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method. 展开更多
关键词 underwater glider fleet cooperative sampling path planning simultaneous launch and recovery clipped-oriented line-ofsight multi-actuation deep-Q network
下载PDF
Simultaneous detection of CH_(4)and CO_(2)through dual modulation off-axis integrated cavity output spectroscopy
14
作者 刘艺璇 王周兵 +3 位作者 韦欣欣 王静静 孟鑫 毛桂林 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期468-475,共8页
This study established a novel method for the simultaneous detection of two-component gases.Radio frequency(RF)white noise disturbance laser current and wavelength modulation were simultaneously used to improve the of... This study established a novel method for the simultaneous detection of two-component gases.Radio frequency(RF)white noise disturbance laser current and wavelength modulation were simultaneously used to improve the off-axis integrated cavity output spectroscopy technique,and a high-precision dual modulation OA-ICOS(RF-WM-OA-ICOS)system was established.The two laser beams were coupled into one laser beam that was applied incident to the cavity of RF-WM-OA-ICOS system.The second harmonic signals of CH_(4)and CO_(2)gas simultaneously appeared in the rising or falling edge of a triangular wave.This method was used to measure CH_(4)and CO_(2)with different concentrations.The results indicated that the proposed system has high stability and can accurately and simultaneously measure the concentrations of CH_(4)and CO_(2),with an optimal integration time of 220 s.The minimum detection limit was 10 ppb for CH_(4)and 1.5 ppm for CO_(2).The corresponding noise equivalent absorption sensitivity values were calculated as 2.67×10^(-13)cm^(-1)·Hz^(-1/2)and 5.18×10^(-11)cm^(-1)·Hz^(-1/2),respectively.The proposed dual-component gas simultaneous detection method can also be used for high-precision simultaneous detection of other gases.Therefore,this study may serve as a reference for developing portable multicomponent gas analyzers. 展开更多
关键词 off-axis integrated cavity output spectroscopy wavelength modulation radio frequency(RF)white noise simultaneous detection
下载PDF
Review of Simultaneous Localization and Mapping Technology in the Agricultural Environment
15
作者 Yaoguang Wei Bingqian Zhou +3 位作者 Jialong Zhang Ling Sun Dong An Jincun Liu 《Journal of Beijing Institute of Technology》 EI CAS 2023年第3期257-274,共18页
Simultaneous localization and mapping(SLAM)is one of the most attractive research hotspots in the field of robotics,and it is also a prerequisite for the autonomous navigation of robots.It can significantly improve th... Simultaneous localization and mapping(SLAM)is one of the most attractive research hotspots in the field of robotics,and it is also a prerequisite for the autonomous navigation of robots.It can significantly improve the autonomous navigation ability of mobile robots and their adaptability to different application environments and contribute to the realization of real-time obstacle avoidance and dynamic path planning.Moreover,the application of SLAM technology has expanded from industrial production,intelligent transportation,special operations and other fields to agricultural environments,such as autonomous navigation,independent weeding,three-dimen-sional(3D)mapping,and independent harvesting.This paper mainly introduces the principle,sys-tem framework,latest development and application of SLAM technology,especially in agricultural environments.Firstly,the system framework and theory of the SLAM algorithm are introduced,and the SLAM algorithm is described in detail according to different sensor types.Then,the devel-opment and application of SLAM in the agricultural environment are summarized from two aspects:environment map construction,and localization and navigation of agricultural robots.Finally,the challenges and future research directions of SLAM in the agricultural environment are discussed. 展开更多
关键词 simultaneous localization and mapping(SLAM) agricultural environment agricultural robots environment map construction localization and navigation
下载PDF
Acute myelomonocytic leukemia and T-lymphoblastic lymphoma as simultaneous bilineage hematologic malignancy treated with decitabine:A case report
16
作者 So-Yeon Jeon Na-Ri Lee +6 位作者 Seungah Cha Ho-Young Yhim Jae-Yong Kwak Kyu Yun Jang Namsu Kim Yong Gon Cho Chang-Hoon Lee 《World Journal of Clinical Cases》 SCIE 2023年第21期5129-5135,共7页
BACKGROUND Simultaneous bilineage hematologic malignancies are rare;however,several cases of acute myeloid leukemia(AML)and T-lymphoblastic lymphoma(T-LBL)cooccurrence have been reported.A standard treatment for simul... BACKGROUND Simultaneous bilineage hematologic malignancies are rare;however,several cases of acute myeloid leukemia(AML)and T-lymphoblastic lymphoma(T-LBL)cooccurrence have been reported.A standard treatment for simultaneous AML and T-LBL has not yet been established,and its prognosis is very poor.Further studies to develop standard treatments are required to increase patient survival rates.CASE SUMMARY A 69-year-old man complaining of pleuritic chest pain visited the emergency room.Computed tomography revealed multiple enlarged lymph nodes(LNs)in the neck and groin and pulmonary thromboembolism with pulmonary infarction.Furthermore,a peripheral blood smear performed due to leukocytosis revealed circulating blasts.Acute myelomonocytic leukemia(AMML)was diagnosed after bone marrow examination,and T-LBL positivity for terminal deoxynucleotidyl transferase,cluster of differentiation(CD)34,and CD4 was confirmed by cervical LN biopsy.Decitabine and dexamethasone were administered because he could not receive intensive chemotherapy due to poor performance status.Complete remission of AMML and T-LBL was achieved after 4 cycles of decitabine plus dexamethasone.CONCLUSION We report the therapeutic effect of decitabine,a hypomethylating agent(HMA),in patients with concurrent bilineage hematologic malignancies and suggest that further studies are required to evaluate the therapeutic effect of HMAs on both lymphoid and bilineage hematologic malignancies. 展开更多
关键词 simultaneous bilineage hematologic malignancies Acute myelomonocytic leukemia T-lymphoblastic lymphoma DECITABINE Pulmonary thromboembolism Case report
下载PDF
Simultaneous pancreas-kidney transplantation for end-stage renal failure in type 1 diabetes mellitus: Current perspectives
17
作者 Lakshmi Nagendra Cornelius James Fernandez Joseph M Pappachan 《World Journal of Transplantation》 2023年第5期208-220,共13页
Type 1 diabetes mellitus(T1DM)is one of the important causes of chronic kidney disease(CKD)and end-stage renal failure(ESRF).Even with the best available treatment options,management of T1DM poses significant challeng... Type 1 diabetes mellitus(T1DM)is one of the important causes of chronic kidney disease(CKD)and end-stage renal failure(ESRF).Even with the best available treatment options,management of T1DM poses significant challenges for clinicians across the world,especially when associated with CKD and ESRF.Substantial increases in morbidity and mortality along with marked rise in treatment costs and marked reduction of quality of life are the usual consequences of onset of CKD and progression to ESRF in patients with T1DM.Simultaneous pancreas-kidney transplant(SPK)is an attractive and promising treatment option for patients with advanced CKD/ESRF and T1DM for potential cure of these diseases and possibly several complications.However,limited availability of the organs for transplantation,the need for long-term immunosuppression to prevent rejection,peri-and post-operative complications of SPK,lack of resources and the expertise for the procedure in many centers,and the cost implications related to the surgery and postoperative care of these patients are major issues faced by clinicians across the globe.This clinical update review compiles the latest evidence and current recommendations of SPK for patients with T1DM and advanced CKD/ESRF to enable clinicians to care for these diseases. 展开更多
关键词 Type 1 diabetes mellitus Chronic kidney disease End-stage renal failure simultaneous pancreas-kidney transplantation Perioperative complications IMMUNOSUPPRESSION
下载PDF
Empirical Research on the Relationship between Education Poverty Alleviation and Rural Revitalization—Spatial Panel Simultaneous Equation Model Based on Provincial Panel Data
18
作者 Ningning Li Shichang Shen 《Open Journal of Applied Sciences》 2023年第11期2032-2046,共15页
On the basis of using entropy weight method to measure China’s education poverty alleviation and rural revitalization evaluation indicators, using the panel data of 30 provinces in China (excluding Xizang, Hong Kong,... On the basis of using entropy weight method to measure China’s education poverty alleviation and rural revitalization evaluation indicators, using the panel data of 30 provinces in China (excluding Xizang, Hong Kong, Macao and Taiwan) from 2012 to 2021, a spatial panel simultaneous equation model is constructed based on adjacency matrix, geographical distance matrix and economic geographical distance matrix deeply study the interaction mechanism and spatial spillover effects between education poverty alleviation and rural revitalization through the generalized spatial three-stage least squares method (GS3SLS). The results indicate that there is a significant spatial spillover effect and a positive spatial correlation between education poverty alleviation and rural revitalization, and there is a significant interactive effect between the two variables, while promoting each other positively. Therefore, the government should clarify the deep relationship between education poverty alleviation and rural revitalization based on the current background, and better consolidate and expand the effective connection between the achievements of education poverty alleviation and rural revitalization. 展开更多
关键词 Education Poverty Alleviation Rural Revitalization Entropy Weight Method Space Panel simultaneous Equation Model GS3SLS
下载PDF
ON SIMULTANEOUS WEAKLY-CHEBYSHEV SUBSPACES
19
作者 Sh. Rezapour H. Alizadeh S. M. Vaezpour 《Analysis in Theory and Applications》 2011年第2期117-124,共8页
In this paper, we shall introduce and characterize simultaneous quasi-Chebyshev (and weakly-Chebyshev) subspaces of normed spaces with respect to a bounded set S by using elements of the dual space.
关键词 dual space best simultaneous approximation simultaneous quasi-Chebyshevsubspace simultaneous weakly-Chebyshev subspace
下载PDF
Simultaneous inversion of petrophysical parameters based on geostatistical a priori information 被引量:11
20
作者 印兴耀 孙瑞莹 +1 位作者 王保丽 张广智 《Applied Geophysics》 SCIE CSCD 2014年第3期311-320,351,共11页
The high-resolution nonlinear simultaneous inversion of petrophysical parameters is based on Bayesian statistics and combines petrophysics with geostatistical a priori information. We used the fast Fourier transform–... The high-resolution nonlinear simultaneous inversion of petrophysical parameters is based on Bayesian statistics and combines petrophysics with geostatistical a priori information. We used the fast Fourier transform–moving average(FFT–MA) and gradual deformation method(GDM) to obtain a reasonable variogram by using structural analysis and geostatistical a priori information of petrophysical parameters. Subsequently, we constructed the likelihood function according to the statistical petrophysical model. Finally, we used the Metropolis algorithm to sample the posteriori probability density and complete the inversion of the petrophysical parameters. We used the proposed method to process data from an oil fi eld in China and found good match between inversion and real data with high-resolution. In addition, the direct inversion of petrophysical parameters avoids the error accumulation and decreases the uncertainty, and increases the computational effi ciency. 展开更多
关键词 Geostatistical a priori information PETROPHYSICS Bayesian statistics simultaneous inversion
下载PDF
上一页 1 2 46 下一页 到第
使用帮助 返回顶部