A record-breaking prolonged and extreme rainstorm occurred in Henan province,China during 18–23 July 2021.Global and regional numerical weather prediction(NWP)models consistently underpredicted both the 24-h accumula...A record-breaking prolonged and extreme rainstorm occurred in Henan province,China during 18–23 July 2021.Global and regional numerical weather prediction(NWP)models consistently underpredicted both the 24-h accumulated rainfall amount and the 1-h extreme precipitation in Zhengzhou city.This study examines the potential impacts of data assimilation(DA)of atmospheric vertical profiles based on the train-based mobile observation(MO)platforms on precipitation forecasts.The research involved assimilating virtual train-based air temperature(Ta),relative humidity(RH),U and V components of wind profile data based on the ERA5 reanalysis datasets into the Weather Research and Forecasting(WRF)model using three-dimensional variational(3DVar)method.Analysis confirms the reliability of Ta,RH,and wind speed(WS)profiles from ERA5 reanalysis datasets.The assimilation of virtual train-based moisture profiles enhanced the RH analysis field.Furthermore,the forecasts more accurately represented the coverage and intensity of the 6-hour and 24-hour accumulated precipitation,as well as areas with maximum rainfall durations exceeding 20 hours.The threat score(TS)and bias metrics for 6-h,12-h and 24-h accumulated precipitation forecasts showed marked improvement for heavy to torrential rain in Henan province,particularly in the Central and Northern regions(hereinafter referred to region CNH).The TS for 24-h accumulated precipitation forecasts at 50 and 100 mm rainfall levels increased by 0.17 and 0.18 in Henan province,and by 0.13 and 0.18 in region CNH.During the rainstorm period,water vapor content increased substantially,with enhanced moisture transport from south of Henan province to region CNH driven by southwesterly winds,accompanied by significantly strengthened updrafts.These improvement in water vapor and upward motion ultimately enhanced the forecasts of this extreme rainstorm event.展开更多
BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.Th...BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.This study aimed to assess the diagnostic value of dual-layer spectral computed tomography(CT)-derived VMIs,in combination with multiplanar reformation(MPR)and evaluation of peritumoral fat stranding(PFS),for improving the accuracy of T staging in CRC.AIM To assess the diagnostic performance of dual-layer spectral CT(DLSCT)VMIs,particularly at low energy levels,and their integration with personalized MPR for preoperative T staging of CRC.METHODS In this retrospective study,157 patients with pathologically confirmed CRC(mean age:63.5±12.1 years)underwent DLSCT within 1 week before surgery.VMIs ranging from 40 keV to 70 keV(at 10 keV intervals)and conventional polyenergetic images(PEIs)were reconstructed.Objective image quality parameters,including image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR),were quantified,alongside subjective image quality scores using a 5-point Likert scale.Interobserver agreement was evaluated usingκstatistics.Taking histopathology as the reference standard,the diagnostic accuracy of T staging(T1-2 vs T3-4)was compared across PEIs and VMIs,both with and without MPR and PFS.RESULTS Low-keV VMIs(40-70 keV)demonstrated significantly higher SNR and CNR than PEIs(all P<0.001).Notably,40-keV VMIs achieved noise levels comparable to PEIs(8.17±3.63 vs 8.53±2.90;P=0.673).Subjective image quality peaked at 40-50 keV VMIs(Likert scores 4.85-4.88 vs 3.97 for PEIs;P<0.001),supported by excellent interobserver agreement(κ=0.812-0.913).The combination of 40-50 keV VMIs with MPR yielded the highest T staging accuracy(94.27%)compared to axial PEIs(70.7%),with a sensitivity and specificity of 83.87%and 96.83%,respectively(Youden index=0.81;P<0.05).While PFS enhanced staging accuracy on PEIs(up to 77.07%with MPR),it provided no significant additional benefit for VMIs.CONCLUSION DLSCT VMIs at 40-50 keV significantly enhanced image quality and improved preoperative T staging accuracy of CRC when combined with MPR.These findings underscored the clinical value of low-keV spectral imaging in tailoring individualized treatment strategies.展开更多
With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided b...With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided by synchronous generators.To address this critical issue,Virtual Synchronous Generator(VSG)technology has emerged as a highly promising solution by emulating the inertia and damping characteristics of conventional synchronous generators.To enhance the operational efficiency of virtual synchronous generators(VSGs),this study employs smallsignal modeling analysis,root locus methods,and synchronous generator power-angle characteristic analysis to comprehensively evaluate how virtual inertia and damping coefficients affect frequency stability and power output during transient processes.Based on these analyses,an adaptive control strategy is proposed:increasing the virtual inertia when the rotor angular velocity undergoes rapid changes,while strengthening the damping coefficient when the speed deviation exceeds a certain threshold to suppress angular velocity oscillations.To validate the effectiveness of the proposed method,a grid-connected VSG simulation platform was developed inMATLAB/Simulink.Comparative simulations demonstrate that the proposed adaptive control strategy outperforms conventional VSGmethods by significantly reducing grid frequency deviations and shortening active power response time during active power command changes and load disturbances.This approach enhances microgrid stability and dynamic performance,confirming its viability for renewable-dominant power systems.Future work should focus on experimental validation and real-world parameter optimization,while further exploring the strategy’s effectiveness in improvingVSG low-voltage ride-through(LVRT)capability and power-sharing applications in multi-parallel configurations.展开更多
Virtual power plant(VPP)integrates a variety of distributed renewable energy and energy storage to participate in electricity market transactions,promote the consumption of renewable energy,and improve economic effici...Virtual power plant(VPP)integrates a variety of distributed renewable energy and energy storage to participate in electricity market transactions,promote the consumption of renewable energy,and improve economic efficiency.In this paper,aiming at the uncertainty of distributed wind power and photovoltaic output,considering the coupling relationship between power,carbon trading,and green cardmarket,the optimal operationmodel and bidding scheme of VPP in spot market,carbon trading market,and green card market are established.On this basis,through the Shapley value and independent risk contribution theory in cooperative game theory,the quantitative analysis of the total income and risk contribution of various distributed resources in the virtual power plant is realized.Moreover,the scheduling strategies of virtual power plants under different risk preferences are systematically compared,and the feasibility and accuracy of the combination of Shapley value and independent risk contribution theory in ensuring fair income distribution and reasonable risk assessment are emphasized.A comprehensive solution for virtual power plants in the multi-market environment is constructed,which integrates operation strategy,income distribution mechanism,and risk control system into a unified analysis framework.Through the simulation of multi-scenario examples,the CPLEXsolver inMATLAB software is used to optimize themodel.The proposed joint optimization scheme can increase the profit of VPP participating in carbon trading and green certificate market by 29%.The total revenue of distributed resources managed by VPP is 9%higher than that of individual participation.展开更多
Conventional surgical teaching techniques face several challenges,highlighting a necessity for ongoing innovation in ophthalmology education to align with the evolving demands of clinical practice.The recent rapid adv...Conventional surgical teaching techniques face several challenges,highlighting a necessity for ongoing innovation in ophthalmology education to align with the evolving demands of clinical practice.The recent rapid advancement of computer technology has enabled the integration of virtual reality(VR)into medical training,thereby revolutionizing ophthalmic surgical education through VRbased educational methods.VR technology offers a safe,risk-free environment for trainees to practice repeatedly,enhancing surgical skills and accelerating the learning curve without compromising patient safety.This research outlines the application of VR technology in ophthalmic surgical skills training,particularly in cataract and vitreoretinal surgery.Including assessing the effectiveness of intraocular surgery training systems,evaluating skills transfer to the operating room,comparing it with wet lab cataract surgery training,and enhancing non-dominant hand training for cataract surgery,among other aspects.Additionally,this paper will identify the limitations of VR technology in ocular surgical skills training,offer improvement strategies,and detail the advantages and prospects,with the objective of guiding subsequent researchers.展开更多
Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the...Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the coordination with virtual power plants(VPPs).The proposed strategy improves systemflexibility and responsiveness by optimizing the power adjustment of flexible resources.In the proposed strategy,theGaussian Process Regression(GPR)is firstly employed to determine the adjustable range of aggregated power within the VPP,facilitating an assessment of its potential contribution to power supply support.Then,an optimal dispatch model based on a leader-follower game is developed to maximize the benefits of the VPP and flexible resources while guaranteeing the power balance at the same time.To solve the proposed optimal dispatch model efficiently,the constraints of the problem are reformulated and resolved using the Karush-Kuhn-Tucker(KKT)optimality conditions and linear programming duality theorem.The effectiveness of the strategy is illustrated through a detailed case study.展开更多
Virtual organization uses information technology to achieve a closer integration and better management of business relationships between internal and external parties. There are many emerging issues in virtual organiz...Virtual organization uses information technology to achieve a closer integration and better management of business relationships between internal and external parties. There are many emerging issues in virtual organization and one of them is knowl- edge sharing. Knowledge sharing that is the core of knowledge management plays a key role in virtual organization. However, game theoretic exploration about knowledge sharing mechanism based on virtual organization is seldom published, In this study, knowledge sharing mechanism in virtual organization enterprise is explored using game theories from two aspects based on the features of knowledge sharing in virtual organization enterprise. Fi- nally, the critical model of knowledge sharing mechanism in virtual organization also is presented based on the perspective of game analysis.展开更多
Drive system is the key device of armored chassis. Its working state and reliability influence the maneuver performance of armored chassis directly. In order to simulate the failure process and evaluate the service re...Drive system is the key device of armored chassis. Its working state and reliability influence the maneuver performance of armored chassis directly. In order to simulate the failure process and evaluate the service reliability of drive system in training or battle missions,a new kind of dynamic simulation model and driving simulation platform of the complete drive system were established based on virtual prototype and finite element technology in this paper. Using the platform, the kinematics and dynamic characteristics of drive system were studied and analyzed in detail,the dynamic load spectrum of key components was obtained,the service life was predicted, and the service reliability evaluation results were provided. A simulation example of transmission gear was shown to illustrate the simulation and evaluation process. The result proves that the simulation method not only can be used to compute and evaluate the service reliability of complex mechanical mechanism, but also has high precision and reasonable computational cost. Therefore,simulation and reliability analysis based on virtual prototype of the armored chassis drive system will provide scientific reference for the formulation of armored chassis reasonable repair cycle.展开更多
To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the...To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the three-dimensional structure of M1 receptor. Virtual screening strategy was used to analyze the Available Chemicals Directory-Screening Compounds （ACD-SC） to identify possible new hits. Twenty-two compounds which fit the pharmacophore model well and are not similar with known M1 agonists were purchased in order to evaluate their M1 receptor agonist activity. One of them shows M1 receptor agonist activity with EC50 of 4.90 μmol/L and maximum response. Multiple of 10.0 which shows it worthy of further study as a new lead compound for M1 agonists.展开更多
The objective of this study was to evaluate the diagnostic value of 128-slice spiral CT combined with virtual colonoscopy in diagnosis of colorectal cancer.We retrospectively analyzed 45 patients of colorectal disease...The objective of this study was to evaluate the diagnostic value of 128-slice spiral CT combined with virtual colonoscopy in diagnosis of colorectal cancer.We retrospectively analyzed 45 patients of colorectal diseases who underwent definition AS+128-slice spiral CT combined with virtual colonoscopy after bowel preparation and gas injection to evaluate the clinical diagnostic value of this technology.All the patients received electronic colonoscopy and were confirmed by pathology.In total,colorectal cancer was confirmed in 42 cases and inflammation in 3 cases.Diagnostic results shows:there were 17 cases of lump,10 cases of infiltration,6 cases of ulcer,9 cases of mixed type,4 cases of liver metastases,and 36 cases of lymph node metastasis.There was no significant difference between 128-slice spiral CT combined with virtual colonoscopy and electronic colonoscopy in detection,localization and characterization of colorectal tumors.CT virtual endoscopy has great advantages in observing the invasion around the lesion and the presence or absence of metastasis in distant organs and lymph node metastasis.It is also possible to understand the shape of the lesion in the intestinal lumen and the length of the lesion involving the lumen of the intestine.展开更多
5G is a new generation of mobile networking that aims to achieve unparalleled speed and performance. To accomplish this, three technologies, Device-to-Device communication (D2D), multi-access edge computing (MEC) and ...5G is a new generation of mobile networking that aims to achieve unparalleled speed and performance. To accomplish this, three technologies, Device-to-Device communication (D2D), multi-access edge computing (MEC) and network function virtualization (NFV) with ClickOS, have been a significant part of 5G, and this paper mainly discusses them. D2D enables direct communication between devices without the relay of base station. In 5G, a two-tier cellular network composed of traditional cellular network system and D2D is an efficient method for realizing high-speed communication. MEC unloads work from end devices and clouds platforms to widespread nodes, and connects the nodes together with outside devices and third-party providers, in order to diminish the overloading effect on any device caused by enormous applications and improve users’ quality of experience (QoE). There is also a NFV method in order to fulfill the 5G requirements. In this part, an optimized virtual machine for middle-boxes named ClickOS is introduced, and it is evaluated in several aspects. Some middle boxes are being implemented in the ClickOS and proved to have outstanding performances.展开更多
The measurement of crack propagation is crucial for revealing the fracture mechanical properties of materials and structures.Based on the virtual principal strain field and Steger’s algorithm,an accurate and automati...The measurement of crack propagation is crucial for revealing the fracture mechanical properties of materials and structures.Based on the virtual principal strain field and Steger’s algorithm,an accurate and automatic method has been proposed for measuring the geometric parameters of crack propagation.The measured geometric parameters of crack propagation include the width,length,and tip location of each crack.The mechanism of the crack-induced virtual principal strain field and the effects of subset,step,and strain window size are analyzed and discussed theoretically.The effectiveness of the derived theoretical equations is verified by the simulation experiments.According to the theoretical equations,it is determined that the distribution of the virtual principal strain field near the crack is similar to the grayscale distribution of the laser fringe image with optimized calculation parameters.Experiments are further conducted to validate the effectiveness of the derived equations.With the optimized calculation parameters,the minimum crack that can be measured is approximately 0.0362 pixel in the laboratory environment,while the measurement error of the crack width is less than 0.025 pixel for two-dimensional digital image correlation(DIC)and 0.020 pixel for three-dimensional DIC.展开更多
The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtua...The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.展开更多
Spatial division multiplexing enabled elastic optical networks(SDM-EONs) are the potential implementation form of future optical transport networks, because it can curve the physical limitation of achievable transmiss...Spatial division multiplexing enabled elastic optical networks(SDM-EONs) are the potential implementation form of future optical transport networks, because it can curve the physical limitation of achievable transmission capacity in single-mode fiber and single-core fiber. However, spectrum fragmentation issue becomes more serious in SDM-EONs compared with simple elastic optical networks(EONs) with single mode fiber or single core fiber. In this paper, multicore virtual concatenation(MCVC) scheme is first proposed considering inter-core crosstalk to solve the spectrum fragmentation issue in SDM-EONs. Simulation results show that the proposed MCVC scheme can achieve better performance compared with the baseline scheme, i.e., single-core virtual concatenation(SCVC) scheme, in terms of blocking probability and spectrum utilization.展开更多
Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the u...Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality(VR)technology.VR has been demonstrated to be an effective treatment for pain associated with medical procedures,as well as for chronic pain conditions for which no effective treatment has been established.The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated.However,the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks.The salience network is diminished,while the default mode network is enhanced.Additionally,the medial prefrontal cortex may establish a stronger connection with the default mode network,which could result in a reduction of pain and anxiety.Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field.展开更多
The serotonin 2A（5-HT2A） receptor has been implicated in several neurological conditions and potent 5-HT2A antagonists have therapeutic effects in the treatment of schizo phrenia and depression.In this study,a poten...The serotonin 2A（5-HT2A） receptor has been implicated in several neurological conditions and potent 5-HT2A antagonists have therapeutic effects in the treatment of schizo phrenia and depression.In this study,a potent novel 5-HT2A inhibitor 05245768 with a Ki value of （593.89±34.10） nmol/L was discovered by integrating a set of computational approaches and experiments（protein structure prediction,pharmacophore-based virtual screening,automated molecular docking and pharmacological bioassay）.The 5-HT2A receptor showed a negatively charged bin-ding pocket.The binding mode of compound 05245768 with 5-HT2A was obtained by GOLD docking procedure,which revealed the conserved interaction between protonated nitrogen in compound 05245768 and carboxylate group of D3.32 at the active site of 5-HT2A.展开更多
Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential role...Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential roles of virtualization in digital forensics, examines the recent progresses which use the virtualization techniques to support modem computer forensics. The influences on digital forensics caused by virtualization technology are identified. Tools and methods in common digital forensic practices are analyzed, and experiences of our practice and reflections in this field are shared.展开更多
CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style=&...CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;"> is one of the most important members of Cyclin-dependent kinases. It is a critical modulator of various oncogenic signaling pathways, and its activity is vital for <span style="font-family:Verdana;">loss<span style="font-family:Verdana;"> of proliferative control during oncogenesis. This work has focused on developing a pharmacophore model for CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;"> inhibitors by using a dataset of known inhibitors as a pre-filter throughout the virtual screening and docking process. Consequently, the best pharmacophore model was made of one hydrogen bond acceptor, and two aromatic ring features with <span style="font-family:Verdana;">a <span style="font-family:Verdana;">high<span style="font-family:""><span style="font-family:Verdana;"> correlation value of 0.906. The validation findings proved out that the selected model can be used as a filter to screen new molecules like Enamine kinase hinge region directed library against CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;">. As a result, 69 hits were subjected to molecular docking studies. Eventually, three compounds<span style="font-family:Verdana;"> (<span style="font-family:""><span style="font-family:Verdana;">5909, 701 <span style="font-family:Verdana;">and<span style="font-family:Verdana;"> 8397<span style="font-family:Verdana;">) <span style="font-family:""><span style="font-family:Verdana;">scored good interaction energy values and strong molecular interactions. Hence, they were identified as leads for novel CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;"> inhibitors as anticancer drugs.展开更多
基金R&D major projects from China State Railway Group Co.,Ltd.(K2022G039)Tibet Autonomous Region Science and Technology Program Project(XZ202402ZD0006-06)+1 种基金Open bidding project for selecting the best candidates from China Meteorological Administration(CMAJBGS202303)The Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0105)。
文摘A record-breaking prolonged and extreme rainstorm occurred in Henan province,China during 18–23 July 2021.Global and regional numerical weather prediction(NWP)models consistently underpredicted both the 24-h accumulated rainfall amount and the 1-h extreme precipitation in Zhengzhou city.This study examines the potential impacts of data assimilation(DA)of atmospheric vertical profiles based on the train-based mobile observation(MO)platforms on precipitation forecasts.The research involved assimilating virtual train-based air temperature(Ta),relative humidity(RH),U and V components of wind profile data based on the ERA5 reanalysis datasets into the Weather Research and Forecasting(WRF)model using three-dimensional variational(3DVar)method.Analysis confirms the reliability of Ta,RH,and wind speed(WS)profiles from ERA5 reanalysis datasets.The assimilation of virtual train-based moisture profiles enhanced the RH analysis field.Furthermore,the forecasts more accurately represented the coverage and intensity of the 6-hour and 24-hour accumulated precipitation,as well as areas with maximum rainfall durations exceeding 20 hours.The threat score(TS)and bias metrics for 6-h,12-h and 24-h accumulated precipitation forecasts showed marked improvement for heavy to torrential rain in Henan province,particularly in the Central and Northern regions(hereinafter referred to region CNH).The TS for 24-h accumulated precipitation forecasts at 50 and 100 mm rainfall levels increased by 0.17 and 0.18 in Henan province,and by 0.13 and 0.18 in region CNH.During the rainstorm period,water vapor content increased substantially,with enhanced moisture transport from south of Henan province to region CNH driven by southwesterly winds,accompanied by significantly strengthened updrafts.These improvement in water vapor and upward motion ultimately enhanced the forecasts of this extreme rainstorm event.
基金Supported by Jiangsu Province 333 Talent Key Industry Field Talent Project,No.[2022]21Key Scientific Research Program of Jiangsu Provincial Health Committee,No.ZD2021059+2 种基金Nantong Key Laboratory Project,No.[2020]163The Project of Nantong City Health Committee,No.MS2023027Young Medical Talents Fund of Health and Family Planning Commission of Nantong,No.QA2019006 and No.QNZ2023027.
文摘BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.This study aimed to assess the diagnostic value of dual-layer spectral computed tomography(CT)-derived VMIs,in combination with multiplanar reformation(MPR)and evaluation of peritumoral fat stranding(PFS),for improving the accuracy of T staging in CRC.AIM To assess the diagnostic performance of dual-layer spectral CT(DLSCT)VMIs,particularly at low energy levels,and their integration with personalized MPR for preoperative T staging of CRC.METHODS In this retrospective study,157 patients with pathologically confirmed CRC(mean age:63.5±12.1 years)underwent DLSCT within 1 week before surgery.VMIs ranging from 40 keV to 70 keV(at 10 keV intervals)and conventional polyenergetic images(PEIs)were reconstructed.Objective image quality parameters,including image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR),were quantified,alongside subjective image quality scores using a 5-point Likert scale.Interobserver agreement was evaluated usingκstatistics.Taking histopathology as the reference standard,the diagnostic accuracy of T staging(T1-2 vs T3-4)was compared across PEIs and VMIs,both with and without MPR and PFS.RESULTS Low-keV VMIs(40-70 keV)demonstrated significantly higher SNR and CNR than PEIs(all P<0.001).Notably,40-keV VMIs achieved noise levels comparable to PEIs(8.17±3.63 vs 8.53±2.90;P=0.673).Subjective image quality peaked at 40-50 keV VMIs(Likert scores 4.85-4.88 vs 3.97 for PEIs;P<0.001),supported by excellent interobserver agreement(κ=0.812-0.913).The combination of 40-50 keV VMIs with MPR yielded the highest T staging accuracy(94.27%)compared to axial PEIs(70.7%),with a sensitivity and specificity of 83.87%and 96.83%,respectively(Youden index=0.81;P<0.05).While PFS enhanced staging accuracy on PEIs(up to 77.07%with MPR),it provided no significant additional benefit for VMIs.CONCLUSION DLSCT VMIs at 40-50 keV significantly enhanced image quality and improved preoperative T staging accuracy of CRC when combined with MPR.These findings underscored the clinical value of low-keV spectral imaging in tailoring individualized treatment strategies.
基金financially supported by the Talent Initiation Fund of Wuxi University(550220008).
文摘With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided by synchronous generators.To address this critical issue,Virtual Synchronous Generator(VSG)technology has emerged as a highly promising solution by emulating the inertia and damping characteristics of conventional synchronous generators.To enhance the operational efficiency of virtual synchronous generators(VSGs),this study employs smallsignal modeling analysis,root locus methods,and synchronous generator power-angle characteristic analysis to comprehensively evaluate how virtual inertia and damping coefficients affect frequency stability and power output during transient processes.Based on these analyses,an adaptive control strategy is proposed:increasing the virtual inertia when the rotor angular velocity undergoes rapid changes,while strengthening the damping coefficient when the speed deviation exceeds a certain threshold to suppress angular velocity oscillations.To validate the effectiveness of the proposed method,a grid-connected VSG simulation platform was developed inMATLAB/Simulink.Comparative simulations demonstrate that the proposed adaptive control strategy outperforms conventional VSGmethods by significantly reducing grid frequency deviations and shortening active power response time during active power command changes and load disturbances.This approach enhances microgrid stability and dynamic performance,confirming its viability for renewable-dominant power systems.Future work should focus on experimental validation and real-world parameter optimization,while further exploring the strategy’s effectiveness in improvingVSG low-voltage ride-through(LVRT)capability and power-sharing applications in multi-parallel configurations.
基金funded by the Department of Education of Liaoning Province and was supported by the Basic Scientific Research Project of the Department of Education of Liaoning Province(Grant No.LJ222411632051)and(Grant No.LJKQZ2021085)Natural Science Foundation Project of Liaoning Province(Grant No.2022-BS-222).
文摘Virtual power plant(VPP)integrates a variety of distributed renewable energy and energy storage to participate in electricity market transactions,promote the consumption of renewable energy,and improve economic efficiency.In this paper,aiming at the uncertainty of distributed wind power and photovoltaic output,considering the coupling relationship between power,carbon trading,and green cardmarket,the optimal operationmodel and bidding scheme of VPP in spot market,carbon trading market,and green card market are established.On this basis,through the Shapley value and independent risk contribution theory in cooperative game theory,the quantitative analysis of the total income and risk contribution of various distributed resources in the virtual power plant is realized.Moreover,the scheduling strategies of virtual power plants under different risk preferences are systematically compared,and the feasibility and accuracy of the combination of Shapley value and independent risk contribution theory in ensuring fair income distribution and reasonable risk assessment are emphasized.A comprehensive solution for virtual power plants in the multi-market environment is constructed,which integrates operation strategy,income distribution mechanism,and risk control system into a unified analysis framework.Through the simulation of multi-scenario examples,the CPLEXsolver inMATLAB software is used to optimize themodel.The proposed joint optimization scheme can increase the profit of VPP participating in carbon trading and green certificate market by 29%.The total revenue of distributed resources managed by VPP is 9%higher than that of individual participation.
基金Supported by the Key Special Project of“Cutting-Edge Biotechnology”in the National Key Research and Development Program of China(No.2024YFC3406200)Sanming Project of Medicine in Shenzhen(No.SZSM202411007)Shenzhen Science and Technology Program(No.JCYJ20240813152704006).
文摘Conventional surgical teaching techniques face several challenges,highlighting a necessity for ongoing innovation in ophthalmology education to align with the evolving demands of clinical practice.The recent rapid advancement of computer technology has enabled the integration of virtual reality(VR)into medical training,thereby revolutionizing ophthalmic surgical education through VRbased educational methods.VR technology offers a safe,risk-free environment for trainees to practice repeatedly,enhancing surgical skills and accelerating the learning curve without compromising patient safety.This research outlines the application of VR technology in ophthalmic surgical skills training,particularly in cataract and vitreoretinal surgery.Including assessing the effectiveness of intraocular surgery training systems,evaluating skills transfer to the operating room,comparing it with wet lab cataract surgery training,and enhancing non-dominant hand training for cataract surgery,among other aspects.Additionally,this paper will identify the limitations of VR technology in ocular surgical skills training,offer improvement strategies,and detail the advantages and prospects,with the objective of guiding subsequent researchers.
基金supported by the Science and Technology Project of Sichuan Electric Power Company“Power Supply Guarantee Strategy for Urban Distribution Networks Considering Coordination with Virtual Power Plant during Extreme Weather Event”(No.521920230003).
文摘Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the coordination with virtual power plants(VPPs).The proposed strategy improves systemflexibility and responsiveness by optimizing the power adjustment of flexible resources.In the proposed strategy,theGaussian Process Regression(GPR)is firstly employed to determine the adjustable range of aggregated power within the VPP,facilitating an assessment of its potential contribution to power supply support.Then,an optimal dispatch model based on a leader-follower game is developed to maximize the benefits of the VPP and flexible resources while guaranteeing the power balance at the same time.To solve the proposed optimal dispatch model efficiently,the constraints of the problem are reformulated and resolved using the Karush-Kuhn-Tucker(KKT)optimality conditions and linear programming duality theorem.The effectiveness of the strategy is illustrated through a detailed case study.
基金Supported by the Natural Science Foundation of Fujian Province(2012D135)
文摘Virtual organization uses information technology to achieve a closer integration and better management of business relationships between internal and external parties. There are many emerging issues in virtual organization and one of them is knowl- edge sharing. Knowledge sharing that is the core of knowledge management plays a key role in virtual organization. However, game theoretic exploration about knowledge sharing mechanism based on virtual organization is seldom published, In this study, knowledge sharing mechanism in virtual organization enterprise is explored using game theories from two aspects based on the features of knowledge sharing in virtual organization enterprise. Fi- nally, the critical model of knowledge sharing mechanism in virtual organization also is presented based on the perspective of game analysis.
文摘Drive system is the key device of armored chassis. Its working state and reliability influence the maneuver performance of armored chassis directly. In order to simulate the failure process and evaluate the service reliability of drive system in training or battle missions,a new kind of dynamic simulation model and driving simulation platform of the complete drive system were established based on virtual prototype and finite element technology in this paper. Using the platform, the kinematics and dynamic characteristics of drive system were studied and analyzed in detail,the dynamic load spectrum of key components was obtained,the service life was predicted, and the service reliability evaluation results were provided. A simulation example of transmission gear was shown to illustrate the simulation and evaluation process. The result proves that the simulation method not only can be used to compute and evaluate the service reliability of complex mechanical mechanism, but also has high precision and reasonable computational cost. Therefore,simulation and reliability analysis based on virtual prototype of the armored chassis drive system will provide scientific reference for the formulation of armored chassis reasonable repair cycle.
基金National Natural Science Foundation of China (Grant No. 30271538)985 program,Ministry of Education of China
文摘To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the three-dimensional structure of M1 receptor. Virtual screening strategy was used to analyze the Available Chemicals Directory-Screening Compounds （ACD-SC） to identify possible new hits. Twenty-two compounds which fit the pharmacophore model well and are not similar with known M1 agonists were purchased in order to evaluate their M1 receptor agonist activity. One of them shows M1 receptor agonist activity with EC50 of 4.90 μmol/L and maximum response. Multiple of 10.0 which shows it worthy of further study as a new lead compound for M1 agonists.
文摘The objective of this study was to evaluate the diagnostic value of 128-slice spiral CT combined with virtual colonoscopy in diagnosis of colorectal cancer.We retrospectively analyzed 45 patients of colorectal diseases who underwent definition AS+128-slice spiral CT combined with virtual colonoscopy after bowel preparation and gas injection to evaluate the clinical diagnostic value of this technology.All the patients received electronic colonoscopy and were confirmed by pathology.In total,colorectal cancer was confirmed in 42 cases and inflammation in 3 cases.Diagnostic results shows:there were 17 cases of lump,10 cases of infiltration,6 cases of ulcer,9 cases of mixed type,4 cases of liver metastases,and 36 cases of lymph node metastasis.There was no significant difference between 128-slice spiral CT combined with virtual colonoscopy and electronic colonoscopy in detection,localization and characterization of colorectal tumors.CT virtual endoscopy has great advantages in observing the invasion around the lesion and the presence or absence of metastasis in distant organs and lymph node metastasis.It is also possible to understand the shape of the lesion in the intestinal lumen and the length of the lesion involving the lumen of the intestine.
文摘5G is a new generation of mobile networking that aims to achieve unparalleled speed and performance. To accomplish this, three technologies, Device-to-Device communication (D2D), multi-access edge computing (MEC) and network function virtualization (NFV) with ClickOS, have been a significant part of 5G, and this paper mainly discusses them. D2D enables direct communication between devices without the relay of base station. In 5G, a two-tier cellular network composed of traditional cellular network system and D2D is an efficient method for realizing high-speed communication. MEC unloads work from end devices and clouds platforms to widespread nodes, and connects the nodes together with outside devices and third-party providers, in order to diminish the overloading effect on any device caused by enormous applications and improve users’ quality of experience (QoE). There is also a NFV method in order to fulfill the 5G requirements. In this part, an optimized virtual machine for middle-boxes named ClickOS is introduced, and it is evaluated in several aspects. Some middle boxes are being implemented in the ClickOS and proved to have outstanding performances.
基金supported by the National Natural Science Foundation of China(NSFC)(11902074).
文摘The measurement of crack propagation is crucial for revealing the fracture mechanical properties of materials and structures.Based on the virtual principal strain field and Steger’s algorithm,an accurate and automatic method has been proposed for measuring the geometric parameters of crack propagation.The measured geometric parameters of crack propagation include the width,length,and tip location of each crack.The mechanism of the crack-induced virtual principal strain field and the effects of subset,step,and strain window size are analyzed and discussed theoretically.The effectiveness of the derived theoretical equations is verified by the simulation experiments.According to the theoretical equations,it is determined that the distribution of the virtual principal strain field near the crack is similar to the grayscale distribution of the laser fringe image with optimized calculation parameters.Experiments are further conducted to validate the effectiveness of the derived equations.With the optimized calculation parameters,the minimum crack that can be measured is approximately 0.0362 pixel in the laboratory environment,while the measurement error of the crack width is less than 0.025 pixel for two-dimensional digital image correlation(DIC)and 0.020 pixel for three-dimensional DIC.
文摘The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.
基金supported in part by NSFC project (61571058, 61601052)
文摘Spatial division multiplexing enabled elastic optical networks(SDM-EONs) are the potential implementation form of future optical transport networks, because it can curve the physical limitation of achievable transmission capacity in single-mode fiber and single-core fiber. However, spectrum fragmentation issue becomes more serious in SDM-EONs compared with simple elastic optical networks(EONs) with single mode fiber or single core fiber. In this paper, multicore virtual concatenation(MCVC) scheme is first proposed considering inter-core crosstalk to solve the spectrum fragmentation issue in SDM-EONs. Simulation results show that the proposed MCVC scheme can achieve better performance compared with the baseline scheme, i.e., single-core virtual concatenation(SCVC) scheme, in terms of blocking probability and spectrum utilization.
文摘Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality(VR)technology.VR has been demonstrated to be an effective treatment for pain associated with medical procedures,as well as for chronic pain conditions for which no effective treatment has been established.The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated.However,the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks.The salience network is diminished,while the default mode network is enhanced.Additionally,the medial prefrontal cortex may establish a stronger connection with the default mode network,which could result in a reduction of pain and anxiety.Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field.
基金Supported by the National High Technology Research and Development Program of China(No.2009AA02Z308)the Major State Basic Research Development Program of China(No.2010CB912601)the National Natural Science Foundation of China (No.20702009)
文摘The serotonin 2A（5-HT2A） receptor has been implicated in several neurological conditions and potent 5-HT2A antagonists have therapeutic effects in the treatment of schizo phrenia and depression.In this study,a potent novel 5-HT2A inhibitor 05245768 with a Ki value of （593.89±34.10） nmol/L was discovered by integrating a set of computational approaches and experiments（protein structure prediction,pharmacophore-based virtual screening,automated molecular docking and pharmacological bioassay）.The 5-HT2A receptor showed a negatively charged bin-ding pocket.The binding mode of compound 05245768 with 5-HT2A was obtained by GOLD docking procedure,which revealed the conserved interaction between protonated nitrogen in compound 05245768 and carboxylate group of D3.32 at the active site of 5-HT2A.
文摘Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential roles of virtualization in digital forensics, examines the recent progresses which use the virtualization techniques to support modem computer forensics. The influences on digital forensics caused by virtualization technology are identified. Tools and methods in common digital forensic practices are analyzed, and experiences of our practice and reflections in this field are shared.
文摘CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;"> is one of the most important members of Cyclin-dependent kinases. It is a critical modulator of various oncogenic signaling pathways, and its activity is vital for <span style="font-family:Verdana;">loss<span style="font-family:Verdana;"> of proliferative control during oncogenesis. This work has focused on developing a pharmacophore model for CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;"> inhibitors by using a dataset of known inhibitors as a pre-filter throughout the virtual screening and docking process. Consequently, the best pharmacophore model was made of one hydrogen bond acceptor, and two aromatic ring features with <span style="font-family:Verdana;">a <span style="font-family:Verdana;">high<span style="font-family:""><span style="font-family:Verdana;"> correlation value of 0.906. The validation findings proved out that the selected model can be used as a filter to screen new molecules like Enamine kinase hinge region directed library against CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;">. As a result, 69 hits were subjected to molecular docking studies. Eventually, three compounds<span style="font-family:Verdana;"> (<span style="font-family:""><span style="font-family:Verdana;">5909, 701 <span style="font-family:Verdana;">and<span style="font-family:Verdana;"> 8397<span style="font-family:Verdana;">) <span style="font-family:""><span style="font-family:Verdana;">scored good interaction energy values and strong molecular interactions. Hence, they were identified as leads for novel CDK<span style="white-space:nowrap;"><sub><sub><span style="font-family:Verdana;">2<span style="white-space:nowrap;"></sub></sub><span style="font-family:Verdana;"> inhibitors as anticancer drugs.
