The traditional transient stability assessment(TSA)model for power systems has three disadvantages:capturing critical information during faults is difficult,aperiodic and oscillatory unstable conditions are not distin...The traditional transient stability assessment(TSA)model for power systems has three disadvantages:capturing critical information during faults is difficult,aperiodic and oscillatory unstable conditions are not distinguished,and poor generalizability is exhibited by systems with high renewable energy penetration.To address these issues,a novel ResGRU architecture for TSA is proposed in this study.First,a residual neural network(ResNet)is used for deep feature extraction of transient information.Second,a bidirectional gated recurrent unit combined with a multi-attention mechanism(BiGRU-Attention)is used to establish temporal feature dependencies.Their combination constitutes a TSA framework based on the ResGRU architecture.This method predicts three transient conditions:oscillatory instability,aperiodic instability,and stability.The model was trained offline using stochastic gradient descent with a thermal restart(SGDR)optimization algorithm in the offline training phase.This significantly improves the generalizability of the model.Finally,simulation tests on IEEE 145-bus and 39-bus systems confirmed that the proposed method has higher adaptability,accuracy,scalability,and rapidity than the conventional TSA approach.The proposed model also has superior robustness for PMU incomplete configurations,PMU noisy data,and packet loss.展开更多
To search the new effective nitrogen reduction reaction(NRR)electrocatalyst is very important for the ammonia-based industry.Herein,we reported the design of a novel NRR electrocatalyst with Ru NPs loaded on oxygen-va...To search the new effective nitrogen reduction reaction(NRR)electrocatalyst is very important for the ammonia-based industry.Herein,we reported the design of a novel NRR electrocatalyst with Ru NPs loaded on oxygen-vacancy TiO2(Ru/TiO2-Vo).Structural characterizations revealed that oxygen vacancy was loaded in the matrix of Ru/TiO2-Vo.Electrocatalytic results indicated that Ru/TiO2-Vo showed good NRR performance(2.11μg h^-1 cm^-2).Contrast tests showed that NRR property of Ru/TiO2-Vo was much better than those of Ru/TiO-12(B)(0.53μg hcm^-2)and Ru/P25(0.42μg h^-1 cm^-2).Furthermore,density functional theory calculation results indicated catalytic mechanism of NRR and rate-determining step(*N2+1/2 H2→*N+*NH)was the potential-determining step with the overpotential requirement of 0.21 V.A combination of electronic structure analysis and catalytic measurement shed light on the synergistic effect of Ru and oxygen vacancy on the NRR performance.展开更多
Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original ar...Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original article has been corrected.展开更多
We discuss the landscape of flavor physics at the Circular Electron-Positron Collider(CEPC),based on the nominal luminosity outlined in its Technical Design Report.The CEPC is designed to operate in multiple modes to ...We discuss the landscape of flavor physics at the Circular Electron-Positron Collider(CEPC),based on the nominal luminosity outlined in its Technical Design Report.The CEPC is designed to operate in multiple modes to address a variety of tasks.At the Z pole,the expected production of 4 Tera Z bosons will provide unique and highly precise measurements of Z boson couplings,while the substantial number of boosted heavy-flavored quarks and leptons produced in clean Z decays will facilitate investigations into their flavor physics with unprecedented precision.We investigate the prospects of measuring various physics benchmarks and discuss their implications for particle theories and phenomenological models.Our studies indicate that,with its highlighted advantages and anticipated excellent detector performance,the CEPC can explore beauty andτphysics in ways that are superior to or complementary with the Belle II and Large-Hadron-Collider-beauty experiments,potentially enabling the detection of new physics at energy scales of 10 TeV and above.This potential also extends to the observation of yet-to-be-discovered rare and exotic processes,as well as testing fundamental principles such as lepton flavor universality,lepton and baryon number conservation,etc.,making the CEPC a vibrant platform for flavor physics research.The WW threshold scan,Higgs-factory operation and top-pair productions of the CEPC further enhance its merits in this regard,especially for measuring the Cabibbo-Kobayashi-Maskawa matrix elements,and Flavor-Changing-NeutralCurrent physics of Higgs boson and top quarks.We outline the requirements for detector performance and considerations for future development to achieve the anticipated scientific goals.The role of machine learning for innovative detector design and advanced reconstruction algorithms is also stressed.The CEPC flavor physics program not only develops new capabilities for exploring flavor physics beyond existing projects but also enriches the physics opportunities of this machine.It should be remarked that,given the richness of the CEPC flavor physics,this manuscript is not meant to be a comprehensive survey,but rather an investigation of representative cases.Uncovering the full potential of flavor physics at the CEPC will require further dedicated explorations in the future.展开更多
Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy...Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).展开更多
In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurem...In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurements for B=Bs!Peltl;l ml;m mT decays,the BaBar’s ReDT and ReD T anomaly,the P05deviation for B0!K 0ltl decay.We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule,the heavy quark effective theory,and the perturbative QCD factorization approach.By using the form factors calculated in the perturbative(pQCD)approach,we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B=Bsmesons.We also made careful phenomenological analysis for these pQCD predictions and found,in general,the following points:(a)For all the considered B=Bssemileptonic decays,the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods;(b)For ReDT and ReD T,the pQCD predictions agree very well with the data,the BaBar’s anomaly of ReDe TT are therefore explained successfully in the standard model by employing the pQCD approach;and(c)We defined several new ratios Rl;s Dand Rl;s Ds,they may be more sensitive to the QCD dynamics which controls the B=Bs!eDe T;De T sT transitions than the old ratios,we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.展开更多
In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization appro...In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization approach.We find that(a)for R(D)and R(D*)ratios,the pQCD predictions are R(D)=0.430-0.026?0.021,R(D*)=0.301±0.013 and agree well with BaBar’s measurements of ReD e?T T;(b)for the newly defined R_D^1 and R_D^s ratios,the pQCD predictions are R_D^l=0.450-0.051+0.064 and R_D^s=0.642-0.070+0.081,which may be more sensitive to the QCD dynamics of the considered semileptonic decays than R(D^(*)) and should be tested by experimental measurements.展开更多
This paper deals with the optimal placement of distributed generation(DG) units in distribution systems via an enhanced multi-objective particle swarm optimization(EMOPSO) algorithm. To pursue a better simulation of t...This paper deals with the optimal placement of distributed generation(DG) units in distribution systems via an enhanced multi-objective particle swarm optimization(EMOPSO) algorithm. To pursue a better simulation of the reality and provide the designer with diverse alternative options, a multi-objective optimization model with technical and operational constraints is constructed to minimize the total power loss and the voltage fluctuation of the power system simultaneously. To enhance the convergence of MOPSO, special techniques including a dynamic inertia weight and acceleration coefficients have been integrated as well as a mutation operator. Besides, to promote the diversity of Pareto-optimal solutions, an improved non-dominated crowding distance sorting technique has been introduced and applied to the selection of particles for the next iteration. After verifying its effectiveness and competitiveness with a set of well-known benchmark functions, the EMOPSO algorithm is employed to achieve the optimal placement of DG units in the IEEE 33-bus system. Simulation results indicate that the EMOPSO algorithm enables the identification of a set of Pareto-optimal solutions with good tradeoff between power loss and voltage stability. Compared with other representative methods, the present results reveal the advantages of optimizing capacities and locations of DG units simultaneously, and exemplify the validity of the EMOPSO algorithm applied for optimally placing DG units.展开更多
Background MicroRNA-29b(miR-29b)has been suggested to possess pro-inflammatory activity,which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody(TNFAIP3).Meanwhile,it al...Background MicroRNA-29b(miR-29b)has been suggested to possess pro-inflammatory activity,which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody(TNFAIP3).Meanwhile,it also promotes thyroid cell proliferation via Smad signaling pathways.The present study aimed to elucidate the role of miR-29b in Henoch Sch(o)nlein purpura nephritis(HSPN)and its underlying molecular mechanism in angiotensinⅡ(AngⅡ)-induced human glomerular mesangial cell(HGMC)activation.Methods We evaluated miR-29b expression in 35 HSPN renal tissues based on crescent formation,glomerular sclerosis,interstitial fibrosis,thrombosis formation and capillary loop necrosis.Meanwhile,HGMCs were cultured,treated with AngⅡand then transfected with LV-hsa-miR-29b-1 to induce miR-29b overexpression or LV-hsa-miR-29b-3p-inhibition to inhibit miR-29b expression.Finally,we examined the effects of miR-29b on cell proliferation and release of inflammatory mediators.Results We observed that miR-29b expression was significantly higher in the crescent group than in the no crescent group.MiR-29b overexpression induced the release of intercellular adhesion molecule-1,interleukin-1β(IL-1β),IL-6,IL-8,the increase of CyclinA2,CyclinD 1,and cell proliferation.It also could inhibit the expressions of TNFAIP3 and NF-kappa-B-repressing factor(NKRF).Correspondingly,miR-29b inhibition produced the opposite effects and increased the expression of TNFAIP3 and NKRF.Conclusion MiR-29b expression is altered in crescent formation of HSPN and accelerates AngⅡ-induced mesangial cell proliferation and release of inflammatory mediators.展开更多
In order to accurately evaluate power system stability in a timely manner after faults,and further improve the feature extraction ability of the model,this paper presents an improved transient stability assessment(TSA...In order to accurately evaluate power system stability in a timely manner after faults,and further improve the feature extraction ability of the model,this paper presents an improved transient stability assessment(TSA)method of CNN+GRU.This comprises a convolutional neural network(CNN)and gated recurrent unit(GRU).CNN has the feature extraction capability for a micro short-term time sequence,while GRU can extract characteristics contained in a macro long-term time sequence.The two are integrated to comprehensively extract the high-order features that are contained in a transient process.To overcome the difficulty of sample misclassification,a multiple parallel(MP)CNN+GRU,with multiple CNN+GRU connected in parallel,is created.Additionally,an improved focal loss(FL)func-tion which can implement self-adaptive adjustment according to the neural network training is introduced to guide model training.Finally,the proposed methods are verified on the IEEE 39 and 145-bus systems.The simulation results indicate that the proposed methods have better TSA performance than other existing methods.展开更多
The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
In this short review we elaborate the significance of resummation in kτ factorization theorem,and summarize the recent progresses in the calculations of the next-to-leading order contributions to B meson decays from ...In this short review we elaborate the significance of resummation in kτ factorization theorem,and summarize the recent progresses in the calculations of the next-to-leading order contributions to B meson decays from the perturbative QCD(PQCD)approach.We also comment on the current sta-tus of the PQCD approach and highlight some key issues to develop it in the near future for more phenomenological applications.展开更多
基金financially supported by State Key Laboratory of HVDC No.SKLHVDC-2023-KF-03.
文摘The traditional transient stability assessment(TSA)model for power systems has three disadvantages:capturing critical information during faults is difficult,aperiodic and oscillatory unstable conditions are not distinguished,and poor generalizability is exhibited by systems with high renewable energy penetration.To address these issues,a novel ResGRU architecture for TSA is proposed in this study.First,a residual neural network(ResNet)is used for deep feature extraction of transient information.Second,a bidirectional gated recurrent unit combined with a multi-attention mechanism(BiGRU-Attention)is used to establish temporal feature dependencies.Their combination constitutes a TSA framework based on the ResGRU architecture.This method predicts three transient conditions:oscillatory instability,aperiodic instability,and stability.The model was trained offline using stochastic gradient descent with a thermal restart(SGDR)optimization algorithm in the offline training phase.This significantly improves the generalizability of the model.Finally,simulation tests on IEEE 145-bus and 39-bus systems confirmed that the proposed method has higher adaptability,accuracy,scalability,and rapidity than the conventional TSA approach.The proposed model also has superior robustness for PMU incomplete configurations,PMU noisy data,and packet loss.
基金supported by the National Natural Science Foundation of China(Nos.21671172,21625604,21776251,21706229and Z86101001)Zhejiang Provincial Natural Science Foundation(No.LR19B010001)
文摘To search the new effective nitrogen reduction reaction(NRR)electrocatalyst is very important for the ammonia-based industry.Herein,we reported the design of a novel NRR electrocatalyst with Ru NPs loaded on oxygen-vacancy TiO2(Ru/TiO2-Vo).Structural characterizations revealed that oxygen vacancy was loaded in the matrix of Ru/TiO2-Vo.Electrocatalytic results indicated that Ru/TiO2-Vo showed good NRR performance(2.11μg h^-1 cm^-2).Contrast tests showed that NRR property of Ru/TiO2-Vo was much better than those of Ru/TiO-12(B)(0.53μg hcm^-2)and Ru/P25(0.42μg h^-1 cm^-2).Furthermore,density functional theory calculation results indicated catalytic mechanism of NRR and rate-determining step(*N2+1/2 H2→*N+*NH)was the potential-determining step with the overpotential requirement of 0.21 V.A combination of electronic structure analysis and catalytic measurement shed light on the synergistic effect of Ru and oxygen vacancy on the NRR performance.
文摘Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original article has been corrected.
基金financial support from the National Natural Science Foundation of China(NSFC)(12125507,12047503,12035008,2211530479,12475094,12135006,12075097,12375086,2022YFA1601903,12061141007,12375091,12342502,12235018,12335003,12105100,12475106,11961141015,12188102,12175245,12205171,12321005,tsqn202312052,2024HWYQ-005,12405121,12447167,12061141006,12405102,12125503,12305115,12075213,12335005,12235008)the Chinese Academy of Sciences(YSBR-101,XDB34030000)+11 种基金the National Key R&D Program of China(2022YFE0116900,2023YFA1606703,2022YFA1601901)the National Key Research and Development Program of China(2023YFA1606300)the Excellent Postdoctoral Program of Jiangsu Province(2023ZB891)the Shenzhen Science and Technology Program(202206193000001,20220816094256002)the Natural Science Foundation for Distinguished Young Scholars of Henan Province(242300421046)the Beijing Municipal Natural Science Foundation(JQ22002)the Area of Excellence(AoE/P-404/18-3)the General Research Fund(16304321)(both grants are issued by the Research Grants Council of Hong Kong S.A.R)the MOST National Key R&D Program(2023YFA1606303)the Shanghai Key Laboratory for Particle Physics and CosmologyKey Laboratory for Particle Astrophysics and Cosmology(Ministry of Education)Shanghai Jiao Tong University。
文摘We discuss the landscape of flavor physics at the Circular Electron-Positron Collider(CEPC),based on the nominal luminosity outlined in its Technical Design Report.The CEPC is designed to operate in multiple modes to address a variety of tasks.At the Z pole,the expected production of 4 Tera Z bosons will provide unique and highly precise measurements of Z boson couplings,while the substantial number of boosted heavy-flavored quarks and leptons produced in clean Z decays will facilitate investigations into their flavor physics with unprecedented precision.We investigate the prospects of measuring various physics benchmarks and discuss their implications for particle theories and phenomenological models.Our studies indicate that,with its highlighted advantages and anticipated excellent detector performance,the CEPC can explore beauty andτphysics in ways that are superior to or complementary with the Belle II and Large-Hadron-Collider-beauty experiments,potentially enabling the detection of new physics at energy scales of 10 TeV and above.This potential also extends to the observation of yet-to-be-discovered rare and exotic processes,as well as testing fundamental principles such as lepton flavor universality,lepton and baryon number conservation,etc.,making the CEPC a vibrant platform for flavor physics research.The WW threshold scan,Higgs-factory operation and top-pair productions of the CEPC further enhance its merits in this regard,especially for measuring the Cabibbo-Kobayashi-Maskawa matrix elements,and Flavor-Changing-NeutralCurrent physics of Higgs boson and top quarks.We outline the requirements for detector performance and considerations for future development to achieve the anticipated scientific goals.The role of machine learning for innovative detector design and advanced reconstruction algorithms is also stressed.The CEPC flavor physics program not only develops new capabilities for exploring flavor physics beyond existing projects but also enriches the physics opportunities of this machine.It should be remarked that,given the richness of the CEPC flavor physics,this manuscript is not meant to be a comprehensive survey,but rather an investigation of representative cases.Uncovering the full potential of flavor physics at the CEPC will require further dedicated explorations in the future.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602200)the National Natural Science Foundation of China(Nos.12341501 and 12405174)the Hefei Comprehensive National Science Center for the strong support on the STCF key technology research project.
文摘Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).
基金supported by the National Natural Science Foundation of China (11235005 and 10975074)
文摘In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurements for B=Bs!Peltl;l ml;m mT decays,the BaBar’s ReDT and ReD T anomaly,the P05deviation for B0!K 0ltl decay.We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule,the heavy quark effective theory,and the perturbative QCD factorization approach.By using the form factors calculated in the perturbative(pQCD)approach,we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B=Bsmesons.We also made careful phenomenological analysis for these pQCD predictions and found,in general,the following points:(a)For all the considered B=Bssemileptonic decays,the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods;(b)For ReDT and ReD T,the pQCD predictions agree very well with the data,the BaBar’s anomaly of ReDe TT are therefore explained successfully in the standard model by employing the pQCD approach;and(c)We defined several new ratios Rl;s Dand Rl;s Ds,they may be more sensitive to the QCD dynamics which controls the B=Bs!eDe T;De T sT transitions than the old ratios,we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.
基金supported by the National Natural Science Foundation of China(10975074 and 11235005)
文摘In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization approach.We find that(a)for R(D)and R(D*)ratios,the pQCD predictions are R(D)=0.430-0.026?0.021,R(D*)=0.301±0.013 and agree well with BaBar’s measurements of ReD e?T T;(b)for the newly defined R_D^1 and R_D^s ratios,the pQCD predictions are R_D^l=0.450-0.051+0.064 and R_D^s=0.642-0.070+0.081,which may be more sensitive to the QCD dynamics of the considered semileptonic decays than R(D^(*)) and should be tested by experimental measurements.
基金Project supported by the Science&Technology Innovation Team of Outstanding Youth of Hubei Provincial Universities(No.T201319)the Scientific Research Foundation for Talents of China Three Gorges University(No.0620130076)
文摘This paper deals with the optimal placement of distributed generation(DG) units in distribution systems via an enhanced multi-objective particle swarm optimization(EMOPSO) algorithm. To pursue a better simulation of the reality and provide the designer with diverse alternative options, a multi-objective optimization model with technical and operational constraints is constructed to minimize the total power loss and the voltage fluctuation of the power system simultaneously. To enhance the convergence of MOPSO, special techniques including a dynamic inertia weight and acceleration coefficients have been integrated as well as a mutation operator. Besides, to promote the diversity of Pareto-optimal solutions, an improved non-dominated crowding distance sorting technique has been introduced and applied to the selection of particles for the next iteration. After verifying its effectiveness and competitiveness with a set of well-known benchmark functions, the EMOPSO algorithm is employed to achieve the optimal placement of DG units in the IEEE 33-bus system. Simulation results indicate that the EMOPSO algorithm enables the identification of a set of Pareto-optimal solutions with good tradeoff between power loss and voltage stability. Compared with other representative methods, the present results reveal the advantages of optimizing capacities and locations of DG units simultaneously, and exemplify the validity of the EMOPSO algorithm applied for optimally placing DG units.
基金This study was supported by Clinical Medicine Science and Technology Project of Jiangsu Province (BL2014007).
文摘Background MicroRNA-29b(miR-29b)has been suggested to possess pro-inflammatory activity,which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody(TNFAIP3).Meanwhile,it also promotes thyroid cell proliferation via Smad signaling pathways.The present study aimed to elucidate the role of miR-29b in Henoch Sch(o)nlein purpura nephritis(HSPN)and its underlying molecular mechanism in angiotensinⅡ(AngⅡ)-induced human glomerular mesangial cell(HGMC)activation.Methods We evaluated miR-29b expression in 35 HSPN renal tissues based on crescent formation,glomerular sclerosis,interstitial fibrosis,thrombosis formation and capillary loop necrosis.Meanwhile,HGMCs were cultured,treated with AngⅡand then transfected with LV-hsa-miR-29b-1 to induce miR-29b overexpression or LV-hsa-miR-29b-3p-inhibition to inhibit miR-29b expression.Finally,we examined the effects of miR-29b on cell proliferation and release of inflammatory mediators.Results We observed that miR-29b expression was significantly higher in the crescent group than in the no crescent group.MiR-29b overexpression induced the release of intercellular adhesion molecule-1,interleukin-1β(IL-1β),IL-6,IL-8,the increase of CyclinA2,CyclinD 1,and cell proliferation.It also could inhibit the expressions of TNFAIP3 and NF-kappa-B-repressing factor(NKRF).Correspondingly,miR-29b inhibition produced the opposite effects and increased the expression of TNFAIP3 and NKRF.Conclusion MiR-29b expression is altered in crescent formation of HSPN and accelerates AngⅡ-induced mesangial cell proliferation and release of inflammatory mediators.
基金funded by the National Natural Science Foundation of China under Grant No.51607105.
文摘In order to accurately evaluate power system stability in a timely manner after faults,and further improve the feature extraction ability of the model,this paper presents an improved transient stability assessment(TSA)method of CNN+GRU.This comprises a convolutional neural network(CNN)and gated recurrent unit(GRU).CNN has the feature extraction capability for a micro short-term time sequence,while GRU can extract characteristics contained in a macro long-term time sequence.The two are integrated to comprehensively extract the high-order features that are contained in a transient process.To overcome the difficulty of sample misclassification,a multiple parallel(MP)CNN+GRU,with multiple CNN+GRU connected in parallel,is created.Additionally,an improved focal loss(FL)func-tion which can implement self-adaptive adjustment according to the neural network training is introduced to guide model training.Finally,the proposed methods are verified on the IEEE 39 and 145-bus systems.The simulation results indicate that the proposed methods have better TSA performance than other existing methods.
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
基金This work was sup-ported by the National Natural Science Foundation of China(NSFC)under Grant Nos.11805060,11975112,and 11775117.
文摘In this short review we elaborate the significance of resummation in kτ factorization theorem,and summarize the recent progresses in the calculations of the next-to-leading order contributions to B meson decays from the perturbative QCD(PQCD)approach.We also comment on the current sta-tus of the PQCD approach and highlight some key issues to develop it in the near future for more phenomenological applications.
