AIM:To explore choroidal thickness(CT)and choroidal vascularity index(CVI)changes around the macula and optic nerve head(ONH)using swept-source optical coherence tomography(SS-OCT)after small-incision lenticule extrac...AIM:To explore choroidal thickness(CT)and choroidal vascularity index(CVI)changes around the macula and optic nerve head(ONH)using swept-source optical coherence tomography(SS-OCT)after small-incision lenticule extraction(SMILE)and evaluate their associations with accommodation and aberrations.METHODS:Participants were divided into more myopic group(43 eyes)and less myopic group(33 eyes)according to refractive error.SS-OCT,negative relative accommodation(NRA),and positive relative accommodation(PRA)were analyzed before and 1d,1wk,and 1mo postoperatively.Root mean square higher-order aberrations(RMS HOAs),spherical aberrations(SAs),and coma were compared preoperative,1wk,and 1mo postoperatively.RESULTS:After surgery,RMS(0.29±0.26)and Coma(0.16±0.19)all increased.In the more myopic group,central and T macular CT(247.58±63.81 a n d 276.45±62.52μm)increased.NRA(0.41±0.51)and PRA(0.10±1.30)decreased,and SAs(0.21±0.21)increased.In the less myopic group,all regional and mean macular CT increased.NRA was correlated with mean and inferior CTs and mean ONH CVI.SE was correlated with macular CT,CVI,and ONH CT.Mean macular and ONH CTs were associated with RMS HOA,SA,and coma.Macular T2 CT was a significant predictor of SA.Macular T2 and N1 CT were correlated with coma.CONCLUSION:More variations in accommodation and aberrations and fewer choroid thickens on macular and ONH are found in more myopic eyes after SMILE.Choroidal values are associated with accommodation and aberrations during SMILE.Choroid parameters on SS-OCT varies in eyes with different refractive errors after SMILE and has an association with accommodation and visual quality.展开更多
My Fair Lady is a movie about how a lower class flower girl turns to an upper class lady by simply changing her language at the help of a linguist.It demonstrates the importance of communication accommodation,especial...My Fair Lady is a movie about how a lower class flower girl turns to an upper class lady by simply changing her language at the help of a linguist.It demonstrates the importance of communication accommodation,especially convergent accommodation,in using language as code and behavior to construct identity in the target community.展开更多
AIM: To assess the value of ultrasonography (US) in evaluation of proximal gastric accommodation disorder in patients with functional dyspepsia (FD). METHODS: Between April 2011 and March 2012, 45 patients with FD and...AIM: To assess the value of ultrasonography (US) in evaluation of proximal gastric accommodation disorder in patients with functional dyspepsia (FD). METHODS: Between April 2011 and March 2012, 45 patients with FD and 27 healthy volunteers were enrolled in this study. Two-dimensional ultrasound (2DUS) and 3-dimensional ultrasound (3DUS) were performed sequentially to measure proximal gastric area (PGA), maximal proximal gastric diameter (MPGD), and proximal gastric volume (PGV). These values were measured separately in the two groups every other 5 min for a duration of 25 min after the beginning of ingestion of a test meal. Air pocket grading was done separately for images of 2DUS and blocks of 3DUS obtained at five scanning time points. RESULTS: Both PGA and PGV of patients were significantly smaller than healthy controls (P = 0.000 and 0.002, respectively). Comparing the two parameters between the groups at each time point, the differences were also statistically significant (P = 0.000-0.013), except at 10 min for the PGV (P = 0.077). However, no overall difference was found between the groups in the MPGD measurements (P = 0.114), though it was statistically significant at a 20-minute examination point (P = 0.026). A total of 360 sets or blocks of images were obtained for both 2DUS and 3DUS. For the images analyzed by 2DUS, none were excluded because of gastric gas, and 50 (13.9%) and 310 (86.1%) sets were determined as air pockets grades 1 and 2, respectively. For the images analyzed by 3DUS, 23 (6.4%) blocks were excluded from the measurement due to presence of a large fundus air pocket (grade 3); fifty (13.9%) and 287 (79.7%) blocks were also graded as 1 and 2, respectively. CONCLUSION: Measurement of both PGA and PGV by 2DUS and 3DUS could be useful for assessment of the proximal gastric accommodation.展开更多
Gastric accommodation is important for the understanding of the pathophysiology in functional dyspepsia and is also relevant for symptom generation in other disorders. The term gastric accommodation has at least three...Gastric accommodation is important for the understanding of the pathophysiology in functional dyspepsia and is also relevant for symptom generation in other disorders. The term gastric accommodation has at least three different meanings： The accommodation process, the accommodation reflex, and the accommodation response. The gastric accommodation process is a complex phenomenon that describes how the size of the gastric compartment changes in response to a meal. The electronic barostat is considered the gold standard in assessing gastric accommodation. Imaging methods, including MRI, SPECT, and ultrasonography may also be used, particularly in patients who are stress-responsive, e.g. functional dyspepsia patients, as a non-invasive and less stress-inducing method is favourable. Ultrasonography satisfies these criteria as it does not by itself distort the physiological response in stress-responsive individuals.展开更多
AIM： To study effects of orthokeratology（Ortho-k） on accommodation function in myopic children. METHODS： A prospective, non-randomized, case-control study was performed from September to October 2016. Eighty-three...AIM： To study effects of orthokeratology（Ortho-k） on accommodation function in myopic children. METHODS： A prospective, non-randomized, case-control study was performed from September to October 2016. Eighty-three children with myopia were divided into two groups. One group was treated with the rigid contact lens for overnight Ortho-k, and the other was treated with single-vision spectacle lens（SVL）. Accommodation function were assessed by accommodative amplitude（AA）, accommodative sensitivity（AS）, accommodative lag（Lag）, negative relative accommodation（NRA）, and positive relative accommodation（PRA） before and 1, 3, 6 and 12 mo after treated. RESULTS： Totally 72 myopic children were finished the follow-up： 37 in Ortho-k group and 35 in SVL group. Wearing time had a significant effect on AA, AS, Lag, and NRA of myopic children in two groups（all P〈0.05）. Meanwhile, there was an interaction effect between wearing time and wearing types（FAA=5.3, FAS=45.5, FLag=7.0, FNRA=3.7, all P〈0.05）. However, the between-group difference of AA（F=0.1）, AS（F=3.2）, Lag（F=1.1）, NRA（F=0.3）, and PRA（F=0.1） showed no significance. AA, AS, NRA, Lag and PRA were improved significantly in Ortho-k group within 1 to 6 mo after wearing. CONCLUSION： Wearing Ortho-k can improve the accommodation function of myopic children, which might be one of the mechanisms for myopia control.展开更多
With the ever-increased installed capacity of renewable energy generation units in a power system,the so-called shared energy storage(SES),a novel business model under the umbrella of the shared economy principle,has ...With the ever-increased installed capacity of renewable energy generation units in a power system,the so-called shared energy storage(SES),a novel business model under the umbrella of the shared economy principle,has the potential to play an essential role in the accommodation of renewable energy generation.However,unified evaluation standards and methods,which can help decision-makers analyze the performance of the SES market,are still not available.In this paper,an evaluation index system of the SES market is designed based on the trading rules of China’s Qinghai province and the structure-conduct-performance(SCP)analytical model.Moreover,the definition and characteristics of the indices,which can show the performance of the SES market from different perspectives,are given.Furthermore,the ideal cases are presented as the evaluation benchmark based on the development expectation of the SES market,and the analytic hierarchy process(AHP)and the technique for order preference by similarity to an ideal solution(TOPSIS)are applied to evaluate the SES market comprehensively.Finally,a case study based on actual data of the SES trading pilot project in Qinghai shows that the evaluation index system can reflect the operation status,existing problems and influencing factors of the SES market.展开更多
Split Hopkinson pressure bar(SHPB)tests were conducted on pre-rolled AZ31 magnesium alloy at 150–350℃ with strain rates of 2150s-1,3430s^(-1) and 4160s-1.The mechanical response,microstructural evolution and accommo...Split Hopkinson pressure bar(SHPB)tests were conducted on pre-rolled AZ31 magnesium alloy at 150–350℃ with strain rates of 2150s-1,3430s^(-1) and 4160s-1.The mechanical response,microstructural evolution and accommodation mechanism of the pre-rolled AZ31 magnesium alloy under high-speed impact loading were investigated.The twin and shear band are prevailing at low temperature,and the coexistence of twins and recrystallized grains is the dominant microstructure at medium temperature,while at high temperature,dynamic recrystallization(DRX)is almost complete.The increment of temperature reduces the critical condition difference between twinning and DRX,and the recrystallized temperature decreases with increasing strain rate.The mechanical response is related to the competition among the shear band strengthen,the twin strengthen and the fine grain strengthen and determined by the prevailing grain structure.The fine grain strengthen could compensate soften caused by the temperature increase and the reduction of twin and shear band.During high-speed deformation,different twin variants,introduced by pre-rolling,induce different deformation mechanism to accommodate plastic deformation and are in favor for non-basal slip.At low temperature,the high-speed deformation is achieved by twinning,dislocation slip and the following deformation shear band at different deformation stages.At high temperature,the high-speed deformation is realized by twinning and dislocation slip of early deformation stage,transition shear band of medium deformation stage and DRX of final deformation stage.展开更多
The increasing proportion of distributed photovoltaics(DPVs)and electric vehicle charging stations in low-voltage distribution networks(LVDNs)has resulted in challenges such as distribution transformer overloads and v...The increasing proportion of distributed photovoltaics(DPVs)and electric vehicle charging stations in low-voltage distribution networks(LVDNs)has resulted in challenges such as distribution transformer overloads and voltage violations.To address these problems,we propose a coordinated planning method for flexible interconnections and energy storage systems(ESSs)to improve the accommodation capacity of DPVs.First,the power-transfer characteristics of flexible interconnection and ESSs are analyzed.The equipment costs of the voltage source converters(VSCs)and ESSs are also analyzed comprehensively,considering the differences in installation and maintenance costs for different installation locations.Second,a bilevel programming model is established to minimize the annual comprehensive cost and yearly total PV curtailment capacity.Within this framework,the upper-level model optimizes the installation locations and capacities of the VSCs and ESSs,whereas the lower-level model optimizes the operating power of the VSCs and ESSs.The proposed model is solved using a non-dominated sorting genetic algorithm with an elite strategy(NSGA-II).The effectiveness of the proposed planning method is validated through an actual LVDN scenario,which demonstrates its advantages in enhancing PV accommodation capacity.In addition,the economic benefits of various planning schemes with different flexible interconnection topologies and different PV grid-connected forms are quantitatively analyzed,demonstrating the adaptability of the proposed coordinated planning method.展开更多
The renewable portfolio standard has been promoted in parallel with the reform of the electricity market,and the flexibility requirement of the power system has rapidly increased.To promote renewable energy consumptio...The renewable portfolio standard has been promoted in parallel with the reform of the electricity market,and the flexibility requirement of the power system has rapidly increased.To promote renewable energy consumption and improve power system flexibility,a bi-level optimal operation model of the electricity market is proposed.A probabilistic model of the flexibility requirement is established,considering the correlation between wind power,photovoltaic power,and load.A bi-level optimization model is established for the multi-markets;the upper and lower models represent the intra-provincial market and inter-provincial market models,respectively.To efficiently solve the model,it is transformed into a mixed-integer linear programming model using the Karush–Kuhn–Tucker condition and Lagrangian duality theory.The economy and flexibility of the model are verified using a provincial power grid as an example.展开更多
The event-triggered fault accommodation problem for a class of nonlinear uncertain systems is considered in this paper.The control signal transmission from the controller to the system is determined by an event-trigge...The event-triggered fault accommodation problem for a class of nonlinear uncertain systems is considered in this paper.The control signal transmission from the controller to the system is determined by an event-triggering scheme with relative and constant triggering thresholds.Considering the event-induced control input error and system fault threat,a novel eventtriggered active fault accommodation scheme is designed,which consists of an event-triggered nominal controller for the time period before detecting the occurrence of faults and an adaptive approximation based event-triggered fault accommodation scheme for handling the unknown faults after detecting the occurrence of faults.The closed-loop stability and inter-event time of the proposed fault accommodation scheme are rigorously analyzed.Special cases for the fault accommodation design under constant triggering threshold are also derived.An example is employed to illustrate the effectiveness of the proposed fault accommodation scheme.展开更多
Impaired gastric accommodation is one of the most important etiologic factors in the pathophysiology of functional dyspepsia.Ultrasound is a potential alternative method to study changes in gastric volume as a reflect...Impaired gastric accommodation is one of the most important etiologic factors in the pathophysiology of functional dyspepsia.Ultrasound is a potential alternative method to study changes in gastric volume as a reflection of gastric accommodation.Ultrasound is suitable for patients because it is a non-invasive,easily repeated and non-radioactive procedure,and a previous study has demonstrated the feasibility of 3-dimensional ultrasound in examining functional dyspepsia.The brief article by Fan et al demonstrated that both the proximal gastric area and volume,measured by 2-and 3-dimensional ultrasound respectively,were significantly smaller in patients with functional dyspepsia than in healthy controls.These results are very interesting,but we raise the relevant point that it should have been mandatory to study both changes in gastric volume and their relationship with upper gastrointestinal symptoms in functional dyspepsia.In fact,the relationship between cardinal symptoms and several pathophysiologic mechanisms in functional dyspepsia remains a matter of debate.Moreover,further evaluation of distal gastric volume that has been previously implicated in the origin of functional dyspeptic symptoms is advisable.Therefore,impaired gastric accommodation does not serve as a clear marker of the cardinal symptoms experienced by patients with functional dyspepsia in daily life.展开更多
This paper proposes a novel idea that classifies faults into two different kinds： serious faults and small faults, and treats them with different strategies respectively. A kind of artificial neural network （ANN） i...This paper proposes a novel idea that classifies faults into two different kinds： serious faults and small faults, and treats them with different strategies respectively. A kind of artificial neural network （ANN） is proposed for detecting serious faults, and variable structure （VS） model-following control is constructed for accommodating small faults. The proposed framework takes both advantages of qualitative way and quantitative way of fault detection and accommodation. Moreover, the uncertainty case is investigated and the VS controller is modified. Simulation results of a remotely piloted aircraft with control actuator failures illustrate the performance of the developed algorithm.展开更多
The accurate prediction of the aeroheating performance of hypersonic vehicles requires more detailed modeling of the catalysis process,rather than merely employing a catalytic coefficient.In this paper,the theoretical...The accurate prediction of the aeroheating performance of hypersonic vehicles requires more detailed modeling of the catalysis process,rather than merely employing a catalytic coefficient.In this paper,the theoretical modeling,as well as the direct simulation Monte Carlo method,is used to preliminarily study the incomplete chemical energy accommodation effects,that is,only a part of the potential energy released in the heterogenous recombination reaction is transferred to the surface,while the remaining is retained as the vibrational energy of the desorbed molecule.An integrated model is proposed to describe the contribution of each energy mode in the rarefied nonequilibrium heat and mass transfer process.Based on the model and several Damko?hler numbers,an analytical formula is derived,and is also shown to compare well with the numerical results.On account of the incomplete accommodations of the chemical and vibrational energy on the wall,a variation up to 20%is observed in predicting the stagnation point heat flux under typical nonequilibrium flow conditions.This study could enrich our understanding of the nonequilibrium heat transfer phenomenon and also shows a potential practical value.展开更多
The accommodative function before and after laser in situ keratomileusis （LASIK） was observed, and the effect of LASIK on accommodation was investigated. In a prospective clinical trial, 48 myopic patients （96 eyes...The accommodative function before and after laser in situ keratomileusis （LASIK） was observed, and the effect of LASIK on accommodation was investigated. In a prospective clinical trial, 48 myopic patients （96 eyes） subject to bilateral LASIK in Refractive Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology （China） from March 2006 to June 2006 were selected and studied. Refractions, accommodative range, amplitude of accommodative response and high frequency component （HFC） of accommodative microfluctuations were measured with NEDIK-730A before and one week and 30 days after operation. Dominant and non-dominant eyes were determined by hole-in-card method. It was found that all of the operative eyes showed an uncorrected visual acuity of 0.8 or better one week postoperatively, and 1.0 or better 30 days postoperatively. Compared with those preoperatively, accommodative range and HFC had no significant difference at first week and 30th day after operation in both dominant eyes and non-dominant eyes （P〉0.05）, but there was a significant difference in the amplitude of accommodative response/accommodative stimulus ratio （A/S） after operation （P〈0.01）, and no significant difference was found in accommodation between one week and 30 days postoperation. No ocular dominance＇s change was noted. There was no significant difference in accommodative function between dominant eyes and non-dominant eyes. It was suggested that LASIK produced no significant effect on accommodation.展开更多
{11-22}compression twin plays an important role in accommodating deformation along the c axis of HCP metals.However,the studies on the interface structure of{11-22}twin boundary(TB),especially the twin tip,and the cor...{11-22}compression twin plays an important role in accommodating deformation along the c axis of HCP metals.However,the studies on the interface structure of{11-22}twin boundary(TB),especially the twin tip,and the corresponding local stress release mechanism are still limited.This work studied the interface characters of{11-22}TB of a deformed pure titanium by transmission electron microscope.The{11-22}TB presented serrated character,consisting of coherent twin boundary(CTB)and(0002)_(T)//(11-2-2)_(M)or(11-2-2)_(T)//(0002)_(M)steps,and the twin tip was fully composed of the basal-pyramidal(BPy)and pyramidal-basal(PyB)steps.The twin tip presents asymmetric morphology and the step height at the twin tip is much larger than that away from the twin tip.Two types of local stress accommodation mechanisms were observed:zonal dislocation emission and hexagonal close packed structure to facecentered cubic structure transformation.The zonal dislocation was produced by the dissociation of the1/3<11-2-3>dislocation that was nucleated at the twin tip and the phase transformation was introduced by emission of Shockley partial dislocations from the{11-22}twin boundary.展开更多
Profound and comprehensive investigations on the morphology characteristics ofαprecipitates are essential for the microstructural control of metastableβtitanium alloys.At the very beginning of aging treatment,intrag...Profound and comprehensive investigations on the morphology characteristics ofαprecipitates are essential for the microstructural control of metastableβtitanium alloys.At the very beginning of aging treatment,intragranularαprecipitates with a dot-like morphology begin to generate nearby the dislocations,then those dot-likeαprecipitates with the same crystallographic orientation tend to connect with each other to develop a lath-like morphology.With the progress of aging treatment,the orientated lath-likeαprecipitates gradually combine with each other to form the V-shaped clusters or the triangular ones.The dislocations of{110}_(β)<111>βedge type are evidenced within theβgrains,and it is found that variant selection ofαprecipitates induced by the transformation strain and the interplay betweenαvariants and the dislocations are confirmed as the key factors for the formation of the V-shaped or triangular clusters.The results of this work could provide underlying knowledge on the morphology characteristics of intraguranularαprecipitates related to the crystal defects and the strain accommodation ofαvariants in metastableβtitanium alloys.展开更多
AIM:To simulate and compare accommodation in accommodative and non-accommodative human eye models.METHODS:Ray tracing and optical design program was used.Three eye models were designed and studied:the Navarro,the Ariz...AIM:To simulate and compare accommodation in accommodative and non-accommodative human eye models.METHODS:Ray tracing and optical design program was used.Three eye models were designed and studied:the Navarro,the Arizona and the Liou-Brennan.In order to make the Navarro and Liou-Brennan models to accommodate,specific geometric parameters of the models were altered with values that were chosen from the literature.For the Arizona model,its’mathematical functions for accommodation were used for the same accommodative demands.The simulation included four distances of accommodation for each model:at infinity,3,1 and 0.5 m.The results were diffraction images of a“letter F”for graphical comparison,spot diagrams on the retinal field and Modulation Transfer Function(MTF)graphs.RESULTS:Zernike coefficients for the aberrations,Airy disk diameter,root mean square(RMS)error diameter and total axial length of the model were provided from the program.These were compared between them in all distances.The Navarro model had the smallest axial length change as a simple model.The Arizona did not change its axial length because it is designed to be accommodative.The Liou-Brennan model had different results concerning the aberrations because of the decentration of the pupil.The MTF graphs showed small differences between the models because of the differences in their designs.CONCLUSION:All the three models are able to simulate accommodation with the expected results.There is no model that can be assumed as the best choice.Accommodation can be simulated in non-accommodativemodels and in customized ones.展开更多
A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults structure.Increasing numbers of fault accommodation zones are being identified in graben basins,in...A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults structure.Increasing numbers of fault accommodation zones are being identified in graben basins,indicating the potential exploration target and petroleum accumulation areas.This study aims to analyze the formation mechanism and development of fault accommodation zones under combined stress by a numerical simulation method considering geomechanical modeling.Using three-dimensional(3-D)seismic interpretation and fractal dimension method,exampled with the Dongxin fault zone,the fault activity and fault combination pattern were conducted to quantitatively characterize the activity difference in fault accommodation zones.Combined with mechanical experiment test,a geomehcanical model was established for fault accommodation zones in a graben basin.Integrating the paleostress numerical simulations and structural physical simulation experiment,the developmental characteristics and genetic mechanism of fault accommodation zones were summarized.Influenced by multi movements and combined stresses,three significant tectonic evolution stages of the Dongxing Fault Zone(DXFZ)were distinguished:During the E_(s)^(3)sedimentary period,the large difference in the stress,strain,and rupture distribution in various faults were significant,and this stage was the key generation period for the prototype of the DXFZ,including the FAZ between large-scale faults.During the E_(s)^(2)sedimentary period,the EW-trending symmetric with opposite dipping normal faults and the NE-SW trending faults with large scale were furtherly developed.The junction area of two secondary normal faults were prone to be ruptured,performing significant period for inheriting and developing characteristics of fault accommodation zones.During the Es1 sedimentary period,the high-order faults in the DXFZ exhibited the obvious fault depressions and strike-slip activity,and the fault accommodation zones were furtherly inherited and developed.This stage was the molded and formative period of the FAZ,the low-order faults,and the depression in the DXFZ.展开更多
基金Supported by the National Natural Science Foundation of China(No.81900910)Natural Science Foundation of Zhejiang Province(No.LQ19H120003)Basic Scientific Research Project of Wenzhou(No.Y20210194,No.Y20190638).
文摘AIM:To explore choroidal thickness(CT)and choroidal vascularity index(CVI)changes around the macula and optic nerve head(ONH)using swept-source optical coherence tomography(SS-OCT)after small-incision lenticule extraction(SMILE)and evaluate their associations with accommodation and aberrations.METHODS:Participants were divided into more myopic group(43 eyes)and less myopic group(33 eyes)according to refractive error.SS-OCT,negative relative accommodation(NRA),and positive relative accommodation(PRA)were analyzed before and 1d,1wk,and 1mo postoperatively.Root mean square higher-order aberrations(RMS HOAs),spherical aberrations(SAs),and coma were compared preoperative,1wk,and 1mo postoperatively.RESULTS:After surgery,RMS(0.29±0.26)and Coma(0.16±0.19)all increased.In the more myopic group,central and T macular CT(247.58±63.81 a n d 276.45±62.52μm)increased.NRA(0.41±0.51)and PRA(0.10±1.30)decreased,and SAs(0.21±0.21)increased.In the less myopic group,all regional and mean macular CT increased.NRA was correlated with mean and inferior CTs and mean ONH CVI.SE was correlated with macular CT,CVI,and ONH CT.Mean macular and ONH CTs were associated with RMS HOA,SA,and coma.Macular T2 CT was a significant predictor of SA.Macular T2 and N1 CT were correlated with coma.CONCLUSION:More variations in accommodation and aberrations and fewer choroid thickens on macular and ONH are found in more myopic eyes after SMILE.Choroidal values are associated with accommodation and aberrations during SMILE.Choroid parameters on SS-OCT varies in eyes with different refractive errors after SMILE and has an association with accommodation and visual quality.
文摘My Fair Lady is a movie about how a lower class flower girl turns to an upper class lady by simply changing her language at the help of a linguist.It demonstrates the importance of communication accommodation,especially convergent accommodation,in using language as code and behavior to construct identity in the target community.
基金Supported by A Grant from the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of China, No. [2008] 101
文摘AIM: To assess the value of ultrasonography (US) in evaluation of proximal gastric accommodation disorder in patients with functional dyspepsia (FD). METHODS: Between April 2011 and March 2012, 45 patients with FD and 27 healthy volunteers were enrolled in this study. Two-dimensional ultrasound (2DUS) and 3-dimensional ultrasound (3DUS) were performed sequentially to measure proximal gastric area (PGA), maximal proximal gastric diameter (MPGD), and proximal gastric volume (PGV). These values were measured separately in the two groups every other 5 min for a duration of 25 min after the beginning of ingestion of a test meal. Air pocket grading was done separately for images of 2DUS and blocks of 3DUS obtained at five scanning time points. RESULTS: Both PGA and PGV of patients were significantly smaller than healthy controls (P = 0.000 and 0.002, respectively). Comparing the two parameters between the groups at each time point, the differences were also statistically significant (P = 0.000-0.013), except at 10 min for the PGV (P = 0.077). However, no overall difference was found between the groups in the MPGD measurements (P = 0.114), though it was statistically significant at a 20-minute examination point (P = 0.026). A total of 360 sets or blocks of images were obtained for both 2DUS and 3DUS. For the images analyzed by 2DUS, none were excluded because of gastric gas, and 50 (13.9%) and 310 (86.1%) sets were determined as air pockets grades 1 and 2, respectively. For the images analyzed by 3DUS, 23 (6.4%) blocks were excluded from the measurement due to presence of a large fundus air pocket (grade 3); fifty (13.9%) and 287 (79.7%) blocks were also graded as 1 and 2, respectively. CONCLUSION: Measurement of both PGA and PGV by 2DUS and 3DUS could be useful for assessment of the proximal gastric accommodation.
文摘Gastric accommodation is important for the understanding of the pathophysiology in functional dyspepsia and is also relevant for symptom generation in other disorders. The term gastric accommodation has at least three different meanings： The accommodation process, the accommodation reflex, and the accommodation response. The gastric accommodation process is a complex phenomenon that describes how the size of the gastric compartment changes in response to a meal. The electronic barostat is considered the gold standard in assessing gastric accommodation. Imaging methods, including MRI, SPECT, and ultrasonography may also be used, particularly in patients who are stress-responsive, e.g. functional dyspepsia patients, as a non-invasive and less stress-inducing method is favourable. Ultrasonography satisfies these criteria as it does not by itself distort the physiological response in stress-responsive individuals.
基金Supported by Special Scientific Research Program of Shaanxi Provincial Education Department(No.17JK0662)
文摘AIM： To study effects of orthokeratology（Ortho-k） on accommodation function in myopic children. METHODS： A prospective, non-randomized, case-control study was performed from September to October 2016. Eighty-three children with myopia were divided into two groups. One group was treated with the rigid contact lens for overnight Ortho-k, and the other was treated with single-vision spectacle lens（SVL）. Accommodation function were assessed by accommodative amplitude（AA）, accommodative sensitivity（AS）, accommodative lag（Lag）, negative relative accommodation（NRA）, and positive relative accommodation（PRA） before and 1, 3, 6 and 12 mo after treated. RESULTS： Totally 72 myopic children were finished the follow-up： 37 in Ortho-k group and 35 in SVL group. Wearing time had a significant effect on AA, AS, Lag, and NRA of myopic children in two groups（all P〈0.05）. Meanwhile, there was an interaction effect between wearing time and wearing types（FAA=5.3, FAS=45.5, FLag=7.0, FNRA=3.7, all P〈0.05）. However, the between-group difference of AA（F=0.1）, AS（F=3.2）, Lag（F=1.1）, NRA（F=0.3）, and PRA（F=0.1） showed no significance. AA, AS, NRA, Lag and PRA were improved significantly in Ortho-k group within 1 to 6 mo after wearing. CONCLUSION： Wearing Ortho-k can improve the accommodation function of myopic children, which might be one of the mechanisms for myopia control.
基金supported by the Science and Technology Project of State Grid Qinghai Electric Power Company(No.106000003367).
文摘With the ever-increased installed capacity of renewable energy generation units in a power system,the so-called shared energy storage(SES),a novel business model under the umbrella of the shared economy principle,has the potential to play an essential role in the accommodation of renewable energy generation.However,unified evaluation standards and methods,which can help decision-makers analyze the performance of the SES market,are still not available.In this paper,an evaluation index system of the SES market is designed based on the trading rules of China’s Qinghai province and the structure-conduct-performance(SCP)analytical model.Moreover,the definition and characteristics of the indices,which can show the performance of the SES market from different perspectives,are given.Furthermore,the ideal cases are presented as the evaluation benchmark based on the development expectation of the SES market,and the analytic hierarchy process(AHP)and the technique for order preference by similarity to an ideal solution(TOPSIS)are applied to evaluate the SES market comprehensively.Finally,a case study based on actual data of the SES trading pilot project in Qinghai shows that the evaluation index system can reflect the operation status,existing problems and influencing factors of the SES market.
基金supported by the National Natural Science Foundation of China(Nos.52071139,51905166,52075167)well as from the Natural Science Foundation of Hunan Province(2020JJ5198)the Open Platform Fund of Hunan Institute of Technology(KFA20014).
文摘Split Hopkinson pressure bar(SHPB)tests were conducted on pre-rolled AZ31 magnesium alloy at 150–350℃ with strain rates of 2150s-1,3430s^(-1) and 4160s-1.The mechanical response,microstructural evolution and accommodation mechanism of the pre-rolled AZ31 magnesium alloy under high-speed impact loading were investigated.The twin and shear band are prevailing at low temperature,and the coexistence of twins and recrystallized grains is the dominant microstructure at medium temperature,while at high temperature,dynamic recrystallization(DRX)is almost complete.The increment of temperature reduces the critical condition difference between twinning and DRX,and the recrystallized temperature decreases with increasing strain rate.The mechanical response is related to the competition among the shear band strengthen,the twin strengthen and the fine grain strengthen and determined by the prevailing grain structure.The fine grain strengthen could compensate soften caused by the temperature increase and the reduction of twin and shear band.During high-speed deformation,different twin variants,introduced by pre-rolling,induce different deformation mechanism to accommodate plastic deformation and are in favor for non-basal slip.At low temperature,the high-speed deformation is achieved by twinning,dislocation slip and the following deformation shear band at different deformation stages.At high temperature,the high-speed deformation is realized by twinning and dislocation slip of early deformation stage,transition shear band of medium deformation stage and DRX of final deformation stage.
基金supported by the Science and Technology Support Program of Guizhou Province([2022]General 012)the Key Science and Technology Project of China Southern Power Grid Corporation(GZKJXM20220043)。
文摘The increasing proportion of distributed photovoltaics(DPVs)and electric vehicle charging stations in low-voltage distribution networks(LVDNs)has resulted in challenges such as distribution transformer overloads and voltage violations.To address these problems,we propose a coordinated planning method for flexible interconnections and energy storage systems(ESSs)to improve the accommodation capacity of DPVs.First,the power-transfer characteristics of flexible interconnection and ESSs are analyzed.The equipment costs of the voltage source converters(VSCs)and ESSs are also analyzed comprehensively,considering the differences in installation and maintenance costs for different installation locations.Second,a bilevel programming model is established to minimize the annual comprehensive cost and yearly total PV curtailment capacity.Within this framework,the upper-level model optimizes the installation locations and capacities of the VSCs and ESSs,whereas the lower-level model optimizes the operating power of the VSCs and ESSs.The proposed model is solved using a non-dominated sorting genetic algorithm with an elite strategy(NSGA-II).The effectiveness of the proposed planning method is validated through an actual LVDN scenario,which demonstrates its advantages in enhancing PV accommodation capacity.In addition,the economic benefits of various planning schemes with different flexible interconnection topologies and different PV grid-connected forms are quantitatively analyzed,demonstrating the adaptability of the proposed coordinated planning method.
基金supported by the National Key R&D Program of China(2018YFA0702200)Science and Technology Project of State Grid Shandong Electric Power Corporation(52062518000Q)。
文摘The renewable portfolio standard has been promoted in parallel with the reform of the electricity market,and the flexibility requirement of the power system has rapidly increased.To promote renewable energy consumption and improve power system flexibility,a bi-level optimal operation model of the electricity market is proposed.A probabilistic model of the flexibility requirement is established,considering the correlation between wind power,photovoltaic power,and load.A bi-level optimization model is established for the multi-markets;the upper and lower models represent the intra-provincial market and inter-provincial market models,respectively.To efficiently solve the model,it is transformed into a mixed-integer linear programming model using the Karush–Kuhn–Tucker condition and Lagrangian duality theory.The economy and flexibility of the model are verified using a provincial power grid as an example.
基金supported by the European Union’s Horizon 2020 research and innovation programme grant agreement No.739551(KIOS CoE)。
文摘The event-triggered fault accommodation problem for a class of nonlinear uncertain systems is considered in this paper.The control signal transmission from the controller to the system is determined by an event-triggering scheme with relative and constant triggering thresholds.Considering the event-induced control input error and system fault threat,a novel eventtriggered active fault accommodation scheme is designed,which consists of an event-triggered nominal controller for the time period before detecting the occurrence of faults and an adaptive approximation based event-triggered fault accommodation scheme for handling the unknown faults after detecting the occurrence of faults.The closed-loop stability and inter-event time of the proposed fault accommodation scheme are rigorously analyzed.Special cases for the fault accommodation design under constant triggering threshold are also derived.An example is employed to illustrate the effectiveness of the proposed fault accommodation scheme.
文摘Impaired gastric accommodation is one of the most important etiologic factors in the pathophysiology of functional dyspepsia.Ultrasound is a potential alternative method to study changes in gastric volume as a reflection of gastric accommodation.Ultrasound is suitable for patients because it is a non-invasive,easily repeated and non-radioactive procedure,and a previous study has demonstrated the feasibility of 3-dimensional ultrasound in examining functional dyspepsia.The brief article by Fan et al demonstrated that both the proximal gastric area and volume,measured by 2-and 3-dimensional ultrasound respectively,were significantly smaller in patients with functional dyspepsia than in healthy controls.These results are very interesting,but we raise the relevant point that it should have been mandatory to study both changes in gastric volume and their relationship with upper gastrointestinal symptoms in functional dyspepsia.In fact,the relationship between cardinal symptoms and several pathophysiologic mechanisms in functional dyspepsia remains a matter of debate.Moreover,further evaluation of distal gastric volume that has been previously implicated in the origin of functional dyspeptic symptoms is advisable.Therefore,impaired gastric accommodation does not serve as a clear marker of the cardinal symptoms experienced by patients with functional dyspepsia in daily life.
基金This work was supported by National Natural Science Foundation of China (60574083)Key Laboratory of Process Industry Automation, Ministry ofEducation of China (PAL200514)Innovation Scientific Fund of Nanjing University of Aeronautics and Astronautics (Y0508-031)
文摘This paper proposes a novel idea that classifies faults into two different kinds： serious faults and small faults, and treats them with different strategies respectively. A kind of artificial neural network （ANN） is proposed for detecting serious faults, and variable structure （VS） model-following control is constructed for accommodating small faults. The proposed framework takes both advantages of qualitative way and quantitative way of fault detection and accommodation. Moreover, the uncertainty case is investigated and the VS controller is modified. Simulation results of a remotely piloted aircraft with control actuator failures illustrate the performance of the developed algorithm.
基金supported by the National Natural Science Foundation of China (Nos. 11672292 and 12072343)the Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2017490)the Strategic Priority Research Program (B) of Chinese Academy of Sciences (No. XDB22040202)
文摘The accurate prediction of the aeroheating performance of hypersonic vehicles requires more detailed modeling of the catalysis process,rather than merely employing a catalytic coefficient.In this paper,the theoretical modeling,as well as the direct simulation Monte Carlo method,is used to preliminarily study the incomplete chemical energy accommodation effects,that is,only a part of the potential energy released in the heterogenous recombination reaction is transferred to the surface,while the remaining is retained as the vibrational energy of the desorbed molecule.An integrated model is proposed to describe the contribution of each energy mode in the rarefied nonequilibrium heat and mass transfer process.Based on the model and several Damko?hler numbers,an analytical formula is derived,and is also shown to compare well with the numerical results.On account of the incomplete accommodations of the chemical and vibrational energy on the wall,a variation up to 20%is observed in predicting the stagnation point heat flux under typical nonequilibrium flow conditions.This study could enrich our understanding of the nonequilibrium heat transfer phenomenon and also shows a potential practical value.
文摘The accommodative function before and after laser in situ keratomileusis （LASIK） was observed, and the effect of LASIK on accommodation was investigated. In a prospective clinical trial, 48 myopic patients （96 eyes） subject to bilateral LASIK in Refractive Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology （China） from March 2006 to June 2006 were selected and studied. Refractions, accommodative range, amplitude of accommodative response and high frequency component （HFC） of accommodative microfluctuations were measured with NEDIK-730A before and one week and 30 days after operation. Dominant and non-dominant eyes were determined by hole-in-card method. It was found that all of the operative eyes showed an uncorrected visual acuity of 0.8 or better one week postoperatively, and 1.0 or better 30 days postoperatively. Compared with those preoperatively, accommodative range and HFC had no significant difference at first week and 30th day after operation in both dominant eyes and non-dominant eyes （P〉0.05）, but there was a significant difference in the amplitude of accommodative response/accommodative stimulus ratio （A/S） after operation （P〈0.01）, and no significant difference was found in accommodation between one week and 30 days postoperation. No ocular dominance＇s change was noted. There was no significant difference in accommodative function between dominant eyes and non-dominant eyes. It was suggested that LASIK produced no significant effect on accommodation.
基金supported by the National Natural Science Foundation of China(grant number 51828102)The Project of Innovation-driven Plan in Central South University(No.2019CX026)。
文摘{11-22}compression twin plays an important role in accommodating deformation along the c axis of HCP metals.However,the studies on the interface structure of{11-22}twin boundary(TB),especially the twin tip,and the corresponding local stress release mechanism are still limited.This work studied the interface characters of{11-22}TB of a deformed pure titanium by transmission electron microscope.The{11-22}TB presented serrated character,consisting of coherent twin boundary(CTB)and(0002)_(T)//(11-2-2)_(M)or(11-2-2)_(T)//(0002)_(M)steps,and the twin tip was fully composed of the basal-pyramidal(BPy)and pyramidal-basal(PyB)steps.The twin tip presents asymmetric morphology and the step height at the twin tip is much larger than that away from the twin tip.Two types of local stress accommodation mechanisms were observed:zonal dislocation emission and hexagonal close packed structure to facecentered cubic structure transformation.The zonal dislocation was produced by the dissociation of the1/3<11-2-3>dislocation that was nucleated at the twin tip and the phase transformation was introduced by emission of Shockley partial dislocations from the{11-22}twin boundary.
基金the Science and Technology Major Project of Shanxi Province(Nos.20191102008 and 20181101014)the Applied Basic Research Foundation of Shanxi Province(Nos.201901D211255 and 201901D211256)+4 种基金Platform and Talent Project of Shanxi Province(No.201805D211036)Guiding Local Science and Technology Development Projects by the Central Government(No.YDZX20191400002796)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2020L0304)Key projects of Equipment Pre-research Foundation(No.61409230407)the Natural Science Research Project of NUC(No.XJJ201916)。
文摘Profound and comprehensive investigations on the morphology characteristics ofαprecipitates are essential for the microstructural control of metastableβtitanium alloys.At the very beginning of aging treatment,intragranularαprecipitates with a dot-like morphology begin to generate nearby the dislocations,then those dot-likeαprecipitates with the same crystallographic orientation tend to connect with each other to develop a lath-like morphology.With the progress of aging treatment,the orientated lath-likeαprecipitates gradually combine with each other to form the V-shaped clusters or the triangular ones.The dislocations of{110}_(β)<111>βedge type are evidenced within theβgrains,and it is found that variant selection ofαprecipitates induced by the transformation strain and the interplay betweenαvariants and the dislocations are confirmed as the key factors for the formation of the V-shaped or triangular clusters.The results of this work could provide underlying knowledge on the morphology characteristics of intraguranularαprecipitates related to the crystal defects and the strain accommodation ofαvariants in metastableβtitanium alloys.
基金Supported by the Marie Curie Grant FP7-LIFEITN-2013-608049-AGEYE
文摘AIM:To simulate and compare accommodation in accommodative and non-accommodative human eye models.METHODS:Ray tracing and optical design program was used.Three eye models were designed and studied:the Navarro,the Arizona and the Liou-Brennan.In order to make the Navarro and Liou-Brennan models to accommodate,specific geometric parameters of the models were altered with values that were chosen from the literature.For the Arizona model,its’mathematical functions for accommodation were used for the same accommodative demands.The simulation included four distances of accommodation for each model:at infinity,3,1 and 0.5 m.The results were diffraction images of a“letter F”for graphical comparison,spot diagrams on the retinal field and Modulation Transfer Function(MTF)graphs.RESULTS:Zernike coefficients for the aberrations,Airy disk diameter,root mean square(RMS)error diameter and total axial length of the model were provided from the program.These were compared between them in all distances.The Navarro model had the smallest axial length change as a simple model.The Arizona did not change its axial length because it is designed to be accommodative.The Liou-Brennan model had different results concerning the aberrations because of the decentration of the pupil.The MTF graphs showed small differences between the models because of the differences in their designs.CONCLUSION:All the three models are able to simulate accommodation with the expected results.There is no model that can be assumed as the best choice.Accommodation can be simulated in non-accommodativemodels and in customized ones.
基金This research was supported by the Major Scientific and Technological Projects of CNPC under grant ZD2019-183-006the National Natural Science Foundation of China(42072234).The authors would like to appreciate all the people,who supported the data,testing,and analyses.Many thanks to the anonymous reviewers,whose comments improve the quality of our manuscript.
文摘A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults structure.Increasing numbers of fault accommodation zones are being identified in graben basins,indicating the potential exploration target and petroleum accumulation areas.This study aims to analyze the formation mechanism and development of fault accommodation zones under combined stress by a numerical simulation method considering geomechanical modeling.Using three-dimensional(3-D)seismic interpretation and fractal dimension method,exampled with the Dongxin fault zone,the fault activity and fault combination pattern were conducted to quantitatively characterize the activity difference in fault accommodation zones.Combined with mechanical experiment test,a geomehcanical model was established for fault accommodation zones in a graben basin.Integrating the paleostress numerical simulations and structural physical simulation experiment,the developmental characteristics and genetic mechanism of fault accommodation zones were summarized.Influenced by multi movements and combined stresses,three significant tectonic evolution stages of the Dongxing Fault Zone(DXFZ)were distinguished:During the E_(s)^(3)sedimentary period,the large difference in the stress,strain,and rupture distribution in various faults were significant,and this stage was the key generation period for the prototype of the DXFZ,including the FAZ between large-scale faults.During the E_(s)^(2)sedimentary period,the EW-trending symmetric with opposite dipping normal faults and the NE-SW trending faults with large scale were furtherly developed.The junction area of two secondary normal faults were prone to be ruptured,performing significant period for inheriting and developing characteristics of fault accommodation zones.During the Es1 sedimentary period,the high-order faults in the DXFZ exhibited the obvious fault depressions and strike-slip activity,and the fault accommodation zones were furtherly inherited and developed.This stage was the molded and formative period of the FAZ,the low-order faults,and the depression in the DXFZ.
