Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes ...Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.展开更多
This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C)in order to provide a theoretical guidance for the rational application of sili...This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C)in order to provide a theoretical guidance for the rational application of silica fume in the cementing engineering.Results showed that silica fume seldom affected the thickening progression of oil well cement slurry at 110-120.C,but when temperature reached above130.C,it would aggravate the bulging degree of thickening curves and significantly extend the thickening time,meanwhile causing the abnormal“temperature-based thickening time reversal”and“dosage-based thickening time reversal”phenomena in the range of 130-160.C and 170-180.C respectively.At 130-160.C,the thickening time of oil well cement slurry was mainly associated with the generation rate of calcium hydroxide(CH)crystal.The introduced silica fume would be attracted to the cement minerals'surface that were hydrating to produce CH and agglomerate together to form an“adsorptive barrier”to hinder further hydration of the inner cement minerals.This“adsorptive barrier”effect strengthened with the rising temperature which extended the thickening time and caused the occurrence of the“temperature-based thickening time reversal”phenomenon.At 170-180.C,the pozzolanic activity of silica fume significantly enhanced and considerable amount of C-S-H was generated,thus the“temperature-based thickening time reversal”vanished and the“dosage-based thickening time reversal”was presented.展开更多
Electric vehicles(EVs)have garnered significant attention as a vital driver of economic growth and environmental sustainability.Nevertheless,ensuring the safety of high-energy batteries is now a top priority that cann...Electric vehicles(EVs)have garnered significant attention as a vital driver of economic growth and environmental sustainability.Nevertheless,ensuring the safety of high-energy batteries is now a top priority that cannot be overlooked during large-scale applications.This paper proposes an innovative active protection and cooling integrated battery module using smart materials,magneto-sensitive shear thickening fluid(MSTF),which is specifically designed to address safety threats posed by lithium-ion batteries(LIBs)exposed to harsh mechanical and environmental conditions.The theoretical framework introduces a novel approach for harnessing the smoothed-particle hydrodynamics(SPH)methodology that incorporates the intricate interplay of non-Newtonian fluid behavior,capturing the fluid-structure coupling inherent to the MSTF.This approach is further advanced by adopting an enhanced Herschel-Bulkley(H-B)model to encapsulate the intricate rheology of the MSTF under the influence of the magnetorheological effect(MRE)and shear thickening(ST)behavior.Numerical simulation results show that in the case of cooling,the MSTF is an effective cooling medium for rapidly reducing the temperature.In terms of mechanical abuse,the MSTF solidifies through actively applying the magnetic field during mechanical compression and impact within the battery module,resulting in 66%and 61.7%reductions in the maximum stress within the battery jellyroll,and 31.1%and 23%reductions in the reaction force,respectively.This mechanism effectively lowers the risk of short-circuit failure.The groundbreaking concepts unveiled in this paper for active protection battery modules are anticipated to be a valuable technological breakthrough in the areas of EV safety and lightweight/integrated design.展开更多
From the perspective of a community energy operator,a two-stage optimal scheduling model of a community integrated energy system is proposed by integrating information on controllable loads.The day-ahead scheduling an...From the perspective of a community energy operator,a two-stage optimal scheduling model of a community integrated energy system is proposed by integrating information on controllable loads.The day-ahead scheduling analyzes whether various controllable loads participate in the optimization and investigates the impact of their responses on the operating economy of the community integrated energy system(IES)before and after;the intra-day scheduling proposes a two-stage rolling optimization model based on the day-ahead scheduling scheme,taking into account the fluctuation of wind turbine output and load within a short period of time and according to the different response rates of heat and cooling power,and solves the adjusted output of each controllable device.The simulation results show that the optimal scheduling of controllable loads effectively reduces the comprehensive operating costs of community IES;the two-stage optimal scheduling model can meet the energy demand of customers while effectively and timely suppressing the random fluctuations on both sides of the source and load during the intra-day stage,realizing the economic and smooth operation of IES.展开更多
Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the ...Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the operating costs of the power system.This paper proposes a two-stage planning method for distributed generation and energy storage systems that considers the hierarchical partitioning of source-storage-load.Firstly,an electrical distance structural index that comprehensively considers active power output and reactive power output is proposed to divide the distributed generation voltage regulation domain and determine the access location and number of distributed power sources.Secondly,a two-stage planning is carried out based on the zoning results.In the phase 1 distribution network-zoning optimization layer,the network loss is minimized so that the node voltage in the area does not exceed the limit,and the distributed generation configuration results are initially determined;in phase 2,the partition-node optimization layer is planned with the goal of economic optimization,and the distance-based improved ant lion algorithm is used to solve the problem to obtain the optimal distributed generation and energy storage systemconfiguration.Finally,the IEEE33 node systemwas used for simulation.The results showed that the voltage quality was significantly improved after optimization,and the overall revenue increased by about 20.6%,verifying the effectiveness of the two-stage planning.展开更多
Rapeseed(Brassica napus L.)harvesting method is critical since it significantly determines the seed yield,oil quality,and industrial efficiency.This study investigated the influences of harvesting methods on the quali...Rapeseed(Brassica napus L.)harvesting method is critical since it significantly determines the seed yield,oil quality,and industrial efficiency.This study investigated the influences of harvesting methods on the quality of cold-pressed rapeseed oil of two varieties.Oil color,peroxide value(POV),tocopherol content,fatty acid composition,and polarity of total polyphenols(PTP)contents of two rapeseed varieties in Huanggang and Xiangyang were compared through artificially simulated combined harvesting and two-stage harvesting.Results showed significant differences in the quality of rapeseed oil between the two harvesting methods.The red value(R-value),POV,total tocopherol contents,linoleic and linolenic acid content,and PTP content of the pressed rapeseed oil prepared by the combined harvesting method were about 27.6,5.7,15.8,2.0,0.5,and 28.6%lower than those of the oil produced from the two-stage harvesting method,respectively.Xiangyang and Huayouza62 performed better in the two regions and two varieties,respectively.To sum up,the rapeseed oil obtained 41–44 days after final flowering of combined harvesting,35 days after final flowering,and six days of post-ripening of the two-stage harvesting had the best quality.展开更多
Water-locking flocs formed by ultrafine tailings particles will damage the thickener underflow concentration in the thickening process during paste preparation.The relationship between the mesostructure and seepage ch...Water-locking flocs formed by ultrafine tailings particles will damage the thickener underflow concentration in the thickening process during paste preparation.The relationship between the mesostructure and seepage characteristics of tail mortar is typically ignored when investigating the deep dehydration stage.A shearing seepage test of an unclassified tailing-sedimentation bed was performed with copper tailings,and the morphology and geometric distribution of micropores were analyzed via X-ray computed tomography.Moreover,the shearing evolution of the micropore structure and seepage channel was investigated to evaluate the dewatering performance of underflow slurry using a three-dimensional reconstruction approach.The results show that porosity decreases considerably under shearing.The connected-pore ratio and the average radius of the throat channel reach peak values of 0.79 and 31.38μm,respectively,when shearing is applied for 10 min.However,the reverse seepage velocity and absolute permeability in the bed decrease to various extents after shearing.Meanwhile,the maximum flow rate reaches 1.537μm/s and the absolute permeability increases by 14.16%.Shearing alters the formation process and the pore structure of the seepage channel.Isolated pores connect to the surrounding flocs to form branch channels,which then become the main seepage channel and create the dominant water-seepage flow channel.展开更多
Tourism route planning is widely applied in the smart tourism field.The Pareto-optimal front obtained by the traditional multi-objective evolutionary algorithm exhibits long tails,sharp peaks and disconnected regions ...Tourism route planning is widely applied in the smart tourism field.The Pareto-optimal front obtained by the traditional multi-objective evolutionary algorithm exhibits long tails,sharp peaks and disconnected regions problems,which leads to uneven distribution and weak diversity of optimization solutions of tourism routes.Inspired by these limitations,we propose a multi-objective evolutionary algorithm for tourism route recommendation(MOTRR)with two-stage and Pareto layering based on decomposition.The method decomposes the multiobjective problem into several subproblems,and improves the distribution of solutions through a two-stage method.The crowding degree mechanism between extreme and intermediate populations is used in the two-stage method.The neighborhood is determined according to the weight of the subproblem for crossover mutation.Finally,Pareto layering is used to improve the updating efficiency and population diversity of the solution.The two-stage method is combined with the Pareto layering structure,which not only maintains the distribution and diversity of the algorithm,but also avoids the same solutions.Compared with several classical benchmark algorithms,the experimental results demonstrate competitive advantages on five test functions,hypervolume(HV)and inverted generational distance(IGD)metrics.Using the experimental results of real scenic spot datasets from two famous tourism social networking sites with vast amounts of users and large-scale online comments in Beijing,our proposed algorithm shows better distribution.It proves that the tourism routes recommended by our proposed algorithm have better distribution and diversity,so that the recommended routes can better meet the personalized needs of tourists.展开更多
After suffering from a grid blackout, distributed energy resources(DERs), such as local renewable energy and controllable distributed generators and energy storage can be used to restore loads enhancing the system’s ...After suffering from a grid blackout, distributed energy resources(DERs), such as local renewable energy and controllable distributed generators and energy storage can be used to restore loads enhancing the system’s resilience. In this study, a multi-source coordinated load restoration strategy was investigated for a distribution network with soft open points(SOPs). Here, the flexible regulation ability of the SOPs is fully utilized to improve the load restoration level while mitigating voltage deviations. Owing to the uncertainty, a scenario-based stochastic optimization approach was employed,and the load restoration problem was formulated as a mixed-integer nonlinear programming model. A computationally efficient solution algorithm was developed for the model using convex relaxation and linearization methods. The algorithm is organized into a two-stage structure, in which the energy storage system is dispatched in the first stage by solving a relaxed convex problem. In the second stage, an integer programming problem is calculated to acquire the outputs of both SOPs and power resources. A numerical test was conducted on both IEEE 33-bus and IEEE 123-bus systems to validate the effectiveness of the proposed strategy.展开更多
Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficient...Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficiently diagnosing and treating PJI is challenging,as there is still no gold standard method to reach the diagnosis as early as desired.There are also international controversies with respect to the best approach to manage PJI cases.In this review,we highlight recent advances in managing PJI following knee arthroplasty surgery and discuss in depth the two-stage revision method.展开更多
Cemented paste backfill(CPB)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPB technology.However,difficult flocculation and substandard concentrations o...Cemented paste backfill(CPB)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPB technology.However,difficult flocculation and substandard concentrations of thickened tailings often occur.The rheological properties and concentration evolution in the thickened tailings remain unclear.Moreover,traditional indoor thickening experiments have yet to quantitatively characterize their rheological properties.An experiment of flocculation condition optimization based on the Box-Behnken design(BBD)was performed in the study,and the two response values were investigated:concentration and the mean weighted chord length(MWCL)of flocs.Thus,optimal flocculation conditions were obtained.In addition,the rheological properties and concentration evolution of different flocculant dosages and ultrafine tailing contents under shear,compression,and compression-shear coupling experimental conditions were tested and compared.The results show that the shear yield stress under compression and compression-shear coupling increases with the growth of compressive yield stress,while the shear yield stress increases slightly under shear.The order of shear yield stress from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Under compression and compression-shear coupling,the concentration first rapidly increases with the growth of compressive yield stress and then slowly increases,while concentration increases slightly under shear.The order of concentration from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Finally,the evolution mechanism of the flocs and drainage channels during the thickening of the thickened tailings under different experimental conditions was revealed.展开更多
Objective:To systematically evaluate the endometrial thickening and Chinese herbal medicine intervention effects during endocrine therapy following breast cancer surgery.Methods:Computerized searches were performed on...Objective:To systematically evaluate the endometrial thickening and Chinese herbal medicine intervention effects during endocrine therapy following breast cancer surgery.Methods:Computerized searches were performed on CNKI,CBM,Wanfang,VIP,Pub Med,Embase,and Cochrane to gather randomized controlled trials(RCTs)of endometrial thickening combined with Chinese herbal medicine intervention during endocrine therapy after breast cancer surgery.The meta analysis is done using Rev Man 5.4,and the retrieval range is from the database's creation to January 2023.Results:There were 710 patients enrolled in a total of 12 RCTs.The results of Meta-analysis were as follows:combined with Chinese herbal medicine treatment for 3 months of endometrial thickness(MD=-1.12,95%CI[-1.47,0.77],P<0.00001);6 months endometrial thickness(MD=-1.90,95%CI[-2.38,-1.42],P<0.00001);endometrial thickness at 12 months(MD=-2.24,95%CI[-2.96,-1.52],P<0.00001);modified Kupperman score(MD=-10.45,95%CI[-19.10,-1.80],P=0.02);TCM syndrome score(SMD=-1.53,95%CI[-1.84,-1.22],P<0.00001);KPS score(MD=3.75,95%CI[2.81,4.68],P<0.00001);there was no significant difference in CA153,CEA,FSH and E2 between the two groups.Conclusion:After breast cancer surgery,endocrine therapy combined with Chinese herbal medicine can significantly lessen endometrial thickening and enhance patient quality of life.展开更多
Limb length discrepancy(LLD)is a common orthopedic condition that can result in significant functional impairment,pain,and cosmetic deformities.Current reconstructive techniques for severe LLD are primarily based on c...Limb length discrepancy(LLD)is a common orthopedic condition that can result in significant functional impairment,pain,and cosmetic deformities.Current reconstructive techniques for severe LLD are primarily based on callus distraction,which is a time-consuming process that can lead to complications,such as significant infection,joint stiffness,and stress fractures.To reduce the therapeutic time and minimize the risk of complications,we investigated the use of vascularized bone flaps as a technical supplement to callus distraction in the reconstruction of short limbs.We present two cases of severe LLD in the upper and lower legs,in which a twostage reconstruction approach was used.In the first stage,external fixation was applied to the affected limb to correct the soft tissue length and convert the short deformity into a bone defect.In the second stage,the bone defect was reconstructed using bilateral(patient A)or unilateral(patient B)free vascularized fibula bone grafts.Both patients had complete survival of the fibular grafts without stress fractures,and bone consolidation took 8 months(patient A)and 4 months(patient B).Compared to the traditional callus distraction,the two-stage approach was found to be more time-saving and reliable.The entire reconstructive scheme required 18 and 4 months for patients A and B,respectively,whereas the traditional callus distraction required 41 and 17 months,respectively.These findings suggest that the use of vascularized bone flaps as a technical supplement for callus distraction may provide an effective and efficient alternative for the treatment of severe LLD.Further studies are needed to validate these results and assess the long-term outcomes of this approach.展开更多
In order to improve the rejection capability of mismatched interferer signals,a new two-stage detector is proposed under homogeneous scenarios with unknown covariance matrix,which is obtained by cascading the adaptive...In order to improve the rejection capability of mismatched interferer signals,a new two-stage detector is proposed under homogeneous scenarios with unknown covariance matrix,which is obtained by cascading the adaptive matched filter(AMF)detector and the enhanced RAO(EnRAO)detector.The new detector has constant false alarm performance,and the closed-form expression of probability of false alarm and probability of detection is derived.The performance of the new detector is assessed,and analyzed in comparison with other detectors.The results show that,the proposed detector can provide enhanced rejection capability in the case of mismatch,but the performance of the detector is slightly lost under the condition of matching.展开更多
Water spewing and muck plugging often occur during earth pressure balance(EPB)shield machines tunnelling in water-rich sandy strata,even though the conventional foam has been employed to condition sandy soils.In this ...Water spewing and muck plugging often occur during earth pressure balance(EPB)shield machines tunnelling in water-rich sandy strata,even though the conventional foam has been employed to condition sandy soils.In this study,a novel thickened foaming agent suitable for EPB shield tunnelling in water-rich sandy strata is developed.In contrast to conventional foam-conditioned sands,the thickened foam-conditioned sand has a low permeability due to the consistent filling of soil pores with the thickened foam,and the initial permeability coefficient decreases by approximately two orders of magnitude.It also exhibits a suitable workability,which is attributed to the enhanced capability of the thickened foam to condition sandy soils.In addition,the effect of concentration on the stability of the foam is explained by the Gibbs-Marangoni effect,and conditioning mechanisms for the thickened foam on sands are discussed from the evolution of foam bubbles.展开更多
Shear thickening fluids (STFs) based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol (PE...Shear thickening fluids (STFs) based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol (PEG) 400, where three types of additives with different molecular chain lengths of PEG4000, PEG6000, and PEG10000 were used. For PEG10000, different concentrations, including 0, 1%, 3%, and 5%, were selected to study the influences of additive concentrations. Rheological properties of the samples were measured with a rheometer. The results show that the shear thickening effect was significantly enhanced with the increase of the concentration and the molecular chain length of additives. The mechanism of enhancement was quantitatively explained with the formation of large particles clusters.展开更多
To address the problem that a general augmented state Kalman filter or a two-stage Kalman filter cannot achieve satisfactory positioning performance when facing uncertain noise of the micro-electro-mechanical system(...To address the problem that a general augmented state Kalman filter or a two-stage Kalman filter cannot achieve satisfactory positioning performance when facing uncertain noise of the micro-electro-mechanical system(MEMS) inertial sensors, a novel interacting multiple model-based two-stage Kalman filter(IMM-TSKF) is proposed to adapt to the uncertain inertial sensor noise. Three bias filters are developed based on different noise characteristics to cover a wide range of noise levels. Then, an accurate estimation of biases is calculated by the interacting multiple model algorithm to correct the bias-free filter. Thus, the vehicle positioning system can achieve good performance when suffering from uncertain inertial sensor noise. The experimental results indicate that the average position error of the proposed IMMTSKF is 25% lower than that of the general TSKF.展开更多
NiSAPO-34 and NiSAPO-34/HZSM-5 were prepared and evaluated for the performance of dimethyl ether (DME) conversion to light olefins (DTO). The processes of two-stage light olefin production, DME synthesis and the f...NiSAPO-34 and NiSAPO-34/HZSM-5 were prepared and evaluated for the performance of dimethyl ether (DME) conversion to light olefins (DTO). The processes of two-stage light olefin production, DME synthesis and the following DTO, were also investigated using biosyngas as feed gas over Cu/Zn/A1/HZSM-5 and the optimized 2%NiSAPO-34/HZSM- 5. The results indicated that adding 2%Ni to SAPO-34 did not change its topology structure, but resulted in the forming of the moderately strong acidity with decreasing acid amounts, which slightly enhanced DME conversion activity and C2=-C3= selectiw ity. Mechanically mixing 2%NiSAPO-34 with HZSM-5 at the weight ratio of 3.0 further prolonged DME conversion activity to be more than 3 h, which was due to the stable acid sites from HZSM-5. The highest selectivity to light olefins of 90.8% was achieved at 2 h time on stream. The application of the optimized 2%NiSAPO-34/HZSM-5 in the second-stage reactor for DTO reaction showed that the catalytic activity was steady for more than 5 h and light olefin yield was as high as 84.6 g/m3syngas when the biosyngas (H2/CO/CO2/N2/CH4=41.5/26.9/14.2/14.6/2.89, vol%) with low H/C ratio of 1.0 was used as feed gas.展开更多
The present experimental study investigates shock wave mitigation capability of potentially new personal protective equipment(PPE) suspension pads made from polyurea and shear thickening fluid(STF).The shock tube test...The present experimental study investigates shock wave mitigation capability of potentially new personal protective equipment(PPE) suspension pads made from polyurea and shear thickening fluid(STF).The shock tube test results show that when placed behind Twaron fabric systems with thickness ranging from 2 mm to 18 mm, the replacement of conventional flexible foam pad with STF and STF-infused foam pads with the same thickness of 20 mm greatly reduces the normalized peak pressure(by about 72% for each pad). However, this benefit is partially offset by a large increase in the normalized impulse(by about78% for the STF pad and 131% for the STF-infused foam pad) which may cause the shock wave mitigation performance of these two pads to become less effective. Interestingly, the use of 4 mm thick polyurea pad can greatly reduce the normalized peak pressure and impulse as well(by about 74% and 49%, respectively). These results reveal that among the potentially new suspension pads tested, the polyurea pad displays the best shock wave mitigation performance. Therefore, polyurea has potential for use as a suspension pad in personal protective equipment requiring shock wave mitigation capability such as fabric ballistic vests, bomb suits and combat helmets.展开更多
基金supported by the National Natural Science Foundation of China (32170367 and 32000146)the Fundamental Research Funds for the Central Universities, China (2021TS066 and GK202103063)the Excellent Graduate Training Program of Shaanxi Normal University, China (LHRCCX23181).
文摘Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.
基金supported by the Basic Research and Strategic Reserve Technology Research Fund Project of China National Petroleum Corporation (Grant No.2021DQ03-14)the National Natu ral Science Foundation of China (Grant No.52204010)Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C)in order to provide a theoretical guidance for the rational application of silica fume in the cementing engineering.Results showed that silica fume seldom affected the thickening progression of oil well cement slurry at 110-120.C,but when temperature reached above130.C,it would aggravate the bulging degree of thickening curves and significantly extend the thickening time,meanwhile causing the abnormal“temperature-based thickening time reversal”and“dosage-based thickening time reversal”phenomena in the range of 130-160.C and 170-180.C respectively.At 130-160.C,the thickening time of oil well cement slurry was mainly associated with the generation rate of calcium hydroxide(CH)crystal.The introduced silica fume would be attracted to the cement minerals'surface that were hydrating to produce CH and agglomerate together to form an“adsorptive barrier”to hinder further hydration of the inner cement minerals.This“adsorptive barrier”effect strengthened with the rising temperature which extended the thickening time and caused the occurrence of the“temperature-based thickening time reversal”phenomenon.At 170-180.C,the pozzolanic activity of silica fume significantly enhanced and considerable amount of C-S-H was generated,thus the“temperature-based thickening time reversal”vanished and the“dosage-based thickening time reversal”was presented.
基金Project supported by the National Natural Science Foundation of China(Nos.12072183 and11872236)the Key Research Project of Zhejiang Laboratory(No.2021PE0AC02)。
文摘Electric vehicles(EVs)have garnered significant attention as a vital driver of economic growth and environmental sustainability.Nevertheless,ensuring the safety of high-energy batteries is now a top priority that cannot be overlooked during large-scale applications.This paper proposes an innovative active protection and cooling integrated battery module using smart materials,magneto-sensitive shear thickening fluid(MSTF),which is specifically designed to address safety threats posed by lithium-ion batteries(LIBs)exposed to harsh mechanical and environmental conditions.The theoretical framework introduces a novel approach for harnessing the smoothed-particle hydrodynamics(SPH)methodology that incorporates the intricate interplay of non-Newtonian fluid behavior,capturing the fluid-structure coupling inherent to the MSTF.This approach is further advanced by adopting an enhanced Herschel-Bulkley(H-B)model to encapsulate the intricate rheology of the MSTF under the influence of the magnetorheological effect(MRE)and shear thickening(ST)behavior.Numerical simulation results show that in the case of cooling,the MSTF is an effective cooling medium for rapidly reducing the temperature.In terms of mechanical abuse,the MSTF solidifies through actively applying the magnetic field during mechanical compression and impact within the battery module,resulting in 66%and 61.7%reductions in the maximum stress within the battery jellyroll,and 31.1%and 23%reductions in the reaction force,respectively.This mechanism effectively lowers the risk of short-circuit failure.The groundbreaking concepts unveiled in this paper for active protection battery modules are anticipated to be a valuable technological breakthrough in the areas of EV safety and lightweight/integrated design.
基金supported in part by the National Natural Science Foundation of China(51977127)Shanghai Municipal Science and Technology Commission(19020500800)“Shuguang Program”(20SG52)Shanghai Education Development Foundation and Shanghai Municipal Education Commission.
文摘From the perspective of a community energy operator,a two-stage optimal scheduling model of a community integrated energy system is proposed by integrating information on controllable loads.The day-ahead scheduling analyzes whether various controllable loads participate in the optimization and investigates the impact of their responses on the operating economy of the community integrated energy system(IES)before and after;the intra-day scheduling proposes a two-stage rolling optimization model based on the day-ahead scheduling scheme,taking into account the fluctuation of wind turbine output and load within a short period of time and according to the different response rates of heat and cooling power,and solves the adjusted output of each controllable device.The simulation results show that the optimal scheduling of controllable loads effectively reduces the comprehensive operating costs of community IES;the two-stage optimal scheduling model can meet the energy demand of customers while effectively and timely suppressing the random fluctuations on both sides of the source and load during the intra-day stage,realizing the economic and smooth operation of IES.
基金supported by North China Electric Power Research Institute’s Self-Funded Science and Technology Project“Research on Distributed Energy Storage Optimal Configuration and Operation Control Technology for Photovoltaic Promotion in the Entire County”(KJZ2022049).
文摘Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the operating costs of the power system.This paper proposes a two-stage planning method for distributed generation and energy storage systems that considers the hierarchical partitioning of source-storage-load.Firstly,an electrical distance structural index that comprehensively considers active power output and reactive power output is proposed to divide the distributed generation voltage regulation domain and determine the access location and number of distributed power sources.Secondly,a two-stage planning is carried out based on the zoning results.In the phase 1 distribution network-zoning optimization layer,the network loss is minimized so that the node voltage in the area does not exceed the limit,and the distributed generation configuration results are initially determined;in phase 2,the partition-node optimization layer is planned with the goal of economic optimization,and the distance-based improved ant lion algorithm is used to solve the problem to obtain the optimal distributed generation and energy storage systemconfiguration.Finally,the IEEE33 node systemwas used for simulation.The results showed that the voltage quality was significantly improved after optimization,and the overall revenue increased by about 20.6%,verifying the effectiveness of the two-stage planning.
基金supported by the National Key R&D Program of China(2021YFD1600502).
文摘Rapeseed(Brassica napus L.)harvesting method is critical since it significantly determines the seed yield,oil quality,and industrial efficiency.This study investigated the influences of harvesting methods on the quality of cold-pressed rapeseed oil of two varieties.Oil color,peroxide value(POV),tocopherol content,fatty acid composition,and polarity of total polyphenols(PTP)contents of two rapeseed varieties in Huanggang and Xiangyang were compared through artificially simulated combined harvesting and two-stage harvesting.Results showed significant differences in the quality of rapeseed oil between the two harvesting methods.The red value(R-value),POV,total tocopherol contents,linoleic and linolenic acid content,and PTP content of the pressed rapeseed oil prepared by the combined harvesting method were about 27.6,5.7,15.8,2.0,0.5,and 28.6%lower than those of the oil produced from the two-stage harvesting method,respectively.Xiangyang and Huayouza62 performed better in the two regions and two varieties,respectively.To sum up,the rapeseed oil obtained 41–44 days after final flowering of combined harvesting,35 days after final flowering,and six days of post-ripening of the two-stage harvesting had the best quality.
基金supported by the National Natural Science Foundation of China (No.51834001)。
文摘Water-locking flocs formed by ultrafine tailings particles will damage the thickener underflow concentration in the thickening process during paste preparation.The relationship between the mesostructure and seepage characteristics of tail mortar is typically ignored when investigating the deep dehydration stage.A shearing seepage test of an unclassified tailing-sedimentation bed was performed with copper tailings,and the morphology and geometric distribution of micropores were analyzed via X-ray computed tomography.Moreover,the shearing evolution of the micropore structure and seepage channel was investigated to evaluate the dewatering performance of underflow slurry using a three-dimensional reconstruction approach.The results show that porosity decreases considerably under shearing.The connected-pore ratio and the average radius of the throat channel reach peak values of 0.79 and 31.38μm,respectively,when shearing is applied for 10 min.However,the reverse seepage velocity and absolute permeability in the bed decrease to various extents after shearing.Meanwhile,the maximum flow rate reaches 1.537μm/s and the absolute permeability increases by 14.16%.Shearing alters the formation process and the pore structure of the seepage channel.Isolated pores connect to the surrounding flocs to form branch channels,which then become the main seepage channel and create the dominant water-seepage flow channel.
基金partially supported by the National Natural Science Foundation of China(41930644,61972439)the Collaborative Innovation Project of Anhui Province(GXXT-2022-093)the Key Program in the Youth Elite Support Plan in Universities of Anhui Province(gxyqZD2019010)。
文摘Tourism route planning is widely applied in the smart tourism field.The Pareto-optimal front obtained by the traditional multi-objective evolutionary algorithm exhibits long tails,sharp peaks and disconnected regions problems,which leads to uneven distribution and weak diversity of optimization solutions of tourism routes.Inspired by these limitations,we propose a multi-objective evolutionary algorithm for tourism route recommendation(MOTRR)with two-stage and Pareto layering based on decomposition.The method decomposes the multiobjective problem into several subproblems,and improves the distribution of solutions through a two-stage method.The crowding degree mechanism between extreme and intermediate populations is used in the two-stage method.The neighborhood is determined according to the weight of the subproblem for crossover mutation.Finally,Pareto layering is used to improve the updating efficiency and population diversity of the solution.The two-stage method is combined with the Pareto layering structure,which not only maintains the distribution and diversity of the algorithm,but also avoids the same solutions.Compared with several classical benchmark algorithms,the experimental results demonstrate competitive advantages on five test functions,hypervolume(HV)and inverted generational distance(IGD)metrics.Using the experimental results of real scenic spot datasets from two famous tourism social networking sites with vast amounts of users and large-scale online comments in Beijing,our proposed algorithm shows better distribution.It proves that the tourism routes recommended by our proposed algorithm have better distribution and diversity,so that the recommended routes can better meet the personalized needs of tourists.
基金supported by the State Grid Tianjin Electric Power Company Science and Technology Project (Grant No. KJ22-1-45)。
文摘After suffering from a grid blackout, distributed energy resources(DERs), such as local renewable energy and controllable distributed generators and energy storage can be used to restore loads enhancing the system’s resilience. In this study, a multi-source coordinated load restoration strategy was investigated for a distribution network with soft open points(SOPs). Here, the flexible regulation ability of the SOPs is fully utilized to improve the load restoration level while mitigating voltage deviations. Owing to the uncertainty, a scenario-based stochastic optimization approach was employed,and the load restoration problem was formulated as a mixed-integer nonlinear programming model. A computationally efficient solution algorithm was developed for the model using convex relaxation and linearization methods. The algorithm is organized into a two-stage structure, in which the energy storage system is dispatched in the first stage by solving a relaxed convex problem. In the second stage, an integer programming problem is calculated to acquire the outputs of both SOPs and power resources. A numerical test was conducted on both IEEE 33-bus and IEEE 123-bus systems to validate the effectiveness of the proposed strategy.
文摘Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficiently diagnosing and treating PJI is challenging,as there is still no gold standard method to reach the diagnosis as early as desired.There are also international controversies with respect to the best approach to manage PJI cases.In this review,we highlight recent advances in managing PJI following knee arthroplasty surgery and discuss in depth the two-stage revision method.
基金financially supported by the National Natural Science Foundation of China(Nos.52130404 and 52304121)the Fundamental Research Funds for the Central Universities(No.FRF-TP-22-112A1)+4 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A 1515110161)the ANID(Chile)through Fondecyt project 1210610the Centro de Modelamiento Matemático(BASAL funds for Centers of Excellence FB210005)the CRHIAM project ANID/FONDAP/15130015 and ANID/FONDAP/1523A0001the Anillo project ANID/ACT210030。
文摘Cemented paste backfill(CPB)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPB technology.However,difficult flocculation and substandard concentrations of thickened tailings often occur.The rheological properties and concentration evolution in the thickened tailings remain unclear.Moreover,traditional indoor thickening experiments have yet to quantitatively characterize their rheological properties.An experiment of flocculation condition optimization based on the Box-Behnken design(BBD)was performed in the study,and the two response values were investigated:concentration and the mean weighted chord length(MWCL)of flocs.Thus,optimal flocculation conditions were obtained.In addition,the rheological properties and concentration evolution of different flocculant dosages and ultrafine tailing contents under shear,compression,and compression-shear coupling experimental conditions were tested and compared.The results show that the shear yield stress under compression and compression-shear coupling increases with the growth of compressive yield stress,while the shear yield stress increases slightly under shear.The order of shear yield stress from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Under compression and compression-shear coupling,the concentration first rapidly increases with the growth of compressive yield stress and then slowly increases,while concentration increases slightly under shear.The order of concentration from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Finally,the evolution mechanism of the flocs and drainage channels during the thickening of the thickened tailings under different experimental conditions was revealed.
基金State Administration of Traditional Chinese Medicine(No.ZyzB-2022-798)National Natural Science Foundation of China(No.82205222)Special Research Project of Beijing Municipal Health Commission on Capital Health Development(No.First edition 2022-4-2234)。
文摘Objective:To systematically evaluate the endometrial thickening and Chinese herbal medicine intervention effects during endocrine therapy following breast cancer surgery.Methods:Computerized searches were performed on CNKI,CBM,Wanfang,VIP,Pub Med,Embase,and Cochrane to gather randomized controlled trials(RCTs)of endometrial thickening combined with Chinese herbal medicine intervention during endocrine therapy after breast cancer surgery.The meta analysis is done using Rev Man 5.4,and the retrieval range is from the database's creation to January 2023.Results:There were 710 patients enrolled in a total of 12 RCTs.The results of Meta-analysis were as follows:combined with Chinese herbal medicine treatment for 3 months of endometrial thickness(MD=-1.12,95%CI[-1.47,0.77],P<0.00001);6 months endometrial thickness(MD=-1.90,95%CI[-2.38,-1.42],P<0.00001);endometrial thickness at 12 months(MD=-2.24,95%CI[-2.96,-1.52],P<0.00001);modified Kupperman score(MD=-10.45,95%CI[-19.10,-1.80],P=0.02);TCM syndrome score(SMD=-1.53,95%CI[-1.84,-1.22],P<0.00001);KPS score(MD=3.75,95%CI[2.81,4.68],P<0.00001);there was no significant difference in CA153,CEA,FSH and E2 between the two groups.Conclusion:After breast cancer surgery,endocrine therapy combined with Chinese herbal medicine can significantly lessen endometrial thickening and enhance patient quality of life.
基金supported by the National Nature Science Foundation(grant nos.81871577 and 81971864)。
文摘Limb length discrepancy(LLD)is a common orthopedic condition that can result in significant functional impairment,pain,and cosmetic deformities.Current reconstructive techniques for severe LLD are primarily based on callus distraction,which is a time-consuming process that can lead to complications,such as significant infection,joint stiffness,and stress fractures.To reduce the therapeutic time and minimize the risk of complications,we investigated the use of vascularized bone flaps as a technical supplement to callus distraction in the reconstruction of short limbs.We present two cases of severe LLD in the upper and lower legs,in which a twostage reconstruction approach was used.In the first stage,external fixation was applied to the affected limb to correct the soft tissue length and convert the short deformity into a bone defect.In the second stage,the bone defect was reconstructed using bilateral(patient A)or unilateral(patient B)free vascularized fibula bone grafts.Both patients had complete survival of the fibular grafts without stress fractures,and bone consolidation took 8 months(patient A)and 4 months(patient B).Compared to the traditional callus distraction,the two-stage approach was found to be more time-saving and reliable.The entire reconstructive scheme required 18 and 4 months for patients A and B,respectively,whereas the traditional callus distraction required 41 and 17 months,respectively.These findings suggest that the use of vascularized bone flaps as a technical supplement for callus distraction may provide an effective and efficient alternative for the treatment of severe LLD.Further studies are needed to validate these results and assess the long-term outcomes of this approach.
基金supported by the National Natural Science Foundation of China(No.61971412).
文摘In order to improve the rejection capability of mismatched interferer signals,a new two-stage detector is proposed under homogeneous scenarios with unknown covariance matrix,which is obtained by cascading the adaptive matched filter(AMF)detector and the enhanced RAO(EnRAO)detector.The new detector has constant false alarm performance,and the closed-form expression of probability of false alarm and probability of detection is derived.The performance of the new detector is assessed,and analyzed in comparison with other detectors.The results show that,the proposed detector can provide enhanced rejection capability in the case of mismatch,but the performance of the detector is slightly lost under the condition of matching.
基金The financial support from the National Natural Science Foundation of China(Grant No.52022112)the Fundamental Research Funds for the Central South University(Grant No.2023ZZTS0366)are acknowledged and appreciated.The authors are also grateful for the help from Dr.Ji Zhao of China University of Mining and Technology.
文摘Water spewing and muck plugging often occur during earth pressure balance(EPB)shield machines tunnelling in water-rich sandy strata,even though the conventional foam has been employed to condition sandy soils.In this study,a novel thickened foaming agent suitable for EPB shield tunnelling in water-rich sandy strata is developed.In contrast to conventional foam-conditioned sands,the thickened foam-conditioned sand has a low permeability due to the consistent filling of soil pores with the thickened foam,and the initial permeability coefficient decreases by approximately two orders of magnitude.It also exhibits a suitable workability,which is attributed to the enhanced capability of the thickened foam to condition sandy soils.In addition,the effect of concentration on the stability of the foam is explained by the Gibbs-Marangoni effect,and conditioning mechanisms for the thickened foam on sands are discussed from the evolution of foam bubbles.
文摘Shear thickening fluids (STFs) based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol (PEG) 400, where three types of additives with different molecular chain lengths of PEG4000, PEG6000, and PEG10000 were used. For PEG10000, different concentrations, including 0, 1%, 3%, and 5%, were selected to study the influences of additive concentrations. Rheological properties of the samples were measured with a rheometer. The results show that the shear thickening effect was significantly enhanced with the increase of the concentration and the molecular chain length of additives. The mechanism of enhancement was quantitatively explained with the formation of large particles clusters.
基金The National Natural Science Foundation of China(No.61273236)the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1637),China Scholarship Council
文摘To address the problem that a general augmented state Kalman filter or a two-stage Kalman filter cannot achieve satisfactory positioning performance when facing uncertain noise of the micro-electro-mechanical system(MEMS) inertial sensors, a novel interacting multiple model-based two-stage Kalman filter(IMM-TSKF) is proposed to adapt to the uncertain inertial sensor noise. Three bias filters are developed based on different noise characteristics to cover a wide range of noise levels. Then, an accurate estimation of biases is calculated by the interacting multiple model algorithm to correct the bias-free filter. Thus, the vehicle positioning system can achieve good performance when suffering from uncertain inertial sensor noise. The experimental results indicate that the average position error of the proposed IMMTSKF is 25% lower than that of the general TSKF.
基金ACKNOWLEDGM ENTS This work was supported by the National Natural Science Foundation of China (No.51006110, No.51276183, and No.51036006), the National Natural Research Foundation of China/Japan Science and Technology Agency (No.51161140331), and National Key Basic Research Program 973 Project Founded by MOST of China (No.2013CB228105).
文摘NiSAPO-34 and NiSAPO-34/HZSM-5 were prepared and evaluated for the performance of dimethyl ether (DME) conversion to light olefins (DTO). The processes of two-stage light olefin production, DME synthesis and the following DTO, were also investigated using biosyngas as feed gas over Cu/Zn/A1/HZSM-5 and the optimized 2%NiSAPO-34/HZSM- 5. The results indicated that adding 2%Ni to SAPO-34 did not change its topology structure, but resulted in the forming of the moderately strong acidity with decreasing acid amounts, which slightly enhanced DME conversion activity and C2=-C3= selectiw ity. Mechanically mixing 2%NiSAPO-34 with HZSM-5 at the weight ratio of 3.0 further prolonged DME conversion activity to be more than 3 h, which was due to the stable acid sites from HZSM-5. The highest selectivity to light olefins of 90.8% was achieved at 2 h time on stream. The application of the optimized 2%NiSAPO-34/HZSM-5 in the second-stage reactor for DTO reaction showed that the catalytic activity was steady for more than 5 h and light olefin yield was as high as 84.6 g/m3syngas when the biosyngas (H2/CO/CO2/N2/CH4=41.5/26.9/14.2/14.6/2.89, vol%) with low H/C ratio of 1.0 was used as feed gas.
基金supported by the Ministry of Education,Singapore(R265000533112)
文摘The present experimental study investigates shock wave mitigation capability of potentially new personal protective equipment(PPE) suspension pads made from polyurea and shear thickening fluid(STF).The shock tube test results show that when placed behind Twaron fabric systems with thickness ranging from 2 mm to 18 mm, the replacement of conventional flexible foam pad with STF and STF-infused foam pads with the same thickness of 20 mm greatly reduces the normalized peak pressure(by about 72% for each pad). However, this benefit is partially offset by a large increase in the normalized impulse(by about78% for the STF pad and 131% for the STF-infused foam pad) which may cause the shock wave mitigation performance of these two pads to become less effective. Interestingly, the use of 4 mm thick polyurea pad can greatly reduce the normalized peak pressure and impulse as well(by about 74% and 49%, respectively). These results reveal that among the potentially new suspension pads tested, the polyurea pad displays the best shock wave mitigation performance. Therefore, polyurea has potential for use as a suspension pad in personal protective equipment requiring shock wave mitigation capability such as fabric ballistic vests, bomb suits and combat helmets.