EBC连接器是5G板对板和板对模块的射频互连元件,通过SMT (Surface Mount Technology)工艺与PCB板焊接连通。由于EBC连接器在SMT之后,出现锡珠、空洞、位置偏移、爬锡高度不良等缺陷,影响天线的波频信号,甚至影响整个产品的可靠性。将介...EBC连接器是5G板对板和板对模块的射频互连元件,通过SMT (Surface Mount Technology)工艺与PCB板焊接连通。由于EBC连接器在SMT之后,出现锡珠、空洞、位置偏移、爬锡高度不良等缺陷,影响天线的波频信号,甚至影响整个产品的可靠性。将介绍基于DOE (Design of Experiments)方法,分析EBC连接器SMT工艺过程中,焊锡不良缺陷特征、规律,导致不良缺陷产生的可能原因;结合所有工序中,设备、工装夹具、物料、工艺参数,确定关键因子,排除非关键因子。通过Minitab软件,在DOE中创建因子,依据设计试验表序列,安排试验。采用响应曲面方法来分析响应变量“不良缺陷率”依赖于自变量因子,找到自变量因子的设置在望目0.5时,在响应曲面设计的响应优化器可得到,降低与解决SMT不良缺陷率最优试验区域:钢网开孔方式“梅花开孔”,锡粉型号TYPE3,回流曲线升温斜率1.166 7℃/s。基于DOE的接器SMT不良缺陷分析方法,可以系统地研究各种因素对不良缺陷的影响,找出关键因子并优化工艺条件。展开更多
由于风力输送导致烟丝造碎,造成烟丝整丝率难以提升的困难。为此,基于实验设计(Design of Experiment,DOE)研究了风力送丝系统整丝率优化,考虑了制丝车间叶丝风送系统的管道风量、管道压力、活门开度对烟丝整丝率的影响,采用单因素实验...由于风力输送导致烟丝造碎,造成烟丝整丝率难以提升的困难。为此,基于实验设计(Design of Experiment,DOE)研究了风力送丝系统整丝率优化,考虑了制丝车间叶丝风送系统的管道风量、管道压力、活门开度对烟丝整丝率的影响,采用单因素实验和DOE方法,并提出工艺参数优化方案。结果说明:单因素实验证明管道风量、管道压力、补风活门开度对烟丝整丝率均存在显著影响;将叶丝线风送系统的管道风量、管道压力和活门开度3个控制型因子进行DOE,得到最佳工艺参数组合为管道风量10353.5 m3/h、管道压力1 500 Pa、活门开度100%;该工艺参数下的烟丝整丝率从原78.5%上升为84.39%,与优化前相比提高了5.89%。在不增加设备改造硬件投资的前提下,采用合适的研究方法解决生产现场的实际问题,具有一定经济实用价值。展开更多
A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order t...A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order to reduce the use of chemical spices in the preparation of different dishes. The Design of Experiments (DOE) methodology was used for the formulation of the spices and their physicochemical, nutritional and sensory characteristics were evaluated by standardized and standard methods. The results obtained showed lipid contents (g/100 g DM) ranging from 10.41 ± 0.26 to 15.64 ± 0.68, total sugars from 4.39 ± 0.32 to 5.46 ± 0.31, protein from 3.65 ± 0.17 to 12.04 ± 0.35 and ash from 5.83 ± 0.01 to 7.02 ± 0.01. The polyphenol content ranged from 9.09 ± 1.60 to 11.33 ± 0.90, and the flavonoid content ranged from 0.65 ± 0.03 to 1.08 ± 0.13. The sensory analysis carried out showed that the spices have generally satisfactory organoleptic characteristics. These results constitute new information in the diet of populations and are an alternative to the chemical spices used in their cooking.展开更多
In this work,the selected icebreaker model experiment is performed in a towing tank.We focus on the influence of seawater salinity on ship ice resistance in the ice floe field and the innovative ice model and ship mod...In this work,the selected icebreaker model experiment is performed in a towing tank.We focus on the influence of seawater salinity on ship ice resistance in the ice floe field and the innovative ice model and ship model test technology,including the similitude rule of ship model tests,test principles,and validation with full-scale ship data.A formula for calculating the relationship between the temperature and salinity of the water is constructed,which can be used to simulate the role of seawater in freshwater ice pools.On this basis,the effect of salinity on the resistance of ships sailing in broken ice fields is studied.A technique in which artificial ice made of polyethylene spheres is used to simulate ice resistance is proposed.With a series of ship model experiments in spherical and triangular ice fields,the effects of salinity and velocity on the ice resistance test of the ship model are analyzed.A relationship of the ice resistance of the ship model to the spherical ice field and the triangular ice field is proposed.The conversion results are consistent with onsite data of the full-size ship,which verifies the method of converting the test results of the ship model to the prototype.展开更多
BACKGROUND Intra-articular hip injections(IAHIs)are commonly used for diagnostic and therapeutic purposes but are often associated with patient anxiety and fear.The disparity between anticipated and experienced pain d...BACKGROUND Intra-articular hip injections(IAHIs)are commonly used for diagnostic and therapeutic purposes but are often associated with patient anxiety and fear.The disparity between anticipated and experienced pain during IAHIs and the role of preinjection local anesthesia in pain modulation remains unclear.AIM To investigate the difference between anticipated and experienced pain during IAHIs and the impact of pre-injection local anesthesia.METHODS This prospective study enrolled 60 patients undergoing IAHI,30 receiving pre-injection superficial local anesthesia and 30 serving as a control group without pre-injection local anesthesia.Pain levels were assessed using numeric rating scales.RESULTS Patients significantly overestimated anticipated pain compared to experienced pain(6.43±2.48 vs 3.68±2.37,P<0.001).Pre-injection local anesthesia did not significantly reduce experienced pain(3.19±2.38 vs 4.20±2.29,P=0.130).CONCLUSION Patients overestimate anticipated pain during IAHIs.Pre-injection local anesthesia does not reduce experienced pain.展开更多
The integration of artificial intelligence (AI) with high-throughput experimentation (HTE) techniques is revolutionizing catalyst design, addressing challenges in efficiency, cost, and scalability. This review explore...The integration of artificial intelligence (AI) with high-throughput experimentation (HTE) techniques is revolutionizing catalyst design, addressing challenges in efficiency, cost, and scalability. This review explores the synergistic application of AI and HTE, highlighting their role in accelerating catalyst discovery, optimizing reaction parameters, and understanding structure-performance relationships. HTE facilitates the rapid preparation, characterization, and evaluation of diverse catalyst formulations, generating large datasets essential for AI model training. Machine learning algorithms, including regression models, neural networks, and active learning frameworks, analyze these datasets to uncover the underlying relationships between the data, predict performance, and optimize experimental workflows in real-time. Case studies across heterogeneous, homogeneous, and electrocatalysis demonstrate significant advancements, including improved reaction selectivity, enhanced material stability, and shorten discovery cycles. The integration of AI with HTE has significantly accelerated discovery cycles, enabling the optimization of catalyst formulations and reaction conditions. Despite these achievements, challenges remain, including reliance on researcher expertise, real-time adaptability, and the complexity of large-scale data analysis. Addressing these limitations through refined experimental protocols, standardized datasets, and interpretable AI models will unlock the full potential of AI-HTE integration.展开更多
The upper bound on the model error will be decreased when the mean square error and the maximum distance deviation are sufficiently small in the uniform designs for mixture experiments and the design is more robust fo...The upper bound on the model error will be decreased when the mean square error and the maximum distance deviation are sufficiently small in the uniform designs for mixture experiments and the design is more robust for the model.However,the analytical expressions of MSED and MD are currently only available in the hypercube,but both types of deviations in other studies are just approximations.Although it can obtain good approximations in the low-dimensional case,the calculation will be more complicated for an experiment with more variables.Therefore,in this paper,an algorithm based on lattice point partitioning design is proposed to obtain the analytical expression of the MSED and MD in the region covered by the lattice points.Furthermore,the design’s optimality is considered and illustrated by examples under the same uniformity.展开更多
With the increasing development of deepburied engineering projects,rockburst disasters have become a frequent concern.Studies have indicated that tunnel diameter is a critical factor influencing the occurrence of rock...With the increasing development of deepburied engineering projects,rockburst disasters have become a frequent concern.Studies have indicated that tunnel diameter is a critical factor influencing the occurrence of rockbursts.To investigate the influence of tunnel diameter on the deformation and failure characteristics of surrounding rock,large-sized rocklike gypsum specimens were tested using a selfdeveloped true triaxial rockburst loading system containing circular tunnels with three different diameters(D=0.07 m,0.11 m,and 0.15 m).Acoustic emission monitoring,together with a miniature intelligent camera,was employed to analyze the entire process,focusing on macroscopic failure patterns,fragment characteristics,and underlying failure mechanisms.In addition,theoretical analyses were carried out and combined with numerical simulations to investigate the differences in energy evolution associated with rockburst physical models.The results indicate that:(1)The rockburst process with different tunnel diameters consistently evolved through three distinct stages—initial particle ejection,crack propagation accompanied by flake spalling,and,finally,fragment ejection leading to the formation of a‘V'-shaped notch.(2)Increasing tunnel diameter reduces rockburst failure load while increasing surrounding rock damage extent,total mass and average size of ejected fragments.Additionally,shear failure proportion decreases with tensile failure becoming increasingly dominant.(3)Larger tunnel diameters reduce the attenuation rate of elastic strain energy,thereby expanding the zone of elastic strain energy accumulation and disturbance and creating conditions for larger volume rockburst.(4)Larger tunnel diameters result in a smaller principal stress ratio at equivalent distances in the surrounding rock,indicating a higher likelihood of tensile failure.(5)Numerical analyses further reveal that larger tunnel diameters reduce the maximum elastic strain energy density around the tunnel,lowering the energy released per unit volume of rockburst fragments and their ejection velocities.However,both the total failure volume and overall energy release from rockburst increase.Model experiments with different tunnel diameters are of great significance for optimizing engineering design and parameter selection,as well as guiding tunnel construction under complex geological conditions.展开更多
The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove vario...The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable, reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation (NCF) and the absolute nodal coordinate formulation (ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility.展开更多
文摘EBC连接器是5G板对板和板对模块的射频互连元件,通过SMT (Surface Mount Technology)工艺与PCB板焊接连通。由于EBC连接器在SMT之后,出现锡珠、空洞、位置偏移、爬锡高度不良等缺陷,影响天线的波频信号,甚至影响整个产品的可靠性。将介绍基于DOE (Design of Experiments)方法,分析EBC连接器SMT工艺过程中,焊锡不良缺陷特征、规律,导致不良缺陷产生的可能原因;结合所有工序中,设备、工装夹具、物料、工艺参数,确定关键因子,排除非关键因子。通过Minitab软件,在DOE中创建因子,依据设计试验表序列,安排试验。采用响应曲面方法来分析响应变量“不良缺陷率”依赖于自变量因子,找到自变量因子的设置在望目0.5时,在响应曲面设计的响应优化器可得到,降低与解决SMT不良缺陷率最优试验区域:钢网开孔方式“梅花开孔”,锡粉型号TYPE3,回流曲线升温斜率1.166 7℃/s。基于DOE的接器SMT不良缺陷分析方法,可以系统地研究各种因素对不良缺陷的影响,找出关键因子并优化工艺条件。
文摘A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order to reduce the use of chemical spices in the preparation of different dishes. The Design of Experiments (DOE) methodology was used for the formulation of the spices and their physicochemical, nutritional and sensory characteristics were evaluated by standardized and standard methods. The results obtained showed lipid contents (g/100 g DM) ranging from 10.41 ± 0.26 to 15.64 ± 0.68, total sugars from 4.39 ± 0.32 to 5.46 ± 0.31, protein from 3.65 ± 0.17 to 12.04 ± 0.35 and ash from 5.83 ± 0.01 to 7.02 ± 0.01. The polyphenol content ranged from 9.09 ± 1.60 to 11.33 ± 0.90, and the flavonoid content ranged from 0.65 ± 0.03 to 1.08 ± 0.13. The sensory analysis carried out showed that the spices have generally satisfactory organoleptic characteristics. These results constitute new information in the diet of populations and are an alternative to the chemical spices used in their cooking.
基金financially supported by Jiangsu Province University(High Tech Ship)Collaborative Innovation Center(Grant No.XTCXKY20230008).
文摘In this work,the selected icebreaker model experiment is performed in a towing tank.We focus on the influence of seawater salinity on ship ice resistance in the ice floe field and the innovative ice model and ship model test technology,including the similitude rule of ship model tests,test principles,and validation with full-scale ship data.A formula for calculating the relationship between the temperature and salinity of the water is constructed,which can be used to simulate the role of seawater in freshwater ice pools.On this basis,the effect of salinity on the resistance of ships sailing in broken ice fields is studied.A technique in which artificial ice made of polyethylene spheres is used to simulate ice resistance is proposed.With a series of ship model experiments in spherical and triangular ice fields,the effects of salinity and velocity on the ice resistance test of the ship model are analyzed.A relationship of the ice resistance of the ship model to the spherical ice field and the triangular ice field is proposed.The conversion results are consistent with onsite data of the full-size ship,which verifies the method of converting the test results of the ship model to the prototype.
基金approved by the Medical Ethics Committee of the Tel Aviv Sourasky Medical Center Institutional Review Board,approval No.TLV-0674-21.
文摘BACKGROUND Intra-articular hip injections(IAHIs)are commonly used for diagnostic and therapeutic purposes but are often associated with patient anxiety and fear.The disparity between anticipated and experienced pain during IAHIs and the role of preinjection local anesthesia in pain modulation remains unclear.AIM To investigate the difference between anticipated and experienced pain during IAHIs and the impact of pre-injection local anesthesia.METHODS This prospective study enrolled 60 patients undergoing IAHI,30 receiving pre-injection superficial local anesthesia and 30 serving as a control group without pre-injection local anesthesia.Pain levels were assessed using numeric rating scales.RESULTS Patients significantly overestimated anticipated pain compared to experienced pain(6.43±2.48 vs 3.68±2.37,P<0.001).Pre-injection local anesthesia did not significantly reduce experienced pain(3.19±2.38 vs 4.20±2.29,P=0.130).CONCLUSION Patients overestimate anticipated pain during IAHIs.Pre-injection local anesthesia does not reduce experienced pain.
基金supported by the Special Project of National Natural Science Foundation(42341204)the the National Natural Science Foundation of China(W2411009).
文摘The integration of artificial intelligence (AI) with high-throughput experimentation (HTE) techniques is revolutionizing catalyst design, addressing challenges in efficiency, cost, and scalability. This review explores the synergistic application of AI and HTE, highlighting their role in accelerating catalyst discovery, optimizing reaction parameters, and understanding structure-performance relationships. HTE facilitates the rapid preparation, characterization, and evaluation of diverse catalyst formulations, generating large datasets essential for AI model training. Machine learning algorithms, including regression models, neural networks, and active learning frameworks, analyze these datasets to uncover the underlying relationships between the data, predict performance, and optimize experimental workflows in real-time. Case studies across heterogeneous, homogeneous, and electrocatalysis demonstrate significant advancements, including improved reaction selectivity, enhanced material stability, and shorten discovery cycles. The integration of AI with HTE has significantly accelerated discovery cycles, enabling the optimization of catalyst formulations and reaction conditions. Despite these achievements, challenges remain, including reliance on researcher expertise, real-time adaptability, and the complexity of large-scale data analysis. Addressing these limitations through refined experimental protocols, standardized datasets, and interpretable AI models will unlock the full potential of AI-HTE integration.
基金Supported by Science and Technology Fund for Basic Research of Guizhou Province([2020]1Y010)National Nature Sciences Foundation of China(11901260,12071096,12501342)Specialized Fund for the Doctoral Development of Kaili University(BS202502028)。
文摘The upper bound on the model error will be decreased when the mean square error and the maximum distance deviation are sufficiently small in the uniform designs for mixture experiments and the design is more robust for the model.However,the analytical expressions of MSED and MD are currently only available in the hypercube,but both types of deviations in other studies are just approximations.Although it can obtain good approximations in the low-dimensional case,the calculation will be more complicated for an experiment with more variables.Therefore,in this paper,an algorithm based on lattice point partitioning design is proposed to obtain the analytical expression of the MSED and MD in the region covered by the lattice points.Furthermore,the design’s optimality is considered and illustrated by examples under the same uniformity.
基金funded by the National Natural Science Foundation of China(Nos.42077228,52174085)。
文摘With the increasing development of deepburied engineering projects,rockburst disasters have become a frequent concern.Studies have indicated that tunnel diameter is a critical factor influencing the occurrence of rockbursts.To investigate the influence of tunnel diameter on the deformation and failure characteristics of surrounding rock,large-sized rocklike gypsum specimens were tested using a selfdeveloped true triaxial rockburst loading system containing circular tunnels with three different diameters(D=0.07 m,0.11 m,and 0.15 m).Acoustic emission monitoring,together with a miniature intelligent camera,was employed to analyze the entire process,focusing on macroscopic failure patterns,fragment characteristics,and underlying failure mechanisms.In addition,theoretical analyses were carried out and combined with numerical simulations to investigate the differences in energy evolution associated with rockburst physical models.The results indicate that:(1)The rockburst process with different tunnel diameters consistently evolved through three distinct stages—initial particle ejection,crack propagation accompanied by flake spalling,and,finally,fragment ejection leading to the formation of a‘V'-shaped notch.(2)Increasing tunnel diameter reduces rockburst failure load while increasing surrounding rock damage extent,total mass and average size of ejected fragments.Additionally,shear failure proportion decreases with tensile failure becoming increasingly dominant.(3)Larger tunnel diameters reduce the attenuation rate of elastic strain energy,thereby expanding the zone of elastic strain energy accumulation and disturbance and creating conditions for larger volume rockburst.(4)Larger tunnel diameters result in a smaller principal stress ratio at equivalent distances in the surrounding rock,indicating a higher likelihood of tensile failure.(5)Numerical analyses further reveal that larger tunnel diameters reduce the maximum elastic strain energy density around the tunnel,lowering the energy released per unit volume of rockburst fragments and their ejection velocities.However,both the total failure volume and overall energy release from rockburst increase.Model experiments with different tunnel diameters are of great significance for optimizing engineering design and parameter selection,as well as guiding tunnel construction under complex geological conditions.
基金the National Natural Science Foundation of China(Nos.11832005,12372042,12232011)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)+1 种基金the Fundamental Research Funds for the Central Universities(No.NS2023002)State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and Astronautics)(No.MCAS-S-0223K04).
文摘The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable, reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation (NCF) and the absolute nodal coordinate formulation (ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility.
