In order to solve existing problems about the method of establishing traditional system structure of decision support system(DSS), O S chart is applied to describe object oriented system structure of general DSS, an...In order to solve existing problems about the method of establishing traditional system structure of decision support system(DSS), O S chart is applied to describe object oriented system structure of general DSS, and a new method of eight specific steps is proposed to establish object oriented system structure of DSS by using the method of O S chart, which is applied successfully to the development of the DSS for the energy system ecology engineering research of the Wangheqiu country. Supplying many scientific effective computing models, decision support ways and a lot of accurate reliable decision data, the DSS plays a critical part in helping engineering researchers to make correct decisions. Because the period for developing the DSS is relatively shorter, the new way improves the efficiency of establishing DSS greatly. It also makes the DSS of system structure more flexible and easy to expand.展开更多
In the study of oriented bounding boxes(OBB)object detection in high-resolution remote sensing images,the problem of missed and wrong detection of small targets occurs because the targets are too small and have differ...In the study of oriented bounding boxes(OBB)object detection in high-resolution remote sensing images,the problem of missed and wrong detection of small targets occurs because the targets are too small and have different orientations.Existing OBB object detection for remote sensing images,although making good progress,mainly focuses on directional modeling,while less consideration is given to the size of the object as well as the problem of missed detection.In this study,a method based on improved YOLOv8 was proposed for detecting oriented objects in remote sensing images,which can improve the detection precision of oriented objects in remote sensing images.Firstly,the ResCBAMG module was innovatively designed,which could better extract channel and spatial correlation information.Secondly,the innovative top-down feature fusion layer network structure was proposed in conjunction with the Efficient Channel Attention(ECA)attention module,which helped to capture inter-local cross-channel interaction information appropriately.Finally,we introduced an innovative ResCBAMG module between the different C2f modules and detection heads of the bottom-up feature fusion layer.This innovative structure helped the model to better focus on the target area.The precision and robustness of oriented target detection were also improved.Experimental results on the DOTA-v1.5 dataset showed that the detection Precision,mAP@0.5,and mAP@0.5:0.95 metrics of the improved model are better compared to the original model.This improvement is effective in detecting small targets and complex scenes.展开更多
Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and...Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.展开更多
In this paper, an object-oriented digital watermarking technique is proposed in the wavelet domain for still images. According to the difference of recognition degree of the human eye to the different region of the im...In this paper, an object-oriented digital watermarking technique is proposed in the wavelet domain for still images. According to the difference of recognition degree of the human eye to the different region of the image, the image is divided into the interested region and uninterested region of human eye vision in this scheme. Using the relativity of position and the difference to ocular sensitivity of the multiresolution wavelet among each subband, the image is processed with layered watermarking append technique. Experimental results show that the proposed technique successfully survives image processing operations, additive noise and JPEG compression.展开更多
This paper discusses the design concept and method about window based and object oriented Graphic User Interface(GUI),and describes the definition of each class in detail. It is developed with Watcom C ++ in...This paper discusses the design concept and method about window based and object oriented Graphic User Interface(GUI),and describes the definition of each class in detail. It is developed with Watcom C ++ in DOS environment.The GUI can be redeveloped conveniently and effectively by users.It consists of window,popup menu,icon,button and other components.展开更多
An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introdu...An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented.展开更多
This study sets out to conduct the effectiveness of process-oriented approach on the ESL writing teaching for non-Eng-lish majors in Yunnan Agricultural University(YAU),with the aim of enhancing the students' Engl...This study sets out to conduct the effectiveness of process-oriented approach on the ESL writing teaching for non-Eng-lish majors in Yunnan Agricultural University(YAU),with the aim of enhancing the students' English writing proficiency andscores.120 non-English major sophomores and 10 English teachers from YAU are involved in it.With the results of questionnaire,interview and the composition scores of the target students,the findings indicate that the students have a positive attitude towardsprocess-oriented writing approach and it can help them write better and make the writing class more interesting.展开更多
Peer revision is a collaborative activity during which student writers can exchange drafts and make suggestions for improvement. It has been widely used at present in process-oriented writing instruction. In this pape...Peer revision is a collaborative activity during which student writers can exchange drafts and make suggestions for improvement. It has been widely used at present in process-oriented writing instruction. In this paper, the researcher carried out an empirical study about the effects and efficacy of peer revision on a group of Chinese Juniors majoring in English. It was found that student writers focused specially on grammar and vocabulary in PE session and organization was the least attended to. PE was quite effective in improving the overall writing quality, as the participants did incorporate most of the revisions suggested by their peers. However, the influences of students'writing proficiencies and of the rhetorical modes of the writing tasks on the effects of PE were proved to be not very significant.展开更多
The effect of the orientation on the magnetostriction in Fe81Ga19 alloy has been investigated experimentally and theoretically. The Fe81Ca19 [001] and [110] oriented crystals were prepared and the magnetostriction was...The effect of the orientation on the magnetostriction in Fe81Ga19 alloy has been investigated experimentally and theoretically. The Fe81Ca19 [001] and [110] oriented crystals were prepared and the magnetostriction was measured under different pre-stress. The saturation magnetostriction of the [001] oriented crystal increases from 170×10^-6 to 330×10^-6 under the pre-stress from 0 to 50 MPa. The [110] oriented crystal has a saturation magnetostriction from 20×10^-6 to 140×10^-6 with the compressive pre-stress from 0 to 40 MPa. The magnetostriction of [001] and [110] oriented crystals has been simulated based on the phenomenological theory. The domain rotation path has been determined and the resultant magnetostriction calculated under different pre-stress. The experimental and simulated results both show that the [001] oriented crystal exhibits better magnetostriction than [110] oriented crystal. The enhancement of the saturation magnetostriction by the compressive pre-stress in the [110] oriented crystal is higher than that in the [001] oriented crystal.展开更多
In this study, commercial biaxially oriented polypropylene （BOPP）, polyvinyl chlo- ride （PVC） and poly （methyl methacrylate） （PMMA） films were treated with nitrogen plasma over different exposure times in a Py...In this study, commercial biaxially oriented polypropylene （BOPP）, polyvinyl chlo- ride （PVC） and poly （methyl methacrylate） （PMMA） films were treated with nitrogen plasma over different exposure times in a Pyrex tube surrounded by a DC variable magnetic field. The chemi- cal changes that appeared on the surface of the samples were investigated using Fourier transform infrared （FT4R） spectroscopy and attenuated total reflectance Fourier transform infrared （ATR- FTIR） spectroscopy after treatment for 2 min, 4 min and 6 rain in a nitrogen plasma chamber. Effects of the plasma treatment on the surface topographies and contact angles of the untreated and plasma treated films were also analyzed by atomic force microscopy （AFM） and a contact angle measuring system. The results show that the plasma treated films become more hydrophilic with an enhanced wettability due to the formation of some new polar groups on the surface of the treated films. Moreover, at higher exposure times, the total surface energy in all treated films increased while a reduction in contact angle occurred. The behavior of surface roughness in each sample was completely different at higher exposure times.展开更多
High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resisti...High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resistivity p and the seebeck coefficient S of the film exhibit an increasing trend with the temperature from 300 K-1000 K and reach up to 4.8 m. cm and 202 V/K at 980 K, resulting in a power factor of 0.85 mW/mK which are comparable to those of the single crystalline samples. A small polaron hopping conduction can be responsible for the conduction mechanism of the film at high temperature. The results demonstrate that the Bi2Sr2Co2Oy thin film has potential application has high temperature thin film thermoelectric devices,展开更多
Based on the guidelines set by Ningbo Theatre who asked me to translate translations and features of performance-oriented drama, this commentary will deal with how I translate characters and cultural specific items fr...Based on the guidelines set by Ningbo Theatre who asked me to translate translations and features of performance-oriented drama, this commentary will deal with how I translate characters and cultural specific items from prospective of skopos theory and explain the reason why I translate it this way.I am required to present vivid characters and bridge the cultural gap while translating. During the process of translation, I try to use specific words or local dialect to differ one person from another. Sometimes, I make one person's language less colloquial which is consistent with his own personality. When encountering some cultural barriers that would make audience confused, I adopt domestication to translate the dialogue. I will add some explanatory words to make audience get to know it and free translation to avoid cultural confusion. In this commentary, six examples are given to show my strategies of translating this book.展开更多
GIS- or CAD-based technology has been widely used for cartographic maps in coal mines, but structural gaps between such maps make it difficult to provide an integrated map service, for any specific purpose, at higher ...GIS- or CAD-based technology has been widely used for cartographic maps in coal mines, but structural gaps between such maps make it difficult to provide an integrated map service, for any specific purpose, at higher levels. There is no uniform platform that can be used to manage all involved maps. The main reason for this is that datasets are submitted by individual coal mines using their individual, diverse software. No consistent model is used within the software for data abstraction and symbolization. This paper first reviews all the essential specifications concerning OGC (Open Geospatial Consortium) interoperability. Then an OGC standard-oriented architecture is proposed to provide distributed coal mine map services. Within this new architecture the management of spatial data archives, and the integration of coal mine maps, are achieved through the interfaces of geospatial services. Finally an open source geospatial approach is suggested to implement the proposed scheme. A case study of the Huaibei Coal Group is used to demonstrate the proposal.展开更多
In recent years,as China's rapid economic development,vocational and technical education has been gradually recognized by the society.As highly educated people,vocational and technical education graduate is an imp...In recent years,as China's rapid economic development,vocational and technical education has been gradually recognized by the society.As highly educated people,vocational and technical education graduate is an important force in the development of vocational education.But in reality,their employment orientation deviate from the trend of the profession and only a small part of them do related work after graducation.Combined with the current development status of vocational education,the article analysis the reasons of this problem and give policy recommendations,so as to create a good environment for vocational and technical education talented people.展开更多
The dynamics of photostopping iodine atoms from electrically oriented ICI molecules was numerically studied based on their orientational probability distribution functions. Velocity distributions of the iodine atoms a...The dynamics of photostopping iodine atoms from electrically oriented ICI molecules was numerically studied based on their orientational probability distribution functions. Velocity distributions of the iodine atoms and their production rates were investigated for orienting electrical fields of various intensities. For the IC1 precursor beams with an initial rotational temperature of ~ 1 K, the production of the iodine atoms near zero speed will be improved by about ~ 5 times when an orienting electrical field of ~ 200 kV/cm is present. A production rate of ~ 0.5%0 is obtained for photostopped iodine atoms with speeds less than 10 m/s, which are suitable for magnetic trapping. The electrical orientation of IC1 precursors and magnetic trapping of photostopped iodine atoms in situ can be conveniently realized with a pair of charged ring magnets. With the maximal value of the trapping field being ~ 0.28 T, the largest trapping speed is ~ 7.0 m/s for the iodine atom.展开更多
Mn-based Heusler alloys have attracted significant research attention as half-metallic materials because of their giant magnetocr.ystalline anisotropy and magnetocaloric properties.We investigate the crystal structure...Mn-based Heusler alloys have attracted significant research attention as half-metallic materials because of their giant magnetocr.ystalline anisotropy and magnetocaloric properties.We investigate the crystal structure and magnetic properties of polycrystalline,[101]-oriented,and[100]-oriented Mn2-δ Sn prepared separately by arc melting,the Bridgeman method,and the flux method.All of these compounds crystallize in a Ni2 In-type structure.In the Mn2-δSn lattice,Mn atoms occupy all of the 2 a and a fraction of the 2 d sites.Site disorder exists between Mn and Sn atoms in the 2 c sites.In addition,these compounds undergo a re-entrant spin-glass-like transition at low temperatures,which is caused by frustration and randomness within the spin system.The magnetic properties of these systems depend on the crystal directions,which means that the magnetic interactions differ significantly along different directions.Furthermore,these materials exhibit a giant magnetocaloric effect near the Curie temperature.The largest value of maximum of magnetic entropy change(-△SM)occurs perpendicular to the[100]direction.Specifically,at 252 K,maximum-△SM is 2.91 and 3.64 J-kg-1K-1 for a magnetic field of 5 and7 T,respectively.The working temperature span over 80 K and the relative cooling power reaches 302 J/kg for a magnetic field of 7 T,which makes the Mn2-δSn compound a promising candidate for a magnetic refrigerator.展开更多
The process of in situ tumors developing into malignant tumors and exhibiting invasive behavior is extremely complicated.From a biophysical point of view,it is a phase change process affected by many factors,including...The process of in situ tumors developing into malignant tumors and exhibiting invasive behavior is extremely complicated.From a biophysical point of view,it is a phase change process affected by many factors,including cell-to-cell,cell-to-chemical material,cell-to-environment interaction,etc.In this study,we constructed spheroids based on green fluorescence metastatic breast cancer cells MDA-MB-231 to simulate malignant tumors in vitro,while constructed a three-dimensional(3D)biochip to simulate a micro-environment for the growth and invasion of spheroids.In the experiment,the 3D spheroid was implanted into the chip,and the oriented collagen fibers controlled by collagen concentration and injection rate could guide the MDA-MB-231 cells in the spheroid to undergo directional invasion.The experiment showed that the oriented fibers greatly accelerated the invasion speed of MDA-MB-231 cells compared with the traditional uniform tumor micro-environment,namely obvious invasive branches appeared on the spheroids within 24 hours.In order to analyze this interesting phenomenon,we have developed a quantitative analyzing approach to explore strong angle correlation between the orientation of collagen fibers and invasive direction of cancer cell.The results showed that the oriented collagen fibers produced by the chip can greatly stimulate the invasion potential of cancer cells.This biochip is not only conducive to modeling cancer cell metastasis and studying cell invasion mechanisms,but also has the potential to build a quantitative evaluation platform that can be used in future chemical drug treatments.展开更多
Let A be a basic,connected finite dimensional algebra over an algebraically closed field with finite representation type, α(A) be the maximum of set consisting of numbers of indecomposable summands in the middle term...Let A be a basic,connected finite dimensional algebra over an algebraically closed field with finite representation type, α(A) be the maximum of set consisting of numbers of indecomposable summands in the middle term of Auslander Reiten sequences in mod A. In this paper we show that if α(A)=1, then Γ A contains oriented cycles if and only if Γ A contains DT r periodic modules. When α(A)2 we give counterexamples to the assertion.展开更多
A 3D temperature field reconstruction method using the colored background oriented schlieren(CBOS)method is proposed to address image blurring due to the different refractive index of the multi-wavelength light and si...A 3D temperature field reconstruction method using the colored background oriented schlieren(CBOS)method is proposed to address image blurring due to the different refractive index of the multi-wavelength light and significant errors produced when the traditional background oriented schlieren(BOS)method is applied to high-temperature gas.First,the traditional method is employed to reconstruct the non-uniform 3D temperature field.Second,the CBOS method is applied to correct the distortion.Then,by analyzing the correlation coefficient among different color points of the colored background pattern,the non-uniform temperature field is reconstructed much more accurately.Finally,the experimental results are verified by applying the Runge-Kutta ray-tracing method and the thermocouple contact measurement method.The maximum average temperature error of the CBOS-reconstructed temperature field is 12.92°C,compared with the thermocouples.Therefore,an accurate three-dimensional reconstruction of the temperature field can be achieved by the proposed method effectively.展开更多
文摘In order to solve existing problems about the method of establishing traditional system structure of decision support system(DSS), O S chart is applied to describe object oriented system structure of general DSS, and a new method of eight specific steps is proposed to establish object oriented system structure of DSS by using the method of O S chart, which is applied successfully to the development of the DSS for the energy system ecology engineering research of the Wangheqiu country. Supplying many scientific effective computing models, decision support ways and a lot of accurate reliable decision data, the DSS plays a critical part in helping engineering researchers to make correct decisions. Because the period for developing the DSS is relatively shorter, the new way improves the efficiency of establishing DSS greatly. It also makes the DSS of system structure more flexible and easy to expand.
文摘In the study of oriented bounding boxes(OBB)object detection in high-resolution remote sensing images,the problem of missed and wrong detection of small targets occurs because the targets are too small and have different orientations.Existing OBB object detection for remote sensing images,although making good progress,mainly focuses on directional modeling,while less consideration is given to the size of the object as well as the problem of missed detection.In this study,a method based on improved YOLOv8 was proposed for detecting oriented objects in remote sensing images,which can improve the detection precision of oriented objects in remote sensing images.Firstly,the ResCBAMG module was innovatively designed,which could better extract channel and spatial correlation information.Secondly,the innovative top-down feature fusion layer network structure was proposed in conjunction with the Efficient Channel Attention(ECA)attention module,which helped to capture inter-local cross-channel interaction information appropriately.Finally,we introduced an innovative ResCBAMG module between the different C2f modules and detection heads of the bottom-up feature fusion layer.This innovative structure helped the model to better focus on the target area.The precision and robustness of oriented target detection were also improved.Experimental results on the DOTA-v1.5 dataset showed that the detection Precision,mAP@0.5,and mAP@0.5:0.95 metrics of the improved model are better compared to the original model.This improvement is effective in detecting small targets and complex scenes.
基金support from the National Natural Science Foundation of China(Grant Nos.11974066,12174041,12104134,T2350007,and 12347178)the Fundamental and Advanced Research Program of Chongqing(Grant No.cstc2019jcyj-msxm X0477)+3 种基金the Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQMSX1260)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202301333)the Scientific Research Fund of Chongqing University of Arts and Sciences(Grant Nos.R2023HH03 and P2022HH05)College Students’Innovation and Entrepreneurship Training Program of Chongqing Municipal(Grant No.S202310642002)。
文摘Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.
文摘In this paper, an object-oriented digital watermarking technique is proposed in the wavelet domain for still images. According to the difference of recognition degree of the human eye to the different region of the image, the image is divided into the interested region and uninterested region of human eye vision in this scheme. Using the relativity of position and the difference to ocular sensitivity of the multiresolution wavelet among each subband, the image is processed with layered watermarking append technique. Experimental results show that the proposed technique successfully survives image processing operations, additive noise and JPEG compression.
文摘This paper discusses the design concept and method about window based and object oriented Graphic User Interface(GUI),and describes the definition of each class in detail. It is developed with Watcom C ++ in DOS environment.The GUI can be redeveloped conveniently and effectively by users.It consists of window,popup menu,icon,button and other components.
文摘An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented.
文摘This study sets out to conduct the effectiveness of process-oriented approach on the ESL writing teaching for non-Eng-lish majors in Yunnan Agricultural University(YAU),with the aim of enhancing the students' English writing proficiency andscores.120 non-English major sophomores and 10 English teachers from YAU are involved in it.With the results of questionnaire,interview and the composition scores of the target students,the findings indicate that the students have a positive attitude towardsprocess-oriented writing approach and it can help them write better and make the writing class more interesting.
文摘Peer revision is a collaborative activity during which student writers can exchange drafts and make suggestions for improvement. It has been widely used at present in process-oriented writing instruction. In this paper, the researcher carried out an empirical study about the effects and efficacy of peer revision on a group of Chinese Juniors majoring in English. It was found that student writers focused specially on grammar and vocabulary in PE session and organization was the least attended to. PE was quite effective in improving the overall writing quality, as the participants did incorporate most of the revisions suggested by their peers. However, the influences of students'writing proficiencies and of the rhetorical modes of the writing tasks on the effects of PE were proved to be not very significant.
基金Project supported by the Key Program of the National Natural Science Foundation of China (Grant No. 50531010)National Science Fund for Distinguished Young Scholars of China (Grant No. 50925101)Science Fund for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 50921003)
文摘The effect of the orientation on the magnetostriction in Fe81Ga19 alloy has been investigated experimentally and theoretically. The Fe81Ca19 [001] and [110] oriented crystals were prepared and the magnetostriction was measured under different pre-stress. The saturation magnetostriction of the [001] oriented crystal increases from 170×10^-6 to 330×10^-6 under the pre-stress from 0 to 50 MPa. The [110] oriented crystal has a saturation magnetostriction from 20×10^-6 to 140×10^-6 with the compressive pre-stress from 0 to 40 MPa. The magnetostriction of [001] and [110] oriented crystals has been simulated based on the phenomenological theory. The domain rotation path has been determined and the resultant magnetostriction calculated under different pre-stress. The experimental and simulated results both show that the [001] oriented crystal exhibits better magnetostriction than [110] oriented crystal. The enhancement of the saturation magnetostriction by the compressive pre-stress in the [110] oriented crystal is higher than that in the [001] oriented crystal.
文摘In this study, commercial biaxially oriented polypropylene （BOPP）, polyvinyl chlo- ride （PVC） and poly （methyl methacrylate） （PMMA） films were treated with nitrogen plasma over different exposure times in a Pyrex tube surrounded by a DC variable magnetic field. The chemi- cal changes that appeared on the surface of the samples were investigated using Fourier transform infrared （FT4R） spectroscopy and attenuated total reflectance Fourier transform infrared （ATR- FTIR） spectroscopy after treatment for 2 min, 4 min and 6 rain in a nitrogen plasma chamber. Effects of the plasma treatment on the surface topographies and contact angles of the untreated and plasma treated films were also analyzed by atomic force microscopy （AFM） and a contact angle measuring system. The results show that the plasma treated films become more hydrophilic with an enhanced wettability due to the formation of some new polar groups on the surface of the treated films. Moreover, at higher exposure times, the total surface energy in all treated films increased while a reduction in contact angle occurred. The behavior of surface roughness in each sample was completely different at higher exposure times.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 10904030)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20091301120002)
文摘High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resistivity p and the seebeck coefficient S of the film exhibit an increasing trend with the temperature from 300 K-1000 K and reach up to 4.8 m. cm and 202 V/K at 980 K, resulting in a power factor of 0.85 mW/mK which are comparable to those of the single crystalline samples. A small polaron hopping conduction can be responsible for the conduction mechanism of the film at high temperature. The results demonstrate that the Bi2Sr2Co2Oy thin film has potential application has high temperature thin film thermoelectric devices,
文摘Based on the guidelines set by Ningbo Theatre who asked me to translate translations and features of performance-oriented drama, this commentary will deal with how I translate characters and cultural specific items from prospective of skopos theory and explain the reason why I translate it this way.I am required to present vivid characters and bridge the cultural gap while translating. During the process of translation, I try to use specific words or local dialect to differ one person from another. Sometimes, I make one person's language less colloquial which is consistent with his own personality. When encountering some cultural barriers that would make audience confused, I adopt domestication to translate the dialogue. I will add some explanatory words to make audience get to know it and free translation to avoid cultural confusion. In this commentary, six examples are given to show my strategies of translating this book.
基金Project 40771167 supported by the National Natural Science Foundation of China
文摘GIS- or CAD-based technology has been widely used for cartographic maps in coal mines, but structural gaps between such maps make it difficult to provide an integrated map service, for any specific purpose, at higher levels. There is no uniform platform that can be used to manage all involved maps. The main reason for this is that datasets are submitted by individual coal mines using their individual, diverse software. No consistent model is used within the software for data abstraction and symbolization. This paper first reviews all the essential specifications concerning OGC (Open Geospatial Consortium) interoperability. Then an OGC standard-oriented architecture is proposed to provide distributed coal mine map services. Within this new architecture the management of spatial data archives, and the integration of coal mine maps, are achieved through the interfaces of geospatial services. Finally an open source geospatial approach is suggested to implement the proposed scheme. A case study of the Huaibei Coal Group is used to demonstrate the proposal.
文摘In recent years,as China's rapid economic development,vocational and technical education has been gradually recognized by the society.As highly educated people,vocational and technical education graduate is an important force in the development of vocational education.But in reality,their employment orientation deviate from the trend of the profession and only a small part of them do related work after graducation.Combined with the current development status of vocational education,the article analysis the reasons of this problem and give policy recommendations,so as to create a good environment for vocational and technical education talented people.
基金supported by the National Natural Science Foundation of China(Grant Nos.11034002,61205198,and 11274114)the National Key Basic Research and Development Program of China(Grant No.2011CB921602)
文摘The dynamics of photostopping iodine atoms from electrically oriented ICI molecules was numerically studied based on their orientational probability distribution functions. Velocity distributions of the iodine atoms and their production rates were investigated for orienting electrical fields of various intensities. For the IC1 precursor beams with an initial rotational temperature of ~ 1 K, the production of the iodine atoms near zero speed will be improved by about ~ 5 times when an orienting electrical field of ~ 200 kV/cm is present. A production rate of ~ 0.5%0 is obtained for photostopped iodine atoms with speeds less than 10 m/s, which are suitable for magnetic trapping. The electrical orientation of IC1 precursors and magnetic trapping of photostopped iodine atoms in situ can be conveniently realized with a pair of charged ring magnets. With the maximal value of the trapping field being ~ 0.28 T, the largest trapping speed is ~ 7.0 m/s for the iodine atom.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11675006,51731001 and 11805006the National Key Research and Development Program of China under Grant Nos 2017YFA0206303,2016YFB0700901 and2017YFA0403701
文摘Mn-based Heusler alloys have attracted significant research attention as half-metallic materials because of their giant magnetocr.ystalline anisotropy and magnetocaloric properties.We investigate the crystal structure and magnetic properties of polycrystalline,[101]-oriented,and[100]-oriented Mn2-δ Sn prepared separately by arc melting,the Bridgeman method,and the flux method.All of these compounds crystallize in a Ni2 In-type structure.In the Mn2-δSn lattice,Mn atoms occupy all of the 2 a and a fraction of the 2 d sites.Site disorder exists between Mn and Sn atoms in the 2 c sites.In addition,these compounds undergo a re-entrant spin-glass-like transition at low temperatures,which is caused by frustration and randomness within the spin system.The magnetic properties of these systems depend on the crystal directions,which means that the magnetic interactions differ significantly along different directions.Furthermore,these materials exhibit a giant magnetocaloric effect near the Curie temperature.The largest value of maximum of magnetic entropy change(-△SM)occurs perpendicular to the[100]direction.Specifically,at 252 K,maximum-△SM is 2.91 and 3.64 J-kg-1K-1 for a magnetic field of 5 and7 T,respectively.The working temperature span over 80 K and the relative cooling power reaches 302 J/kg for a magnetic field of 7 T,which makes the Mn2-δSn compound a promising candidate for a magnetic refrigerator.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974066 and 11674043)the Fundamental Research Funds for the Central Universities,China(Grant No.2019CDYGYB007)the Natural Science Foundation of Chongqing,China(Grant No.cstc2019jcyj-msxmX0477).
文摘The process of in situ tumors developing into malignant tumors and exhibiting invasive behavior is extremely complicated.From a biophysical point of view,it is a phase change process affected by many factors,including cell-to-cell,cell-to-chemical material,cell-to-environment interaction,etc.In this study,we constructed spheroids based on green fluorescence metastatic breast cancer cells MDA-MB-231 to simulate malignant tumors in vitro,while constructed a three-dimensional(3D)biochip to simulate a micro-environment for the growth and invasion of spheroids.In the experiment,the 3D spheroid was implanted into the chip,and the oriented collagen fibers controlled by collagen concentration and injection rate could guide the MDA-MB-231 cells in the spheroid to undergo directional invasion.The experiment showed that the oriented fibers greatly accelerated the invasion speed of MDA-MB-231 cells compared with the traditional uniform tumor micro-environment,namely obvious invasive branches appeared on the spheroids within 24 hours.In order to analyze this interesting phenomenon,we have developed a quantitative analyzing approach to explore strong angle correlation between the orientation of collagen fibers and invasive direction of cancer cell.The results showed that the oriented collagen fibers produced by the chip can greatly stimulate the invasion potential of cancer cells.This biochip is not only conducive to modeling cancer cell metastasis and studying cell invasion mechanisms,but also has the potential to build a quantitative evaluation platform that can be used in future chemical drug treatments.
文摘Let A be a basic,connected finite dimensional algebra over an algebraically closed field with finite representation type, α(A) be the maximum of set consisting of numbers of indecomposable summands in the middle term of Auslander Reiten sequences in mod A. In this paper we show that if α(A)=1, then Γ A contains oriented cycles if and only if Γ A contains DT r periodic modules. When α(A)2 we give counterexamples to the assertion.
基金Supported by the National Natural Science Foundation of China(52005500)Foundation of Tianjin Educational Committee(2018KJ242)Basic Science-Research Funds of National University(3122019088)。
文摘A 3D temperature field reconstruction method using the colored background oriented schlieren(CBOS)method is proposed to address image blurring due to the different refractive index of the multi-wavelength light and significant errors produced when the traditional background oriented schlieren(BOS)method is applied to high-temperature gas.First,the traditional method is employed to reconstruct the non-uniform 3D temperature field.Second,the CBOS method is applied to correct the distortion.Then,by analyzing the correlation coefficient among different color points of the colored background pattern,the non-uniform temperature field is reconstructed much more accurately.Finally,the experimental results are verified by applying the Runge-Kutta ray-tracing method and the thermocouple contact measurement method.The maximum average temperature error of the CBOS-reconstructed temperature field is 12.92°C,compared with the thermocouples.Therefore,an accurate three-dimensional reconstruction of the temperature field can be achieved by the proposed method effectively.
