Significant developments in colorectal cancer screening are underway and include new screening guidelines that incorporate considerations for patients aged 45 years,with unique features and new techniques at the foref...Significant developments in colorectal cancer screening are underway and include new screening guidelines that incorporate considerations for patients aged 45 years,with unique features and new techniques at the forefront of screening.One of these new techniques is artificial intelligence which can increase adenoma detection rate and reduce the prevalence of colonic neoplasia.展开更多
After discovering high temperature superconducting materials 20 years ago, the preparation of applicable HTS materials has been pursued along with HTS mechanism and characteristic study. At present, the focus on the a...After discovering high temperature superconducting materials 20 years ago, the preparation of applicable HTS materials has been pursued along with HTS mechanism and characteristic study. At present, the focus on the applied HTS technology has been moving to the industrial preparations from the laboratory research stage, and the technology has been well verified for practical applications from small to large scales. The fabrication techniques of engineering HTS materials are being industrialized; and various HTS devices are also on the way towards practical applications. This paper provides a comprehensive summary on the applied high temperature superconductivity with regard to various applicable HTS materials, their preparation techniques and charac- terization, and applications in a wide range.展开更多
A new method of 3D transient eddy current field calculation is proposed. The Maxwell equations with time component elimination （METCE） are derived under the assumption of magnetic quasi static approximation, especia...A new method of 3D transient eddy current field calculation is proposed. The Maxwell equations with time component elimination （METCE） are derived under the assumption of magnetic quasi static approximation, especially for the sample of low conductivity. Based on METCE, we deduce a more efficient reconstruction algorithm of a 3D transient eddy current field. The computational burden is greatly reduced through the new algorithm, and the computational efficiency is improved. This new algorithm decompounds the space-time variables into two individual variables. The idea is to solve the spatial vector component firstly, and then multiply it by the corresponded time component. The iterative methods based on METCE are introduced to recover the distribution of conductivity in magneto-acoustic tomography. The reconstructed images of conductivity are consistent with the original distribution, which validate the new method.展开更多
A simple three-dimensional tidal model is used to examine the M2 tidal current distribution in a northeastern part of the East China Sea, especially the vertical variation of the current in the region. Computed M2 cur...A simple three-dimensional tidal model is used to examine the M2 tidal current distribution in a northeastern part of the East China Sea, especially the vertical variation of the current in the region. Computed M2 current is compared with observations available and found to be in good agreement.Main features of the calculating method in this study are: (1) Vertical variation of the tidal current is taken as a funetion of the depth-mean velocity: (2) the method is applicable to a variety of the vertical eddy viscosities; (3) it has a fine vertical resolution, especially near the sea bootom. So, this method not only enables us to get a steady state solution easily but also depicts effects of the friction on the vertical variation of the current much better.展开更多
The design process in power electronics is driven by increased utilisation level of the used components to gain performance whilst keeping cost low. This article provides an overview on challenges in low-voltage high-...The design process in power electronics is driven by increased utilisation level of the used components to gain performance whilst keeping cost low. This article provides an overview on challenges in low-voltage high-current systems, e.g. used in automotive applications. The main content points are： topology selection--single systems vs. cascaded systems, PCB manufacturing technology overview, current measurement methods, bulk capacitor design （ceramic DC link） and PCB design instructions for high-current systems. The PCB design instructions target on optimised thermal design for maximised PCB utilisation and on optimised track design for a low inductance DC link interconnection. The paper bases on calculations, measurements and simulations.展开更多
In recent ten years in China,the application research of hypobaric storage was extended to the non-freeze preservation of cooked food,fresh-cut vegetables,edible fungi and fruits,preliminary processing of growing area...In recent ten years in China,the application research of hypobaric storage was extended to the non-freeze preservation of cooked food,fresh-cut vegetables,edible fungi and fruits,preliminary processing of growing area and vacuum cold fresh chain to the cold chain breakage for horticultural products,and also to the investigation of principle and theory but the investigation results would have some evident difference. This paper will simply summarize the basic conception,principle,two withdrawing air type hypobaric storage technologies,and introduce many examples as mentioned above extending in China. This paper thinks that the master mechanism of preservation of LP for fresh horticultural products effectively inhibits the activity change of manifold enzymes,which are PAL,POD,PPO,CAT,CAD,SOD et al.,affecting the maturation and caducity of fresh horticultural products during LP storage for a short period,as a result,to reduce both risk of physiology obstacle and disease and to prolong their postharvest life; for the foreseeable future Burg's hypobaric storage technology and hypobaric short period treatment technology will play an important role in the preservation on fresh agricultural products and food preservation in storage and transportation,the preliminary processing of growing area,fresh logistics,establishing the operating platform of perishable food and high business value,fresh e-business,and fresh delivery for scattered families,establishing the operating platform of fresh-cut vegetables including edible fungi and so on in China or in the world.展开更多
文摘Significant developments in colorectal cancer screening are underway and include new screening guidelines that incorporate considerations for patients aged 45 years,with unique features and new techniques at the forefront of screening.One of these new techniques is artificial intelligence which can increase adenoma detection rate and reduce the prevalence of colonic neoplasia.
文摘After discovering high temperature superconducting materials 20 years ago, the preparation of applicable HTS materials has been pursued along with HTS mechanism and characteristic study. At present, the focus on the applied HTS technology has been moving to the industrial preparations from the laboratory research stage, and the technology has been well verified for practical applications from small to large scales. The fabrication techniques of engineering HTS materials are being industrialized; and various HTS devices are also on the way towards practical applications. This paper provides a comprehensive summary on the applied high temperature superconductivity with regard to various applicable HTS materials, their preparation techniques and charac- terization, and applications in a wide range.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51137004,61427806 and 51577184the Equipment Development Project of Chinese Academy of Sciences under Grant No YZ201507
文摘A new method of 3D transient eddy current field calculation is proposed. The Maxwell equations with time component elimination （METCE） are derived under the assumption of magnetic quasi static approximation, especially for the sample of low conductivity. Based on METCE, we deduce a more efficient reconstruction algorithm of a 3D transient eddy current field. The computational burden is greatly reduced through the new algorithm, and the computational efficiency is improved. This new algorithm decompounds the space-time variables into two individual variables. The idea is to solve the spatial vector component firstly, and then multiply it by the corresponded time component. The iterative methods based on METCE are introduced to recover the distribution of conductivity in magneto-acoustic tomography. The reconstructed images of conductivity are consistent with the original distribution, which validate the new method.
文摘A simple three-dimensional tidal model is used to examine the M2 tidal current distribution in a northeastern part of the East China Sea, especially the vertical variation of the current in the region. Computed M2 current is compared with observations available and found to be in good agreement.Main features of the calculating method in this study are: (1) Vertical variation of the tidal current is taken as a funetion of the depth-mean velocity: (2) the method is applicable to a variety of the vertical eddy viscosities; (3) it has a fine vertical resolution, especially near the sea bootom. So, this method not only enables us to get a steady state solution easily but also depicts effects of the friction on the vertical variation of the current much better.
文摘The design process in power electronics is driven by increased utilisation level of the used components to gain performance whilst keeping cost low. This article provides an overview on challenges in low-voltage high-current systems, e.g. used in automotive applications. The main content points are： topology selection--single systems vs. cascaded systems, PCB manufacturing technology overview, current measurement methods, bulk capacitor design （ceramic DC link） and PCB design instructions for high-current systems. The PCB design instructions target on optimised thermal design for maximised PCB utilisation and on optimised track design for a low inductance DC link interconnection. The paper bases on calculations, measurements and simulations.
文摘In recent ten years in China,the application research of hypobaric storage was extended to the non-freeze preservation of cooked food,fresh-cut vegetables,edible fungi and fruits,preliminary processing of growing area and vacuum cold fresh chain to the cold chain breakage for horticultural products,and also to the investigation of principle and theory but the investigation results would have some evident difference. This paper will simply summarize the basic conception,principle,two withdrawing air type hypobaric storage technologies,and introduce many examples as mentioned above extending in China. This paper thinks that the master mechanism of preservation of LP for fresh horticultural products effectively inhibits the activity change of manifold enzymes,which are PAL,POD,PPO,CAT,CAD,SOD et al.,affecting the maturation and caducity of fresh horticultural products during LP storage for a short period,as a result,to reduce both risk of physiology obstacle and disease and to prolong their postharvest life; for the foreseeable future Burg's hypobaric storage technology and hypobaric short period treatment technology will play an important role in the preservation on fresh agricultural products and food preservation in storage and transportation,the preliminary processing of growing area,fresh logistics,establishing the operating platform of perishable food and high business value,fresh e-business,and fresh delivery for scattered families,establishing the operating platform of fresh-cut vegetables including edible fungi and so on in China or in the world.
