The purpose of this study was to determine if there is an effect of liner and porcelain application (layering and pressing techniques) on the surface of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), ...The purpose of this study was to determine if there is an effect of liner and porcelain application (layering and pressing techniques) on the surface of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), which were exposed to permutations of liner, layered porcelain, and pressed porcelain. Scanning electron microscope (SEM)/energy dispersive spectroscope (EDS) was used to identify changes in composition and microstructure after removing liner and porcelain with hydrofluoric acid. Simulated aging was also conducted to determine the effect of liner and porcelain on low-temperature degradation. The control group had a typical equiaxed grain structure, referred to as unaffected. When covered with liner or porcelain, some areas changed in structure and composition and were termed affected. The frequency of affected sbructure decreased when liner was covered with either layered porcelain or pressed porcelain. There were statistical differences (P〈0.05) in the composition between affected and unaffected for zirconium (layered porcelain with liner: affected = 60% (0.8%) (m/m), unaffected = 69% (4%), layered porcelain without liner: affected = 59% (3%), unaffected = 65% (3%)) and oxygen (layered porcelain with liner: affected = 35% (2%), unaffected = 26% (4%), layered porcelain without liner: affected = 35% (3%), unaffected = 30% (2%)). However, there were statistical differences (P〈0.05) in the composition for zirconium and oxygen of the aged layered porcelain without liner only. The liner should not be used before porcelain application, especially when using the layering technique for zirconia restorations. Furthermore, pressing should be considered the technique of choice over layering.展开更多
Jingdezhen city lies in the Northeast of Jiangxi Province.It is located in the transitional area between the Huangshan-Huaiyushan mountain range and the Plain of Poyang Lake and is known as the historical"capital...Jingdezhen city lies in the Northeast of Jiangxi Province.It is located in the transitional area between the Huangshan-Huaiyushan mountain range and the Plain of Poyang Lake and is known as the historical"capital of porcelain"with a history of about 1000 years.It was listed as the four展开更多
Porcelain electrical equipment (PEE), such as current transformers, is critical to power supply systems, but its seismic performance during past earthquakes has not been satisfactory. This paper studies the seismic ...Porcelain electrical equipment (PEE), such as current transformers, is critical to power supply systems, but its seismic performance during past earthquakes has not been satisfactory. This paper studies the seismic performance of two typical types of PEE and proposes a damping method for PEE based on multiple tuned mass dampers (MTMD). An MTMD damping device involving three mass units, named a triple tuned mass damper (TTMD), is designed and manufactured. Through shake table tests and finite element analysis, the dynamic characteristics of the PEE are studied and the effectiveness of the MTMD damping method is verified. The adverse influence of MTMD redundant mass to damping efficiency is studied and relevant equations are derived. MTMD robustness is verified through adjusting TTMD control frequencies. The damping effectiveness of TTMD, when the peak ground acceleration far exceeds the design value, is studied. Both shake table tests and finite element analysis indicate that MTMD is effective and robust in attenuating PEE seismic responses. TTMD remains effective when the PGA far exceeds the design value and when control deviations are considered.展开更多
The characteristics of broken surfaces were r esearched by a scanning electron microscope (SEM) and a reflection microscope, a nd the fractal dimensions of broken surfaces were measured by the Slit Island me thod. Th...The characteristics of broken surfaces were r esearched by a scanning electron microscope (SEM) and a reflection microscope, a nd the fractal dimensions of broken surfaces were measured by the Slit Island me thod. The experimental results indicate that the broken surface of aluminum elec tric porcelain is a fractal body in statistics, and the fractal dimensions of br oken surfaces are different with the different amplification multiple value.In a ll of measured fractal dimensions,both of values measured in 100× under reflect ion microscope and in 500× under SEM are maximum, whereas the values measur ed in 63× under reflection microscope and in 2000× under SEM are obviously min imum. The fractal dimensions of broken surfaces are also affected by the degrees of gray comparison and the kinds of measuring methods. The relationships betwee n the fractal dimensions of broken surfaces and porcelain bend strengths are tha t they are in positive correlation on the low multiples and in negative correlat ion on the high multiples.展开更多
Usually the thermal expansion coefficients (TEC) of metals are higher than that of porcelains. In order to match the TECs in the case of coating porcelains on metals, high TEC porcelains are needed. In this research, ...Usually the thermal expansion coefficients (TEC) of metals are higher than that of porcelains. In order to match the TECs in the case of coating porcelains on metals, high TEC porcelains are needed. In this research, the high TEC phase leucite (KAlSi2 O6) in the high TEC porcelain was prepared by sol-gel method. The crystal size of leucite made by sol-gel is about 77nm through controlling the process parameters. The process from xerogel to leucite was investigated by means of DSC (differential scanning calorimetry), TG (thermogravimetry), XRD ( X-ray diffraction) and IR (infrared absorption spectrum). Leucite had been detected after the gel was treated at 900℃, this formation temperature is about 250℃ lower than that of melting method. The porcelain made from 50% of the leucite powder and 50% of low fused temperature frit has an average TEC of 19.2×10-6/℃ C from room temperature to 450℃, which is much higher than the common porcelains.展开更多
Bauxite porcelain can be sintered to make its bending strength reach 179Mpa by using sintered bauxite, clay and potash feldspar and albite as the main raw materials in oxidation atmosphere under the normal pressure. X...Bauxite porcelain can be sintered to make its bending strength reach 179Mpa by using sintered bauxite, clay and potash feldspar and albite as the main raw materials in oxidation atmosphere under the normal pressure. XRD, SEM and so on are utilized to study the relationships between factors like the composition of ingot, reduction particle size and heat insulating time at sintering temperature and the phase composition, microstructure and bending strength of ceramic body. The results show that the main phases in bauxite porcelain are corundum, mullite and glass, and the mullite is composed of two parts: primary mullite formed by clay conversion and secondary mullite whiskers precipitating from high temperature melt. The bending strength of ceramic body can be improved by enhancing the content of sintered bauxite in the formula: the smaller the particle size of the ceramic body is, the higher the bending strength will be. The high-temperature heat insulating technique is beneficial to the precipitation of certain quantitative secondary mullite whiskers so as to remarkably improve the strength of glass phase and ceramic body.展开更多
A shard of Chinese underglaze copper-red porcelain from the Yuan dynasty (AD 1271–1368) made in the Jingdezhen kiln was measured by synchrotron radiation- induced X-ray fluorescence mapping and X-ray absorption near-...A shard of Chinese underglaze copper-red porcelain from the Yuan dynasty (AD 1271–1368) made in the Jingdezhen kiln was measured by synchrotron radiation- induced X-ray fluorescence mapping and X-ray absorption near-edge spectroscopy to investigate the influence of copper element distribution and speciation on the color of porcelain. In black-colored region, copper accumulates at the interface between the body and glaze layers with metallic copper particles as the main speciation. In contrast, Cu is irregularly distributed in the red-colored region with multi-valence speciation. The differences in Cu distribution and speciation in black- and red-colored regions indicate that they are the main factors influencing the different colors of copper-red underglaze porcelain.展开更多
Porcelain enamel coatings were widely applied for the protection of steel products because they offered high corrosion protection,resistance to heat and abrasion,high hardness,hygiene and ease of cleaning.The typical ...Porcelain enamel coatings were widely applied for the protection of steel products because they offered high corrosion protection,resistance to heat and abrasion,high hardness,hygiene and ease of cleaning.The typical process to produce enameled steels is roughly divided into two stages:the first stage consists of a forming process to give the desired shape to a steel substrate,and the second stage consists of a firing process to bond enamel frits on the substrate.This firing process requires a high temperature above 800 °C,which may lead to austenitic transformation and severe thermal deformation of the steel substrate.The aim of this study is to develop a finite element analysis (FE analysis) technique to predict the mechanical and thermal deformations of the enameled steels during forming and any further enameling process,including firing.The FE analysis involves analyzing the strain history of the steel substrate,which comprises the stress and thickness distributions of the substrate and its deformed shape,and the high-temperature behavior of the enamel coating layer.The validity of the FE analysis is verified through the U-bending test and firing test with various numbers and positions of enamel coating layers on the substrate.The results reveal that the FE analysis results agree well with the experimental results with 8% error.展开更多
Porcelain aorta(PA)is an asymptomatic atherosclerotic disease,characterized by circumferential calcification throughout the whole perimeter of the aorta.It is seen in 2%to 9.3%of patients undergoing elective coronary ...Porcelain aorta(PA)is an asymptomatic atherosclerotic disease,characterized by circumferential calcification throughout the whole perimeter of the aorta.It is seen in 2%to 9.3%of patients undergoing elective coronary artery bypass grafting(CABG)and makes manipulation of the ascending aorta impossible.It has been clearly shown that most emboli seen and detected during the CABG procedure occur during aortic cross-clamping and aortic side-clamping.Manipulation of porcelain or a severely atherosclerotic aorta increases the risk of perioperative stroke.The incidence of stroke after CABG is between 0.48%and 2.9%,and the risk is correlated with the extent and severity of the atherosclerotic disease.A conventional CABG procedure involves successive steps that include cannulation of the ascending aorta,application of a cross-clamp to the aorta,and partial clamping of the aorta to create the proximal anastomosis.Therefore in procedures that involve cannulation,clamping,or proximal anastomosis,and where aortic manipulation is inevitable,preassessment of the atherosclerotic aortic plaques is crucial.Although many surgeons still rely on intraoperative manual aortic palpation,this approach has very low sensitivity and underestimates the severity of the atherosclerotic illness.Imaging methods including preoperative computed tomography or intraoperative epiaortic ultrasonography enable modification of the surgical technique according to the severity of atherosclerosis.Various surgical techniques have been described to reduce the risk of atheroembolism that may lead to cerebrovascular events in patients with severely atherosclerotic ascending aorta.Anaortic or“no-touch”techniques that do not utilize aortic manipulation may significantly decrease the development of neurological complications by avoiding aortic maneuvers known to cause emboli.In cases where severe atherosclerotic disease or other factors preclude safe use of the ascending aorta,modifications in the surgical techniques,such as switching to different cannulation sites including the axillary/subclavian,femoral and innominate arteries,or using hypothermic ventricular fibrillation and in-situ pedicled arterial grafts,or performing proximal anastomoses at alternative anatomical locations will enable CABG operations to be performed safely with low morbidity and mortality rates in patients with porcelain aortas.展开更多
This paper introduces the ceramic materials fusion method to use porcelain crucible instead of platinum crucible. By this method, not only the funds can be saved, but also the operation becomes simple and the analysed...This paper introduces the ceramic materials fusion method to use porcelain crucible instead of platinum crucible. By this method, not only the funds can be saved, but also the operation becomes simple and the analysed results are accurate and reliable. On the other hand, the high fusion point materials, such as high aluminum ceramic raw ma- terials, can also be melted and their aluminum contents can be determined by this method. Thus, it can be widely used in the students laboratory and routine analysis of small and middle industrial enterprises.展开更多
In this paper the relatienship between mi-crostructwtie and strength of alnminiiim-totighed porcelain insu-lator has been investigated .the microstructural characteristic of the porcelain insulator has been put forwar...In this paper the relatienship between mi-crostructwtie and strength of alnminiiim-totighed porcelain insu-lator has been investigated .the microstructural characteristic of the porcelain insulator has been put forward. The results shoiu that the main factors that lead to the strength decreasement of aluminium toughened porcelain insulator are pore, fracture,' coarse alumina grain, aluminium agglomerate and bearing fer-ric matter. The technological factors have also been analysed and appropriate measures have been taken.展开更多
The Zr coating was deposited on titanium surface using the magnetron sputtering technique. Effects of Zr coating on microstructure and mechanical properties of porcelain fired to titanium have been investigated. The r...The Zr coating was deposited on titanium surface using the magnetron sputtering technique. Effects of Zr coating on microstructure and mechanical properties of porcelain fired to titanium have been investigated. The results show that interdiffusion of elements occurs during porcelain firing, and the Zr coating can effectively protect titanium surface from excess oxidation. The strength of bond zone with Zr coating deposited for 1 hour reaches 29. 7 MPa, which has increased by 26.4% as compared with that of bond zone without coating (23.5 MPa).展开更多
The famous kinds of porcelain produced in Jingdezhen, China, are the blue and white, blue and white rice pattern, famille rose, colourglazed and sculptured porcelains. Their production has a long history of excellent ...The famous kinds of porcelain produced in Jingdezhen, China, are the blue and white, blue and white rice pattern, famille rose, colourglazed and sculptured porcelains. Their production has a long history of excellent workmanship and they are in different styles. Blue and white and blue and white rice pattern porcelains are coated with a layer of underglaze blue fired at a high temperature. However, similar展开更多
THERE is a folk saying in China,"piles of gold aren’t worth a single piece of Jun porcelain,"which fully explains the value of Jun porcelain that has been fervently sought by Chinese collectors generation a...THERE is a folk saying in China,"piles of gold aren’t worth a single piece of Jun porcelain,"which fully explains the value of Jun porcelain that has been fervently sought by Chinese collectors generation after generation.It first appeared in the Tang Dynasty(618-907),and prevailed in the Song Dynasry(960-1279),reputed as展开更多
Objectives: The aim of this study was to evaluate the effect of different acidic agents on surface roughness of feldspathic porcelain. Materials and Methods: In this study, totally 60 disc shaped Noritake and Ceramco ...Objectives: The aim of this study was to evaluate the effect of different acidic agents on surface roughness of feldspathic porcelain. Materials and Methods: In this study, totally 60 disc shaped Noritake and Ceramco 3 feldspathic porcelain were used. The samples were divided into five groups and immersed in five acidic agents (coke, orange juice, lemonade, mineral water and black-carrot juice). After 168 hours, the specimens were evaluated surface roughness with profilometer. Results: The results showed that the highest surface roughness value (4.46 ± 2.9 μm) was identified in lemonade at Noritake porcelain and the lowest surface roughness value (1.06 ± 0.56 μm) was identified in mineral water at Ceramco 3 porcelain. The result of two-way analysis of variance test showed that there were no statistically significant differences between acidic agents on surface roughness of feldspathic porcelain (p > 0.05). Conclusions: The obtained data presented that the acidic drinks affected the surface roughness of feldspathic porcelain.展开更多
In order to expand the development of the Shouzhou kiln porcelain market and meet the diverse needs of the crowd,a deduction model for the shape design of Shouzhou kiln porcelain under the effect of shape grammar and ...In order to expand the development of the Shouzhou kiln porcelain market and meet the diverse needs of the crowd,a deduction model for the shape design of Shouzhou kiln porcelain under the effect of shape grammar and genetic constraints was constructed.Based on the shape classification of the original samples of Shouzhou kiln porcelain,the characteristic genes of Shouzhou kiln porcelain were analyzed,and genetic constraints were determined.By extracting the shape characteristics of the porcelain and combining the questionnaires,the initial shape was screened and brought into the shape grammar deduction rule library.Under the dual effect of genetic constraints and deduction rules,the preliminary plans were generated.Finally,the preliminary plans were further screened and optimized by the fuzzy evaluation method to obtain the best plan.The shape grammar and product gene constraints were applied to the shape design of Shouzhou kiln porcelain.While inheriting and expanding the shape of Shouzhou kiln porcelain,it verified the effectiveness of the theory in design and application,and helps to improve the continuous innovation of designers and enterprises.展开更多
CHINA is home to porcelain. There are thousands of art forms related to porcelain in the country. Among these art froms, carved porcelain is a very unique kind.
Formulation of traditional hard porcelain generally requires 50% kaolin, 25% silica and 25% feldspar. Four porcelains formulation using the casting method, were prepared with different percentages of kaolinitic clay, ...Formulation of traditional hard porcelain generally requires 50% kaolin, 25% silica and 25% feldspar. Four porcelains formulation using the casting method, were prepared with different percentages of kaolinitic clay, sand and pegmatite referenced respectively NONG, SAB and PEG. The physico-chemical, mechanical and mineralogical characteristics were evaluated on specimens formulated and sintered at different temperatures from 1200<span style="white-space:normal;">˚</span>C to 1300<span style="white-space:normal;"><span style="white-space:normal;">˚</span></span>C. X-ray diffraction has revealed the presence of mullite and quartz as essentially crystalline phases. The specimen formulated with 55% NONG, 25% PEG and 20% SAB and sintered at 1240<span style="white-space:normal;"><span style="white-space:normal;">˚</span></span>C gives better performance (water absorption: 0.17%, density: 2.42, open porosity: 0.42% and flexural strength: 53.54 MPa).展开更多
文摘The purpose of this study was to determine if there is an effect of liner and porcelain application (layering and pressing techniques) on the surface of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), which were exposed to permutations of liner, layered porcelain, and pressed porcelain. Scanning electron microscope (SEM)/energy dispersive spectroscope (EDS) was used to identify changes in composition and microstructure after removing liner and porcelain with hydrofluoric acid. Simulated aging was also conducted to determine the effect of liner and porcelain on low-temperature degradation. The control group had a typical equiaxed grain structure, referred to as unaffected. When covered with liner or porcelain, some areas changed in structure and composition and were termed affected. The frequency of affected sbructure decreased when liner was covered with either layered porcelain or pressed porcelain. There were statistical differences (P〈0.05) in the composition between affected and unaffected for zirconium (layered porcelain with liner: affected = 60% (0.8%) (m/m), unaffected = 69% (4%), layered porcelain without liner: affected = 59% (3%), unaffected = 65% (3%)) and oxygen (layered porcelain with liner: affected = 35% (2%), unaffected = 26% (4%), layered porcelain without liner: affected = 35% (3%), unaffected = 30% (2%)). However, there were statistical differences (P〈0.05) in the composition for zirconium and oxygen of the aged layered porcelain without liner only. The liner should not be used before porcelain application, especially when using the layering technique for zirconia restorations. Furthermore, pressing should be considered the technique of choice over layering.
文摘Jingdezhen city lies in the Northeast of Jiangxi Province.It is located in the transitional area between the Huangshan-Huaiyushan mountain range and the Plain of Poyang Lake and is known as the historical"capital of porcelain"with a history of about 1000 years.It was listed as the four
基金Scientific Research Fund of IEM,CEA under Grant Nos.2016B09,2014B12China Natural Science Foundation under Grant Nos.51478442,51408565
文摘Porcelain electrical equipment (PEE), such as current transformers, is critical to power supply systems, but its seismic performance during past earthquakes has not been satisfactory. This paper studies the seismic performance of two typical types of PEE and proposes a damping method for PEE based on multiple tuned mass dampers (MTMD). An MTMD damping device involving three mass units, named a triple tuned mass damper (TTMD), is designed and manufactured. Through shake table tests and finite element analysis, the dynamic characteristics of the PEE are studied and the effectiveness of the MTMD damping method is verified. The adverse influence of MTMD redundant mass to damping efficiency is studied and relevant equations are derived. MTMD robustness is verified through adjusting TTMD control frequencies. The damping effectiveness of TTMD, when the peak ground acceleration far exceeds the design value, is studied. Both shake table tests and finite element analysis indicate that MTMD is effective and robust in attenuating PEE seismic responses. TTMD remains effective when the PGA far exceeds the design value and when control deviations are considered.
基金Funded by the Natural Science Foundation of Shaanxi Province(No.2003E225)
文摘The characteristics of broken surfaces were r esearched by a scanning electron microscope (SEM) and a reflection microscope, a nd the fractal dimensions of broken surfaces were measured by the Slit Island me thod. The experimental results indicate that the broken surface of aluminum elec tric porcelain is a fractal body in statistics, and the fractal dimensions of br oken surfaces are different with the different amplification multiple value.In a ll of measured fractal dimensions,both of values measured in 100× under reflect ion microscope and in 500× under SEM are maximum, whereas the values measur ed in 63× under reflection microscope and in 2000× under SEM are obviously min imum. The fractal dimensions of broken surfaces are also affected by the degrees of gray comparison and the kinds of measuring methods. The relationships betwee n the fractal dimensions of broken surfaces and porcelain bend strengths are tha t they are in positive correlation on the low multiples and in negative correlat ion on the high multiples.
基金This research was funded by the National High Technology Research and Development Program of China(Grant No.2002AA302204)Science and Technology Program of Guangdong Provrince of China(Grant No.2001A1070102).
文摘Usually the thermal expansion coefficients (TEC) of metals are higher than that of porcelains. In order to match the TECs in the case of coating porcelains on metals, high TEC porcelains are needed. In this research, the high TEC phase leucite (KAlSi2 O6) in the high TEC porcelain was prepared by sol-gel method. The crystal size of leucite made by sol-gel is about 77nm through controlling the process parameters. The process from xerogel to leucite was investigated by means of DSC (differential scanning calorimetry), TG (thermogravimetry), XRD ( X-ray diffraction) and IR (infrared absorption spectrum). Leucite had been detected after the gel was treated at 900℃, this formation temperature is about 250℃ lower than that of melting method. The porcelain made from 50% of the leucite powder and 50% of low fused temperature frit has an average TEC of 19.2×10-6/℃ C from room temperature to 450℃, which is much higher than the common porcelains.
基金Supported by the Industrial Foster of the Education Department of Shaanxi Province (No. 3JC11)
文摘Bauxite porcelain can be sintered to make its bending strength reach 179Mpa by using sintered bauxite, clay and potash feldspar and albite as the main raw materials in oxidation atmosphere under the normal pressure. XRD, SEM and so on are utilized to study the relationships between factors like the composition of ingot, reduction particle size and heat insulating time at sintering temperature and the phase composition, microstructure and bending strength of ceramic body. The results show that the main phases in bauxite porcelain are corundum, mullite and glass, and the mullite is composed of two parts: primary mullite formed by clay conversion and secondary mullite whiskers precipitating from high temperature melt. The bending strength of ceramic body can be improved by enhancing the content of sintered bauxite in the formula: the smaller the particle size of the ceramic body is, the higher the bending strength will be. The high-temperature heat insulating technique is beneficial to the precipitation of certain quantitative secondary mullite whiskers so as to remarkably improve the strength of glass phase and ceramic body.
基金supported by Natural Science Foundation of China(Nos.51762027 and 11875312)Jiangxi Collaborative Innovation Center of Ceramic Relics Conservation and Imperial Kiln Research
文摘A shard of Chinese underglaze copper-red porcelain from the Yuan dynasty (AD 1271–1368) made in the Jingdezhen kiln was measured by synchrotron radiation- induced X-ray fluorescence mapping and X-ray absorption near-edge spectroscopy to investigate the influence of copper element distribution and speciation on the color of porcelain. In black-colored region, copper accumulates at the interface between the body and glaze layers with metallic copper particles as the main speciation. In contrast, Cu is irregularly distributed in the red-colored region with multi-valence speciation. The differences in Cu distribution and speciation in black- and red-colored regions indicate that they are the main factors influencing the different colors of copper-red underglaze porcelain.
基金Project(NRF-2012R1A5A1048294)supported by the National Research Foundation of Korea(NRF)Grant funded by the Ministry of Education,Science and Technologythe LG Electronics
文摘Porcelain enamel coatings were widely applied for the protection of steel products because they offered high corrosion protection,resistance to heat and abrasion,high hardness,hygiene and ease of cleaning.The typical process to produce enameled steels is roughly divided into two stages:the first stage consists of a forming process to give the desired shape to a steel substrate,and the second stage consists of a firing process to bond enamel frits on the substrate.This firing process requires a high temperature above 800 °C,which may lead to austenitic transformation and severe thermal deformation of the steel substrate.The aim of this study is to develop a finite element analysis (FE analysis) technique to predict the mechanical and thermal deformations of the enameled steels during forming and any further enameling process,including firing.The FE analysis involves analyzing the strain history of the steel substrate,which comprises the stress and thickness distributions of the substrate and its deformed shape,and the high-temperature behavior of the enamel coating layer.The validity of the FE analysis is verified through the U-bending test and firing test with various numbers and positions of enamel coating layers on the substrate.The results reveal that the FE analysis results agree well with the experimental results with 8% error.
文摘Porcelain aorta(PA)is an asymptomatic atherosclerotic disease,characterized by circumferential calcification throughout the whole perimeter of the aorta.It is seen in 2%to 9.3%of patients undergoing elective coronary artery bypass grafting(CABG)and makes manipulation of the ascending aorta impossible.It has been clearly shown that most emboli seen and detected during the CABG procedure occur during aortic cross-clamping and aortic side-clamping.Manipulation of porcelain or a severely atherosclerotic aorta increases the risk of perioperative stroke.The incidence of stroke after CABG is between 0.48%and 2.9%,and the risk is correlated with the extent and severity of the atherosclerotic disease.A conventional CABG procedure involves successive steps that include cannulation of the ascending aorta,application of a cross-clamp to the aorta,and partial clamping of the aorta to create the proximal anastomosis.Therefore in procedures that involve cannulation,clamping,or proximal anastomosis,and where aortic manipulation is inevitable,preassessment of the atherosclerotic aortic plaques is crucial.Although many surgeons still rely on intraoperative manual aortic palpation,this approach has very low sensitivity and underestimates the severity of the atherosclerotic illness.Imaging methods including preoperative computed tomography or intraoperative epiaortic ultrasonography enable modification of the surgical technique according to the severity of atherosclerosis.Various surgical techniques have been described to reduce the risk of atheroembolism that may lead to cerebrovascular events in patients with severely atherosclerotic ascending aorta.Anaortic or“no-touch”techniques that do not utilize aortic manipulation may significantly decrease the development of neurological complications by avoiding aortic maneuvers known to cause emboli.In cases where severe atherosclerotic disease or other factors preclude safe use of the ascending aorta,modifications in the surgical techniques,such as switching to different cannulation sites including the axillary/subclavian,femoral and innominate arteries,or using hypothermic ventricular fibrillation and in-situ pedicled arterial grafts,or performing proximal anastomoses at alternative anatomical locations will enable CABG operations to be performed safely with low morbidity and mortality rates in patients with porcelain aortas.
文摘This paper introduces the ceramic materials fusion method to use porcelain crucible instead of platinum crucible. By this method, not only the funds can be saved, but also the operation becomes simple and the analysed results are accurate and reliable. On the other hand, the high fusion point materials, such as high aluminum ceramic raw ma- terials, can also be melted and their aluminum contents can be determined by this method. Thus, it can be widely used in the students laboratory and routine analysis of small and middle industrial enterprises.
文摘In this paper the relatienship between mi-crostructwtie and strength of alnminiiim-totighed porcelain insu-lator has been investigated .the microstructural characteristic of the porcelain insulator has been put forward. The results shoiu that the main factors that lead to the strength decreasement of aluminium toughened porcelain insulator are pore, fracture,' coarse alumina grain, aluminium agglomerate and bearing fer-ric matter. The technological factors have also been analysed and appropriate measures have been taken.
文摘The Zr coating was deposited on titanium surface using the magnetron sputtering technique. Effects of Zr coating on microstructure and mechanical properties of porcelain fired to titanium have been investigated. The results show that interdiffusion of elements occurs during porcelain firing, and the Zr coating can effectively protect titanium surface from excess oxidation. The strength of bond zone with Zr coating deposited for 1 hour reaches 29. 7 MPa, which has increased by 26.4% as compared with that of bond zone without coating (23.5 MPa).
文摘The famous kinds of porcelain produced in Jingdezhen, China, are the blue and white, blue and white rice pattern, famille rose, colourglazed and sculptured porcelains. Their production has a long history of excellent workmanship and they are in different styles. Blue and white and blue and white rice pattern porcelains are coated with a layer of underglaze blue fired at a high temperature. However, similar
文摘THERE is a folk saying in China,"piles of gold aren’t worth a single piece of Jun porcelain,"which fully explains the value of Jun porcelain that has been fervently sought by Chinese collectors generation after generation.It first appeared in the Tang Dynasty(618-907),and prevailed in the Song Dynasry(960-1279),reputed as
文摘Objectives: The aim of this study was to evaluate the effect of different acidic agents on surface roughness of feldspathic porcelain. Materials and Methods: In this study, totally 60 disc shaped Noritake and Ceramco 3 feldspathic porcelain were used. The samples were divided into five groups and immersed in five acidic agents (coke, orange juice, lemonade, mineral water and black-carrot juice). After 168 hours, the specimens were evaluated surface roughness with profilometer. Results: The results showed that the highest surface roughness value (4.46 ± 2.9 μm) was identified in lemonade at Noritake porcelain and the lowest surface roughness value (1.06 ± 0.56 μm) was identified in mineral water at Ceramco 3 porcelain. The result of two-way analysis of variance test showed that there were no statistically significant differences between acidic agents on surface roughness of feldspathic porcelain (p > 0.05). Conclusions: The obtained data presented that the acidic drinks affected the surface roughness of feldspathic porcelain.
文摘In order to expand the development of the Shouzhou kiln porcelain market and meet the diverse needs of the crowd,a deduction model for the shape design of Shouzhou kiln porcelain under the effect of shape grammar and genetic constraints was constructed.Based on the shape classification of the original samples of Shouzhou kiln porcelain,the characteristic genes of Shouzhou kiln porcelain were analyzed,and genetic constraints were determined.By extracting the shape characteristics of the porcelain and combining the questionnaires,the initial shape was screened and brought into the shape grammar deduction rule library.Under the dual effect of genetic constraints and deduction rules,the preliminary plans were generated.Finally,the preliminary plans were further screened and optimized by the fuzzy evaluation method to obtain the best plan.The shape grammar and product gene constraints were applied to the shape design of Shouzhou kiln porcelain.While inheriting and expanding the shape of Shouzhou kiln porcelain,it verified the effectiveness of the theory in design and application,and helps to improve the continuous innovation of designers and enterprises.
文摘CHINA is home to porcelain. There are thousands of art forms related to porcelain in the country. Among these art froms, carved porcelain is a very unique kind.
文摘Formulation of traditional hard porcelain generally requires 50% kaolin, 25% silica and 25% feldspar. Four porcelains formulation using the casting method, were prepared with different percentages of kaolinitic clay, sand and pegmatite referenced respectively NONG, SAB and PEG. The physico-chemical, mechanical and mineralogical characteristics were evaluated on specimens formulated and sintered at different temperatures from 1200<span style="white-space:normal;">˚</span>C to 1300<span style="white-space:normal;"><span style="white-space:normal;">˚</span></span>C. X-ray diffraction has revealed the presence of mullite and quartz as essentially crystalline phases. The specimen formulated with 55% NONG, 25% PEG and 20% SAB and sintered at 1240<span style="white-space:normal;"><span style="white-space:normal;">˚</span></span>C gives better performance (water absorption: 0.17%, density: 2.42, open porosity: 0.42% and flexural strength: 53.54 MPa).