Academics in Taiwan have been working on geo-conservation for 20 years.Numerous studies focus on investigation,assessment,monitoring and education of special scientific important geoheritages. However,few researches h...Academics in Taiwan have been working on geo-conservation for 20 years.Numerous studies focus on investigation,assessment,monitoring and education of special scientific important geoheritages. However,few researches have been done on the issues of local stakeholder participation and community development.The authors choose one of the national-level geoheritages,the Lichi Badland展开更多
Microstructural features and ionic conductivity of divalent(Mg 2+)and trivalent(Gd 3+)cations co-doped ceria electrolyte system Ce_ 0.8-xGd_ 0.2Mg_xO_ 1.9-x were investigated by scanning electron microscopy(SEM)and AC...Microstructural features and ionic conductivity of divalent(Mg 2+)and trivalent(Gd 3+)cations co-doped ceria electrolyte system Ce_ 0.8-xGd_ 0.2Mg_xO_ 1.9-x were investigated by scanning electron microscopy(SEM)and AC impedance analysis.The experimental results exhibit that addition of MgO to GDC reduces the average binding energy of GDC by decreasing the energy barrier of oxygen ion migration in ceria matrix and the ionic conductivity of 2 mol% magnesium doped GDC(0.018 S/cm)is higher than that of GDC matrix at 650℃(0.0105 S/cm).Co-doping Mg 2+ and Gd 3+ is found to increase the ionic conductivity of ceria and hence decreases the operation temperature as well as the cost of solid oxide fuel cell(SOFC).展开更多
Diamond grits are indispensable for sawing granite or concrete.Each year about 1 000 tons of diamond grits are consumed for such purposes.In all cases,mono crystalline diamond is used.However, polycrystalline grits(po...Diamond grits are indispensable for sawing granite or concrete.Each year about 1 000 tons of diamond grits are consumed for such purposes.In all cases,mono crystalline diamond is used.However, polycrystalline grits(polygrits) are generally better performed than mono grits as abrasives.For example,poly grits of cubic boron nitride(e.g.Borazon(?) CBN-550 of Diamond Innovations) can cut faster and they last longer than mono grits(e.g.Borazon(?) CBN-500). Polygrits of alumina(e.g.Cubitron(?) of 3M) also out perform by far glassy grits(e.g.white alumina).For diamond superabrasives,micron polygrits formed by shock waves may polish as fast as mono grits of the same size,but without causing as much scratches due to the presence of smaller sintered grains.The improved performance of poly grits is attributed to their ability to micro chipping that renews the sharp cutting corners from time to time.By contrast,mono grits tend to round off at low cutting force or macro fracture at high cutting force,so they may lose the cutting ability rapidly. For sawing granite with mesh sizes 40/50 or coarser,poly grits of diamond have not been available until recently.In this research,we have made polygrits in mini cube with sizes of 18/20,20/25,and 30/40.Turbo grinders and wire saws were made by brazing both mono grits and polygrits on steel substrates.Cutting performance on granite demonstrated that grinding speed was faster with turbo grinder,and the surface finish was smoother with wire saw for poly grits than mono ones. Polygrits and mono grits of diamond were mixed for comparison(upper left).Polygrits of mini cubes were brazed on the pearl of a wire saw(upper right).Mono diamond grits were brazed on a turbo grinder(bottom diagrams ).展开更多
Diamond pad conditioners can determine the efficiency of CMP processes and the quality of polished wafers.The polishing rate of a wafer is dependent on the amplitude(height) of pad asperities.The polishing uniformity ...Diamond pad conditioners can determine the efficiency of CMP processes and the quality of polished wafers.The polishing rate of a wafer is dependent on the amplitude(height) of pad asperities.The polishing uniformity is controlled by the frequency(density) of such asperities.Current diamond pad conditioners cannot dress the pad to produce microns sized asperities at high density.This is because the tips of diamond grits cannot be leveled to the same height so the grooved pad top is uneven with excessive asperities that may ruin the wafer and under sized asperities that is easily glazed. New designs of diamond pad conditioners have markedly improved the leveling of diamond tips.Organic diamond disks(ODD) are manufactured by reverse casting of polymers.Due to the uniform spacing of diamond grits and their controlled tip heights,none of the diamond grits will be overly stressed.Moreover,all diamond grits are sharing the dressing work.Consequently,the number of working grits of ODD is significantly higher than conventional designs.Moreover,because no diamond will cut pad unecessarily,the pad life is greatly lengthened.Furthermore,due to the uniform distribution of pad asperities,the slurry will be held efficiently so the run off is avoided.As a result,the slurry usage is reduced.ODD is therefore a significant savor of CMP consumables for semiconductor manufacture.展开更多
With the relentless densification of interconnected circuitry dictated by Moore’ s Law,the CMP manufacture of such delicate wafers requires the significant reduction of polishing pressure of integrated circuits,not o...With the relentless densification of interconnected circuitry dictated by Moore’ s Law,the CMP manufacture of such delicate wafers requires the significant reduction of polishing pressure of integrated circuits,not only globally,but also locally on every tip of the pad asperities.Conventional diamond disks used for dressing the polyurethane pads cannot produce asperities to achieve such uniformity.A new design of diamond disk was fabricated by casting diamond film on a silicon wafer that contains patterned etching pits. This silicon mold was subsequently removed by dissolution in a hydroxide solution.The diamond film followed the profile of the etching pits on silicon to form pyramids of identical in size and shape.The variation of their tip heights was in microns of single digit that was about one order of magnitude smaller than conventional diamond disks for CMP production.Moreover,the diamond film contained no metal that might contaminate the circuits on polished wafer during a CMP operation.The continuous diamond film could resist any corrosive attack by slurry of acid or base.Consequently,in-situ dressing during CMP is possible that may improve wafer uniformity and production throughput.This ideal diamond disk(IDD) is designed for the future manufacture of advanced semiconductor chips with node sizes of 32 nm or smaller.展开更多
Effectiveness of microwave sintering process through investigation of microstructural characteristics and electrical properties of x(0.94PbZn_ 1/3Nb_ 2/3O_3 + 0.06BaTiO_3)+(1-x)PbZr_yTi_ 1-yO_3(PBZNZT)ceramics with x=...Effectiveness of microwave sintering process through investigation of microstructural characteristics and electrical properties of x(0.94PbZn_ 1/3Nb_ 2/3O_3 + 0.06BaTiO_3)+(1-x)PbZr_yTi_ 1-yO_3(PBZNZT)ceramics with x=0.6 and y=0.52 was evaluated.The relative density of 95% was achieved with sintering at 800℃ for 2 h.The small grain growth exponents indicate how easy the grain growth in these materials sintered using microwave radiation.Grain growth rate increases abruptly and is higher than that of conventional sintering at a temperature higher than 1050℃.This is attributed to the lower activation energy and higher grain boundary mobility.The activation energy required for the grain growth is found to be 132kJ/mol.Higher remanent polarization(Pr=50.1μC/cm2)and increase in remanent polarization with sintering temperature are observed in microwave sintering process when compared to that of conventional sintering process,due to fast increase in grain growth rate and homogeneity in the specimen.The results indicate lower sintering energy and reduction of PbO pollution in the working environment by microwave sintering process.展开更多
Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNo...Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNoD) as the interface for transmitting Rayleigh wave was studied extensively .However,in all cases,nano crystalline or microcrystalline AlN coatings were deposited,typically by sputtering or CVD,on polycrystalline diamond film.The diamond film itself may contain nano or micro grains that are deposited by CVD.The presence of extensive grain boundaries in AlN can attenuate rapidly the propagation of Rayleigh wave.Moreover,the bonding between loose atomic packing of AlN and tight lattice of diamond is weak so much of the mechanical energy is dissipated as heat.In fact,the energy loss is much higher than energy transmitted during the resonating process.In this research,we attempted to improve the matching of atoms at the interface of AlNoD by doping AlN lattice with boron atoms.The shrinking of the lattice may allow more atoms are aligned at the interface.Moreover,a method of coupling single crystal AlN on single crystal diamond is proposed.Such a coupling can maximize the signal-to-noise ratio of the resonating AlNoD at the same time minimize the insertion loss of the SAW filter.展开更多
Diamond grits may be thermally weakened during the high temperature cycle of brazing.This weakening may exhibit as diamond breakage.During the dressing action,taller diamond grits are more likely to break due to the h...Diamond grits may be thermally weakened during the high temperature cycle of brazing.This weakening may exhibit as diamond breakage.During the dressing action,taller diamond grits are more likely to break due to the higher stress present.展开更多
As a cutting tool,diamond films made by chemical vapor deposition(CVD) outperformed polycrystalline diamond(PCD) sintered under ultrahigh pressure.For example,the longevity of the CVD tools may be 2～5 times that of P...As a cutting tool,diamond films made by chemical vapor deposition(CVD) outperformed polycrystalline diamond(PCD) sintered under ultrahigh pressure.For example,the longevity of the CVD tools may be 2～5 times that of PCD inserts.In addition,the former cutting paths are strainghter with less chipping on the edge.However,there have been no report on CVD diamond films that were used as a roller scriber for splitting large glass panels.Our research demonstrated that the CVD diamond film could concentrate the energy in a smaller area(about 1/4),so the glass compressed by the tip of the diamond film was under a larger tensile stress in perpendicular to the direction of compression.The tensile stress then initiated the microcracks that were more in line with the direction of the compression. The reason that CVD diamond film could concentrate the compressive stress was due to its 100%diamond content.The high diamond content could allow the tip to be polished sharper.In contrast,the PCD cutting tip contained micro grains of cobalt that were softer than glass.As a result,the compressional stress was spreading out due to the larger area of contact.Consequently,the microcracks initiated at the PCD tip were random and they might not propagate along the direction of cutting.展开更多
Polycrystalline grits(polygrits) have been used widely in industry as abrasives.Due to their higher impact strength and the friable nature,polygrits are more endurable and more efficient than monocrystal grits (monogr...Polycrystalline grits(polygrits) have been used widely in industry as abrasives.Due to their higher impact strength and the friable nature,polygrits are more endurable and more efficient than monocrystal grits (monogrits) in material removal applications.For example,polygrits of alumina may last longer and cut faster than monogrits.Similarly,polygrits of cubic boron nitride is a superior superabrasive than monogrits of the same. Although diamond superabrasives have been indispensable for constructional sawing applications and industrial grinding applications,there has no polygrits of diamond that are commercially available.In this research,we used a novel technology to sinter micron diamond fines to form polygrits of diamond.The characterization demonstrated that polygrits of diamond can be tough to withstand impact.But due to the presence of micro grains,the grit can sharpen itself without dulling by shedding the worn grains.This paper revealed many examples of using diamond polygrits.展开更多
OBJECTIVE To investigate the pharmacological effect of a plant sesquiterpene lactone(designated D)and its semi-organically synthesized novel derivative(designated S)and the role of lipid mediators,viz.,oxylipins in at...OBJECTIVE To investigate the pharmacological effect of a plant sesquiterpene lactone(designated D)and its semi-organically synthesized novel derivative(designated S)and the role of lipid mediators,viz.,oxylipins in attenuating vemurafenib-induced cutaneous side effects.METHODS A DMBA/TPAinduced skin carcinogenesis mouse model mimicking cutaneous side effect caused by vemurafenib was established to evaluate the efficacy of compound D and S in reversal of vemurafenib side effect.Comparative oxylipin metabolomics platform using UPLC-TQD mass spectrometry coupled with partial least squares-discriminant analysis(PLS-DA)analysis,cell-based assays,and immunochemistry analysis were performed to elucidate the mechanism insights of DET and S compounds and the role of specific oxylipins in skin cancer carcinogenesis.RESULTS Vemurafenib treatment expedited the skin papillomas formation in DMBA-TPA treated mouse from week 6 to week 3.Both D and S compounds could suppress the vemurafenib side effect and also decrease total papillomas numbers(55% to 72%)and average sizes(66% to 89%).Oxylipins metabolome analysis shows that specific arachidonic acid metabolites may play a role in vemurafenib-induced squamous cell carcinoma or keratoacanthomas formation in mouse skin that can be deregulated by D or S compound treatment.Notably,S compound can inhibit vemurafenib-induced paradoxical activation of MAP kinases in mouse skin or in NRAS mutant melanoma cells.CONCLUSION Our results indicate that plant sesquiterpene lactone D and its novel analog can reduce cutaneous side effect of vemurafenib through novel modes of action by inhibiting paradoxical activation of MAP kinases and de-regulating pro-inflammation mediators COX-2 and specific ecosanoid-type of oxylipins.This study may suggest a novel adjuvant therapy approach in treatment of BRAFV600 Emutant melanoma.展开更多
More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCan<sup>TM</sup> techno...More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCan<sup>TM</sup> technology with patterned diamond seeding can boost the production yield of coarse mesh diamonds（e.g. 30/40）.Moreover,the DiaMind crystals formed contain a visible core.This diamond-in-diamond architecture allows self-sharpening during sawing application.Furthermore,a revolutionary polycrystalline diamond superabrasive with cubical shape was fabricated to further increase the sawing efficiency and tool longevity.Such DiaCube<sup>TM</sup> polygrits were made tools by brazing them on pearls of wire saws and on the surface of turbo grinders. The pros and cons of major designs of high-pressure equipment for diamond synthesis were discussed with the recommendation to combine the merits of belt apparatus and cubic press.This tooling synergism may increase diamond yield at reduced cost for massive production of saw grits. In 1997 Sung Chien-Min filed a series US patents that described the art of making patterned diamond tools with diamond grits forming an array in three dimensions.He also made the debut of the world’ s first brazing tools with patterned diamond distribution at the stone exhibition in Verona in 1998（also in Nuremberg in 1999）.The patterned diamond saws were introduced by Korean companies in 2005 with the demonstration of increased cutting speeds and prolonged tool lives.展开更多
Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and smaller.However,the CMP community achieved the low stress by reducing the down force that press the...Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and smaller.However,the CMP community achieved the low stress by reducing the down force that press the wafer against a rotating pad.The reduced down force also decrease the removal rate of the wafer. As a result,the productivity suffers.In order to cope with this problem,an electrical potential is applied to the copper layer during polishing,in this case,the chemical oxidation is accelearated and hence the removal rate. Alternatively,the rotating pad must be softened to minimize the defects of wafers caused by CMP. In this research,we report a simpler solution to achieve low stress polishing without investing in new equipment and in developing new pad materials.The conventional CMP is proceeded by dressing the pad with a PCD dresser that can form 10×more asperities on the pad surface.The fluffy surface can then polish delicate IC without using the brutal force.As a result,the removal rate of wafers can be maintained without causing defectivity on the IC layer.展开更多
A new process was used for producing FeAl alloy pow de rs with double consumable rotating electrodes and the powders made in this appar atus were analyzed. In this new technology, tungsten rod serves as a cathode ele ...A new process was used for producing FeAl alloy pow de rs with double consumable rotating electrodes and the powders made in this appar atus were analyzed. In this new technology, tungsten rod serves as a cathode ele ctrode, while the alloy rod as an anode electrode. The conventional rotating ele ctrode process must have an anode with pre-melting alloys; however, in this new process, using pure iron as cathode electrode and pure aluminum as anode electr ode can eliminate the step of pre-melting. The effects of process variables, which include electrode rotational speed, a nd electrode diameter of the mean particle diameter were determined. Results showed that both the rotational speed and diameter of electrodes would a ffect the mean diameter of particles. There are three kinds of powders with diff erent composition produced in this study and the possible mechanisms are discuss ed. The process parameters and volume mean diameter of the powders have been cor related to find an experimental equation. The results show that when the rotational speed and the diameter of the anode el ectrode are increased, the powders size will decrease. However, the powders size will increase with cathode electrode.展开更多
文摘Academics in Taiwan have been working on geo-conservation for 20 years.Numerous studies focus on investigation,assessment,monitoring and education of special scientific important geoheritages. However,few researches have been done on the issues of local stakeholder participation and community development.The authors choose one of the national-level geoheritages,the Lichi Badland
文摘Microstructural features and ionic conductivity of divalent(Mg 2+)and trivalent(Gd 3+)cations co-doped ceria electrolyte system Ce_ 0.8-xGd_ 0.2Mg_xO_ 1.9-x were investigated by scanning electron microscopy(SEM)and AC impedance analysis.The experimental results exhibit that addition of MgO to GDC reduces the average binding energy of GDC by decreasing the energy barrier of oxygen ion migration in ceria matrix and the ionic conductivity of 2 mol% magnesium doped GDC(0.018 S/cm)is higher than that of GDC matrix at 650℃(0.0105 S/cm).Co-doping Mg 2+ and Gd 3+ is found to increase the ionic conductivity of ceria and hence decreases the operation temperature as well as the cost of solid oxide fuel cell(SOFC).
文摘Diamond grits are indispensable for sawing granite or concrete.Each year about 1 000 tons of diamond grits are consumed for such purposes.In all cases,mono crystalline diamond is used.However, polycrystalline grits(polygrits) are generally better performed than mono grits as abrasives.For example,poly grits of cubic boron nitride(e.g.Borazon(?) CBN-550 of Diamond Innovations) can cut faster and they last longer than mono grits(e.g.Borazon(?) CBN-500). Polygrits of alumina(e.g.Cubitron(?) of 3M) also out perform by far glassy grits(e.g.white alumina).For diamond superabrasives,micron polygrits formed by shock waves may polish as fast as mono grits of the same size,but without causing as much scratches due to the presence of smaller sintered grains.The improved performance of poly grits is attributed to their ability to micro chipping that renews the sharp cutting corners from time to time.By contrast,mono grits tend to round off at low cutting force or macro fracture at high cutting force,so they may lose the cutting ability rapidly. For sawing granite with mesh sizes 40/50 or coarser,poly grits of diamond have not been available until recently.In this research,we have made polygrits in mini cube with sizes of 18/20,20/25,and 30/40.Turbo grinders and wire saws were made by brazing both mono grits and polygrits on steel substrates.Cutting performance on granite demonstrated that grinding speed was faster with turbo grinder,and the surface finish was smoother with wire saw for poly grits than mono ones. Polygrits and mono grits of diamond were mixed for comparison(upper left).Polygrits of mini cubes were brazed on the pearl of a wire saw(upper right).Mono diamond grits were brazed on a turbo grinder(bottom diagrams ).
文摘Diamond pad conditioners can determine the efficiency of CMP processes and the quality of polished wafers.The polishing rate of a wafer is dependent on the amplitude(height) of pad asperities.The polishing uniformity is controlled by the frequency(density) of such asperities.Current diamond pad conditioners cannot dress the pad to produce microns sized asperities at high density.This is because the tips of diamond grits cannot be leveled to the same height so the grooved pad top is uneven with excessive asperities that may ruin the wafer and under sized asperities that is easily glazed. New designs of diamond pad conditioners have markedly improved the leveling of diamond tips.Organic diamond disks(ODD) are manufactured by reverse casting of polymers.Due to the uniform spacing of diamond grits and their controlled tip heights,none of the diamond grits will be overly stressed.Moreover,all diamond grits are sharing the dressing work.Consequently,the number of working grits of ODD is significantly higher than conventional designs.Moreover,because no diamond will cut pad unecessarily,the pad life is greatly lengthened.Furthermore,due to the uniform distribution of pad asperities,the slurry will be held efficiently so the run off is avoided.As a result,the slurry usage is reduced.ODD is therefore a significant savor of CMP consumables for semiconductor manufacture.
文摘With the relentless densification of interconnected circuitry dictated by Moore’ s Law,the CMP manufacture of such delicate wafers requires the significant reduction of polishing pressure of integrated circuits,not only globally,but also locally on every tip of the pad asperities.Conventional diamond disks used for dressing the polyurethane pads cannot produce asperities to achieve such uniformity.A new design of diamond disk was fabricated by casting diamond film on a silicon wafer that contains patterned etching pits. This silicon mold was subsequently removed by dissolution in a hydroxide solution.The diamond film followed the profile of the etching pits on silicon to form pyramids of identical in size and shape.The variation of their tip heights was in microns of single digit that was about one order of magnitude smaller than conventional diamond disks for CMP production.Moreover,the diamond film contained no metal that might contaminate the circuits on polished wafer during a CMP operation.The continuous diamond film could resist any corrosive attack by slurry of acid or base.Consequently,in-situ dressing during CMP is possible that may improve wafer uniformity and production throughput.This ideal diamond disk(IDD) is designed for the future manufacture of advanced semiconductor chips with node sizes of 32 nm or smaller.
文摘Effectiveness of microwave sintering process through investigation of microstructural characteristics and electrical properties of x(0.94PbZn_ 1/3Nb_ 2/3O_3 + 0.06BaTiO_3)+(1-x)PbZr_yTi_ 1-yO_3(PBZNZT)ceramics with x=0.6 and y=0.52 was evaluated.The relative density of 95% was achieved with sintering at 800℃ for 2 h.The small grain growth exponents indicate how easy the grain growth in these materials sintered using microwave radiation.Grain growth rate increases abruptly and is higher than that of conventional sintering at a temperature higher than 1050℃.This is attributed to the lower activation energy and higher grain boundary mobility.The activation energy required for the grain growth is found to be 132kJ/mol.Higher remanent polarization(Pr=50.1μC/cm2)and increase in remanent polarization with sintering temperature are observed in microwave sintering process when compared to that of conventional sintering process,due to fast increase in grain growth rate and homogeneity in the specimen.The results indicate lower sintering energy and reduction of PbO pollution in the working environment by microwave sintering process.
文摘Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNoD) as the interface for transmitting Rayleigh wave was studied extensively .However,in all cases,nano crystalline or microcrystalline AlN coatings were deposited,typically by sputtering or CVD,on polycrystalline diamond film.The diamond film itself may contain nano or micro grains that are deposited by CVD.The presence of extensive grain boundaries in AlN can attenuate rapidly the propagation of Rayleigh wave.Moreover,the bonding between loose atomic packing of AlN and tight lattice of diamond is weak so much of the mechanical energy is dissipated as heat.In fact,the energy loss is much higher than energy transmitted during the resonating process.In this research,we attempted to improve the matching of atoms at the interface of AlNoD by doping AlN lattice with boron atoms.The shrinking of the lattice may allow more atoms are aligned at the interface.Moreover,a method of coupling single crystal AlN on single crystal diamond is proposed.Such a coupling can maximize the signal-to-noise ratio of the resonating AlNoD at the same time minimize the insertion loss of the SAW filter.
文摘Diamond grits may be thermally weakened during the high temperature cycle of brazing.This weakening may exhibit as diamond breakage.During the dressing action,taller diamond grits are more likely to break due to the higher stress present.
文摘As a cutting tool,diamond films made by chemical vapor deposition(CVD) outperformed polycrystalline diamond(PCD) sintered under ultrahigh pressure.For example,the longevity of the CVD tools may be 2～5 times that of PCD inserts.In addition,the former cutting paths are strainghter with less chipping on the edge.However,there have been no report on CVD diamond films that were used as a roller scriber for splitting large glass panels.Our research demonstrated that the CVD diamond film could concentrate the energy in a smaller area(about 1/4),so the glass compressed by the tip of the diamond film was under a larger tensile stress in perpendicular to the direction of compression.The tensile stress then initiated the microcracks that were more in line with the direction of the compression. The reason that CVD diamond film could concentrate the compressive stress was due to its 100%diamond content.The high diamond content could allow the tip to be polished sharper.In contrast,the PCD cutting tip contained micro grains of cobalt that were softer than glass.As a result,the compressional stress was spreading out due to the larger area of contact.Consequently,the microcracks initiated at the PCD tip were random and they might not propagate along the direction of cutting.
文摘Polycrystalline grits(polygrits) have been used widely in industry as abrasives.Due to their higher impact strength and the friable nature,polygrits are more endurable and more efficient than monocrystal grits (monogrits) in material removal applications.For example,polygrits of alumina may last longer and cut faster than monogrits.Similarly,polygrits of cubic boron nitride is a superior superabrasive than monogrits of the same. Although diamond superabrasives have been indispensable for constructional sawing applications and industrial grinding applications,there has no polygrits of diamond that are commercially available.In this research,we used a novel technology to sinter micron diamond fines to form polygrits of diamond.The characterization demonstrated that polygrits of diamond can be tough to withstand impact.But due to the presence of micro grains,the grit can sharpen itself without dulling by shedding the worn grains.This paper revealed many examples of using diamond polygrits.
基金The project supported by a research grant from Ministry of Science and Technology(MOST 103-2320-B-001-008-MY3),Chinese Taipei
文摘OBJECTIVE To investigate the pharmacological effect of a plant sesquiterpene lactone(designated D)and its semi-organically synthesized novel derivative(designated S)and the role of lipid mediators,viz.,oxylipins in attenuating vemurafenib-induced cutaneous side effects.METHODS A DMBA/TPAinduced skin carcinogenesis mouse model mimicking cutaneous side effect caused by vemurafenib was established to evaluate the efficacy of compound D and S in reversal of vemurafenib side effect.Comparative oxylipin metabolomics platform using UPLC-TQD mass spectrometry coupled with partial least squares-discriminant analysis(PLS-DA)analysis,cell-based assays,and immunochemistry analysis were performed to elucidate the mechanism insights of DET and S compounds and the role of specific oxylipins in skin cancer carcinogenesis.RESULTS Vemurafenib treatment expedited the skin papillomas formation in DMBA-TPA treated mouse from week 6 to week 3.Both D and S compounds could suppress the vemurafenib side effect and also decrease total papillomas numbers(55% to 72%)and average sizes(66% to 89%).Oxylipins metabolome analysis shows that specific arachidonic acid metabolites may play a role in vemurafenib-induced squamous cell carcinoma or keratoacanthomas formation in mouse skin that can be deregulated by D or S compound treatment.Notably,S compound can inhibit vemurafenib-induced paradoxical activation of MAP kinases in mouse skin or in NRAS mutant melanoma cells.CONCLUSION Our results indicate that plant sesquiterpene lactone D and its novel analog can reduce cutaneous side effect of vemurafenib through novel modes of action by inhibiting paradoxical activation of MAP kinases and de-regulating pro-inflammation mediators COX-2 and specific ecosanoid-type of oxylipins.This study may suggest a novel adjuvant therapy approach in treatment of BRAFV600 Emutant melanoma.
文摘More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCan<sup>TM</sup> technology with patterned diamond seeding can boost the production yield of coarse mesh diamonds（e.g. 30/40）.Moreover,the DiaMind crystals formed contain a visible core.This diamond-in-diamond architecture allows self-sharpening during sawing application.Furthermore,a revolutionary polycrystalline diamond superabrasive with cubical shape was fabricated to further increase the sawing efficiency and tool longevity.Such DiaCube<sup>TM</sup> polygrits were made tools by brazing them on pearls of wire saws and on the surface of turbo grinders. The pros and cons of major designs of high-pressure equipment for diamond synthesis were discussed with the recommendation to combine the merits of belt apparatus and cubic press.This tooling synergism may increase diamond yield at reduced cost for massive production of saw grits. In 1997 Sung Chien-Min filed a series US patents that described the art of making patterned diamond tools with diamond grits forming an array in three dimensions.He also made the debut of the world’ s first brazing tools with patterned diamond distribution at the stone exhibition in Verona in 1998（also in Nuremberg in 1999）.The patterned diamond saws were introduced by Korean companies in 2005 with the demonstration of increased cutting speeds and prolonged tool lives.
文摘Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and smaller.However,the CMP community achieved the low stress by reducing the down force that press the wafer against a rotating pad.The reduced down force also decrease the removal rate of the wafer. As a result,the productivity suffers.In order to cope with this problem,an electrical potential is applied to the copper layer during polishing,in this case,the chemical oxidation is accelearated and hence the removal rate. Alternatively,the rotating pad must be softened to minimize the defects of wafers caused by CMP. In this research,we report a simpler solution to achieve low stress polishing without investing in new equipment and in developing new pad materials.The conventional CMP is proceeded by dressing the pad with a PCD dresser that can form 10×more asperities on the pad surface.The fluffy surface can then polish delicate IC without using the brutal force.As a result,the removal rate of wafers can be maintained without causing defectivity on the IC layer.
文摘A new process was used for producing FeAl alloy pow de rs with double consumable rotating electrodes and the powders made in this appar atus were analyzed. In this new technology, tungsten rod serves as a cathode ele ctrode, while the alloy rod as an anode electrode. The conventional rotating ele ctrode process must have an anode with pre-melting alloys; however, in this new process, using pure iron as cathode electrode and pure aluminum as anode electr ode can eliminate the step of pre-melting. The effects of process variables, which include electrode rotational speed, a nd electrode diameter of the mean particle diameter were determined. Results showed that both the rotational speed and diameter of electrodes would a ffect the mean diameter of particles. There are three kinds of powders with diff erent composition produced in this study and the possible mechanisms are discuss ed. The process parameters and volume mean diameter of the powders have been cor related to find an experimental equation. The results show that when the rotational speed and the diameter of the anode el ectrode are increased, the powders size will decrease. However, the powders size will increase with cathode electrode.
