The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of...The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.展开更多
The research on plasma immersion ion implantation has been conducted for a little over ten years. Much is needed to investigate including processing technlogy, plasma sheath dynamics, interaction of plasma and surface...The research on plasma immersion ion implantation has been conducted for a little over ten years. Much is needed to investigate including processing technlogy, plasma sheath dynamics, interaction of plasma and surface, etc. Of the processing methods elavated temperature technique is usually used in PIII to produce a thick modified layer by means of the thermal diffusion. Meanwhile plasma ion heating is more recently developed by Ronghua Wei et al[1]. Therefore the temeperature is a critical parameter in plasma ion processing. In this paper we present the theoretical model and analysize the effect of imlantation voltage, plasma density, ion mass,etc on the temperature rise.展开更多
The nondendritic semi-solid slurry preparation of 60Si2Mn spring steel is studied in this paper. The experiments show that when stirred for 2 minutes under the test condition, the semi-solid slurry with 50%-60% fracti...The nondendritic semi-solid slurry preparation of 60Si2Mn spring steel is studied in this paper. The experiments show that when stirred for 2 minutes under the test condition, the semi-solid slurry with 50%-60% fraction solid phase and spherical primary austenite in the size of 100-300μm can be obtained and is easy to be discharged from the little bottom hole of the stirring chamber. The more homogeneous temperature field and solute distribution of the 60Si2Mn spring steel melt appear because of the electromagnetic stirring, which restrains the formation of large primary austenitic dendrites and create a base to form spheroidized structure. The stronger temperature fluctuation in the melt with many rosette primary austenites caused by stirring and the remelting of the secondary arm roots in the same time are the most important reasons for deposition of spheroidized primary austenites.展开更多
The sodium silicate, ferric chloride, ferrous sulfate, sodium chlorate and other common inorganic materials were used to synthesize two new poly silicate iron coagulants： Polysilicate Ferric Chloride （PFSiC） and Po...The sodium silicate, ferric chloride, ferrous sulfate, sodium chlorate and other common inorganic materials were used to synthesize two new poly silicate iron coagulants： Polysilicate Ferric Chloride （PFSiC） and Polymeric Ferric Silicate Sulfate （PFSiS）. Their coagulation effect on micro-polluted water was compared with the poly ferric choride （PFC） saled in the market. The results showed that turbidity, organic matter, total phosphorus, total nitrogen removal rate ofPFSiC, PFSiS coagulant were better than PFC on micro-polluted water treatment at the same dosage. The coagulation effect of PFSiC was the best. The surface morphology of three coagulants was observed by scanning electron microscopy （SEM）, and the coagulation mechanism was discussed preliminarily.展开更多
Cerium dioxide, CeO2, is a potentially superior material in a myriad of areas, and many methods have been proposed to deposit single crystal CeO2 thin films. A novel fabrication technique utilizing dual plasma generat...Cerium dioxide, CeO2, is a potentially superior material in a myriad of areas, and many methods have been proposed to deposit single crystal CeO2 thin films. A novel fabrication technique utilizing dual plasma generated by metal vacuum arc (MEVVA) and radio frequency (RF) is discussed in this paper. We have recently conducted a systematic investigation to determine the optimal process window to deposit CeO2 thin films'on Si(100) substrates. The X-ray diffraction results show the existence of CeO2(100) in the as-deposited sample.展开更多
By Using （scanning） transmission electron microscopy, localized-corrosion morphology variations of the AA7055 AIZn（Cu）Mg alloy with different thermal processes and their underlying microscopic causes were investig...By Using （scanning） transmission electron microscopy, localized-corrosion morphology variations of the AA7055 AIZn（Cu）Mg alloy with different thermal processes and their underlying microscopic causes were investigated systematically. Our study shows that the corrosion resistance of the nanoscale precipitates varies with their structure type and Cu-content. Just like the Al-matrix, the early-stage precipitates are corrosion resistant, as compared with the ηp/η-precipitates without high Cu-content. With a high Cu-content, however, the η-precipitates become most corrosion resistant among all phases involved. Hence, tailoring the precipitate microstructure and chemistry though thermal processes may change the overall corrosion morphology and improve corrosion resistance property of the alloy.展开更多
Plasma immersion ion implantation (PIII), unrestricted by sight-light process, is considered a proper method for inner surface strengthening. Two-dimensional simulation oj inner surface PIII process of cylindrical bo...Plasma immersion ion implantation (PIII), unrestricted by sight-light process, is considered a proper method for inner surface strengthening. Two-dimensional simulation oj inner surface PIII process of cylindrical bores were carried out in this paper using cold plasma fluid model, and influence of the bore's dimension on impact energy, retained dose and uniformity of inner surface were investigated.展开更多
A new method for unconstrained optimization problems is presented. It belongs to the class of trust region method, in which the descent direction is sought by using the trust region steps within the restricted subspac...A new method for unconstrained optimization problems is presented. It belongs to the class of trust region method, in which the descent direction is sought by using the trust region steps within the restricted subspace. Because this subspace can be specified to include information about previous steps, the method is also related to a supermemory descent method without performing multiple dimensional searches. Trust region methods have attractive global convergence property. Supermemory information has good scale independence property. Since the method possesses the characteristics of both the trust region methods and the supermemory descent methods, it is endowed with rapidly convergence. Numerical tests illustrate this point.展开更多
Some observations are reported on the simulation of two thermomechanical routes to produce ultrafine ferrite grainsize in steels. One C-Mn grade and Nb, Nb-Ti and Nb-high Ti bearing steels were used in the tests perfo...Some observations are reported on the simulation of two thermomechanical routes to produce ultrafine ferrite grainsize in steels. One C-Mn grade and Nb, Nb-Ti and Nb-high Ti bearing steels were used in the tests performed ona Gleeble simulator and a laboratory rolling mill. The routes included severe hot deformation of prior grain-refinedaustenite at the temperature close to Ar3 (DIF) and static recrystallization of fine-grained cold-rolled martensite(SRM). It was observed that the hot deformation induces the formation of ferrite above the Ar3 temperature of thesteel, but severe reductions are required for the complete transformation. Strain of 1.2 can result in about 70% offerrite with the grain size of about 1.4～2μm in all the studied steels. Similarly, in short annealing of cold-workedmartensite, the static recrystallization can also lead to a grain size of about 1.5 μm. The distribution of carbonvaries in the microstructures, carbon being in the second phase in the DIF route and in carbide particles in the SRMroute, which may have a significant influence on the mechanical properties and the thermal stability of ultrafine grainstructure.展开更多
Effects of growth temperature on the structural and electrical properties of Li-N-H codoped ZnO thin films grown by DC reactive magnetron sputtering were investigated. Scanning electron microscopy and X-ray diffractio...Effects of growth temperature on the structural and electrical properties of Li-N-H codoped ZnO thin films grown by DC reactive magnetron sputtering were investigated. Scanning electron microscopy and X-ray diffraction results showed that increasing growth temperature could improve the crystalline quality. But Hall measurement results showed that growth temperature had a nonlinear influence on the electrical property. The variation of electrical properties with the growth temperature was found to be related to the activated concentration of N in ZnO and the evaporation of Li during the growth process, derived from the Hall measurement and the second ion mass spectroscopy measurement.展开更多
Objective:To assess delivery outcomes in women with placental malaria who presented at public hospitals in Kisumu,a holoendemic region in western Kenya. Methods:A crosssectional study using both histology andmolecular...Objective:To assess delivery outcomes in women with placental malaria who presented at public hospitals in Kisumu,a holoendemic region in western Kenya. Methods:A crosssectional study using both histology andmolecular biologywas conducted with 90 consecutive pregnant women who presented at 3 hospitals during a 2-week period. Data collectors completed standardized questionnaires using each patient’s hospital record and physical examination results,and registered birth indices such as weight,head circumference,and weight-head ratio. Malaria infection of the placenta was assessed using a molecular biology approach (for genomic differences among parasite species) as well as histology techniques. Of the 5 histologic classes of placental infection,class 1 corresponds to active infection and class 4 to past infection; class 2 and 3 to active chronic infection; and class 5 to uninfected individuals. Plasmodium species typing was determined by polymerase chain reaction amplification of the parasite’s genome. Results:In newborns at term,low birth weight was directly associated with classes 2 and 4 of placental infection (P = 0.053 and P = 0.003,respectively),and differences in birth weight remained significant between the 5 classes (P < 0.001) even after adjusting for parity and mother’s age. Plasmodium falciparum was the only detected parasite. Conclusions:In Kisumu,infection with P. falciparum is an important cause of low birth weight and morbidity when it is associated with histologic classes 2 and 4 of placental infection. Moreover,polymerase chain reaction assays should be supported by ministries of health as an ancillary method of collecting data for malaria control during pregnancy and providing a baseline for future interventions.展开更多
Bright long afterglow phosphorescence glasses were prepared by using SrAl2O4： Eu^2＋, Dy^3＋ phosphors and suitable glass frits together. The SrAl2O4： Eu^2＋, Dy^3＋ phosphors were initially prepared by the solid re...Bright long afterglow phosphorescence glasses were prepared by using SrAl2O4： Eu^2＋, Dy^3＋ phosphors and suitable glass frits together. The SrAl2O4： Eu^2＋, Dy^3＋ phosphors were initially prepared by the solid reaction method. Three kinds of glass frits were prepared to match the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. Effects of the compositions of the glass frits, the ratios of the phosphors to the frits us well us the firing temperature and firing times on the properties of the samples were discussed. XRD analysis indicated the samples exhibited the typical diffraction peaks of SrAlwO4： Eu^2＋, Dy^3＋. The emission spectra of the samples showed broad bands peaking at 510nm.The excitation spectra of the samples showed broad bands ranging from 300 to 480hm. These are believed due to the 5d4f-4f transitions of Eu^2＋ in the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. The afterglow luminescence of the samples excited by a 40W fluorescence lamp for 30min can be observed in the dark for more lOh with the naked eyes. It can find wide applications in many fields.展开更多
In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone o...In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone oxidation were compared. The experimental results showed that： stripping and catalytic ozone oxidation technology has a significant effect on landfill leachate treatment. The removal rate of the COD and NH3-N can reach 88.60% and 98.00% under the initial concentration of COD and NH3-N were 2053.35 mg/L and l 123. 76 mg/L separately.展开更多
Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic disorder usually seen in acral regions in elderly women. It presents clinically as asymptomatic red-to-brown tumors, wit...Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic disorder usually seen in acral regions in elderly women. It presents clinically as asymptomatic red-to-brown tumors, with a tendency to confluence. It must be distinguished from other diverse cutaneous lesions, notably dermatofibroma, Kaposi sarcoma, and angiofibroma. Methods: We report the clinical, histopathological, and immunohistochemical findings of five patients, all women aged between 51 and 78 years. All except the first presented lesions on both of the lower limbs. None of the patients developed spontaneous resolution of the lesions and one was successfully treated by cryosurgery. Comments: Multinucleate cells are characteristic, but neither exclusive nor pathognomonic, of multinucleate cell angiohistiocytoma,since they can also appear in other inflammatory, neoplastic, or reactive processes. The presence of these cells and vascular proliferation in dermis media are the principal histopathological findings in this infrequent entity. In immunohistochemical studies, the multinucleate cells are often positive for vimentin and factor XIIIa.展开更多
The projector-augmented plane wave potentials method under the density functional theory (DFT ) was used to calcu-late the electronic structure of perfect and native point defective β-FeSi2 crystal. The calculated ba...The projector-augmented plane wave potentials method under the density functional theory (DFT ) was used to calcu-late the electronic structure of perfect and native point defective β-FeSi2 crystal. The calculated band structure shows that the band gap of perfect crystal is about 0.74eV, which is a little smaller than the experimental of about 0.9eV. The density of states results predicts that β-FeSi2 with Fe vacancies behaves n-type, and that with Si vacancies will shows p-type, which is in accordant with the experimental results.展开更多
Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic exp...Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.展开更多
The factors of heat treatments were discussed, which affect the formability of two low carbon, low alloy steels. Experiment concerns mechanical properties, R-values, orientation intensity, texture internal friction an...The factors of heat treatments were discussed, which affect the formability of two low carbon, low alloy steels. Experiment concerns mechanical properties, R-values, orientation intensity, texture internal friction and their relationship with annealing and ageing.展开更多
基金supported by the National Key R&D Program of China under Contract No.2022YFA1602200the International Partnership Program of the Chineses Academy of Sciences under Grant No.211134KYSB20200057the STCF Key Technology Research and Development Project.
文摘The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.
文摘The research on plasma immersion ion implantation has been conducted for a little over ten years. Much is needed to investigate including processing technlogy, plasma sheath dynamics, interaction of plasma and surface, etc. Of the processing methods elavated temperature technique is usually used in PIII to produce a thick modified layer by means of the thermal diffusion. Meanwhile plasma ion heating is more recently developed by Ronghua Wei et al[1]. Therefore the temeperature is a critical parameter in plasma ion processing. In this paper we present the theoretical model and analysize the effect of imlantation voltage, plasma density, ion mass,etc on the temperature rise.
基金supported by the National Natural Science Foundation of China(No.59995440).
文摘The nondendritic semi-solid slurry preparation of 60Si2Mn spring steel is studied in this paper. The experiments show that when stirred for 2 minutes under the test condition, the semi-solid slurry with 50%-60% fraction solid phase and spherical primary austenite in the size of 100-300μm can be obtained and is easy to be discharged from the little bottom hole of the stirring chamber. The more homogeneous temperature field and solute distribution of the 60Si2Mn spring steel melt appear because of the electromagnetic stirring, which restrains the formation of large primary austenitic dendrites and create a base to form spheroidized structure. The stronger temperature fluctuation in the melt with many rosette primary austenites caused by stirring and the remelting of the secondary arm roots in the same time are the most important reasons for deposition of spheroidized primary austenites.
文摘The sodium silicate, ferric chloride, ferrous sulfate, sodium chlorate and other common inorganic materials were used to synthesize two new poly silicate iron coagulants： Polysilicate Ferric Chloride （PFSiC） and Polymeric Ferric Silicate Sulfate （PFSiS）. Their coagulation effect on micro-polluted water was compared with the poly ferric choride （PFC） saled in the market. The results showed that turbidity, organic matter, total phosphorus, total nitrogen removal rate ofPFSiC, PFSiS coagulant were better than PFC on micro-polluted water treatment at the same dosage. The coagulation effect of PFSiC was the best. The surface morphology of three coagulants was observed by scanning electron microscopy （SEM）, and the coagulation mechanism was discussed preliminarily.
基金The work was supported by Hong Kong RGC CERG9040344 and 9040412, RGC / Germany Joint Schemes9050084 and 9050150, and CityU S
文摘Cerium dioxide, CeO2, is a potentially superior material in a myriad of areas, and many methods have been proposed to deposit single crystal CeO2 thin films. A novel fabrication technique utilizing dual plasma generated by metal vacuum arc (MEVVA) and radio frequency (RF) is discussed in this paper. We have recently conducted a systematic investigation to determine the optimal process window to deposit CeO2 thin films'on Si(100) substrates. The X-ray diffraction results show the existence of CeO2(100) in the as-deposited sample.
基金financially supported by the National Natural Science Foundation of China(Nos.51501059,51471067,51501060,and 11427806)the National Key Research and Development Program of China(No.2016YFB0300801)
文摘By Using （scanning） transmission electron microscopy, localized-corrosion morphology variations of the AA7055 AIZn（Cu）Mg alloy with different thermal processes and their underlying microscopic causes were investigated systematically. Our study shows that the corrosion resistance of the nanoscale precipitates varies with their structure type and Cu-content. Just like the Al-matrix, the early-stage precipitates are corrosion resistant, as compared with the ηp/η-precipitates without high Cu-content. With a high Cu-content, however, the η-precipitates become most corrosion resistant among all phases involved. Hence, tailoring the precipitate microstructure and chemistry though thermal processes may change the overall corrosion morphology and improve corrosion resistance property of the alloy.
文摘Plasma immersion ion implantation (PIII), unrestricted by sight-light process, is considered a proper method for inner surface strengthening. Two-dimensional simulation oj inner surface PIII process of cylindrical bores were carried out in this paper using cold plasma fluid model, and influence of the bore's dimension on impact energy, retained dose and uniformity of inner surface were investigated.
文摘A new method for unconstrained optimization problems is presented. It belongs to the class of trust region method, in which the descent direction is sought by using the trust region steps within the restricted subspace. Because this subspace can be specified to include information about previous steps, the method is also related to a supermemory descent method without performing multiple dimensional searches. Trust region methods have attractive global convergence property. Supermemory information has good scale independence property. Since the method possesses the characteristics of both the trust region methods and the supermemory descent methods, it is endowed with rapidly convergence. Numerical tests illustrate this point.
文摘Some observations are reported on the simulation of two thermomechanical routes to produce ultrafine ferrite grainsize in steels. One C-Mn grade and Nb, Nb-Ti and Nb-high Ti bearing steels were used in the tests performed ona Gleeble simulator and a laboratory rolling mill. The routes included severe hot deformation of prior grain-refinedaustenite at the temperature close to Ar3 (DIF) and static recrystallization of fine-grained cold-rolled martensite(SRM). It was observed that the hot deformation induces the formation of ferrite above the Ar3 temperature of thesteel, but severe reductions are required for the complete transformation. Strain of 1.2 can result in about 70% offerrite with the grain size of about 1.4～2μm in all the studied steels. Similarly, in short annealing of cold-workedmartensite, the static recrystallization can also lead to a grain size of about 1.5 μm. The distribution of carbonvaries in the microstructures, carbon being in the second phase in the DIF route and in carbide particles in the SRMroute, which may have a significant influence on the mechanical properties and the thermal stability of ultrafine grainstructure.
基金supported by the National Basic Research Program of China under Grant No.2006CB604906the National Natural Science Foundation of China under Grant No.51072181the Doctoral Fund of Ministry of Education of China under Grant No.20060335087
文摘Effects of growth temperature on the structural and electrical properties of Li-N-H codoped ZnO thin films grown by DC reactive magnetron sputtering were investigated. Scanning electron microscopy and X-ray diffraction results showed that increasing growth temperature could improve the crystalline quality. But Hall measurement results showed that growth temperature had a nonlinear influence on the electrical property. The variation of electrical properties with the growth temperature was found to be related to the activated concentration of N in ZnO and the evaporation of Li during the growth process, derived from the Hall measurement and the second ion mass spectroscopy measurement.
文摘Objective:To assess delivery outcomes in women with placental malaria who presented at public hospitals in Kisumu,a holoendemic region in western Kenya. Methods:A crosssectional study using both histology andmolecular biologywas conducted with 90 consecutive pregnant women who presented at 3 hospitals during a 2-week period. Data collectors completed standardized questionnaires using each patient’s hospital record and physical examination results,and registered birth indices such as weight,head circumference,and weight-head ratio. Malaria infection of the placenta was assessed using a molecular biology approach (for genomic differences among parasite species) as well as histology techniques. Of the 5 histologic classes of placental infection,class 1 corresponds to active infection and class 4 to past infection; class 2 and 3 to active chronic infection; and class 5 to uninfected individuals. Plasmodium species typing was determined by polymerase chain reaction amplification of the parasite’s genome. Results:In newborns at term,low birth weight was directly associated with classes 2 and 4 of placental infection (P = 0.053 and P = 0.003,respectively),and differences in birth weight remained significant between the 5 classes (P < 0.001) even after adjusting for parity and mother’s age. Plasmodium falciparum was the only detected parasite. Conclusions:In Kisumu,infection with P. falciparum is an important cause of low birth weight and morbidity when it is associated with histologic classes 2 and 4 of placental infection. Moreover,polymerase chain reaction assays should be supported by ministries of health as an ancillary method of collecting data for malaria control during pregnancy and providing a baseline for future interventions.
基金supported by the Jilin Provincial Natural Science Foundation of China(No.20040506-1).
文摘Bright long afterglow phosphorescence glasses were prepared by using SrAl2O4： Eu^2＋, Dy^3＋ phosphors and suitable glass frits together. The SrAl2O4： Eu^2＋, Dy^3＋ phosphors were initially prepared by the solid reaction method. Three kinds of glass frits were prepared to match the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. Effects of the compositions of the glass frits, the ratios of the phosphors to the frits us well us the firing temperature and firing times on the properties of the samples were discussed. XRD analysis indicated the samples exhibited the typical diffraction peaks of SrAlwO4： Eu^2＋, Dy^3＋. The emission spectra of the samples showed broad bands peaking at 510nm.The excitation spectra of the samples showed broad bands ranging from 300 to 480hm. These are believed due to the 5d4f-4f transitions of Eu^2＋ in the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. The afterglow luminescence of the samples excited by a 40W fluorescence lamp for 30min can be observed in the dark for more lOh with the naked eyes. It can find wide applications in many fields.
文摘In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone oxidation were compared. The experimental results showed that： stripping and catalytic ozone oxidation technology has a significant effect on landfill leachate treatment. The removal rate of the COD and NH3-N can reach 88.60% and 98.00% under the initial concentration of COD and NH3-N were 2053.35 mg/L and l 123. 76 mg/L separately.
文摘Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic disorder usually seen in acral regions in elderly women. It presents clinically as asymptomatic red-to-brown tumors, with a tendency to confluence. It must be distinguished from other diverse cutaneous lesions, notably dermatofibroma, Kaposi sarcoma, and angiofibroma. Methods: We report the clinical, histopathological, and immunohistochemical findings of five patients, all women aged between 51 and 78 years. All except the first presented lesions on both of the lower limbs. None of the patients developed spontaneous resolution of the lesions and one was successfully treated by cryosurgery. Comments: Multinucleate cells are characteristic, but neither exclusive nor pathognomonic, of multinucleate cell angiohistiocytoma,since they can also appear in other inflammatory, neoplastic, or reactive processes. The presence of these cells and vascular proliferation in dermis media are the principal histopathological findings in this infrequent entity. In immunohistochemical studies, the multinucleate cells are often positive for vimentin and factor XIIIa.
文摘The projector-augmented plane wave potentials method under the density functional theory (DFT ) was used to calcu-late the electronic structure of perfect and native point defective β-FeSi2 crystal. The calculated band structure shows that the band gap of perfect crystal is about 0.74eV, which is a little smaller than the experimental of about 0.9eV. The density of states results predicts that β-FeSi2 with Fe vacancies behaves n-type, and that with Si vacancies will shows p-type, which is in accordant with the experimental results.
文摘Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.
基金This boas was financially seaported by SAIC FUND 3166A.
文摘The factors of heat treatments were discussed, which affect the formability of two low carbon, low alloy steels. Experiment concerns mechanical properties, R-values, orientation intensity, texture internal friction and their relationship with annealing and ageing.
