A fully integrated class-E power amplifier（PA） at 2.4 GHz implemented in a 0. 18 μm 6-metal-layer mixed/RF CMOS （ complementary metal-oxide-semiconductor transistor ） technology is presented. A two-stage amplific...A fully integrated class-E power amplifier（PA） at 2.4 GHz implemented in a 0. 18 μm 6-metal-layer mixed/RF CMOS （ complementary metal-oxide-semiconductor transistor ） technology is presented. A two-stage amplification structure is chosen for this PA. The driving stage produces a high swing switch signal by using resonation technology. The output stage is designed as a class-E topology to realize the power amplification. Under a 1.2 V power supply, the PA delivers a maximum output power of 8. 8 dBm with a power-added efficiency （PAE） of 44%. A new power control method for the class-E power amplifier is described. By changing the amplitude and duty cycle of the signal which enters the class-E switch transistor, the output power can be covered from - 3 to 8. 8 dBm through a three-bit control word. The proposed PA can be used in low power applications, such as wireless sensor networks and biotelemetry systems.展开更多
Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examinatio...Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examination to detect G.lamblia infection,and to exclude other intestinal pathogens.On the basis of their microscopic findings,a group of 80 children were chosen as giardiasis cases,another 80 children were confirmed as Giardia free control group by immunochromatographic test,and the remaining children were excluded.Both giardiasis and control groups were then subjected to blood examination to identify their genetic type of HLA-DRB1 alleles.Results:HLA class-ⅡDRB1*03:01 and DRB1*13:01 alleles were significantly associated with G.lamblia infection(P<0.001 for each variable).On the other hand,HLA class-ⅡDRB1*04:02,DRB1*10:01,DRB1*14:01 and DRB1*15:01 alleles were significantly demonstrated in Giardia free children.However,other HLA-DRB1 alleles did not show any significant association with giardiasis.Conclusions:HLA class-ⅡDRB1*03,DRB1*13,DRB1*04,DRB1*10,DRB1*14 and DRB1*15 alleles may be involved in the establishment of host immune response to G.lamblia infection.展开更多
提出了1种基于0.18μm CMOS工艺的低压低功耗、宽锁定范围、低复杂度的2分频直接注入锁定分频器.该分频器采用Class-C的LC-tank架构来降低电源电压,同时改善LC振荡器的起振情况.此外还采用双端注入混频技术来扩大锁定范围.仿真结果表明...提出了1种基于0.18μm CMOS工艺的低压低功耗、宽锁定范围、低复杂度的2分频直接注入锁定分频器.该分频器采用Class-C的LC-tank架构来降低电源电压,同时改善LC振荡器的起振情况.此外还采用双端注入混频技术来扩大锁定范围.仿真结果表明该分频器有很好的混频性能,且分频器核心电路(不包括输出buffer)在800 m V电源电压下的功耗仅为0.91 m W.在注入信号的功率为0 d Bm时,该分频器在没有任何调谐单元时的锁定范围为6.4-8.5 GHz.展开更多
The feasibility of utilization of flue gas desulfurization （FGD） gypsum and Class-C fly ash （CFA） to prepare CFA-based geopolymer were studied. The results showed that geopolymer made from 90% CFA and 10% FGD gyps...The feasibility of utilization of flue gas desulfurization （FGD） gypsum and Class-C fly ash （CFA） to prepare CFA-based geopolymer were studied. The results showed that geopolymer made from 90% CFA and 10% FGD gypsum （FGDG） which was thermally treated at 800 ℃ for 1 h obtained the better compressive strength of 37.0 MPa. The micro characteristics and structures of the geopolymer samples of CFA and CFA-FGDG were tested by XRD, FT-IR, and SEM-EDXA after these samples cured at 75 ℃ for 8 h followed by 23 ℃ for 28 d. Both the geopolymer samples of CFA and CFA-FGDG have significant asymmetric stretching of A1-O/Si-O bonds and Si-O-Si / Si-O-A1 bending band. In geopolymer sample of CFA-FGDG, a small quantity of lathy products probably being the ettringite wrapped over the spherical fly ash particle, and the concentration of sulfur is much more than that in geopolymer sample of CFA. It is indicated that FGD gypsum may react during alkali-activated and geopolymeric process.展开更多
Recall that a subgroup H of a finite group G is called a TI-subgroup if H ∩ H^9 = 1 or H for each g ∈ G. Suppose that G is a finite group whose second maximal subgroups are TI-subgroups. It is shown that every class...Recall that a subgroup H of a finite group G is called a TI-subgroup if H ∩ H^9 = 1 or H for each g ∈ G. Suppose that G is a finite group whose second maximal subgroups are TI-subgroups. It is shown that every class-preserving Coleman automorphism of G is an inner automorphism. As an immediate consequence of this result, we obtain that the normalizer property holds for G.展开更多
To achieve online automatic classification of product is a great need of e-commerce de-velopment. By analyzing the characteristics of product images, we proposed a fast supervised image classifier which is based on cl...To achieve online automatic classification of product is a great need of e-commerce de-velopment. By analyzing the characteristics of product images, we proposed a fast supervised image classifier which is based on class-specific Pyramid Histogram Of Words (PHOW) descriptor and Im-age-to-Class distance (PHOW/I2C). In the training phase, the local features are densely sampled and represented as soft-voting PHOW descriptors, and then the class-specific descriptors are built with the means and variances of distribution of each visual word in each labelled class. For online testing, the normalized chi-square distance is calculated between the descriptor of query image and each class-specific descriptor. The class label corresponding to the least I2C distance is taken as the final winner. Experiments demonstrate the effectiveness and quickness of our method in the tasks of product clas-sification.展开更多
AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was c...AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was conducted on the cohorts of CHC individuals identified as responders or non-responders to antiviral therapy. Myeloid DCs were isolated from the peripheral blood of each subject using CD1c(BDCA1)+ DC isolation Kit. Monocytes from healthy donor were cultured with DC growth factors such as IL-4 and GM-CSF either in the presence or absence of hepatitis C virus(HCV) viral proteins followed by LPS stimulation. Phenotyping was done by flowcytometry and gene expression profiling was evaluated by real-time PCR.RESULTS: Non-responders [sustained virological response(SVR)-ve] to conventional antiviral therapy had significantly higher expression of genes associated with interferon responsive element such as IDO1 and PD-L1(6-fold) and negative regulators of JAK-STAT pathway such as SOCS(6-fold) as compared to responders(SVR+ve) to antiviral therapy. The downregulated genes in non-responders included factors involved in antigen processing and presentation mainly belonging to major histocompatibility complex(MHC) Class-Ⅱ family as HLA-DP, HLA-DQ(2-fold) and superoxide dismutase(2-fold). Cells grown in the presence of HCV viral proteins had genes downregulated for factors involved in innate response, interferon signaling, DC maturation and co-stimulatory signaling to T-cells, while the genes for cytokine signaling and Toll-like receptors(4-fold) were upregulated as compared to cells grown in absence of viral proteins.CONCLUSION: Underexpressed MHC class-Ⅱ genes and upregulated negative regulators in non-responders indicate diminished capacity to present antigen and may constitute mechanism of functionally defective state of DCs.展开更多
The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the ...The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the light of the properties of the class- waters and lastly, analyses the effect of application.展开更多
Many studies have been conducted by analyzing crash data that included road profile, site conditions, vehicle configurations and weights, driver behavior, etc.. However, limited studies have been conducted evaluating ...Many studies have been conducted by analyzing crash data that included road profile, site conditions, vehicle configurations and weights, driver behavior, etc.. However, limited studies have been conducted evaluating the impact of these factors on crashes and/or rollover through simulations. This is mainly due to lack of availability of verified full vehicle flexible-body models. The verification process is costly as it requires instrumentation of a heavy vehicle, scanning of road surfaces, and collection of data by running the vehicle over different road conditions, performing various maneuvering, etc. This paper presents the reverse engineering process of a class-8 truck and validation of a full flexible-body simulation model of a Wabash 53-foot trailer against the strain data recoded from proving ground testing of an instrumented truck. Simulation results show that, with the exception of the noise from the strain gage data from instrumented test run at 30 mph, there is a good agreement in periodicity and relative amplitude with the ADAMS model. A comparison of strain data from the flex-body model and the instrumented truck shows that the modeling and verification approach presented in this paper can be confidently used to validate the full flexible-body models developed for specific analyses.展开更多
This paper presents a 1.8 GHz class-E controlled power amplifier (PA). The proposed power amplifier is designed with two-stage architecture. The main advantage of the proposed technique for output control power is a h...This paper presents a 1.8 GHz class-E controlled power amplifier (PA). The proposed power amplifier is designed with two-stage architecture. The main advantage of the proposed technique for output control power is a high 37 dB output power dynamic range with good average power adding efficiency. The measurement results show that the PA achieves a high power gain of 23 dBm and power added efficiency (PAE) by 38%. The circuit was post layout simulated in a standard 0.18 μm CMOS technology.展开更多
The appearance of third-generation semiconductors represented by gallium nitride （GaN） material greatly improves the output power of a power amplifier （PA）, but the efficiency of the PA needs to be further improve...The appearance of third-generation semiconductors represented by gallium nitride （GaN） material greatly improves the output power of a power amplifier （PA）, but the efficiency of the PA needs to be further improved. The Class-F PA reduces the overlap of drain voltage and current by tuning harmonic impedance so that high efficiency is achieved. This paper begins with the principle of class-F PA, regards the third harmonic voltage as an independent variable, analyzes the influence of the third harmonic on fundamental, and points out how drain efficiency and output power vary with the third harmonic voltage with an I-V knee effect. Finally, the best third harmonic impedance is found mathematically. We compare our results with the Loadpull technique in advanced design system environment and conclude that an optimized third harmonic impedance is open in an ideal case, while it is not at an open point with the I-V knee effect, and the drain efficiency with optimized third harmonic impedance is 4% higher than that with the third harmonic open.展开更多
基金The National High Technology Research and Development Program of China(863 Program)(No.2007AA01Z2A7)
文摘A fully integrated class-E power amplifier（PA） at 2.4 GHz implemented in a 0. 18 μm 6-metal-layer mixed/RF CMOS （ complementary metal-oxide-semiconductor transistor ） technology is presented. A two-stage amplification structure is chosen for this PA. The driving stage produces a high swing switch signal by using resonation technology. The output stage is designed as a class-E topology to realize the power amplification. Under a 1.2 V power supply, the PA delivers a maximum output power of 8. 8 dBm with a power-added efficiency （PAE） of 44%. A new power control method for the class-E power amplifier is described. By changing the amplitude and duty cycle of the signal which enters the class-E switch transistor, the output power can be covered from - 3 to 8. 8 dBm through a three-bit control word. The proposed PA can be used in low power applications, such as wireless sensor networks and biotelemetry systems.
文摘Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examination to detect G.lamblia infection,and to exclude other intestinal pathogens.On the basis of their microscopic findings,a group of 80 children were chosen as giardiasis cases,another 80 children were confirmed as Giardia free control group by immunochromatographic test,and the remaining children were excluded.Both giardiasis and control groups were then subjected to blood examination to identify their genetic type of HLA-DRB1 alleles.Results:HLA class-ⅡDRB1*03:01 and DRB1*13:01 alleles were significantly associated with G.lamblia infection(P<0.001 for each variable).On the other hand,HLA class-ⅡDRB1*04:02,DRB1*10:01,DRB1*14:01 and DRB1*15:01 alleles were significantly demonstrated in Giardia free children.However,other HLA-DRB1 alleles did not show any significant association with giardiasis.Conclusions:HLA class-ⅡDRB1*03,DRB1*13,DRB1*04,DRB1*10,DRB1*14 and DRB1*15 alleles may be involved in the establishment of host immune response to G.lamblia infection.
文摘提出了1种基于0.18μm CMOS工艺的低压低功耗、宽锁定范围、低复杂度的2分频直接注入锁定分频器.该分频器采用Class-C的LC-tank架构来降低电源电压,同时改善LC振荡器的起振情况.此外还采用双端注入混频技术来扩大锁定范围.仿真结果表明该分频器有很好的混频性能,且分频器核心电路(不包括输出buffer)在800 m V电源电压下的功耗仅为0.91 m W.在注入信号的功率为0 d Bm时,该分频器在没有任何调谐单元时的锁定范围为6.4-8.5 GHz.
基金Funded by the National Natural Science Foundation of China(Nos.51208370,51172164)the Specialized Research Fund for the Doctoral Program of Higher Education(Nos.20110072120046,20090072110010)of China
文摘The feasibility of utilization of flue gas desulfurization （FGD） gypsum and Class-C fly ash （CFA） to prepare CFA-based geopolymer were studied. The results showed that geopolymer made from 90% CFA and 10% FGD gypsum （FGDG） which was thermally treated at 800 ℃ for 1 h obtained the better compressive strength of 37.0 MPa. The micro characteristics and structures of the geopolymer samples of CFA and CFA-FGDG were tested by XRD, FT-IR, and SEM-EDXA after these samples cured at 75 ℃ for 8 h followed by 23 ℃ for 28 d. Both the geopolymer samples of CFA and CFA-FGDG have significant asymmetric stretching of A1-O/Si-O bonds and Si-O-Si / Si-O-A1 bending band. In geopolymer sample of CFA-FGDG, a small quantity of lathy products probably being the ettringite wrapped over the spherical fly ash particle, and the concentration of sulfur is much more than that in geopolymer sample of CFA. It is indicated that FGD gypsum may react during alkali-activated and geopolymeric process.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1117116911071155)the Doc-toral Foundation of Shandong Province(Grant No.BS2012SF003)
文摘Recall that a subgroup H of a finite group G is called a TI-subgroup if H ∩ H^9 = 1 or H for each g ∈ G. Suppose that G is a finite group whose second maximal subgroups are TI-subgroups. It is shown that every class-preserving Coleman automorphism of G is an inner automorphism. As an immediate consequence of this result, we obtain that the normalizer property holds for G.
基金Supported by the Major Funded Project of National Natural Science Foundation of China (No. 70890083)
文摘To achieve online automatic classification of product is a great need of e-commerce de-velopment. By analyzing the characteristics of product images, we proposed a fast supervised image classifier which is based on class-specific Pyramid Histogram Of Words (PHOW) descriptor and Im-age-to-Class distance (PHOW/I2C). In the training phase, the local features are densely sampled and represented as soft-voting PHOW descriptors, and then the class-specific descriptors are built with the means and variances of distribution of each visual word in each labelled class. For online testing, the normalized chi-square distance is calculated between the descriptor of query image and each class-specific descriptor. The class label corresponding to the least I2C distance is taken as the final winner. Experiments demonstrate the effectiveness and quickness of our method in the tasks of product clas-sification.
基金Supported by Council of Scientific and Industrial Research,No.27(0262)12/EMR-II
文摘AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was conducted on the cohorts of CHC individuals identified as responders or non-responders to antiviral therapy. Myeloid DCs were isolated from the peripheral blood of each subject using CD1c(BDCA1)+ DC isolation Kit. Monocytes from healthy donor were cultured with DC growth factors such as IL-4 and GM-CSF either in the presence or absence of hepatitis C virus(HCV) viral proteins followed by LPS stimulation. Phenotyping was done by flowcytometry and gene expression profiling was evaluated by real-time PCR.RESULTS: Non-responders [sustained virological response(SVR)-ve] to conventional antiviral therapy had significantly higher expression of genes associated with interferon responsive element such as IDO1 and PD-L1(6-fold) and negative regulators of JAK-STAT pathway such as SOCS(6-fold) as compared to responders(SVR+ve) to antiviral therapy. The downregulated genes in non-responders included factors involved in antigen processing and presentation mainly belonging to major histocompatibility complex(MHC) Class-Ⅱ family as HLA-DP, HLA-DQ(2-fold) and superoxide dismutase(2-fold). Cells grown in the presence of HCV viral proteins had genes downregulated for factors involved in innate response, interferon signaling, DC maturation and co-stimulatory signaling to T-cells, while the genes for cytokine signaling and Toll-like receptors(4-fold) were upregulated as compared to cells grown in absence of viral proteins.CONCLUSION: Underexpressed MHC class-Ⅱ genes and upregulated negative regulators in non-responders indicate diminished capacity to present antigen and may constitute mechanism of functionally defective state of DCs.
文摘The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the light of the properties of the class- waters and lastly, analyses the effect of application.
文摘Many studies have been conducted by analyzing crash data that included road profile, site conditions, vehicle configurations and weights, driver behavior, etc.. However, limited studies have been conducted evaluating the impact of these factors on crashes and/or rollover through simulations. This is mainly due to lack of availability of verified full vehicle flexible-body models. The verification process is costly as it requires instrumentation of a heavy vehicle, scanning of road surfaces, and collection of data by running the vehicle over different road conditions, performing various maneuvering, etc. This paper presents the reverse engineering process of a class-8 truck and validation of a full flexible-body simulation model of a Wabash 53-foot trailer against the strain data recoded from proving ground testing of an instrumented truck. Simulation results show that, with the exception of the noise from the strain gage data from instrumented test run at 30 mph, there is a good agreement in periodicity and relative amplitude with the ADAMS model. A comparison of strain data from the flex-body model and the instrumented truck shows that the modeling and verification approach presented in this paper can be confidently used to validate the full flexible-body models developed for specific analyses.
文摘This paper presents a 1.8 GHz class-E controlled power amplifier (PA). The proposed power amplifier is designed with two-stage architecture. The main advantage of the proposed technique for output control power is a high 37 dB output power dynamic range with good average power adding efficiency. The measurement results show that the PA achieves a high power gain of 23 dBm and power added efficiency (PAE) by 38%. The circuit was post layout simulated in a standard 0.18 μm CMOS technology.
文摘The appearance of third-generation semiconductors represented by gallium nitride （GaN） material greatly improves the output power of a power amplifier （PA）, but the efficiency of the PA needs to be further improved. The Class-F PA reduces the overlap of drain voltage and current by tuning harmonic impedance so that high efficiency is achieved. This paper begins with the principle of class-F PA, regards the third harmonic voltage as an independent variable, analyzes the influence of the third harmonic on fundamental, and points out how drain efficiency and output power vary with the third harmonic voltage with an I-V knee effect. Finally, the best third harmonic impedance is found mathematically. We compare our results with the Loadpull technique in advanced design system environment and conclude that an optimized third harmonic impedance is open in an ideal case, while it is not at an open point with the I-V knee effect, and the drain efficiency with optimized third harmonic impedance is 4% higher than that with the third harmonic open.
