[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by...[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by determination of the contents of four cell wall materials, six routine chemical components, as well as aroma constituents. [Result] Pectinase could effectively reduce the contents of cell wall materials in tobacco stems, with the largest decrease of 6.84%; after pectinase treatment,the content of reducing sugar in tobacco stems increased obviously, and the contents of total sugar, potassium ion, chloride ion and total nitrogen increased to varying degrees, of which the contents of potassium ion and reducing sugar displayed upward trends with the increase of pectinase concentration. Pectinase treatment significantly increased the contents of Maillard reaction products, with the most increase of 67.2%;the contents of carotenoid degradation products, phenylalanine degradation products and neophytadiene all increased to varying extents, and the contents of both Maillard reaction products and phenylalanine degradation products revealed ascending trends with the increase of pectinase concentration. [Conclusion] Pectinase treatment can effectively decompose cell wall materials in tobacco stems, improve routine chemical constituents, and increase the contents of aroma constituents.展开更多
A heated air circulation standard curing barn was used for baking tobacco leaves, and the effects of different yellowing conditions during the baking process on contents of neutral aroma components and smoking quality...A heated air circulation standard curing barn was used for baking tobacco leaves, and the effects of different yellowing conditions during the baking process on contents of neutral aroma components and smoking quality of upper leaves were studied by setting different yellowing time and color-fixing time. The results showed that during the baking process, only by prolonging the yellowing time by 24 h on the basis of control, the content of every kind of neutral aroma components in- creased obviously and the content of solanone increased by nearly 2.20 times. It was unfavorable for the degradation and accumulation of aroma components when only prolonging color-fixing time by 24 h. Prolonging both yellowing time and color- fixing time by 24 h mainly promoted the accumulation of chlorophyll degradation product neophytadiene, which increased by 33.24%, while the degradation and ac- cumulation of some aroma components were inhibited, indicating that only prolonging the yellowing time by 24 h could promote the accumulation of various kinds of neu- tral aroma components and improve the quality of tobacco leaves. The regression models were established of neutral aroma components in the first and second prin- cipal components to total aroma content, which were y=x+0.053 47 (R^2=0.919 7) and y=x+0.147 5 (R^2=0.698 4), respectively, and they were verified to be feasible.展开更多
Large-scale synthesis of ZnO hexagonal pyramids was achieved by a simple thermal decomposition route of precursor at 240 oC in the presence of PEG400. The precursor was obtained by room-temperature solid-state grindin...Large-scale synthesis of ZnO hexagonal pyramids was achieved by a simple thermal decomposition route of precursor at 240 oC in the presence of PEG400. The precursor was obtained by room-temperature solid-state grinding reaction between Zn(CH3COO)2-2H2O and Na2CO3. Crystal structure and morphology of the products were analyzed and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results of further experiments show that PEG400 has an important role in the formation of ZnO hexagonal pyramids. Difference between the single and double hexagonal pyramid structure may come from the special thermal decomposition reaction. The photoluminescence (PL) spectra of ZnO hexagonal pyramids exhibit strong near-band-edge emission at about 386 nm and weak green emission at about 550 nm. The Raman-active vibration at about 435 cm-1 suggests that the ZnO hexagonal pyramids have high crystallinity.展开更多
The evolution of stresses due to inhomogeneity in metal injection molding (MIM) parts during sintering was investigated. The sintering model of porous materials during densification process was developed based on th...The evolution of stresses due to inhomogeneity in metal injection molding (MIM) parts during sintering was investigated. The sintering model of porous materials during densification process was developed based on the continuum mechanics and thermal elasto-viseoplastic constitutive law. Model parameters were identified from the dilatometer sintering experiment. The real density distribution of green body was measured by X-ray computed tomography (CT), which was regarded as the initial condition of sintering model. Numerical calculation of the above sintering model was carried out with the finite element soRware Abaqus, through the user-defined material mechanical behavior (UMAT). The calculation results showed that shrinkages of low density regions were faster than those of high density regions during sintering, which led to internal stresses. Compressive stresses existed in high density regions and tensile stresses existed in low density regions. The densification of local regions depended on not only the initial density, but also the evolution of stresses during the sintering stage.展开更多
Taking Ti6Al4V titanium alloy powder as the research object,on the basis of single layer scanning and single channel scanning experiment,this paper studies the influence of selective laser melting(SLM)process paramete...Taking Ti6Al4V titanium alloy powder as the research object,on the basis of single layer scanning and single channel scanning experiment,this paper studies the influence of selective laser melting(SLM)process parameters on Ti6Al4V alloy material formability,and block forming experiment is carried out.Through the design of orthogonal experiment,morphology observation of sample and density analysis,results show that the best block molding parameters of SLM technology in Ti6Al4V alloy powder are laser power of 400 W,lap rate of 1 and the scanning speed of 750 mm/min,density can up to 96.17%.展开更多
A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NM...A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.展开更多
Influence of molecular composition in hemicyanine Langmuir-Blodgett (LB) films on the aggregation features was investigated by using steady state and time-resolved photoluminescence spectroscopy.It was found that a lo...Influence of molecular composition in hemicyanine Langmuir-Blodgett (LB) films on the aggregation features was investigated by using steady state and time-resolved photoluminescence spectroscopy.It was found that a lower degree of H-aggregation (smaller aggregate size) could be realized in hemicyanine LB films with larger donor groups,leading to a smaller photoluminescence peak blue shift with respect to their solution spectra and longer aggregate lifetime.展开更多
An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2][6-(6'-(4"-( 5"-phenyl- 1", 3", 4"-oxadiazole-2"-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by IH NMR and elementary ...An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2][6-(6'-(4"-( 5"-phenyl- 1", 3", 4"-oxadiazole-2"-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by IH NMR and elementary analysis in order to study the effect of ancillary ligand of the oxadiazole-based picolinic acid derivative on optophysical properties of its iridium complex, and further to obtain an iridium complex with highly-efficient blue emission. The thermal stability, UV absorption and photoluminescent properties of this iridium complex were investigated. Compared with iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2](picolinate) reported as a highly-efficient blue electroluminescent material, this iridium complex bearing an oxadiazole-based picolinic acid derivative presents higher thermal stability, more intense UV absorption at 291 nm and similar photoluminescent spectrum peaked at 469 nm. This indicates that tuning ancillary ligand of picolinic acid with an oxadiazole unit can improve the optophysical properties of its iridium complex.展开更多
In this study,based on the body wave arrival data of 5506 earthquakes recorded by 32 fi xed stations and 94 temporary stations in Yangbi and surrounding areas,the source parameters of Yangbi Ms6.4 earthquake sequence ...In this study,based on the body wave arrival data of 5506 earthquakes recorded by 32 fi xed stations and 94 temporary stations in Yangbi and surrounding areas,the source parameters of Yangbi Ms6.4 earthquake sequence and three-dimensional(3-D)fi ne Vp,Vs,and Vp/Vs were inverted by using the consistency-constrained double-diff erence tomography method.The results showed that the focal depth after relocation was mostly in the range of 3–10 km,evidently nearly horizontally distributed,and concentrated in the weak area of the high-velocity body or at the side of the high-low-velocity body transition zone toward the high-velocity body,showing a good corresponding relationship with the velocity structure.The velocity structure in the Yangbi area has remarkably uneven characteristics.The seismic activity area is dominated by high-velocity bodies prone to brittle fracture near the surface.As the depth increases,low-velocity anomalies appear.A signifi cant diff erence was observed in the wave velocity ratio between the upper and lower sides of the seismically dense strip.Based on the focal mechanism of the Yangbi Ms6.4 earthquake and the fine 3-D velocity structure,this article concludes that the Yangbi Ms6.4 earthquake was caused by a strong regional tectonic stress concentrated in the relatively weak area by hard high-velocity bodies on the northwest sides.The Ms5.6 foreshock broke the inherent balance of regional stress and promoted the occurrence of the Yangbi Ms6.4 mainshock.Afterward,the stress was adjusted to a new equilibrium state through a large number of aftershocks,forming a foreshock–mainshock–aftershock type of seismic activity model.Based on the activity law of the Yangbi Ms6.4 earthquake sequence and characteristics of the 3D velocity structure distribution,this paper speculates that the seismogenic structure of the Yangbi earthquake was possibly a northwest strike-slip buried fault with a depth of 3–10 km on the southwest side of the Weixi–Qiaohou fault.展开更多
A novel photothermal drive method was proposed. A novel photothermal micro-actuator (PTA) was developed with this method. We introduced the deflection mechanism of the asymmetric expansive arms with different widths...A novel photothermal drive method was proposed. A novel photothermal micro-actuator (PTA) was developed with this method. We introduced the deflection mechanism of the asymmetric expansive arms with different widths. When a beam of infrared laser irradiates the arms, the different increase temperature and photothermal expansion controlled by the different rates of specific surface area cause a magnified lateral deflection. A prototyping micro-actuator of 1000 μm length was manufactured by using anexcimer laser micromachining system, and using polypropylene material. Experiments have been carded out to check the feasibility of deflection, with a laser diode (650 nm) as the external power source to activate the micro-actuator. The results show that the actuator can practically generate an obvious lateral deflection without considering the size or the location of the irradiated light spot strictly. The deflection status of the micro-actuator could be controlled remotely from 0 μm to 14.33 μm by changing the laser power from 0 mW to 10 mW. This kind of novel PTA is quite simple and convenient for operation. It will be quite useful for the applications in the fields of micro/nano-technology and with large displacement/actuation force and remote controlling.展开更多
The sequence of the densification and hydrocarbon charging of the Xu2 reservoir in the Anyue–Hechuan area of Central Sichuan Basin is discussed.The diagenetic sequence is considered a time line to determine the histo...The sequence of the densification and hydrocarbon charging of the Xu2 reservoir in the Anyue–Hechuan area of Central Sichuan Basin is discussed.The diagenetic sequence is considered a time line to determine the historical relationship between the densification process and the hydrocarbon charging of the Xu2 reservoir in the study area:Early diagenetic stage B(the first stage of hydrocarbon charging,which was about 200–160 Ma ago,with a porosity of about 20%,consolidated and not tight)→middle diagenetic stage A(the second stage of hydrocarbon charging,which was about 140–120 Ma ago,with a porosity of 10%–20%and relatively tight)→middle diagenetic stage B(the third stage of hydrocarbon charging,which was about 20–5 Ma ago,with a porosity of 6%–10%and tight;However,fractures have developed).The study results prove that large-scale hydrocarbon charging and accumulation completed before the densification of the Xu2 reservoir,showing that the Upper Triassic Xujiahe Fm unconventional tight reservoir in the Sichuan Basin is prospective for exploration.展开更多
Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the pos...Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the possi-ble mechanism.Methods.Human umbilical vein endothelial ce lls(HUVECs )were obtained from normal fetus,and cul-tured conventionally.Then the HUVECs were exposed to test agents(linolenic acid,linoleic acid,oleic acid,stearic acid and prostaglandin J 2 respectively)in varying concentrations with fresh media.RT -PCR and ELISA were applied to determine the expression of PPARs and PAI-1in HUVECs.Results.PPARα,PPARδand PPARγmRNA were detected by using RT-PCR in HUVECs.Treatment of HUVECs with PPARαand PPARγactivators---linolenic acid,linoleic acid,oleic acid and prostaglandin J 2 respectively,but not with stearic a cid could augment PAI-I mRNA expression and protein secretion in a concentration-dependent manner.However,the mRNA expressions of 3subclasses of PPAR with their activators in HUVECs were not changed compared w ith controls.Conclusion.HUVECs express PPARs.PPARs activators may increase PAI-1expression in ECs,but the underlying mechanism remains uncle ar.Although PPARs expression was not enhanced after stimulated by their activators in ECs,the role of functionally active PPARs in regulating PA I-1expression in ECs needs to be further investigated by using transient gen e transfection assay.展开更多
The ancient Chinese people had developed, on the relationship between the human body, disease and the environment, a variety of explanatory models. "From the disease caused by insects", the theoretical resources bui...The ancient Chinese people had developed, on the relationship between the human body, disease and the environment, a variety of explanatory models. "From the disease caused by insects", the theoretical resources built one of the concepts of disease of the Chinese people in the Late Qing Dynasty. From the middle of the nineteenth century, the pathogenicity of bacteria was not only born in the West, but also translated into China through various channels. When China's "insects" and "mushroom" encountered the Western bacterial pathogenicity, "insects" and "mushroom" have become the concept of access to the knowledge base of bacteria. Xi Jun (,~11]~) is one of the many new nouns born in the late Qing Dynasty. China often uses "bi ta li ya" (~d^J~]~) and other transliteration, such as microbial, mold and other names for translation. Behind the translated name, the complex and diverse knowledge of the people at that time are reflected, showing a reasonable imagination of flying insects in the wind.展开更多
Parity testing is one of the compact testing techniques, which, traditionally, relies on applying all 2^n input combinations to an n-input combinational circuit without need of knowing the implementation of the circui...Parity testing is one of the compact testing techniques, which, traditionally, relies on applying all 2^n input combinations to an n-input combinational circuit without need of knowing the implementation of the circuits under test. The faults can be detected just by observing and comparing its parity of whole output of circuit with the expectation one. The way seemed to be less interesting to the test eagineers in the past days, mainly due to the reasons of its exhaustive testing and time-cousuming, which became a barrier as the number of input lines gets growing. However its great facility and convenience in testing still interest to the engineers who need to have a quick look at the qualities of the circuits without generating the test patterns for a given circuit to be tested. In this paper, a new approach called pseudo-parity testing is presented to deal with the dilemma we are facing: i. e. to change an exhaustive parity testing into a non-exhaustive one, followed by a pseudo- parity testable design to help realize the new way of pseudo-parity testing. The idea of pseudo-parity testing presented in this paper may resume its spirits towards its promising future.展开更多
Background: Plasmodium falciparum malaria remains a major life-threatening disease. Recently, the Plasmodium apoptosis-linked pathogenicity factors (PALPF) have been identified. These antigens PALPF are expressed o...Background: Plasmodium falciparum malaria remains a major life-threatening disease. Recently, the Plasmodium apoptosis-linked pathogenicity factors (PALPF) have been identified. These antigens PALPF are expressed only by P falciparum-infected erythrocytes triggering endothelial cell apoptosis (apoptogenic). Methods: We designed ten synthetic peptides (PI to P10) from PALPF: PF07 0032, PF10_0226, PFI0130c, PFD0875c and MAL13P1.206, and analyzed their antigenicity with an ELISA method using plasma samples from subjects living in Dienga, Gabon. Results: Four peptides showed good reactivity with human antibodies. The prevalence rate of specific IgG was 61%, 51%, 44% and 34% for P5, P6, P4 and P2, respectively. The median optical density of total IgG anti-P2 was higher than that directed against P4 and P6 (P = 0.009; P = 0.012 respectively). The prevalence rate oflgG subclasses determined with plasma samples recognizing peptide 5 for IgGl, 2, 3 and 4 isotypes was 69%, 45%, 76% and 62%, respectively. All the subjects had at least one immunoglobulin subclass, while 13 (44%) had both IgG1 and IgG3 antibodies. There was no significant difference in the prevalence rate of anti-P5 IgG1, IgG3 and IgG4. Conclusion: These results warrant further immunogenicity studies of peptides 2, 4, 5 and 6 with a view of a tentative to antimalarial vaccine development.展开更多
基金Supported by the Special Fund of Hongyun Honghe Tobacco(Group)Co.,Ltd~~
文摘[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by determination of the contents of four cell wall materials, six routine chemical components, as well as aroma constituents. [Result] Pectinase could effectively reduce the contents of cell wall materials in tobacco stems, with the largest decrease of 6.84%; after pectinase treatment,the content of reducing sugar in tobacco stems increased obviously, and the contents of total sugar, potassium ion, chloride ion and total nitrogen increased to varying degrees, of which the contents of potassium ion and reducing sugar displayed upward trends with the increase of pectinase concentration. Pectinase treatment significantly increased the contents of Maillard reaction products, with the most increase of 67.2%;the contents of carotenoid degradation products, phenylalanine degradation products and neophytadiene all increased to varying extents, and the contents of both Maillard reaction products and phenylalanine degradation products revealed ascending trends with the increase of pectinase concentration. [Conclusion] Pectinase treatment can effectively decompose cell wall materials in tobacco stems, improve routine chemical constituents, and increase the contents of aroma constituents.
基金Supported by Major Special Project of Strong-flavor Characteristic High-quality Tobacco Development of China National Tobacco Company(110201101001 TS-01)China Tobacco Project of Jilin Province(JY2013001)~~
文摘A heated air circulation standard curing barn was used for baking tobacco leaves, and the effects of different yellowing conditions during the baking process on contents of neutral aroma components and smoking quality of upper leaves were studied by setting different yellowing time and color-fixing time. The results showed that during the baking process, only by prolonging the yellowing time by 24 h on the basis of control, the content of every kind of neutral aroma components in- creased obviously and the content of solanone increased by nearly 2.20 times. It was unfavorable for the degradation and accumulation of aroma components when only prolonging color-fixing time by 24 h. Prolonging both yellowing time and color- fixing time by 24 h mainly promoted the accumulation of chlorophyll degradation product neophytadiene, which increased by 33.24%, while the degradation and ac- cumulation of some aroma components were inhibited, indicating that only prolonging the yellowing time by 24 h could promote the accumulation of various kinds of neu- tral aroma components and improve the quality of tobacco leaves. The regression models were established of neutral aroma components in the first and second prin- cipal components to total aroma content, which were y=x+0.053 47 (R^2=0.919 7) and y=x+0.147 5 (R^2=0.698 4), respectively, and they were verified to be feasible.
基金Project (BK2009379) supported by the Natural Science Foundation of Jiangsu Province, ChinaProject (1006-56XNA12069) supported by the Nanjing University of Aeronautics and Astronautics Research Funding, China+3 种基金Projects (51172108, 91023020) supported by the National Natural Science Foundation of ChinaProject (IRT0968) supported by the Program for Changjiang Scholars and Innovative Research Team in University, ChinaProject (NCET-10-0070) supported by the Program for New Century Excellent Talents in University, ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘Large-scale synthesis of ZnO hexagonal pyramids was achieved by a simple thermal decomposition route of precursor at 240 oC in the presence of PEG400. The precursor was obtained by room-temperature solid-state grinding reaction between Zn(CH3COO)2-2H2O and Na2CO3. Crystal structure and morphology of the products were analyzed and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results of further experiments show that PEG400 has an important role in the formation of ZnO hexagonal pyramids. Difference between the single and double hexagonal pyramid structure may come from the special thermal decomposition reaction. The photoluminescence (PL) spectra of ZnO hexagonal pyramids exhibit strong near-band-edge emission at about 386 nm and weak green emission at about 550 nm. The Raman-active vibration at about 435 cm-1 suggests that the ZnO hexagonal pyramids have high crystallinity.
基金Project(2011CB606306)supported by the National Basic Research Program of ChinaProject(FRF-TP-10-003B)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(51274040)supported by the National Natural Science Foundation of China
文摘The evolution of stresses due to inhomogeneity in metal injection molding (MIM) parts during sintering was investigated. The sintering model of porous materials during densification process was developed based on the continuum mechanics and thermal elasto-viseoplastic constitutive law. Model parameters were identified from the dilatometer sintering experiment. The real density distribution of green body was measured by X-ray computed tomography (CT), which was regarded as the initial condition of sintering model. Numerical calculation of the above sintering model was carried out with the finite element soRware Abaqus, through the user-defined material mechanical behavior (UMAT). The calculation results showed that shrinkages of low density regions were faster than those of high density regions during sintering, which led to internal stresses. Compressive stresses existed in high density regions and tensile stresses existed in low density regions. The densification of local regions depended on not only the initial density, but also the evolution of stresses during the sintering stage.
文摘Taking Ti6Al4V titanium alloy powder as the research object,on the basis of single layer scanning and single channel scanning experiment,this paper studies the influence of selective laser melting(SLM)process parameters on Ti6Al4V alloy material formability,and block forming experiment is carried out.Through the design of orthogonal experiment,morphology observation of sample and density analysis,results show that the best block molding parameters of SLM technology in Ti6Al4V alloy powder are laser power of 400 W,lap rate of 1 and the scanning speed of 750 mm/min,density can up to 96.17%.
文摘A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.
文摘Influence of molecular composition in hemicyanine Langmuir-Blodgett (LB) films on the aggregation features was investigated by using steady state and time-resolved photoluminescence spectroscopy.It was found that a lower degree of H-aggregation (smaller aggregate size) could be realized in hemicyanine LB films with larger donor groups,leading to a smaller photoluminescence peak blue shift with respect to their solution spectra and longer aggregate lifetime.
基金Projects(20772101,50473046) supported by the National Natural Science Foundation of ChinaProject(2007FJ3017) supported by the Hunan Provincial Science Foundation, ChinaProject(07C764) supported by the Science Foundation of the Education Department of Hunan Province,China
文摘An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2][6-(6'-(4"-( 5"-phenyl- 1", 3", 4"-oxadiazole-2"-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by IH NMR and elementary analysis in order to study the effect of ancillary ligand of the oxadiazole-based picolinic acid derivative on optophysical properties of its iridium complex, and further to obtain an iridium complex with highly-efficient blue emission. The thermal stability, UV absorption and photoluminescent properties of this iridium complex were investigated. Compared with iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2](picolinate) reported as a highly-efficient blue electroluminescent material, this iridium complex bearing an oxadiazole-based picolinic acid derivative presents higher thermal stability, more intense UV absorption at 291 nm and similar photoluminescent spectrum peaked at 469 nm. This indicates that tuning ancillary ligand of picolinic acid with an oxadiazole unit can improve the optophysical properties of its iridium complex.
基金supported by the Research Project of Tianjin Earthquake Agency (No. Yb202101, Zd202101)
文摘In this study,based on the body wave arrival data of 5506 earthquakes recorded by 32 fi xed stations and 94 temporary stations in Yangbi and surrounding areas,the source parameters of Yangbi Ms6.4 earthquake sequence and three-dimensional(3-D)fi ne Vp,Vs,and Vp/Vs were inverted by using the consistency-constrained double-diff erence tomography method.The results showed that the focal depth after relocation was mostly in the range of 3–10 km,evidently nearly horizontally distributed,and concentrated in the weak area of the high-velocity body or at the side of the high-low-velocity body transition zone toward the high-velocity body,showing a good corresponding relationship with the velocity structure.The velocity structure in the Yangbi area has remarkably uneven characteristics.The seismic activity area is dominated by high-velocity bodies prone to brittle fracture near the surface.As the depth increases,low-velocity anomalies appear.A signifi cant diff erence was observed in the wave velocity ratio between the upper and lower sides of the seismically dense strip.Based on the focal mechanism of the Yangbi Ms6.4 earthquake and the fine 3-D velocity structure,this article concludes that the Yangbi Ms6.4 earthquake was caused by a strong regional tectonic stress concentrated in the relatively weak area by hard high-velocity bodies on the northwest sides.The Ms5.6 foreshock broke the inherent balance of regional stress and promoted the occurrence of the Yangbi Ms6.4 mainshock.Afterward,the stress was adjusted to a new equilibrium state through a large number of aftershocks,forming a foreshock–mainshock–aftershock type of seismic activity model.Based on the activity law of the Yangbi Ms6.4 earthquake sequence and characteristics of the 3D velocity structure distribution,this paper speculates that the seismogenic structure of the Yangbi earthquake was possibly a northwest strike-slip buried fault with a depth of 3–10 km on the southwest side of the Weixi–Qiaohou fault.
基金the National High Technology Research and Development Program of China (Grant No.2006AA04Z237)
文摘A novel photothermal drive method was proposed. A novel photothermal micro-actuator (PTA) was developed with this method. We introduced the deflection mechanism of the asymmetric expansive arms with different widths. When a beam of infrared laser irradiates the arms, the different increase temperature and photothermal expansion controlled by the different rates of specific surface area cause a magnified lateral deflection. A prototyping micro-actuator of 1000 μm length was manufactured by using anexcimer laser micromachining system, and using polypropylene material. Experiments have been carded out to check the feasibility of deflection, with a laser diode (650 nm) as the external power source to activate the micro-actuator. The results show that the actuator can practically generate an obvious lateral deflection without considering the size or the location of the irradiated light spot strictly. The deflection status of the micro-actuator could be controlled remotely from 0 μm to 14.33 μm by changing the laser power from 0 mW to 10 mW. This kind of novel PTA is quite simple and convenient for operation. It will be quite useful for the applications in the fields of micro/nano-technology and with large displacement/actuation force and remote controlling.
基金Project(41372141) supported by the National Natural Science Foundation of ChinaProject(2008ZX05001–05–01) supported by Special and Significant Project of National Science and Technology,China
文摘The sequence of the densification and hydrocarbon charging of the Xu2 reservoir in the Anyue–Hechuan area of Central Sichuan Basin is discussed.The diagenetic sequence is considered a time line to determine the historical relationship between the densification process and the hydrocarbon charging of the Xu2 reservoir in the study area:Early diagenetic stage B(the first stage of hydrocarbon charging,which was about 200–160 Ma ago,with a porosity of about 20%,consolidated and not tight)→middle diagenetic stage A(the second stage of hydrocarbon charging,which was about 140–120 Ma ago,with a porosity of 10%–20%and relatively tight)→middle diagenetic stage B(the third stage of hydrocarbon charging,which was about 20–5 Ma ago,with a porosity of 6%–10%and tight;However,fractures have developed).The study results prove that large-scale hydrocarbon charging and accumulation completed before the densification of the Xu2 reservoir,showing that the Upper Triassic Xujiahe Fm unconventional tight reservoir in the Sichuan Basin is prospective for exploration.
文摘Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the possi-ble mechanism.Methods.Human umbilical vein endothelial ce lls(HUVECs )were obtained from normal fetus,and cul-tured conventionally.Then the HUVECs were exposed to test agents(linolenic acid,linoleic acid,oleic acid,stearic acid and prostaglandin J 2 respectively)in varying concentrations with fresh media.RT -PCR and ELISA were applied to determine the expression of PPARs and PAI-1in HUVECs.Results.PPARα,PPARδand PPARγmRNA were detected by using RT-PCR in HUVECs.Treatment of HUVECs with PPARαand PPARγactivators---linolenic acid,linoleic acid,oleic acid and prostaglandin J 2 respectively,but not with stearic a cid could augment PAI-I mRNA expression and protein secretion in a concentration-dependent manner.However,the mRNA expressions of 3subclasses of PPAR with their activators in HUVECs were not changed compared w ith controls.Conclusion.HUVECs express PPARs.PPARs activators may increase PAI-1expression in ECs,but the underlying mechanism remains uncle ar.Although PPARs expression was not enhanced after stimulated by their activators in ECs,the role of functionally active PPARs in regulating PA I-1expression in ECs needs to be further investigated by using transient gen e transfection assay.
基金This paper is sponsored by the Beijing YuRun Foundation (北京玉润公益基金会).
文摘The ancient Chinese people had developed, on the relationship between the human body, disease and the environment, a variety of explanatory models. "From the disease caused by insects", the theoretical resources built one of the concepts of disease of the Chinese people in the Late Qing Dynasty. From the middle of the nineteenth century, the pathogenicity of bacteria was not only born in the West, but also translated into China through various channels. When China's "insects" and "mushroom" encountered the Western bacterial pathogenicity, "insects" and "mushroom" have become the concept of access to the knowledge base of bacteria. Xi Jun (,~11]~) is one of the many new nouns born in the late Qing Dynasty. China often uses "bi ta li ya" (~d^J~]~) and other transliteration, such as microbial, mold and other names for translation. Behind the translated name, the complex and diverse knowledge of the people at that time are reflected, showing a reasonable imagination of flying insects in the wind.
基金This work was supported by National Natural Science Foundation of China under the grant No .60173029 and 60473033
文摘Parity testing is one of the compact testing techniques, which, traditionally, relies on applying all 2^n input combinations to an n-input combinational circuit without need of knowing the implementation of the circuits under test. The faults can be detected just by observing and comparing its parity of whole output of circuit with the expectation one. The way seemed to be less interesting to the test eagineers in the past days, mainly due to the reasons of its exhaustive testing and time-cousuming, which became a barrier as the number of input lines gets growing. However its great facility and convenience in testing still interest to the engineers who need to have a quick look at the qualities of the circuits without generating the test patterns for a given circuit to be tested. In this paper, a new approach called pseudo-parity testing is presented to deal with the dilemma we are facing: i. e. to change an exhaustive parity testing into a non-exhaustive one, followed by a pseudo- parity testable design to help realize the new way of pseudo-parity testing. The idea of pseudo-parity testing presented in this paper may resume its spirits towards its promising future.
文摘Background: Plasmodium falciparum malaria remains a major life-threatening disease. Recently, the Plasmodium apoptosis-linked pathogenicity factors (PALPF) have been identified. These antigens PALPF are expressed only by P falciparum-infected erythrocytes triggering endothelial cell apoptosis (apoptogenic). Methods: We designed ten synthetic peptides (PI to P10) from PALPF: PF07 0032, PF10_0226, PFI0130c, PFD0875c and MAL13P1.206, and analyzed their antigenicity with an ELISA method using plasma samples from subjects living in Dienga, Gabon. Results: Four peptides showed good reactivity with human antibodies. The prevalence rate of specific IgG was 61%, 51%, 44% and 34% for P5, P6, P4 and P2, respectively. The median optical density of total IgG anti-P2 was higher than that directed against P4 and P6 (P = 0.009; P = 0.012 respectively). The prevalence rate oflgG subclasses determined with plasma samples recognizing peptide 5 for IgGl, 2, 3 and 4 isotypes was 69%, 45%, 76% and 62%, respectively. All the subjects had at least one immunoglobulin subclass, while 13 (44%) had both IgG1 and IgG3 antibodies. There was no significant difference in the prevalence rate of anti-P5 IgG1, IgG3 and IgG4. Conclusion: These results warrant further immunogenicity studies of peptides 2, 4, 5 and 6 with a view of a tentative to antimalarial vaccine development.