AIM:To ascertain the pattern of investigations at first contact in uveitic patients and evaluate compliance to treatment.METHODS:An observational study comprised of 201 uveitic patients presenting for the first time t...AIM:To ascertain the pattern of investigations at first contact in uveitic patients and evaluate compliance to treatment.METHODS:An observational study comprised of 201 uveitic patients presenting for the first time to our centre from January 2019 to June 2020.Detailed information regarding systemic investigations undertaken by specialists at the time of first contact and the cost of these investigations were reviewed on the first visit to our centre.Compliance with the treatment was determined and reasons behind non-compliance were evaluated on the first follow-up in patients who had no improvement in clinical signs and symptoms.RESULTS:The mean age of the study group was 35.35±14.1y and gender composition was 59.7%males and 40.3%females.Anterior uveitis was observed in 45.3%of patients,intermediate uveitis in 31.8%of patients,posterior uveitis in 14.9%of patients and panuveitis in 8.0%of patients.Association with a systemic disease was evident in 17.9%of patients.When compared with standard guidelines and uveitis patterns,systemic investigations were identified to be relevant only in 38.3%of patients.Non-compliance to treatment was documented in 22.4%of patients.Common reasons for non-compliance were inadequate counselling by the treating physician about treatment in 26.7%of patients and a busy schedule at work/school in 22.2%of patients.CONCLUSION:Significant number of investigations performed at first contact is found to be contrary to standard guidelines and are not contributory to the care.About a quarter of patients in this study are found to be non-compliant with the treatment.Compliance is more challenging to achieve in school-going children and working adults.The availability of comprehensive,periodically updated,evidence-based guidelines on the role of investigations and the use of trained counsellors may help to channelize proper evaluation and improve compliance to treatment,respectively,in patients with uveitis.展开更多
Rabies is an infectious disease that almost always leads to death as soon as the first signs appear, and is still endemic in several regions, including Côte d’Ivoire. Epidemiological investigations are carried o...Rabies is an infectious disease that almost always leads to death as soon as the first signs appear, and is still endemic in several regions, including Côte d’Ivoire. Epidemiological investigations are carried out and response measures implemented in the event of any death from human rabies. However, the quality of these investigations does not always allow the adoption of response measures. The aim of this work was to evaluate the reports of epidemiological investigations and response actions carried out during the occurrence of human rabies deaths from 2016 to 2018. This was a cross-sectional study that took place from April to September 2021 at the National Institute of Public Hygiene and focused on human rabies deaths notified from 206 to 2018. Of sixty-one (61) human rabies deaths recorded, sixty (60) were investigated, among which fifty-nine (59) deaths had been subject to response. Most deaths occurred in rural areas (75%), and the main vector was the dog (98%). Several shortcomings were noted: response actions were not carried out promptly;joint interventions bringing together human and animal health professionals were rare, there was little communication about rabies to communities (36%), and very little vaccination of the vector, the source of the disease (12%);an almost total absence of capacity-building for local players (7%);the health districts of Abobo-Ouest, Bondoukou, Divo and Fresco, which had regularly recorded human rabies deaths, had not benefited from dog vaccination, which is supposed to break the circulation of the virus. The persistence of rabies deaths in the health districts could probably be linked to these shortcomings. Faced with these realities, it is essential to strengthen the epidemiological investigation capacities of the players involved, in order to improve the quality of investigations and ensure an effective response.展开更多
Rabies is an infectious disease that almost always leads to death as soon as the first signs appear, and is still endemic in several regions, including Côte d’Ivoire. Epidemiological investigations are carried o...Rabies is an infectious disease that almost always leads to death as soon as the first signs appear, and is still endemic in several regions, including Côte d’Ivoire. Epidemiological investigations are carried out and response measures implemented in the event of any death from human rabies. However, the quality of these investigations does not always allow the adoption of response measures. The aim of this work was to evaluate the reports of epidemiological investigations and response actions carried out during the occurrence of human rabies deaths from 2016 to 2018. This was a cross-sectional study that took place from April to September 2021 at the National Institute of Public Hygiene and focused on human rabies deaths notified from 206 to 2018. Of sixty-one (61) human rabies deaths recorded, sixty (60) were investigated, among which fifty-nine (59) deaths had been subject to response. Most deaths occurred in rural areas (75%), and the main vector was the dog (98%). Several shortcomings were noted: response actions were not carried out promptly;joint interventions bringing together human and animal health professionals were rare, there was little communication about rabies to communities (36%), and very little vaccination of the vector, the source of the disease (12%);an almost total absence of capacity-building for local players (7%);the health districts of Abobo-Ouest, Bondoukou, Divo and Fresco, which had regularly recorded human rabies deaths, had not benefited from dog vaccination, which is supposed to break the circulation of the virus. The persistence of rabies deaths in the health districts could probably be linked to these shortcomings. Faced with these realities, it is essential to strengthen the epidemiological investigation capacities of the players involved, in order to improve the quality of investigations and ensure an effective response.展开更多
In this study,the texture evolutions of two Mg materials during tension are explored.In-situ X-ray synchrotron and Visco-Plastic SelfConsistent(VPSC) modeling are employed to investigate the different deformation mode...In this study,the texture evolutions of two Mg materials during tension are explored.In-situ X-ray synchrotron and Visco-Plastic SelfConsistent(VPSC) modeling are employed to investigate the different deformation modes between pure Mg and Mg-15Gd(wt.%) alloy.These two materials with a strong extrusion texture show large different slip/twinning activity behaviors during tensile deformation.The basal(a) slip has the highest contribution to the initial stage of plastic deformation for pure Mg.During the subsequent plastic deformation,the prismatic slip is dominant due to the strong ED//(100) fiber texture.In contrast,the deformation behavior of Mg-15Gd alloy is more complex.Twinning and basal slip are dominant at the early stage of plastic deformation,but further deformation results in the increased activation of prismatic and pyramidal slips.In comparison to pure Mg,the ratios of the critical resolved shear stress(CRSS) between non-basal slip and basal slip of the Mg-15Gd alloy are much lower.展开更多
Thermal performance enhancement in a square channel heat exchanger(HX)using a passive technique is presented.Vortex turbulator insertion in a square channel HX as a passive technique is selected for thermal improvemen...Thermal performance enhancement in a square channel heat exchanger(HX)using a passive technique is presented.Vortex turbulator insertion in a square channel HX as a passive technique is selected for thermal improvement.The vortex turbulator of interest is discrete X-V baffles(XVB).The discrete XVBs are inserted in the square channel with the main aim of generating vortex flow.The vortex flow generated can support the enhanced convective heat transfer coefficient and also enhance HX performance.Effects of baffle configuration(type A and B),baffle size(w/H=0.05,0.10,0.15 and 0.20),baffle distance(e/H=1,1.5 and 2)and flow direction(±x air flow paths)on fluid flow and thermal topologies are numerically investigated by using a commercial code.As shown by the numerical results,the predicted flow configuration with the discrete XVB insertions,which include impinging and vortex streams,is found through the HX channel.The perturbing thermal boundary layer and greater air blending are also found through the HX channel inserted with the discrete XVB.These mechanisms promote and augment the convection heat transfer coefficient,heat transfer rate and rise thermal potentiality.The maximum Nusselt number of the channel with the baffles inserted is 11.01 times upper than that of the smooth channel,while the greatest thermal performance factor(TPF)is observed to be around 3.45.展开更多
Ground penetrating radar （GPR） attribute technology has been applied to many aspects in recent years but there are very few examples in the field of archaeology. Especially how can we extract effective attributes fr...Ground penetrating radar （GPR） attribute technology has been applied to many aspects in recent years but there are very few examples in the field of archaeology. Especially how can we extract effective attributes from the two- or three-dimensional radar data so that we can map and describe numerous archaeological targets in a large cultural site？ In this paper, we applied GPR attribute technology to investigate the ancient Nanzhao castle-site in Tengchong, Yunnan Province. In order to get better archaeological target （the ancient wall, the ancient kiln site, and the ancient tomb） analysis and description, we collated the GPR data by collected standardization and then put them to the seismic data processing and interpretation workstation. The data was processed, including a variety of GPR attribute extraction, analysis, and optimization and combined with the archaeological drilling data. We choose the RMS Amplitude, Average Peak Amplitude, Instantaneous Phase, and Maximum Peak Time to interpret three archaeological targets. By comparative analysis, we have clarified that we should use different attributes to interpret different archaeological targets and the results of attribute analysis after horizon tracking is much better than the results based on a time slice.展开更多
Careful and thorough incident investigations and pre-job safety analyses completed by knowledgeable and competent individuals can significantly reduce workplace incidents. Working parties must act together to make the...Careful and thorough incident investigations and pre-job safety analyses completed by knowledgeable and competent individuals can significantly reduce workplace incidents. Working parties must act together to make these safety tools effective. To get the staff units to work together in a co-ordinated manner, they must be shown the value of their work in preventing accidents. Examples of actual accidents investigated during the author's 18 years as a mine inspector in Saskatchewan are discussed within the context of pre-job safety analyses. The causes of the accidents are explored with close reference to how pre-job safety analyses could have prevented their occurrence.展开更多
In order to reveal combustion characteristics of H_2/air mixture in a micro-combustor with and without bluff body, the effects of inlet velocities, equivalence ratios and bluff body's blockage ratios on the temper...In order to reveal combustion characteristics of H_2/air mixture in a micro-combustor with and without bluff body, the effects of inlet velocities, equivalence ratios and bluff body's blockage ratios on the temperature field, pressure of the combustor wall, combustion efficiency and blow-off limit were investigated. The numerical results indicate that the sudden expansion plate micro combustor with bluff body could enhance the turbulent disturbance of the mixed gas in the combustion chamber and the combustion condition is improved. Moreover, a low-speed and high temperature recirculation region was formed between the sudden expansion step and the bluff body so that the high and uniform wall temperature(>1000 K) could be gotten. As a result, it could strengthen the mixing process, prolong the residence time of gas, control the flame position effectively and widen the operation range by the synergistic effect of the bluff body and steps. When the blockage ratio ranged from 0.3 to 0.6, it could be found that the bluff body could play a stabilizing effect and expand combustion blow burning limit, and combustion efficiency firstly was increased with the inlet velocity and equivalence ratio, and then was decreased.展开更多
The electronic structures of PF and PF＋ are calculated with the high-level configuration interaction method. To improve the precision of calculations, the spin-orbit coupling effect, the scalar relativistic effect, a...The electronic structures of PF and PF＋ are calculated with the high-level configuration interaction method. To improve the precision of calculations, the spin-orbit coupling effect, the scalar relativistic effect, and the Davidson correction（q-Q） are also considered. The spectroscopic parameters of bound states are derived by the electronic structures of PF and PF＋, which are in good accordance with the measurements. The transition dipole moments of spin-allowed transitions are evaluated, and the radiative lifetimes of several A S states of PF and PF＋ are obtained.展开更多
Aluminum/steel electric transition joints (ETJs) are used in aluminum reduction cell for the purpose of welding aluminum rod and steel bracket components. Solid state welding process used for joining aluminum and stee...Aluminum/steel electric transition joints (ETJs) are used in aluminum reduction cell for the purpose of welding aluminum rod and steel bracket components. Solid state welding process used for joining aluminum and steel at the electric transition joints have the drawbacks of cracking and separation at the interface surfaces. Cracking and separation at the electric transition joints are caused by the stress singularities that developed due to the mismatch in thermal and mechanical properties of each material. To overcome the drawback of electric transition joints, aluminum/steel functionally graded may be used as electric transition joints or proposed. Therefore manufacturing and investigation of aluminum/steel functionally graded materials fabricated by powder metallurgy process were carried out through the current work. Different samples with different layers of aluminum/steel functionally graded materials were compacted using steel die and punch at the same compacted pressure and sintered temperature. After investigating the different samples of aluminum/steel functionally graded materials under different fabrication conditions, the suitable fabrication regime was determined with the aid of microscopic observations.展开更多
Crystal structure predictions of Pb0.5Ba0.5 Ti03 alloys under different pressures are performed based on the parti- cle swarming optimization algorithm. The predicted stable ground-state and high-pressure phases are t...Crystal structure predictions of Pb0.5Ba0.5 Ti03 alloys under different pressures are performed based on the parti- cle swarming optimization algorithm. The predicted stable ground-state and high-pressure phases are tetragonal ferroelectric （I4mm） and cubic para-electric （Fm3m）, respectively, whose structural details have not been re- ported. The pressure-induced colossal enhancements in piezoelectric response are associated with the mechanical and dynamical instabilities instead of polarization rotation. The band gap of the tetragonM phase is indirect and that of the cubic phase is always direct. As pressure increases, the alloy displays the similar band-gap behaviors to PbTiO3, while different from BaTiO5, which is attributed to the different orbital contributions to the valence bands. Our calculated results are in good agreement with the available data.展开更多
Described here are the fabrication and characterization of carbon fiber cylinder ultramicroelectrodes with cylinder length of less than 100 am, total tip diameter of several hundreds nanometers. The electrodes have be...Described here are the fabrication and characterization of carbon fiber cylinder ultramicroelectrodes with cylinder length of less than 100 am, total tip diameter of several hundreds nanometers. The electrodes have been fabricated by direct etching of carbon fiber using an ion beam thinner. Optical microscopy, scanning electron microscopy (SEM), cyclic voltammetry have been employed to characterize those electrodes. The experimental results obtained indicate the electrodes can be used for in vivo detection of neurotransmitters such as dopamine, 5—hydroxytryptamine in a single cell.展开更多
Iron ions were used as probes to explore the structural and magnetic properties of 70TeO2'25B2O3' 5SrF2 vitreous matrix. The distribution of Fe3+ ions on different structural aggregates was revealed by means ...Iron ions were used as probes to explore the structural and magnetic properties of 70TeO2'25B2O3' 5SrF2 vitreous matrix. The distribution of Fe3+ ions on different structural aggregates was revealed by means of EPR, as depending on Fe2O3 concentration. Strongly distorted octahedral sites were detected for the isolated paramagnetic ions, and also clusters of Fe ions especially at high Fe2O3 content of samples. Magnetic susceptibility measurements evidenced both dipoledipole and superexchange type interactions involving iron ions. Mixed valence states of iron ions were also detected展开更多
The effects of pressure on phonon modes of ferroeleetrie tetragonal P4mm and paraelectric cubic Pm3m PbTiOa are systematically investigated by using first-principles simulations. The pressure-induced tetragonal-to-cub...The effects of pressure on phonon modes of ferroeleetrie tetragonal P4mm and paraelectric cubic Pm3m PbTiOa are systematically investigated by using first-principles simulations. The pressure-induced tetragonal-to-cubie and subsequent cubic-to-tetragonal phase transitions are the second-order transitions, which are different from the phase transitions induced by temperature [Phys. Rev. Lett. 25 （1970） 167]. As pressure increases, the lowest A1 and E modes of the tetragonal phase become softer and converge to the F1u mode of the cubic phase. As pressure further increases, the lowest Flu mode first hardens and then softens again, and finally diverges into A1 and E modes. The behaviors of optical phonon modes confirm the ferroelectric-to-paraelectric-to-ferroeleetric phase transitions.展开更多
The question of possible teleconnections between the middle latitude general circulation and the Indian south-west monsoon was investigated in this paper. Within the framework of a simple model it was shown that there...The question of possible teleconnections between the middle latitude general circulation and the Indian south-west monsoon was investigated in this paper. Within the framework of a simple model it was shown that there can exist such an interaction via the ultra-long Rossby waves.展开更多
Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-2...Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-20 May 1983 were taken. In this paper we have examined the diurnal variation of electric field in the Arabian Sea, Indian Ocean and Bay of Bengal regions covered during the cruise of the research ship ORV Gaveshani. An aspect of electric field dependence on coastal distance and Aitken Nuclei concentration has also been studied. An attempt to examine the latitude dependence of field was also made. Results obtained in the above studies are presented and compared with those obtained elsewhere.展开更多
A comprehensive Ground Penetration Radar (GPR) investigations and hazard assessment for the rehabilitation and strengthening of Habib Sakakini’s Palace in Cairo is presented herein, which is considered one of the mos...A comprehensive Ground Penetration Radar (GPR) investigations and hazard assessment for the rehabilitation and strengthening of Habib Sakakini’s Palace in Cairo is presented herein, which is considered one of the most significant architectural heritage sites in Egypt. The palace located on an ancient water pond at the eastern side of Egyptian gulf besiding Sultan Bebris Al-Bondoqdary mosque is a place also called “Prince Qraja al-Turkumany pond”. That pond had been filled down by Habib Sakakini at 1892 to construct his famous palace in 1897. The integrated geophysical survey of the palace allowed the identification of several targets of potential archaeological and geotechnical engineering interest buried in fill and silty clay in the depth range between 100 - 700 cm. the methodological development focused on Multi-Fold (MF) Ground Penetrating Radar (GPR) imaging and subsurface characterization based on integrated velocity and attenuation analysis. Eight hundred sqm of Ground penetration Radar (GPR) profiling have been conducted to monitor the subsurface conditions. 600 meters are made in the surrounding area of the Palace and 200 sqm at the basement. The aim is to monitor the soil conditions beneath and around the Palace and to identify potential geological discontinuities, or the presence of faults and cavities. A suitable single and dual antenna are used (500 - 100 MHZ) is used to penetrate the desired depth of 7 meters (ASTM D6432). The GPR is used also detect the water table. At the building basement the GPR is used to identify the foundation thickness and soil-basement interface. As well as the inspection of cracks in some supporting columns, piers and masonry walls. The GPR also was used to investigate the floors and ceilings conditions and structural mapping. The results were validated by the geotechnical and structural surveys. All these results together with the seismic hazard analysis will be used for the complete analysis of the palace in the framework of the rehabilitation and strengthening works foreseen in a second stage.展开更多
A new type of saddle field ion gun has been developed in our laboratories, and it can emit ions and a large proportion of energetic neutrals.The ion gun has been used in the neutral and ion impact radiation （NIIR） s...A new type of saddle field ion gun has been developed in our laboratories, and it can emit ions and a large proportion of energetic neutrals.The ion gun has been used in the neutral and ion impact radiation （NIIR） spectrometer to decrease the effect of charge accumulation on the surfaces of specimens. Some metals, including aluminium, copper and nickel and their oxides had been analysed by NIIR. By comparing the intensities of the spectral lines of the above metals and their oxides the intensification effect due to oxidation had been found. The ratio of intensities between Al I（3962（?）） for Al<sub>2</sub>O<sub>3</sub> and Al I （3962（?）） for Al is 120, so the effect can be seen clearly from the above experimental results. The mechanism of the intensification effect has been discussed in the paper.展开更多
This study reveals the most known barriers to successful marine safety investigations important role of effective marine accident investigation in the improvement of the maritime safety through prevention similar casu...This study reveals the most known barriers to successful marine safety investigations important role of effective marine accident investigation in the improvement of the maritime safety through prevention similar casualties from occurring in the future and explores the legal obligations of all parties under different international maritime conventions and codes.Since marine safety investigations results and recommendations are important for the maritime safety,so this paper determines,the shortage of application of the international regulations adopted by IMO related to maritime safety,and the shortage of legal measures to support safety at sea and protection or reduce marine pollution.This paper also aims to improve special measures for procedures of marine accident investigation and highlights the importance of identifying the liability and effective recommendations.展开更多
As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections i...As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections is very useful.In Uzbekistan,long-term investigations towards development展开更多
文摘AIM:To ascertain the pattern of investigations at first contact in uveitic patients and evaluate compliance to treatment.METHODS:An observational study comprised of 201 uveitic patients presenting for the first time to our centre from January 2019 to June 2020.Detailed information regarding systemic investigations undertaken by specialists at the time of first contact and the cost of these investigations were reviewed on the first visit to our centre.Compliance with the treatment was determined and reasons behind non-compliance were evaluated on the first follow-up in patients who had no improvement in clinical signs and symptoms.RESULTS:The mean age of the study group was 35.35±14.1y and gender composition was 59.7%males and 40.3%females.Anterior uveitis was observed in 45.3%of patients,intermediate uveitis in 31.8%of patients,posterior uveitis in 14.9%of patients and panuveitis in 8.0%of patients.Association with a systemic disease was evident in 17.9%of patients.When compared with standard guidelines and uveitis patterns,systemic investigations were identified to be relevant only in 38.3%of patients.Non-compliance to treatment was documented in 22.4%of patients.Common reasons for non-compliance were inadequate counselling by the treating physician about treatment in 26.7%of patients and a busy schedule at work/school in 22.2%of patients.CONCLUSION:Significant number of investigations performed at first contact is found to be contrary to standard guidelines and are not contributory to the care.About a quarter of patients in this study are found to be non-compliant with the treatment.Compliance is more challenging to achieve in school-going children and working adults.The availability of comprehensive,periodically updated,evidence-based guidelines on the role of investigations and the use of trained counsellors may help to channelize proper evaluation and improve compliance to treatment,respectively,in patients with uveitis.
文摘Rabies is an infectious disease that almost always leads to death as soon as the first signs appear, and is still endemic in several regions, including Côte d’Ivoire. Epidemiological investigations are carried out and response measures implemented in the event of any death from human rabies. However, the quality of these investigations does not always allow the adoption of response measures. The aim of this work was to evaluate the reports of epidemiological investigations and response actions carried out during the occurrence of human rabies deaths from 2016 to 2018. This was a cross-sectional study that took place from April to September 2021 at the National Institute of Public Hygiene and focused on human rabies deaths notified from 206 to 2018. Of sixty-one (61) human rabies deaths recorded, sixty (60) were investigated, among which fifty-nine (59) deaths had been subject to response. Most deaths occurred in rural areas (75%), and the main vector was the dog (98%). Several shortcomings were noted: response actions were not carried out promptly;joint interventions bringing together human and animal health professionals were rare, there was little communication about rabies to communities (36%), and very little vaccination of the vector, the source of the disease (12%);an almost total absence of capacity-building for local players (7%);the health districts of Abobo-Ouest, Bondoukou, Divo and Fresco, which had regularly recorded human rabies deaths, had not benefited from dog vaccination, which is supposed to break the circulation of the virus. The persistence of rabies deaths in the health districts could probably be linked to these shortcomings. Faced with these realities, it is essential to strengthen the epidemiological investigation capacities of the players involved, in order to improve the quality of investigations and ensure an effective response.
文摘Rabies is an infectious disease that almost always leads to death as soon as the first signs appear, and is still endemic in several regions, including Côte d’Ivoire. Epidemiological investigations are carried out and response measures implemented in the event of any death from human rabies. However, the quality of these investigations does not always allow the adoption of response measures. The aim of this work was to evaluate the reports of epidemiological investigations and response actions carried out during the occurrence of human rabies deaths from 2016 to 2018. This was a cross-sectional study that took place from April to September 2021 at the National Institute of Public Hygiene and focused on human rabies deaths notified from 206 to 2018. Of sixty-one (61) human rabies deaths recorded, sixty (60) were investigated, among which fifty-nine (59) deaths had been subject to response. Most deaths occurred in rural areas (75%), and the main vector was the dog (98%). Several shortcomings were noted: response actions were not carried out promptly;joint interventions bringing together human and animal health professionals were rare, there was little communication about rabies to communities (36%), and very little vaccination of the vector, the source of the disease (12%);an almost total absence of capacity-building for local players (7%);the health districts of Abobo-Ouest, Bondoukou, Divo and Fresco, which had regularly recorded human rabies deaths, had not benefited from dog vaccination, which is supposed to break the circulation of the virus. The persistence of rabies deaths in the health districts could probably be linked to these shortcomings. Faced with these realities, it is essential to strengthen the epidemiological investigation capacities of the players involved, in order to improve the quality of investigations and ensure an effective response.
基金sponsored by the China Postdoctoral Science Foundation (Grant No. 2020M673156)Shanghai Pujiang Program (Grant No. 20PJ1404900)。
文摘In this study,the texture evolutions of two Mg materials during tension are explored.In-situ X-ray synchrotron and Visco-Plastic SelfConsistent(VPSC) modeling are employed to investigate the different deformation modes between pure Mg and Mg-15Gd(wt.%) alloy.These two materials with a strong extrusion texture show large different slip/twinning activity behaviors during tensile deformation.The basal(a) slip has the highest contribution to the initial stage of plastic deformation for pure Mg.During the subsequent plastic deformation,the prismatic slip is dominant due to the strong ED//(100) fiber texture.In contrast,the deformation behavior of Mg-15Gd alloy is more complex.Twinning and basal slip are dominant at the early stage of plastic deformation,but further deformation results in the increased activation of prismatic and pyramidal slips.In comparison to pure Mg,the ratios of the critical resolved shear stress(CRSS) between non-basal slip and basal slip of the Mg-15Gd alloy are much lower.
文摘Thermal performance enhancement in a square channel heat exchanger(HX)using a passive technique is presented.Vortex turbulator insertion in a square channel HX as a passive technique is selected for thermal improvement.The vortex turbulator of interest is discrete X-V baffles(XVB).The discrete XVBs are inserted in the square channel with the main aim of generating vortex flow.The vortex flow generated can support the enhanced convective heat transfer coefficient and also enhance HX performance.Effects of baffle configuration(type A and B),baffle size(w/H=0.05,0.10,0.15 and 0.20),baffle distance(e/H=1,1.5 and 2)and flow direction(±x air flow paths)on fluid flow and thermal topologies are numerically investigated by using a commercial code.As shown by the numerical results,the predicted flow configuration with the discrete XVB insertions,which include impinging and vortex streams,is found through the HX channel.The perturbing thermal boundary layer and greater air blending are also found through the HX channel inserted with the discrete XVB.These mechanisms promote and augment the convection heat transfer coefficient,heat transfer rate and rise thermal potentiality.The maximum Nusselt number of the channel with the baffles inserted is 11.01 times upper than that of the smooth channel,while the greatest thermal performance factor(TPF)is observed to be around 3.45.
基金sponsored by the National Natural Science Foundation of China(Grant No.41176167)the Projects of Cultural Heritage Protection,Zhejiang Province(Grant No.2010001 and No.2011008)
文摘Ground penetrating radar （GPR） attribute technology has been applied to many aspects in recent years but there are very few examples in the field of archaeology. Especially how can we extract effective attributes from the two- or three-dimensional radar data so that we can map and describe numerous archaeological targets in a large cultural site？ In this paper, we applied GPR attribute technology to investigate the ancient Nanzhao castle-site in Tengchong, Yunnan Province. In order to get better archaeological target （the ancient wall, the ancient kiln site, and the ancient tomb） analysis and description, we collated the GPR data by collected standardization and then put them to the seismic data processing and interpretation workstation. The data was processed, including a variety of GPR attribute extraction, analysis, and optimization and combined with the archaeological drilling data. We choose the RMS Amplitude, Average Peak Amplitude, Instantaneous Phase, and Maximum Peak Time to interpret three archaeological targets. By comparative analysis, we have clarified that we should use different attributes to interpret different archaeological targets and the results of attribute analysis after horizon tracking is much better than the results based on a time slice.
文摘Careful and thorough incident investigations and pre-job safety analyses completed by knowledgeable and competent individuals can significantly reduce workplace incidents. Working parties must act together to make these safety tools effective. To get the staff units to work together in a co-ordinated manner, they must be shown the value of their work in preventing accidents. Examples of actual accidents investigated during the author's 18 years as a mine inspector in Saskatchewan are discussed within the context of pre-job safety analyses. The causes of the accidents are explored with close reference to how pre-job safety analyses could have prevented their occurrence.
基金Project(51176045)supported by the National Natural Science Foundation of ChinaProject(201208430262)supported by the National Studying Abroad Foundation of China
文摘In order to reveal combustion characteristics of H_2/air mixture in a micro-combustor with and without bluff body, the effects of inlet velocities, equivalence ratios and bluff body's blockage ratios on the temperature field, pressure of the combustor wall, combustion efficiency and blow-off limit were investigated. The numerical results indicate that the sudden expansion plate micro combustor with bluff body could enhance the turbulent disturbance of the mixed gas in the combustion chamber and the combustion condition is improved. Moreover, a low-speed and high temperature recirculation region was formed between the sudden expansion step and the bluff body so that the high and uniform wall temperature(>1000 K) could be gotten. As a result, it could strengthen the mixing process, prolong the residence time of gas, control the flame position effectively and widen the operation range by the synergistic effect of the bluff body and steps. When the blockage ratio ranged from 0.3 to 0.6, it could be found that the bluff body could play a stabilizing effect and expand combustion blow burning limit, and combustion efficiency firstly was increased with the inlet velocity and equivalence ratio, and then was decreased.
基金Supported by the National Natural Science Foundation of China under Grant No 11404180the Natural Science Foundation of Heilongjiang Province under Grant Nos F201335,A2015010,and A2015011the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province under Grant No LBH-Q14159
文摘The electronic structures of PF and PF＋ are calculated with the high-level configuration interaction method. To improve the precision of calculations, the spin-orbit coupling effect, the scalar relativistic effect, and the Davidson correction（q-Q） are also considered. The spectroscopic parameters of bound states are derived by the electronic structures of PF and PF＋, which are in good accordance with the measurements. The transition dipole moments of spin-allowed transitions are evaluated, and the radiative lifetimes of several A S states of PF and PF＋ are obtained.
文摘Aluminum/steel electric transition joints (ETJs) are used in aluminum reduction cell for the purpose of welding aluminum rod and steel bracket components. Solid state welding process used for joining aluminum and steel at the electric transition joints have the drawbacks of cracking and separation at the interface surfaces. Cracking and separation at the electric transition joints are caused by the stress singularities that developed due to the mismatch in thermal and mechanical properties of each material. To overcome the drawback of electric transition joints, aluminum/steel functionally graded may be used as electric transition joints or proposed. Therefore manufacturing and investigation of aluminum/steel functionally graded materials fabricated by powder metallurgy process were carried out through the current work. Different samples with different layers of aluminum/steel functionally graded materials were compacted using steel die and punch at the same compacted pressure and sintered temperature. After investigating the different samples of aluminum/steel functionally graded materials under different fabrication conditions, the suitable fabrication regime was determined with the aid of microscopic observations.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No 2013QNA38
文摘Crystal structure predictions of Pb0.5Ba0.5 Ti03 alloys under different pressures are performed based on the parti- cle swarming optimization algorithm. The predicted stable ground-state and high-pressure phases are tetragonal ferroelectric （I4mm） and cubic para-electric （Fm3m）, respectively, whose structural details have not been re- ported. The pressure-induced colossal enhancements in piezoelectric response are associated with the mechanical and dynamical instabilities instead of polarization rotation. The band gap of the tetragonM phase is indirect and that of the cubic phase is always direct. As pressure increases, the alloy displays the similar band-gap behaviors to PbTiO3, while different from BaTiO5, which is attributed to the different orbital contributions to the valence bands. Our calculated results are in good agreement with the available data.
基金This project was supported by the National Science Foundation of China and Doctoral Programme from State Education Commission Foundation of China
文摘Described here are the fabrication and characterization of carbon fiber cylinder ultramicroelectrodes with cylinder length of less than 100 am, total tip diameter of several hundreds nanometers. The electrodes have been fabricated by direct etching of carbon fiber using an ion beam thinner. Optical microscopy, scanning electron microscopy (SEM), cyclic voltammetry have been employed to characterize those electrodes. The experimental results obtained indicate the electrodes can be used for in vivo detection of neurotransmitters such as dopamine, 5—hydroxytryptamine in a single cell.
文摘Iron ions were used as probes to explore the structural and magnetic properties of 70TeO2'25B2O3' 5SrF2 vitreous matrix. The distribution of Fe3+ ions on different structural aggregates was revealed by means of EPR, as depending on Fe2O3 concentration. Strongly distorted octahedral sites were detected for the isolated paramagnetic ions, and also clusters of Fe ions especially at high Fe2O3 content of samples. Magnetic susceptibility measurements evidenced both dipoledipole and superexchange type interactions involving iron ions. Mixed valence states of iron ions were also detected
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No 2013RC19
文摘The effects of pressure on phonon modes of ferroeleetrie tetragonal P4mm and paraelectric cubic Pm3m PbTiOa are systematically investigated by using first-principles simulations. The pressure-induced tetragonal-to-cubie and subsequent cubic-to-tetragonal phase transitions are the second-order transitions, which are different from the phase transitions induced by temperature [Phys. Rev. Lett. 25 （1970） 167]. As pressure increases, the lowest A1 and E modes of the tetragonal phase become softer and converge to the F1u mode of the cubic phase. As pressure further increases, the lowest Flu mode first hardens and then softens again, and finally diverges into A1 and E modes. The behaviors of optical phonon modes confirm the ferroelectric-to-paraelectric-to-ferroeleetric phase transitions.
文摘The question of possible teleconnections between the middle latitude general circulation and the Indian south-west monsoon was investigated in this paper. Within the framework of a simple model it was shown that there can exist such an interaction via the ultra-long Rossby waves.
文摘Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-20 May 1983 were taken. In this paper we have examined the diurnal variation of electric field in the Arabian Sea, Indian Ocean and Bay of Bengal regions covered during the cruise of the research ship ORV Gaveshani. An aspect of electric field dependence on coastal distance and Aitken Nuclei concentration has also been studied. An attempt to examine the latitude dependence of field was also made. Results obtained in the above studies are presented and compared with those obtained elsewhere.
文摘A comprehensive Ground Penetration Radar (GPR) investigations and hazard assessment for the rehabilitation and strengthening of Habib Sakakini’s Palace in Cairo is presented herein, which is considered one of the most significant architectural heritage sites in Egypt. The palace located on an ancient water pond at the eastern side of Egyptian gulf besiding Sultan Bebris Al-Bondoqdary mosque is a place also called “Prince Qraja al-Turkumany pond”. That pond had been filled down by Habib Sakakini at 1892 to construct his famous palace in 1897. The integrated geophysical survey of the palace allowed the identification of several targets of potential archaeological and geotechnical engineering interest buried in fill and silty clay in the depth range between 100 - 700 cm. the methodological development focused on Multi-Fold (MF) Ground Penetrating Radar (GPR) imaging and subsurface characterization based on integrated velocity and attenuation analysis. Eight hundred sqm of Ground penetration Radar (GPR) profiling have been conducted to monitor the subsurface conditions. 600 meters are made in the surrounding area of the Palace and 200 sqm at the basement. The aim is to monitor the soil conditions beneath and around the Palace and to identify potential geological discontinuities, or the presence of faults and cavities. A suitable single and dual antenna are used (500 - 100 MHZ) is used to penetrate the desired depth of 7 meters (ASTM D6432). The GPR is used also detect the water table. At the building basement the GPR is used to identify the foundation thickness and soil-basement interface. As well as the inspection of cracks in some supporting columns, piers and masonry walls. The GPR also was used to investigate the floors and ceilings conditions and structural mapping. The results were validated by the geotechnical and structural surveys. All these results together with the seismic hazard analysis will be used for the complete analysis of the palace in the framework of the rehabilitation and strengthening works foreseen in a second stage.
文摘A new type of saddle field ion gun has been developed in our laboratories, and it can emit ions and a large proportion of energetic neutrals.The ion gun has been used in the neutral and ion impact radiation （NIIR） spectrometer to decrease the effect of charge accumulation on the surfaces of specimens. Some metals, including aluminium, copper and nickel and their oxides had been analysed by NIIR. By comparing the intensities of the spectral lines of the above metals and their oxides the intensification effect due to oxidation had been found. The ratio of intensities between Al I（3962（?）） for Al<sub>2</sub>O<sub>3</sub> and Al I （3962（?）） for Al is 120, so the effect can be seen clearly from the above experimental results. The mechanism of the intensification effect has been discussed in the paper.
文摘This study reveals the most known barriers to successful marine safety investigations important role of effective marine accident investigation in the improvement of the maritime safety through prevention similar casualties from occurring in the future and explores the legal obligations of all parties under different international maritime conventions and codes.Since marine safety investigations results and recommendations are important for the maritime safety,so this paper determines,the shortage of application of the international regulations adopted by IMO related to maritime safety,and the shortage of legal measures to support safety at sea and protection or reduce marine pollution.This paper also aims to improve special measures for procedures of marine accident investigation and highlights the importance of identifying the liability and effective recommendations.
文摘As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections is very useful.In Uzbekistan,long-term investigations towards development
