This study analyzed how impressions are formed online depending on the type of social media and the implications that may come from the over-disclosure of information. Using a Qualtrics survey, 97 participants viewed ...This study analyzed how impressions are formed online depending on the type of social media and the implications that may come from the over-disclosure of information. Using a Qualtrics survey, 97 participants viewed the profile of a female teaching assistant on Twitter and Facebook. While there was little difference between the two social media, the use of self-disclosure on Twitter seemed slightly more inappropriate for sharing personal information.展开更多
Intelligent personal assistants play a pivotal role in in-vehicle systems,significantly enhancing life efficiency,driving safety,and decision-making support.In this study,the multi-modal design elements of intelligent...Intelligent personal assistants play a pivotal role in in-vehicle systems,significantly enhancing life efficiency,driving safety,and decision-making support.In this study,the multi-modal design elements of intelligent personal assistants within the context of visual,auditory,and somatosensory interactions with drivers were discussed.Their impact on the driver’s psychological state through various modes such as visual imagery,voice interaction,and gesture interaction were explored.The study also introduced innovative designs for in-vehicle intelligent personal assistants,incorporating design principles such as driver-centricity,prioritizing passenger safety,and utilizing timely feedback as a criterion.Additionally,the study employed design methods like driver behavior research and driving situation analysis to enhance the emotional connection between drivers and their vehicles,ultimately improving driver satisfaction and trust.展开更多
This article examines the implementation of a virtual health assistant powered by Retrieval-Augmented Generation (RAG) and GPT-4, aimed at enhancing clinical support through personalized, real-time interactions with p...This article examines the implementation of a virtual health assistant powered by Retrieval-Augmented Generation (RAG) and GPT-4, aimed at enhancing clinical support through personalized, real-time interactions with patients. The system is hypothesized to improve healthcare accessibility, operational efficiency, and patient outcomes by automating routine tasks and delivering accurate health information. The assistant leverages natural language processing and real-time data retrieval models to respond to patient inquiries, schedule appointments, provide medication reminders, assist with symptom triage, and answer insurance-related questions. By integrating RAG-based virtual care, the system reduces the burden on healthcare specialists and helps mitigate healthcare disparities, particularly in rural areas where traditional care is limited. Although the initial scope of testing did not validate all potential benefits, the results demonstrated high patient satisfaction and strong response accuracy, both critical for systems of this nature. These findings underscore the transformative potential of AI-driven virtual health assistants in enhancing patient engagement, streamlining operational workflows, and improving healthcare accessibility, ultimately contributing to better outcomes and more cost-effective care delivery.展开更多
In this paper,we propose a sub-6GHz channel assisted hybrid beamforming(HBF)for mmWave system under both line-of-sight(LOS)and non-line-of-sight(NLOS)scenarios without mmWave channel estimation.Meanwhile,we resort to ...In this paper,we propose a sub-6GHz channel assisted hybrid beamforming(HBF)for mmWave system under both line-of-sight(LOS)and non-line-of-sight(NLOS)scenarios without mmWave channel estimation.Meanwhile,we resort to the selfsupervised approach to eliminate the need for labels,thus avoiding the accompanied high cost of data collection and annotation.We first construct the dense connection network(DCnet)with three modules:the feature extraction module for extracting channel characteristic from a large amount of channel data,the feature fusion module for combining multidimensional features,and the prediction module for generating the HBF matrices.Next,we establish a lightweight network architecture,named as LDnet,to reduce the number of model parameters and computational complexity.The proposed sub-6GHz assisted approach eliminates mmWave pilot resources compared to the method using mmWave channel information directly.The simulation results indicate that the proposed DCnet and LDnet can achieve the spectral efficiency that is superior to the traditional orthogonal matching pursuit(OMP)algorithm by 13.66% and 10.44% under LOS scenarios and by 32.35% and 27.75% under NLOS scenarios,respectively.Moreover,the LDnet achieves 98.52% reduction in the number of model parameters and 22.93% reduction in computational complexity compared to DCnet.展开更多
Background: The maternal and neonatal morbidity caused by prolonged labour, maternal exhaustion and other factors push clinicians to speed up the delivery process by employing equipment such as vacuum suction or force...Background: The maternal and neonatal morbidity caused by prolonged labour, maternal exhaustion and other factors push clinicians to speed up the delivery process by employing equipment such as vacuum suction or forceps to save the newborn. The purpose of this study was to determine the prevalence of vacuum-assisted vaginal delivery (VAVD) and its associated short-term maternal and neonatal outcomes at Ndola Teaching Hospital. Methods: A retrospective cross-sectional descriptive study through the analysis of routine data for women with singleton-term pregnancies who delivered by vacuum compared with spontaneous vaginal delivery was done at a tertiary hospital for the years 2020 and 2021. Chi-square and Logistic regression were used to investigate factors of vacuum delivery and to adjust for potential confounders. Results: Results showed that VAVD was mostly performed in women who had delayed second stage of labour (25.4%), maternal exhaustion (16.0%), foetal distress in the second stage of labour (12.3%). The overall VAVD prevalence was 3.7% (581/15591). Logistic regression showed that multiparous women were noted to be 87.5% (aOR 0.125;95% CI 0.025 - 0.629;p = 0.012) less likely to undergo VAVD compared to nulliparous women. Registrars were almost 6 times (aOR 5.650;95% CI 1.458 - 22.222, p = 0.012) more likely to conduct VAVD compared to midwives. Episiotomy was 3 times (aOR 3.390;95% CI 1.185 - 9.524;p Conclusion: The findings indicate the underutilisation of VAVD at NTH based on the low prevalence of 3.7%. VAVD outcomes were affected by multiparity, skill level and Episiotomy procedure, in addition, VAVD influenced admission to the NICU. Hence, there is a need to increase skills in VAVD among first-line healthcare workers such as midwives and intern doctors.展开更多
Nano SiO2/NR composites were prepared through blending nano SiO2 emulsion with natural rubber latex and then concreting with acetic acid. The emulsion nano SiO2 was prepared with Na2SiO3-9H2O and hydrochloric acid und...Nano SiO2/NR composites were prepared through blending nano SiO2 emulsion with natural rubber latex and then concreting with acetic acid. The emulsion nano SiO2 was prepared with Na2SiO3-9H2O and hydrochloric acid under the reaction of the assistant agents. The was analyzed effect of the application rates of assistant agents such as silane coupling agent, surfactant, nucleating agent and dispersant on the properties and interface structure of the nano SiO2/NR composites with IR, TEM, SEM, DMA was analyzed. An orthogonal test was arranged to select optimum condition. The results show that the best combination for preparing nano SiO2/NR composites is as follows： the rate of the silane coupling agent （TESPT）, the surfactant（dodecyl benzene sulfonate natrium）, nucleating agent（AlCl3） and dispersant（ethylene diamine tetraacetie acid） in the course of preparing nano SiO2 are 15%, 2.0%, 2.5% and 0.4%, respectively. Several replications in the experiment had produced desirable nano SiO2 products and nano SiO2/NR composites with better properties.展开更多
Conceptual design, data model and key techniques of "Geo-engineer 3D assistant", an underground 3D GIS oriented to geology and mine application, were discussed. In particular, the importance of high-order sm...Conceptual design, data model and key techniques of "Geo-engineer 3D assistant", an underground 3D GIS oriented to geology and mine application, were discussed. In particular, the importance of high-order smoothing triangular pieces to surface's fine expression in geological modeling was emphasized. The contour mode is the most favorite mode of the three modes about surface expression: DEM, TIN and contour. Topology in underground 3D modeling with CAGD was compared. From the view of boundary and coboundary, which is soul of IS 19107 (Geographic information spatial schema), 3D underground topology was re-examined.展开更多
Cocatalysts play a vital role in accelerating the reaction kinetics and improving the charge separation of photocatalysts for solar hydrogen production.The promotion of the photocatalytic activity largely relies on th...Cocatalysts play a vital role in accelerating the reaction kinetics and improving the charge separation of photocatalysts for solar hydrogen production.The promotion of the photocatalytic activity largely relies on the loading approach of the cocatalysts.Herein,we introduce a metal-seed assistant photodeposition approach to load the hydrogen evolution cocatalyst of platinum onto the surface of Ta_(3)N_(5) photocatalyst,which exhibits about 3.6 times of higher photocatalytic proton reduction activity with respect to the corresponding impregnation or photodeposition loading.Based on our characterizations,the increscent contact area of the cocatalyst/semiconductor interface with metal-seed assistant photodeposition method is proposed to be responsible for the promoted charge separation as well as enhanced photocatalytic H2 evolution activity.It is interesting to note that this innovative deposition strategy can be easily extended to loading of platinum cocatalyst with other noble or non-noble metal seeds for promoted activities,demonstrating its good generality.Our work may provide an alternative way of depositing cocatalyst for better photocatalytic performances.展开更多
Stealth security has always been considered as an important guarantee for the vitality and combat effectiveness of submarines.In accordance with the stealth requirements of submarines performing stealth voyage tasks,t...Stealth security has always been considered as an important guarantee for the vitality and combat effectiveness of submarines.In accordance with the stealth requirements of submarines performing stealth voyage tasks,this paper proposes a stealth assistant decision system.Firstly,the submarine stealth posture is acquired.A fuzzy neural network inference engine based on improved simplified particle swarm optimization is designed.The auxiliary decision-making scheme for state control and maneuver avoidance of submarine and its equipment is automatically generated.Secondly,the simulation and deduction of the assistant decision-making scheme are realized by the calculation modules of sound source level,propagation loss,and stealth situation.The assistant decision-making scheme and simulation result provide decision support for the commander.Thirdly,the simulation experiment platform of the submarine stealth assistant decision system is constructed.The submarine stealth assistant decision system described in this paper can quickly and efficiently produce assistant decision-making schemes,including submarine and equipment control and maneuver avoidance.The scheme is in line with the combat experience and the results of the pre-model simulation experiments,whereas the simulation deduction evaluates the rationality and effectiveness of the selected scheme.The submarine stealth assistant decision system can adapt to a complex battlefield environment in addition to rapidly and accurately providing assistance in decision-making.展开更多
A slow bromination process of butyl rubber （IIR） suffers from low efficiency and low selectivity （S） of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixin...A slow bromination process of butyl rubber （IIR） suffers from low efficiency and low selectivity （S） of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%（by volume） dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product （xA1s） of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r＆#183;min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed （RPB） reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.展开更多
Sutong Bridge is a cable-stayed steel box girder bridge with a main span of 1 088 m. The erection of upper structure adopts geometry control method and requires no change to the unit＇ s size and the structure＇ s non...Sutong Bridge is a cable-stayed steel box girder bridge with a main span of 1 088 m. The erection of upper structure adopts geometry control method and requires no change to the unit＇ s size and the structure＇ s none-stress geometry. Before main span closure, the cantilever of girder reaches 540.8 m, the structure state is noticeably influenced by extemal circumstances, the main span closure face great difficulty. By abstracting the advantage of the pullback method abroad and the domestic temperature-cutting method, a new assistant pullback method have put forward and bring into practice actually. In this paper, the analysis key point of practice conditions, key parameter of practice, main measures of the method and the performance is introduced.展开更多
BACKGROUND A clutch cutter is a scissor-type knife used in endoscopic submucosal dissection(ESD)for gastrointestinal tract tumors.The assistant during the ESD using a clutch cutter(ESD-C)needs to rotate the device and...BACKGROUND A clutch cutter is a scissor-type knife used in endoscopic submucosal dissection(ESD)for gastrointestinal tract tumors.The assistant during the ESD using a clutch cutter(ESD-C)needs to rotate the device and grasp the target tissue appropriately;therefore,the assistant’s skill may affect the technical outcomes of ESD-C.AIM To determine how assistant skill level affected the technical outcomes of gastric ESD-C using an ex vivo porcine training model.METHODS In this pilot study,mock lesions of 15-30 mm in diameter were created in the middle or lower third of the porcine stomach.A total of 32 ESD-C procedures were performed by 16 trainees.Each trainee operator performed two ESD-C procedures;one ESD-C was assisted by an expert(ESD-C-E),and the other was assisted by a non-expert(ESD-C-NE).The total procedure time of the ESD was set as the primary outcome,and en bloc resection rate,complete procedure rate,perforation rate,and each procedure time/speed for mucosal incision or submucosal dissection were set as the secondary outcomes.In addition,we investigated factors associated with the difficulty of ESD including incompletion of ESD procedure,a long procedure time(≥20 min)or intraoperative perforation.RESULTS The median total procedure time of the ESD-C-E was significantly shorter than that of the ESD-C-NE(12.9 min vs 21.9 min,P=0.001).The en bloc resection rate was 100%in both groups.Complete resection rates of the ESD-C-E and ESD-C-NE groups were 100%and 93.8%,respectively.No intraoperative perforation was observed in both groups.In the multivariate analysis,assistant skill was significantly associated with the difficulty of ESD,with the highest odds ratio of 16.5.CONCLUSION Assistance by an expert is an important factor when trainees perform ESD-C procedures.展开更多
The keratins of wool underwent Photooxidation to form a weaker luminophor in visible blue region (λ_(max)=420nm),that reacts with cerium ion to produce an enhanced luminophor complex (λ_(max)=426 nm),it makes wool w...The keratins of wool underwent Photooxidation to form a weaker luminophor in visible blue region (λ_(max)=420nm),that reacts with cerium ion to produce an enhanced luminophor complex (λ_(max)=426 nm),it makes wool white obviously.展开更多
A compound machine tool was designed, which combined rotary ultrasonic assisted grinding, electrical discharge machining(EDM) and multi-axis milling. Experimental results indicated that its positioning accuracy was le...A compound machine tool was designed, which combined rotary ultrasonic assisted grinding, electrical discharge machining(EDM) and multi-axis milling. Experimental results indicated that its positioning accuracy was less than 5.6 μm and its repetitive positioning accuracy was less than 1.8 μm; the vibration amplitude of ultrasonic grinding system was uniform and stable, and the EDM system worked well and stably.A smooth surface of K9 optical glass component was achieved by the grinding method.展开更多
文摘This study analyzed how impressions are formed online depending on the type of social media and the implications that may come from the over-disclosure of information. Using a Qualtrics survey, 97 participants viewed the profile of a female teaching assistant on Twitter and Facebook. While there was little difference between the two social media, the use of self-disclosure on Twitter seemed slightly more inappropriate for sharing personal information.
文摘Intelligent personal assistants play a pivotal role in in-vehicle systems,significantly enhancing life efficiency,driving safety,and decision-making support.In this study,the multi-modal design elements of intelligent personal assistants within the context of visual,auditory,and somatosensory interactions with drivers were discussed.Their impact on the driver’s psychological state through various modes such as visual imagery,voice interaction,and gesture interaction were explored.The study also introduced innovative designs for in-vehicle intelligent personal assistants,incorporating design principles such as driver-centricity,prioritizing passenger safety,and utilizing timely feedback as a criterion.Additionally,the study employed design methods like driver behavior research and driving situation analysis to enhance the emotional connection between drivers and their vehicles,ultimately improving driver satisfaction and trust.
文摘This article examines the implementation of a virtual health assistant powered by Retrieval-Augmented Generation (RAG) and GPT-4, aimed at enhancing clinical support through personalized, real-time interactions with patients. The system is hypothesized to improve healthcare accessibility, operational efficiency, and patient outcomes by automating routine tasks and delivering accurate health information. The assistant leverages natural language processing and real-time data retrieval models to respond to patient inquiries, schedule appointments, provide medication reminders, assist with symptom triage, and answer insurance-related questions. By integrating RAG-based virtual care, the system reduces the burden on healthcare specialists and helps mitigate healthcare disparities, particularly in rural areas where traditional care is limited. Although the initial scope of testing did not validate all potential benefits, the results demonstrated high patient satisfaction and strong response accuracy, both critical for systems of this nature. These findings underscore the transformative potential of AI-driven virtual health assistants in enhancing patient engagement, streamlining operational workflows, and improving healthcare accessibility, ultimately contributing to better outcomes and more cost-effective care delivery.
基金supported in part by the National Natural Science Foundation of China under Grants 62325107,62341107,62261160650,and U23A20272in part by the Beijing Natural Science Foundation under Grant L222002.
文摘In this paper,we propose a sub-6GHz channel assisted hybrid beamforming(HBF)for mmWave system under both line-of-sight(LOS)and non-line-of-sight(NLOS)scenarios without mmWave channel estimation.Meanwhile,we resort to the selfsupervised approach to eliminate the need for labels,thus avoiding the accompanied high cost of data collection and annotation.We first construct the dense connection network(DCnet)with three modules:the feature extraction module for extracting channel characteristic from a large amount of channel data,the feature fusion module for combining multidimensional features,and the prediction module for generating the HBF matrices.Next,we establish a lightweight network architecture,named as LDnet,to reduce the number of model parameters and computational complexity.The proposed sub-6GHz assisted approach eliminates mmWave pilot resources compared to the method using mmWave channel information directly.The simulation results indicate that the proposed DCnet and LDnet can achieve the spectral efficiency that is superior to the traditional orthogonal matching pursuit(OMP)algorithm by 13.66% and 10.44% under LOS scenarios and by 32.35% and 27.75% under NLOS scenarios,respectively.Moreover,the LDnet achieves 98.52% reduction in the number of model parameters and 22.93% reduction in computational complexity compared to DCnet.
文摘Background: The maternal and neonatal morbidity caused by prolonged labour, maternal exhaustion and other factors push clinicians to speed up the delivery process by employing equipment such as vacuum suction or forceps to save the newborn. The purpose of this study was to determine the prevalence of vacuum-assisted vaginal delivery (VAVD) and its associated short-term maternal and neonatal outcomes at Ndola Teaching Hospital. Methods: A retrospective cross-sectional descriptive study through the analysis of routine data for women with singleton-term pregnancies who delivered by vacuum compared with spontaneous vaginal delivery was done at a tertiary hospital for the years 2020 and 2021. Chi-square and Logistic regression were used to investigate factors of vacuum delivery and to adjust for potential confounders. Results: Results showed that VAVD was mostly performed in women who had delayed second stage of labour (25.4%), maternal exhaustion (16.0%), foetal distress in the second stage of labour (12.3%). The overall VAVD prevalence was 3.7% (581/15591). Logistic regression showed that multiparous women were noted to be 87.5% (aOR 0.125;95% CI 0.025 - 0.629;p = 0.012) less likely to undergo VAVD compared to nulliparous women. Registrars were almost 6 times (aOR 5.650;95% CI 1.458 - 22.222, p = 0.012) more likely to conduct VAVD compared to midwives. Episiotomy was 3 times (aOR 3.390;95% CI 1.185 - 9.524;p Conclusion: The findings indicate the underutilisation of VAVD at NTH based on the low prevalence of 3.7%. VAVD outcomes were affected by multiparity, skill level and Episiotomy procedure, in addition, VAVD influenced admission to the NICU. Hence, there is a need to increase skills in VAVD among first-line healthcare workers such as midwives and intern doctors.
基金Funded by the Special Fund of Basic Scientific Research of Rubber Research Institute of CATASKey Laboratory of Ministry of Agriculture for Natural Rubber Processing (No. xjszx-13 and No. xjsbywfzx2009-19, 706057)
文摘Nano SiO2/NR composites were prepared through blending nano SiO2 emulsion with natural rubber latex and then concreting with acetic acid. The emulsion nano SiO2 was prepared with Na2SiO3-9H2O and hydrochloric acid under the reaction of the assistant agents. The was analyzed effect of the application rates of assistant agents such as silane coupling agent, surfactant, nucleating agent and dispersant on the properties and interface structure of the nano SiO2/NR composites with IR, TEM, SEM, DMA was analyzed. An orthogonal test was arranged to select optimum condition. The results show that the best combination for preparing nano SiO2/NR composites is as follows： the rate of the silane coupling agent （TESPT）, the surfactant（dodecyl benzene sulfonate natrium）, nucleating agent（AlCl3） and dispersant（ethylene diamine tetraacetie acid） in the course of preparing nano SiO2 are 15%, 2.0%, 2.5% and 0.4%, respectively. Several replications in the experiment had produced desirable nano SiO2 products and nano SiO2/NR composites with better properties.
基金Project(A11024)supported by the Key Laboratory Fund of Geo-Informatics of State Bureau of Surveying and MappingProject(7771022)supported by the Basic Research Fund for Chinese Academy of Surveying and MappingProject(2010AA22202)supported by the National High-tech Research and Development Program of China
文摘Conceptual design, data model and key techniques of "Geo-engineer 3D assistant", an underground 3D GIS oriented to geology and mine application, were discussed. In particular, the importance of high-order smoothing triangular pieces to surface's fine expression in geological modeling was emphasized. The contour mode is the most favorite mode of the three modes about surface expression: DEM, TIN and contour. Topology in underground 3D modeling with CAGD was compared. From the view of boundary and coboundary, which is soul of IS 19107 (Geographic information spatial schema), 3D underground topology was re-examined.
基金supported by the National Natural Science Foundation of China(21633009,21925206,21902156)the Dalian National Laboratory for Clean Energy(DNL)Cooperation Fund,CAS(no.DNL 201913)+2 种基金the International Partnership Program of Chinese Academy of Sciences(121421KYSB20190025)the DICP foundation of innovative research(DICP I201927)the support from Liao Ning Revitalization Talents Program(XLYC1807241)。
文摘Cocatalysts play a vital role in accelerating the reaction kinetics and improving the charge separation of photocatalysts for solar hydrogen production.The promotion of the photocatalytic activity largely relies on the loading approach of the cocatalysts.Herein,we introduce a metal-seed assistant photodeposition approach to load the hydrogen evolution cocatalyst of platinum onto the surface of Ta_(3)N_(5) photocatalyst,which exhibits about 3.6 times of higher photocatalytic proton reduction activity with respect to the corresponding impregnation or photodeposition loading.Based on our characterizations,the increscent contact area of the cocatalyst/semiconductor interface with metal-seed assistant photodeposition method is proposed to be responsible for the promoted charge separation as well as enhanced photocatalytic H2 evolution activity.It is interesting to note that this innovative deposition strategy can be easily extended to loading of platinum cocatalyst with other noble or non-noble metal seeds for promoted activities,demonstrating its good generality.Our work may provide an alternative way of depositing cocatalyst for better photocatalytic performances.
基金Funding National Natural Science Foundation of China(51709061,51779057).
文摘Stealth security has always been considered as an important guarantee for the vitality and combat effectiveness of submarines.In accordance with the stealth requirements of submarines performing stealth voyage tasks,this paper proposes a stealth assistant decision system.Firstly,the submarine stealth posture is acquired.A fuzzy neural network inference engine based on improved simplified particle swarm optimization is designed.The auxiliary decision-making scheme for state control and maneuver avoidance of submarine and its equipment is automatically generated.Secondly,the simulation and deduction of the assistant decision-making scheme are realized by the calculation modules of sound source level,propagation loss,and stealth situation.The assistant decision-making scheme and simulation result provide decision support for the commander.Thirdly,the simulation experiment platform of the submarine stealth assistant decision system is constructed.The submarine stealth assistant decision system described in this paper can quickly and efficiently produce assistant decision-making schemes,including submarine and equipment control and maneuver avoidance.The scheme is in line with the combat experience and the results of the pre-model simulation experiments,whereas the simulation deduction evaluates the rationality and effectiveness of the selected scheme.The submarine stealth assistant decision system can adapt to a complex battlefield environment in addition to rapidly and accurately providing assistance in decision-making.
基金Supported by the National Natural Science Foundation of China(21176014,20990221,21121064)the Science-Technology Project for Supervisors of Excellent Doctor Degree Thesis of Beijing(20111001001)
文摘A slow bromination process of butyl rubber （IIR） suffers from low efficiency and low selectivity （S） of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%（by volume） dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product （xA1s） of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r＆#183;min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed （RPB） reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.
基金National Science and Technology Support Program of China(No.2006BAG04B03)
文摘Sutong Bridge is a cable-stayed steel box girder bridge with a main span of 1 088 m. The erection of upper structure adopts geometry control method and requires no change to the unit＇ s size and the structure＇ s none-stress geometry. Before main span closure, the cantilever of girder reaches 540.8 m, the structure state is noticeably influenced by extemal circumstances, the main span closure face great difficulty. By abstracting the advantage of the pullback method abroad and the domestic temperature-cutting method, a new assistant pullback method have put forward and bring into practice actually. In this paper, the analysis key point of practice conditions, key parameter of practice, main measures of the method and the performance is introduced.
文摘BACKGROUND A clutch cutter is a scissor-type knife used in endoscopic submucosal dissection(ESD)for gastrointestinal tract tumors.The assistant during the ESD using a clutch cutter(ESD-C)needs to rotate the device and grasp the target tissue appropriately;therefore,the assistant’s skill may affect the technical outcomes of ESD-C.AIM To determine how assistant skill level affected the technical outcomes of gastric ESD-C using an ex vivo porcine training model.METHODS In this pilot study,mock lesions of 15-30 mm in diameter were created in the middle or lower third of the porcine stomach.A total of 32 ESD-C procedures were performed by 16 trainees.Each trainee operator performed two ESD-C procedures;one ESD-C was assisted by an expert(ESD-C-E),and the other was assisted by a non-expert(ESD-C-NE).The total procedure time of the ESD was set as the primary outcome,and en bloc resection rate,complete procedure rate,perforation rate,and each procedure time/speed for mucosal incision or submucosal dissection were set as the secondary outcomes.In addition,we investigated factors associated with the difficulty of ESD including incompletion of ESD procedure,a long procedure time(≥20 min)or intraoperative perforation.RESULTS The median total procedure time of the ESD-C-E was significantly shorter than that of the ESD-C-NE(12.9 min vs 21.9 min,P=0.001).The en bloc resection rate was 100%in both groups.Complete resection rates of the ESD-C-E and ESD-C-NE groups were 100%and 93.8%,respectively.No intraoperative perforation was observed in both groups.In the multivariate analysis,assistant skill was significantly associated with the difficulty of ESD,with the highest odds ratio of 16.5.CONCLUSION Assistance by an expert is an important factor when trainees perform ESD-C procedures.
文摘The keratins of wool underwent Photooxidation to form a weaker luminophor in visible blue region (λ_(max)=420nm),that reacts with cerium ion to produce an enhanced luminophor complex (λ_(max)=426 nm),it makes wool white obviously.
基金Supported by the National High Technology Research and Development Program of China("863" Program,No.2009AA044204)
文摘A compound machine tool was designed, which combined rotary ultrasonic assisted grinding, electrical discharge machining(EDM) and multi-axis milling. Experimental results indicated that its positioning accuracy was less than 5.6 μm and its repetitive positioning accuracy was less than 1.8 μm; the vibration amplitude of ultrasonic grinding system was uniform and stable, and the EDM system worked well and stably.A smooth surface of K9 optical glass component was achieved by the grinding method.
