The internal carotid artery occlusion caused by head and neck trauma,also known as traumatic intracranial artery occlusion,is relatively rare clinically.Traumatic skull base fracture is a common complication of trauma...The internal carotid artery occlusion caused by head and neck trauma,also known as traumatic intracranial artery occlusion,is relatively rare clinically.Traumatic skull base fracture is a common complication of traumatic brain injury.Traumatic skull base fracture is one of the causes of traumatic internal carotid artery occlusion.If not detected early and treated in time,the prognosis of patients is poor.This editorial makes a relevant analysis of this disease.展开更多
OBJECTIVE: To formulate an evidence-based treatment for one patient with acute spinal cord injury and summarize evidence for evaluating acute spinal cord injury treatment. METHODS: Studies related to the treatment f...OBJECTIVE: To formulate an evidence-based treatment for one patient with acute spinal cord injury and summarize evidence for evaluating acute spinal cord injury treatment. METHODS: Studies related to the treatment for acute spinal cord injury were identified via a search of National Guideline Clearinghouse (NGC, 2000 11), the Cochrane Library (Issue 1,2011), TRIP Database (2000 11), and PubMed (1966-2011). Treatment strategies were formulated according to three basic principles: best evidence, doctor's professional experience, and wishes of the patient. RESULTS: A total of 34 articles were selected, including 1 NGC guideline, 22 systematic reviews, and 11 randomized controlled trials. Based on our review, we arrived at the following recommendations: no clinical evidence exists definitively to recommend the use of any of neuroprotective pharmaceuticals; surgery should be undertaken early; mechanical compression devices and low-molecular weight heparin should be employed to prevent thrombosis; respiratory muscle training is beneficial for pulmonary function and quality of life; and functional electrical stimulation and acupuncture can promote functional recovery. The patient accordingly underwent surgery 6 hours after trauma without receiving any neuroprotective pharmaceuticals; low-molecular weight heparin and intermittent pneumatic compression were applied to prevent thrombosis. He also underwent respiratory muscle training daily for 8 weeks and received functional electrical stimulation for 15 minutes and acupuncture for 30 minutes every day. After follow-up for 3 months, the above therapeutic regimen was confirmed efficacious for acute spinal cord injury. CONCLUSION: Evidence-based medicine provides an individualized treatment protocol for acute spinal cord injury, which can significantly improve the therapeutic effect and prognosis.展开更多
Purpose: Based on the National Natural Science Foundation of China, we collect and sort out the literature published in approximately the last 30 years, which use prescriptions in Synopsis of the Golden Chamber to tre...Purpose: Based on the National Natural Science Foundation of China, we collect and sort out the literature published in approximately the last 30 years, which use prescriptions in Synopsis of the Golden Chamber to treat pelvic inflammatory disease (PID). This study provides theoretical basis for the treatment of PID;we recommend this achievement to colleagues. Method: Firstly, we searched and collected the literatures from last three decades in CNKI, Wanfang and VIP databases, which are about classical prescriptions treating endometriosis. Then, by screening all the literatures, we obtained the clinical research literatures and individual case reports. Finally, we went through the internal quality of the two categories of literatures to get the dominant prescriptions. Using a retrospective study of evidence-based medicine research, we comprehensively collect literature, standardize the disease spectrum, classify the evidence, and then evaluate the internal quality. Results: We refine 4 prescriptions which commonly are used in the treatment of PID;in other words, they are also the clinical symptoms of PID: Gui Zhi Fu Ling Wan symptom, which manifests blood stasis and cold-damp stagnancy;Dang Gui Shao Yao San symptom, which manifests disharmony of liver and spleen, qi-blood stasis and damp obstruction;Da Huang Mu Dan Tang symptom, which manifests the gathering toxic heat and qi-blood stasis;Yi Yi Fu Zi Bai Jiang San symptom, which manifests the internal toxic heat and qi-blood injury. Conclusion: This study is gospel for the patients with recurrent episodes of PID who can’t often use antibiotics. At the same time, it is also a green therapeutics which Chinese ancients dedicated to human medicine.展开更多
To investigate the effects of homogenizing and aging treatments on the microstructure of an Nb-Ti-Cr-Si based ultrahigh temperature alloy,coupons were homogenized at 1 200-1 500 °C for 24 h,and then aged at 1 000...To investigate the effects of homogenizing and aging treatments on the microstructure of an Nb-Ti-Cr-Si based ultrahigh temperature alloy,coupons were homogenized at 1 200-1 500 °C for 24 h,and then aged at 1 000 °C for 24 h.The results show that the heat-treated alloy is composed of Nb solid solution(Nbss),(Nb,X)5Si3 and Cr2Nb phases.With the increase of heat-treatment temperature,previous Nbss dendrites transformed into equiaxed grains,and petal-like Nbss/(Nb,X)5Si3 eutectic colonies gradually changed into small(Nb,X)5Si3 particles distributed in Nbss matrix.A drastic change occurred in the morphology of the Laves phase after homogenizing treatment.Previously coarse Cr2Nb blocks dissolved during homogenizing at temperature above 1 300 °C,and then much finer and crowded Cr2Nb flakes precipitated in the Nbss matrix in cooling.Aging treatment at 1 000 °C for 24 h led to further precipitation of fine particles of Laves phase in Nbss matrix and made the difference in concentrations of Ti,Hf and Al in Nbss,(Nb,X)5Si3 and Cr2Nb phases reduced.展开更多
Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and f...Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and fireclay as binding system. The results showed that with temperature rising, Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded. The modulus of rupture (MOR) and the cold crushing strength (CCS) inereased firstly and then decreased from 110 ℃ to 600 ℃ , then increased obviously. Thermal expansion coefficient increased from 110 ℃ to 760 ℃, decreased from 760 ℃ to 1 300 ℃ , and increased from 1 300 ℃ to1500 ℃.展开更多
The effects of a new technology, multi-step thermo-mechanical treatment, on the microstructure, deformation substructure and mechanical properties at ambient and elevated tempemture of can-forged Ti-33 Al-3 Cr-0.5Mo (...The effects of a new technology, multi-step thermo-mechanical treatment, on the microstructure, deformation substructure and mechanical properties at ambient and elevated tempemture of can-forged Ti-33 Al-3 Cr-0.5Mo (wt%) Alloy were investigated.The results show that, after multi-step thermo-mechanical treatment of can-forged specimens, homogeneous, fine microstructures can be obtained in the whole TiAl-based alloy specimens. Furthermore, the specimen with homogeneous and fine full lamellae microstructure demonstrutes excellent comprehensive mechanical properties at ambient and elevated temperature.展开更多
The morphological evolution of the γ' phase in nickel-based superalloy жc6y during various solution heat treatments was investigated. The significant changes of the γ' precipitates were observed in the solu...The morphological evolution of the γ' phase in nickel-based superalloy жc6y during various solution heat treatments was investigated. The significant changes of the γ' precipitates were observed in the solution-treated samples. The coarsening and dissolution of γ' phase simulta-neously occurred at intermediate temperatures. In some areas, the primary precipitates became blunt and the adjacent ones were intercon-nected with each other via a diffuse neck, indicating a coarsening process of the primary γ' population. The coarsening was dominated by the precipitate agglomeration mechanism (PAM) rather than by the well-known Ostwald ripening mechanism. In other areas, the partial dissolu-tion of the γ' precipitates began to occur, spreading gradually from dendrite cores to interdendritic regions. In addition, a flower-like γ' struc-ture was developed during the subsolvus solution treatments. The observable long filaments composed of erraticly shaped precipitates were caused by the heterogeneous nucleation of the cooling precipitates during water quenching.展开更多
Plasma tungstening followed by carburization(W-C duplex treatment)was performed on the Ti2AlNb-based(O phase) alloy by using the double glow plasma process to enhance its wear resistance.The microstructure and high-te...Plasma tungstening followed by carburization(W-C duplex treatment)was performed on the Ti2AlNb-based(O phase) alloy by using the double glow plasma process to enhance its wear resistance.The microstructure and high-temperature tribological behaviors of the un-treated and W-C duplex-treated samples were investigated.The results show that the duplex-treated layer is mainly composed of W2C or W6C2.54 phases and the contents of W and C elements in the alloyed layer change gradually along the depth by surface plasma duplex treatment.The diffusion depth of W is about 12μm,while the carbon atoms most exist in the depth more than 12μm.High temperature tribometer tests indicate that the friction coefficient of the W-C duplex-treated layer is approximately 1/6 that of substrate.The wear rate of the duplex-treated layer is about 28%that of the untreated one.So,plasma surface W-C duplex treatment can obviously improve the high-temperature tribological resistance of Ti2AlNb-based alloy.The tribological mechanism of the duplex-treated layer is discussed by dividing the friction process of the duplex-treated layer into three fluctuate stages.The first stage is the formation of oxide film between W-C duplex-treated layer and counterface.The second stage is the detachment of oxide film,acting as "the third body" .The last stage is the period that the friction and wear occur between the compact particle layer and counterface.展开更多
A 1040°C-hot-deformed Ti_2AlNb-based alloy solution-treated at 950°C and aged at different temperatures was quantitatively investigated. The microstructure, size of the phase, and microhardness of the deform...A 1040°C-hot-deformed Ti_2AlNb-based alloy solution-treated at 950°C and aged at different temperatures was quantitatively investigated. The microstructure, size of the phase, and microhardness of the deformed alloys were measured. The results indicated that the microstructure of the deformed Ti_2AlNb-based alloy specimens comprise coarse O lath, fine O lath, equiaxed O/α_2, and acicular O phase. More O phase was generated in the deformed alloy after heat treatment because the acicular O phase was more likely to nucleate and grow along the deformation-induced crystal defects such as dislocations and subgrain boundaries. After deformation and subsequent heat treatment, the acicular O phase of the resultant alloy became finer compared to that of the undeformed alloy, and the acicular O phase became coarser and longer with the elevated aging temperature, while the width of the O lath exhibited unobvious variations. The hot deformation facilitated the dissolution of the O lath but accelerated the precipitation of the acicular O phase. When the 950°C-solution-treated deformed Ti_2AlNb-based alloy was then aged at 750°C for different periods, the phase content was nearly invariable, O and B2 phases eventually reached equilibrium, and the microstructure became stable and homogeneous.展开更多
Microstructural evolution of a forged TiAl based alloy during heat treatment from 1 180 ℃ to 1 300 ℃ was investigated. The grain sizes of the alpha phases as well as the sizes and the volume fractions of the gamma p...Microstructural evolution of a forged TiAl based alloy during heat treatment from 1 180 ℃ to 1 300 ℃ was investigated. The grain sizes of the alpha phases as well as the sizes and the volume fractions of the gamma phases were evaluated as a function of heat treatment temperature and time. When the alloys are isothermally heat treated at subtransus temperatures, the sizes of gamma phases(D γ) increase slightly with heat treatment temperature and time and those of alpha phases(D α) and the volume fractions of gamma phases(φ γ) vary significantly with holding time in the early stages of heat treatments, but after heat treatments for 2 h, φ γ reveal little variations with holding times and D α approach limits, which can be described by D α0 =0.65D γ/φ γ. Besides, it has been found that the alpha phases in the specimens heat treated at 1 260 ℃ and 1 300 ℃ contain lamellar structures, at low temperatures, however, appear featureless.展开更多
The effect of heat-treatment process on the properties of Mm0.8Mg0.2(NiCoAlMn)3.5 hydrogen storage alloy was discussed . The electrochemical properties such as cycling stability, activation property, and the plateau v...The effect of heat-treatment process on the properties of Mm0.8Mg0.2(NiCoAlMn)3.5 hydrogen storage alloy was discussed . The electrochemical properties such as cycling stability, activation property, and the plateau voltage of the alloy which was heat-treated in various temperatures and times had different changes during the cycle process, the optimum heat-treatment conditions of this alloy were determined by this work.展开更多
After different heat treatment processes, the metal compound, the microstructure and the hardness of the C-Cr-W- Mo-V-RE Fe-based hardfacing layers are investigated by means of metallographic microscope, X-ray diffrac...After different heat treatment processes, the metal compound, the microstructure and the hardness of the C-Cr-W- Mo-V-RE Fe-based hardfacing layers are investigated by means of metallographic microscope, X-ray diffraction ( XRD ), energy dispersive spectrum( EDS ), transmission electron microscope(TEM) and hardness tester. The results show that the hardfacing layers have higher tempering stability and secondary hardening property. After quenching at 820 ℃ ,the hardness value( HRC37 ) and the microstructure of the layers are similar to that normalized at 820 - 1 000 ℃. The tempering stability and the hardness increases with increasing quench temperature, which is attributed to the amount of the alloy element in the matrix. These results are very helpful for improving the mechanical properties of the hardfacing layers.展开更多
Children with attention deficit and hyper activity disorder have various problems such as low academic performance, social and communication problems, anxiety, depression, aggression, conduct disorder and delinquency,...Children with attention deficit and hyper activity disorder have various problems such as low academic performance, social and communication problems, anxiety, depression, aggression, conduct disorder and delinquency, and also when they become adults, they have problems in social relationships that these problems can increase or decrease in dealing with family. Hence, this study was performed in order to examine the impact of family-based behavioral treatment compared with Barkley behavior therapy in reducing symptoms of children with attention deficit disorder—ADHD. To meet the aim, 20 of children with age range of 7 to 12 years old with attention deficit disorder—hyperactivity were selected in both experimental and control groups, and exposed to the treatment of behavioral family therapy groups and changes in behavior Barkley. Before and after the treatment, they were evaluated according to the scale of the Conner’s Parent Rating Scale-Revised Short Form (CPRS-R: S). Results of multivariate analysis of covariance indicated that there were significant differences between the experimental group who had received family-based behavioral treatments based on changes in behavior Barkley and a control group who had received drug treatment in variables, including conduct problems, learning problems, psychosomatic symptoms, and signs of impulsive hyperactivity, anxiety and hyperactivity (p < 0.01). These results could be guidance for counsel or sand therapists for children with attention deficit disorder—ADHD.展开更多
The coronavirus disease 2019(COVID-19)mortality rate in 55 African countries is almost 4.5 times lower than in the coronavirus disease 2019(COVID-19)despite Africa having over 4.2 times more people.This mortality para...The coronavirus disease 2019(COVID-19)mortality rate in 55 African countries is almost 4.5 times lower than in the coronavirus disease 2019(COVID-19)despite Africa having over 4.2 times more people.This mortality paradox is also evident when comparing Nigeria,a heavily populated,poorly vaccinated and weakly mandated country to Israel,a small,highly vaccinated and strictly mandated country.Nigeria has almost 4 times lower COVID mortality than Israel.In this Field of Vision perspective,I explain how this paradox has evolved drawing upon my academic,clinical and social experience.Since April 2020,I’ve developed and been using the Egyptian immune-modulatory Kelleni’s protocol to manage COVID-19 patients including pediatric,geriatric,pregnant,immune-compromised and other individuals suffering from multiple comorbidities.It’s unfortunate that severe acute respiratory syndrome coronavirus 2 is still evolving accompanied by more deaths.However in Africa,we’ve been able to live without anxiety or mandates throughout the pandemic because we trust science and adopted early treatment using safe,and effective repurposed drugs that have saved the majority of COVID-19 patients.This article represents an African and Egyptian tale of honor.展开更多
The effects of rapid heating cyclic heat treatment on mechanical properties of a TiAl based alloy (Ti 33Al 3Cr) were studied by means of an induction heating machine. The results show that: 1) fine fully lamellar micr...The effects of rapid heating cyclic heat treatment on mechanical properties of a TiAl based alloy (Ti 33Al 3Cr) were studied by means of an induction heating machine. The results show that: 1) fine fully lamellar microstructure with colony size of about 50 μm and lamellar spacing of about 0.12 μm can be obtained; 2) the compression mechanical properties can be improved to a large extent and the best comprehensive compression mechanical properties can reach the yield stress 745 MPa, the large flow stress 1 672 MPa and the compression ratio 19.4%; and 3) the compression fracture at room temperature after induction heat treatment and aging is still typical cleavage fracture.展开更多
COVID-19 is highly infectious and epidemic,which belongs to the"plague"disease of traditional Chinese medicine and seriously endangers the safety of human life.Based on the theory of Guangwenyilun combined w...COVID-19 is highly infectious and epidemic,which belongs to the"plague"disease of traditional Chinese medicine and seriously endangers the safety of human life.Based on the theory of Guangwenyilun combined with the treatment experience of COVID-19 in TCM,syndrome differentiation-based treatment and the clinical characteristic of COVID-19 is being deeply analysed.COVID-19 began because of the"epidemic pathogenic factors",and the pathogenesis is that the dampness and heat generated toxin which blocked the qi movement.The early onset of this disease is in the pleurodiaphragmatic interspace,and its transmission can be divided into sequential transmission and reverse transmission.Regardless of the direction of its transmission,grasping the transmission of"epidemic pathogenic factors"on the diagnosis and treatment combined with"five distinguishing thought,exterior and interior,accompanying symptoms"theory will be of great importance to help to improve the effect of treatment.At the same time,this clinical approach will also provide reference for the diagnosis and treatment of any possible new diseases.展开更多
Based on the concept of "precision medicine", this paper is to probe into the thinking innovation thought anddevelopment direction of "dialectical theory" of TCM, and to compare the development prospects of "synd...Based on the concept of "precision medicine", this paper is to probe into the thinking innovation thought anddevelopment direction of "dialectical theory" of TCM, and to compare the development prospects of "syndromedifferentiation" and "genetic constitution". It points out that the dialectical concept of "syndrome differentiation andtreatment" is combined with the concept of high and new technology of "precision medicine" to further clarify thescientific connotation of traditional Chinese medicine.展开更多
Objective:To evaluate the clinical efficacy of stone needle therapy based on blood stasis theory for different traditional Chinese medicine(TCM)syndrome types of patients with knee osteoarthritis in early and middle s...Objective:To evaluate the clinical efficacy of stone needle therapy based on blood stasis theory for different traditional Chinese medicine(TCM)syndrome types of patients with knee osteoarthritis in early and middle stage.Methods:Totally 36 patients with knee osteoarthritis were enrolled in the orthopaedic ward between March 2016 and December 2017,and diagnosed as qi stagnation and blood stasis syndrome,cold dampness and stasis syndrome,or phlegm and stasis syndrome according to TCM syndrome differentiation.After treatment,stone needle was used for ironing on the different meridian acupoints according to different syndrome.The efficacy of patients with the above three syndromes was respectively evaluated,and the visual analogue scale(VAS)score and western ontario and mcMaster universities arthritis Index(WOMAC)score of the three groups were calculated before treatment,2 weeks,and 4 weeks after treatment.Results:The effective rates of the three groups were 86.67%,81.82%,and 80.00%,respectively.After 2 weeks and 4 weeks of treatment,the VAS and WOMAC scores of the three groups decreased significantly compared to treatment before(P<0.05).Conclusion:Stone needle therapy for ironing on the acupoints around the knee joint has a good therapeutic effect on knee osteoarthritis of different syndrome types,which is worthy of further application.展开更多
基金Supported by the Science and Technology Program of Nantong Health Committee,No.MA2019003 and No.MA2021017Science and Technology Program of Nantong City,No.Key003 and No.JCZ2022040Kangda College of Nanjing Medical University,No.KD2021JYYJYB025,No.KD2022KYJJZD019,and No.KD2022KYJJZD022.
文摘The internal carotid artery occlusion caused by head and neck trauma,also known as traumatic intracranial artery occlusion,is relatively rare clinically.Traumatic skull base fracture is a common complication of traumatic brain injury.Traumatic skull base fracture is one of the causes of traumatic internal carotid artery occlusion.If not detected early and treated in time,the prognosis of patients is poor.This editorial makes a relevant analysis of this disease.
文摘OBJECTIVE: To formulate an evidence-based treatment for one patient with acute spinal cord injury and summarize evidence for evaluating acute spinal cord injury treatment. METHODS: Studies related to the treatment for acute spinal cord injury were identified via a search of National Guideline Clearinghouse (NGC, 2000 11), the Cochrane Library (Issue 1,2011), TRIP Database (2000 11), and PubMed (1966-2011). Treatment strategies were formulated according to three basic principles: best evidence, doctor's professional experience, and wishes of the patient. RESULTS: A total of 34 articles were selected, including 1 NGC guideline, 22 systematic reviews, and 11 randomized controlled trials. Based on our review, we arrived at the following recommendations: no clinical evidence exists definitively to recommend the use of any of neuroprotective pharmaceuticals; surgery should be undertaken early; mechanical compression devices and low-molecular weight heparin should be employed to prevent thrombosis; respiratory muscle training is beneficial for pulmonary function and quality of life; and functional electrical stimulation and acupuncture can promote functional recovery. The patient accordingly underwent surgery 6 hours after trauma without receiving any neuroprotective pharmaceuticals; low-molecular weight heparin and intermittent pneumatic compression were applied to prevent thrombosis. He also underwent respiratory muscle training daily for 8 weeks and received functional electrical stimulation for 15 minutes and acupuncture for 30 minutes every day. After follow-up for 3 months, the above therapeutic regimen was confirmed efficacious for acute spinal cord injury. CONCLUSION: Evidence-based medicine provides an individualized treatment protocol for acute spinal cord injury, which can significantly improve the therapeutic effect and prognosis.
文摘Purpose: Based on the National Natural Science Foundation of China, we collect and sort out the literature published in approximately the last 30 years, which use prescriptions in Synopsis of the Golden Chamber to treat pelvic inflammatory disease (PID). This study provides theoretical basis for the treatment of PID;we recommend this achievement to colleagues. Method: Firstly, we searched and collected the literatures from last three decades in CNKI, Wanfang and VIP databases, which are about classical prescriptions treating endometriosis. Then, by screening all the literatures, we obtained the clinical research literatures and individual case reports. Finally, we went through the internal quality of the two categories of literatures to get the dominant prescriptions. Using a retrospective study of evidence-based medicine research, we comprehensively collect literature, standardize the disease spectrum, classify the evidence, and then evaluate the internal quality. Results: We refine 4 prescriptions which commonly are used in the treatment of PID;in other words, they are also the clinical symptoms of PID: Gui Zhi Fu Ling Wan symptom, which manifests blood stasis and cold-damp stagnancy;Dang Gui Shao Yao San symptom, which manifests disharmony of liver and spleen, qi-blood stasis and damp obstruction;Da Huang Mu Dan Tang symptom, which manifests the gathering toxic heat and qi-blood stasis;Yi Yi Fu Zi Bai Jiang San symptom, which manifests the internal toxic heat and qi-blood injury. Conclusion: This study is gospel for the patients with recurrent episodes of PID who can’t often use antibiotics. At the same time, it is also a green therapeutics which Chinese ancients dedicated to human medicine.
基金Project (51071124) supported by the National Natural Science Foundation of ChinaProject (20096102110012) supported by the Ministry of Education, China Project (07-TP-2008) supported by the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,China
文摘To investigate the effects of homogenizing and aging treatments on the microstructure of an Nb-Ti-Cr-Si based ultrahigh temperature alloy,coupons were homogenized at 1 200-1 500 °C for 24 h,and then aged at 1 000 °C for 24 h.The results show that the heat-treated alloy is composed of Nb solid solution(Nbss),(Nb,X)5Si3 and Cr2Nb phases.With the increase of heat-treatment temperature,previous Nbss dendrites transformed into equiaxed grains,and petal-like Nbss/(Nb,X)5Si3 eutectic colonies gradually changed into small(Nb,X)5Si3 particles distributed in Nbss matrix.A drastic change occurred in the morphology of the Laves phase after homogenizing treatment.Previously coarse Cr2Nb blocks dissolved during homogenizing at temperature above 1 300 °C,and then much finer and crowded Cr2Nb flakes precipitated in the Nbss matrix in cooling.Aging treatment at 1 000 °C for 24 h led to further precipitation of fine particles of Laves phase in Nbss matrix and made the difference in concentrations of Ti,Hf and Al in Nbss,(Nb,X)5Si3 and Cr2Nb phases reduced.
文摘Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and fireclay as binding system. The results showed that with temperature rising, Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded. The modulus of rupture (MOR) and the cold crushing strength (CCS) inereased firstly and then decreased from 110 ℃ to 600 ℃ , then increased obviously. Thermal expansion coefficient increased from 110 ℃ to 760 ℃, decreased from 760 ℃ to 1 300 ℃ , and increased from 1 300 ℃ to1500 ℃.
文摘The effects of a new technology, multi-step thermo-mechanical treatment, on the microstructure, deformation substructure and mechanical properties at ambient and elevated tempemture of can-forged Ti-33 Al-3 Cr-0.5Mo (wt%) Alloy were investigated.The results show that, after multi-step thermo-mechanical treatment of can-forged specimens, homogeneous, fine microstructures can be obtained in the whole TiAl-based alloy specimens. Furthermore, the specimen with homogeneous and fine full lamellae microstructure demonstrutes excellent comprehensive mechanical properties at ambient and elevated temperature.
基金supported by the Aviation Industry Corporation of China (No. 201110026-01)
文摘The morphological evolution of the γ' phase in nickel-based superalloy жc6y during various solution heat treatments was investigated. The significant changes of the γ' precipitates were observed in the solution-treated samples. The coarsening and dissolution of γ' phase simulta-neously occurred at intermediate temperatures. In some areas, the primary precipitates became blunt and the adjacent ones were intercon-nected with each other via a diffuse neck, indicating a coarsening process of the primary γ' population. The coarsening was dominated by the precipitate agglomeration mechanism (PAM) rather than by the well-known Ostwald ripening mechanism. In other areas, the partial dissolu-tion of the γ' precipitates began to occur, spreading gradually from dendrite cores to interdendritic regions. In addition, a flower-like γ' struc-ture was developed during the subsolvus solution treatments. The observable long filaments composed of erraticly shaped precipitates were caused by the heterogeneous nucleation of the cooling precipitates during water quenching.
基金Project supported by the Scientific Research Foundation of Nanjing University of Information and Technology,China
文摘Plasma tungstening followed by carburization(W-C duplex treatment)was performed on the Ti2AlNb-based(O phase) alloy by using the double glow plasma process to enhance its wear resistance.The microstructure and high-temperature tribological behaviors of the un-treated and W-C duplex-treated samples were investigated.The results show that the duplex-treated layer is mainly composed of W2C or W6C2.54 phases and the contents of W and C elements in the alloyed layer change gradually along the depth by surface plasma duplex treatment.The diffusion depth of W is about 12μm,while the carbon atoms most exist in the depth more than 12μm.High temperature tribometer tests indicate that the friction coefficient of the W-C duplex-treated layer is approximately 1/6 that of substrate.The wear rate of the duplex-treated layer is about 28%that of the untreated one.So,plasma surface W-C duplex treatment can obviously improve the high-temperature tribological resistance of Ti2AlNb-based alloy.The tribological mechanism of the duplex-treated layer is discussed by dividing the friction process of the duplex-treated layer into three fluctuate stages.The first stage is the formation of oxide film between W-C duplex-treated layer and counterface.The second stage is the detachment of oxide film,acting as "the third body" .The last stage is the period that the friction and wear occur between the compact particle layer and counterface.
基金the National Natural Science Foundation of China(Nos.51474156 and U1660201)the National Magnetic Confinement Fusion Energy Research Program of China(No.2015GB119001)for their grants and financial supports
文摘A 1040°C-hot-deformed Ti_2AlNb-based alloy solution-treated at 950°C and aged at different temperatures was quantitatively investigated. The microstructure, size of the phase, and microhardness of the deformed alloys were measured. The results indicated that the microstructure of the deformed Ti_2AlNb-based alloy specimens comprise coarse O lath, fine O lath, equiaxed O/α_2, and acicular O phase. More O phase was generated in the deformed alloy after heat treatment because the acicular O phase was more likely to nucleate and grow along the deformation-induced crystal defects such as dislocations and subgrain boundaries. After deformation and subsequent heat treatment, the acicular O phase of the resultant alloy became finer compared to that of the undeformed alloy, and the acicular O phase became coarser and longer with the elevated aging temperature, while the width of the O lath exhibited unobvious variations. The hot deformation facilitated the dissolution of the O lath but accelerated the precipitation of the acicular O phase. When the 950°C-solution-treated deformed Ti_2AlNb-based alloy was then aged at 750°C for different periods, the phase content was nearly invariable, O and B2 phases eventually reached equilibrium, and the microstructure became stable and homogeneous.
文摘Microstructural evolution of a forged TiAl based alloy during heat treatment from 1 180 ℃ to 1 300 ℃ was investigated. The grain sizes of the alpha phases as well as the sizes and the volume fractions of the gamma phases were evaluated as a function of heat treatment temperature and time. When the alloys are isothermally heat treated at subtransus temperatures, the sizes of gamma phases(D γ) increase slightly with heat treatment temperature and time and those of alpha phases(D α) and the volume fractions of gamma phases(φ γ) vary significantly with holding time in the early stages of heat treatments, but after heat treatments for 2 h, φ γ reveal little variations with holding times and D α approach limits, which can be described by D α0 =0.65D γ/φ γ. Besides, it has been found that the alpha phases in the specimens heat treated at 1 260 ℃ and 1 300 ℃ contain lamellar structures, at low temperatures, however, appear featureless.
文摘The effect of heat-treatment process on the properties of Mm0.8Mg0.2(NiCoAlMn)3.5 hydrogen storage alloy was discussed . The electrochemical properties such as cycling stability, activation property, and the plateau voltage of the alloy which was heat-treated in various temperatures and times had different changes during the cycle process, the optimum heat-treatment conditions of this alloy were determined by this work.
文摘After different heat treatment processes, the metal compound, the microstructure and the hardness of the C-Cr-W- Mo-V-RE Fe-based hardfacing layers are investigated by means of metallographic microscope, X-ray diffraction ( XRD ), energy dispersive spectrum( EDS ), transmission electron microscope(TEM) and hardness tester. The results show that the hardfacing layers have higher tempering stability and secondary hardening property. After quenching at 820 ℃ ,the hardness value( HRC37 ) and the microstructure of the layers are similar to that normalized at 820 - 1 000 ℃. The tempering stability and the hardness increases with increasing quench temperature, which is attributed to the amount of the alloy element in the matrix. These results are very helpful for improving the mechanical properties of the hardfacing layers.
文摘Children with attention deficit and hyper activity disorder have various problems such as low academic performance, social and communication problems, anxiety, depression, aggression, conduct disorder and delinquency, and also when they become adults, they have problems in social relationships that these problems can increase or decrease in dealing with family. Hence, this study was performed in order to examine the impact of family-based behavioral treatment compared with Barkley behavior therapy in reducing symptoms of children with attention deficit disorder—ADHD. To meet the aim, 20 of children with age range of 7 to 12 years old with attention deficit disorder—hyperactivity were selected in both experimental and control groups, and exposed to the treatment of behavioral family therapy groups and changes in behavior Barkley. Before and after the treatment, they were evaluated according to the scale of the Conner’s Parent Rating Scale-Revised Short Form (CPRS-R: S). Results of multivariate analysis of covariance indicated that there were significant differences between the experimental group who had received family-based behavioral treatments based on changes in behavior Barkley and a control group who had received drug treatment in variables, including conduct problems, learning problems, psychosomatic symptoms, and signs of impulsive hyperactivity, anxiety and hyperactivity (p < 0.01). These results could be guidance for counsel or sand therapists for children with attention deficit disorder—ADHD.
文摘The coronavirus disease 2019(COVID-19)mortality rate in 55 African countries is almost 4.5 times lower than in the coronavirus disease 2019(COVID-19)despite Africa having over 4.2 times more people.This mortality paradox is also evident when comparing Nigeria,a heavily populated,poorly vaccinated and weakly mandated country to Israel,a small,highly vaccinated and strictly mandated country.Nigeria has almost 4 times lower COVID mortality than Israel.In this Field of Vision perspective,I explain how this paradox has evolved drawing upon my academic,clinical and social experience.Since April 2020,I’ve developed and been using the Egyptian immune-modulatory Kelleni’s protocol to manage COVID-19 patients including pediatric,geriatric,pregnant,immune-compromised and other individuals suffering from multiple comorbidities.It’s unfortunate that severe acute respiratory syndrome coronavirus 2 is still evolving accompanied by more deaths.However in Africa,we’ve been able to live without anxiety or mandates throughout the pandemic because we trust science and adopted early treatment using safe,and effective repurposed drugs that have saved the majority of COVID-19 patients.This article represents an African and Egyptian tale of honor.
文摘The effects of rapid heating cyclic heat treatment on mechanical properties of a TiAl based alloy (Ti 33Al 3Cr) were studied by means of an induction heating machine. The results show that: 1) fine fully lamellar microstructure with colony size of about 50 μm and lamellar spacing of about 0.12 μm can be obtained; 2) the compression mechanical properties can be improved to a large extent and the best comprehensive compression mechanical properties can reach the yield stress 745 MPa, the large flow stress 1 672 MPa and the compression ratio 19.4%; and 3) the compression fracture at room temperature after induction heat treatment and aging is still typical cleavage fracture.
文摘COVID-19 is highly infectious and epidemic,which belongs to the"plague"disease of traditional Chinese medicine and seriously endangers the safety of human life.Based on the theory of Guangwenyilun combined with the treatment experience of COVID-19 in TCM,syndrome differentiation-based treatment and the clinical characteristic of COVID-19 is being deeply analysed.COVID-19 began because of the"epidemic pathogenic factors",and the pathogenesis is that the dampness and heat generated toxin which blocked the qi movement.The early onset of this disease is in the pleurodiaphragmatic interspace,and its transmission can be divided into sequential transmission and reverse transmission.Regardless of the direction of its transmission,grasping the transmission of"epidemic pathogenic factors"on the diagnosis and treatment combined with"five distinguishing thought,exterior and interior,accompanying symptoms"theory will be of great importance to help to improve the effect of treatment.At the same time,this clinical approach will also provide reference for the diagnosis and treatment of any possible new diseases.
文摘Based on the concept of "precision medicine", this paper is to probe into the thinking innovation thought anddevelopment direction of "dialectical theory" of TCM, and to compare the development prospects of "syndromedifferentiation" and "genetic constitution". It points out that the dialectical concept of "syndrome differentiation andtreatment" is combined with the concept of high and new technology of "precision medicine" to further clarify thescientific connotation of traditional Chinese medicine.
文摘Objective:To evaluate the clinical efficacy of stone needle therapy based on blood stasis theory for different traditional Chinese medicine(TCM)syndrome types of patients with knee osteoarthritis in early and middle stage.Methods:Totally 36 patients with knee osteoarthritis were enrolled in the orthopaedic ward between March 2016 and December 2017,and diagnosed as qi stagnation and blood stasis syndrome,cold dampness and stasis syndrome,or phlegm and stasis syndrome according to TCM syndrome differentiation.After treatment,stone needle was used for ironing on the different meridian acupoints according to different syndrome.The efficacy of patients with the above three syndromes was respectively evaluated,and the visual analogue scale(VAS)score and western ontario and mcMaster universities arthritis Index(WOMAC)score of the three groups were calculated before treatment,2 weeks,and 4 weeks after treatment.Results:The effective rates of the three groups were 86.67%,81.82%,and 80.00%,respectively.After 2 weeks and 4 weeks of treatment,the VAS and WOMAC scores of the three groups decreased significantly compared to treatment before(P<0.05).Conclusion:Stone needle therapy for ironing on the acupoints around the knee joint has a good therapeutic effect on knee osteoarthritis of different syndrome types,which is worthy of further application.