Objective To compare the differences of therapeutic effect of chronic fatigue syndrome （CFS） treated with the combined therapy of Panlongci （coiling dragon needling） and cupping on back and the western medicine th...Objective To compare the differences of therapeutic effect of chronic fatigue syndrome （CFS） treated with the combined therapy of Panlongci （coiling dragon needling） and cupping on back and the western medicine therapy with prednisone. Methods Seventy-two cases were randomly divided into 2 groups of acupuncture-cupping group （37 cases） and prednisone group （35 cases）. In acupuncture-cupping group, Jiaji points （夹脊 EX-B 2） of the level of T1–L5 were applied with coiling dragon needling once a day, combining with moving cupping on back once every two days. In prednisone group, prednisone tablets of 10 mg were orally taken at 8：00 am everyday. Seven days were counted as one treatment course, and 2 courses were carried on totally. FS-14 scale and BELL’s CFS integral table were applied to evaluate the fatigue degree of patients before and after the treatment, and the therapeutic effects of both groups were compared. Results After one course of treatment, the BELL’s scores of both groups were obviously improved （both P0.01）, but there was no significant difference between the 2 groups （P0.05）; after 2 courses of treatment, the BELL’s score in acupuncture-cupping group improved more obviously than that of the prednisone group （P0.05）, and the total effective rate of 91.9% （34/37） in acupuncture-cupping group was superior to that of 71.4% （25/35） in prednisone group （P0.05）. Conclusion The therapeutic effect of chronic fatigue syndrome treated with coiling dragon needling and moving cupping on back is positive, which is superior to that of prednisone with oral administration.展开更多
Many strip materials are coiled after rolling process. The stresses are imposed on the material wound on the automatically controlled collapse mandrel under the coiling tension. The coiling process can be described by...Many strip materials are coiled after rolling process. The stresses are imposed on the material wound on the automatically controlled collapse mandrel under the coiling tension. The coiling process can be described by three typical cases: winding without automatic adjustment, winding with automatic adjustment and after mandrel removal. A new model of equations for predicting the stresses during the strip coiling process is built by consideration of the three cases respectively. By solving the equations of different typical cases, the radial stresses and tangential stress of the layers of coil can be calculated. Also, the coiling parameters, such as strip thickness, coiling tension and necking critical pressure, affecting the coil performance are investigated. It is believed that the present model can be used for design and control of the automatically controlled collapse mandrel.展开更多
Influence of coiling temperature(CT)on the microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V was elucidated.The precipitation behavior of nano-sized particles w...Influence of coiling temperature(CT)on the microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V was elucidated.The precipitation behavior of nano-sized particles was investigated by theoretical calculation and quantitative analysis.And the results revealed that V-enriched(Ti,Mo,V)C precipitated in the ferrite matrix.As the CT decreased,the site fractions of Ti in(Ti,Mo,V)C changed little,the site fractions of Mo increased,and the site fractions of V decreased accordingly.Moreover,the low CT could refine the microstructure and precipitated particles but suppress the precipitation of(Ti,Mo,V)C particles simultaneously,leading to the volume fraction of(Ti,Mo,V)C significantly decreasing,consequently causing an increment of grain refinement strengthening and a reduction in precipitation hardening.When the CT was 600℃,the steel characterized by fine polygonal ferrite,a small amount of bainite and nano-sized(Ti,Mo,V)C precipitates exhibited the optimum mechanical properties with the ultimate tensile strength of 870 MPa,yield strength of 807 MPa and elongation to fracture of 17%.展开更多
The influences of coiling temperature and cooling condition on structural transformation of the hot-rolled tertiary oxide scale formed under continuous cooling conditions were studied by thermal gravimetric analyzer. ...The influences of coiling temperature and cooling condition on structural transformation of the hot-rolled tertiary oxide scale formed under continuous cooling conditions were studied by thermal gravimetric analyzer. The fourth oxide scale formed under different conditions were classified and plotted. Because the oxide scale structure transformation is diffusion-controlled and the transformation law is similar to ＂C＂ curve, the eutectoid transformation nose temperature is 450 ℃. Under condition of low temperature and high cooling rate, ion diffusion behavior is restricted so that the eutectoid reaction is suppressed, resulting in that the fourth oxide scale is mainly made up of pre-eutectoid Fe304 and FeO without eu- tectoid products. From scale structure transition diagram, the eutectoid reaction process was affected by coiling temperature and cooling rate, leading to various scale structures.展开更多
The microstructure characteristics and properties(especially hole expansion property)of 800 MPa hot-rolled complex phase steel with different coiling temperatures were studied.The microstructure consisted of polygonal...The microstructure characteristics and properties(especially hole expansion property)of 800 MPa hot-rolled complex phase steel with different coiling temperatures were studied.The microstructure consisted of polygonal ferrite and precipitates when the steel was coiled at 550℃,and when the steel was coiled between 460–520℃,the microstructure was composed of granular bainite and martensite and austenite(M/A)islands.The morphology of the crack was analyzed by scanning electron microscopy,and the in situ scanning electron microscope tensile test was used to find out the fracture mechanism and deformation behavior of the steel with different coiling temperatures.When the steel was coiled at 550℃,the cracks initiated at the ferrite grain boundary and propagated through the grains or along the grain boundaries.When the steel was coiled at 520℃,the cracks first initiated at the junction of ferrite and M/A island and then propagated through the grains.The steel coiled at 520℃ has quite good mechanical properties and relatively high hole expansion ratio.展开更多
Mice deficient in the transcription factor pleomorphic adenoma gene 1(PLAG1)exhibit reproductive issues that are characterized,in part,by decreased progressive sperm motility in the male.However,the underlying cause o...Mice deficient in the transcription factor pleomorphic adenoma gene 1(PLAG1)exhibit reproductive issues that are characterized,in part,by decreased progressive sperm motility in the male.However,the underlying cause of this impairment is unknown.As epididymal transit is critical for sperm maturation and motility,the morphology of the epididymis of Plag1-deficient mice was investigated and the spatial expression patterns of PLAG1 protein and mRNA were identified.Using X-gal staining and in situ hybridization,PLAG1 was shown to be widely expressed in both the epithelium and stroma in all regions of the mouse epididymis.Interestingly,the X-gal staining pattern was markedly different in the cauda,where it could be suggestive of PLAG1 secretion into the epididymal lumen.At all ages investigated,the morphology of epididymides from Plag1 knockout(KO)mice was aberrant;the tubule failed to elongate and coil,particularly in the corpus and cauda,and the cauda was malformed,lacking its usual bulbous shape.Moreover,the epididymides from Plag1 KO mice were significantly reduced in size relative to body weight.In 20%of Plag1-deficient mice,the left testicle and epididymis were lacking.The impaired morphogenesis of the epididymal tubule is likely to be a major contributing factor to the fertility problems observed in male Plag1-deficient mice.These results also establish PLAG1 as an important regulator of male reproduction,not only through its involvement in testicular sperm production,but also via its role in the development and function of the epididymis.展开更多
The strength-to-weight ratio is an important property of high-strength low-alloy(HSLA)steel in pipeline,whose precipitation strengthening can be improved.The final rolling temperature(FRT)and coiling temperature(CT)ar...The strength-to-weight ratio is an important property of high-strength low-alloy(HSLA)steel in pipeline,whose precipitation strengthening can be improved.The final rolling temperature(FRT)and coiling temperature(CT)are the key process parameters in the control of precipitates and microstructure.Continuous cooling rate was fixed at 10℃/s,and the effects of deformation and coiling temperatures on precipitates and microstructure of Ti-Nb microalloyed HSLA steel were investigated through thermo-mechanical controlled processing on Gleeble 3500.The microstructure is mainly acicular ferrite with high density dislocation and several microns scale.The size and volume fraction of the precipitates were studied under transmission electron microscopy.The results showed that the diameter of the precipitates was in the range between 4 and 240 nm.The optimized combination of parameters is FRT of 820℃and CT of 550℃,and the volume fraction of precipitates obtained under this process is 0.59%.展开更多
Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiog...Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.展开更多
The effects of hot-strip coiling temperature on Ti（C,N） precipitation, texture and hydrogen permeation behavior in DC06 EK enamel steel were investigated by TEM, EBSD test and electrochemical hydrogen permeation exp...The effects of hot-strip coiling temperature on Ti（C,N） precipitation, texture and hydrogen permeation behavior in DC06 EK enamel steel were investigated by TEM, EBSD test and electrochemical hydrogen permeation experiment. It was found that the Ti（C,N） particles in hot-strip coarsened with increasing coiling temperature, whereas after cold-rolling and annealing, the size difference of Ti（C,N） particles was lessened. The hot-strip coiling temperature has a significant impact on the recrystallized texture in the subsequent cold-rolled and annealed sheet. Hot-strip using high temperature（700 ℃） coiling leads to strong {111} recrystallized texture in annealed sheet, with peak intensity 9.2. On the contrary, in annealed sheets using hot-strip coiling at 650 ℃, their {111} recrystallized textures were weaker, which was also reflected in their rmvalues. Even though the hydrogen diffusion coefficient is slightly lower（7.76×10^（-5） mm^2/s） in annealed sheet using low temperature coiling（600 ℃）, appropriately higher coiling temperature is more suitable for DC06 EK enamel steel combining both good drawability and fish-scale resistance.展开更多
Low-carbon steel is widely used for household appliance and automotive panel steel because of its excellent plasticity.Unfortunately,yield point phenomena easily appear in the low-carbon steel produced by a continuous...Low-carbon steel is widely used for household appliance and automotive panel steel because of its excellent plasticity.Unfortunately,yield point phenomena easily appear in the low-carbon steel produced by a continuous annealing process and cause degradation to the surface quality during processing.The effect of the coiling temperature(600-750℃)and annealing temperature(740-820℃)on the yield point behavior is studied.Tensile tests show that coiling temperature has a greater effect on yield point elongation(YPE)and aging index(AI)than the annealing temperature.Microstructure observations show that coiling temperature at 750℃would make the micron-sized carbides appearing at the grain boundary disappear and a number of dispersed nanoscale carbides precipitate in grain interior,corresponding to the highest solid solution carbon content in the matrix of 750℃coiled sample.The experimental results suggest that AI rather than YPE has a positive relationship with the solid solution carbon content of the low-carbon steel.And YPE has a positive relationship with the upper/lower yield strength.展开更多
Background:To evaluate the efficacy of stent-assisted coiling(SAC)for the treatment of carotid ophthalmic segment aneurysm segment aneurysms(OSAs)of the internal carotid artery(ICA)through detailed long-term follow-up...Background:To evaluate the efficacy of stent-assisted coiling(SAC)for the treatment of carotid ophthalmic segment aneurysm segment aneurysms(OSAs)of the internal carotid artery(ICA)through detailed long-term follow-up of a large patient cohort.Methods:We retrospectively analyzed 88 consecutive patients with OSAs between January 2009 and January 2020 at our center.Angiographic results were evaluated using the modified Raymond grading system and clinical outcomes were evaluated using the mRS scale.The primary endpoints were major aneurysm recurrence and poor clinical outcomes for at least 18 months of follow-up.The patients were asked to attend clinical follow-up assessments and possibly undergo DSA or MR via telephone.Results:We enrolled 88 patients with 99 OSAs treated with coiling,of whom 76 were treated with SAC.The coiling procedures were successful in all 88 patients.Overall,complications occurred in 8 patients(9.1%).No procedure-related mortality was observed.67(76.1%)experienced immediate aneurysm occlusion at the end of the procedure.Long-term angiographic follow-up(18 months)was available in 45/88 aneurysms(51%)(average 18.7±5.2 months).Four patients continued their follow-up for 5 years after initial aneurysm treatment.After a clinical follow-up time of 28.7 months(range,12-51 months),85 patients(95.5%)achieved favorable clinical outcomes(mRS scores of 0-2).Conclusions:This study indicates that SAC treatment is a safe and effective therapeutic alternative for ruptured and unruptured OSAs.The procedural risks are low with relatively long-term effectiveness.展开更多
Various hot rolling schedules were applied to a Nb,V,Ti contained HSLA steel.Coiling temperature had crucial effects on not only yield strength,but also yield ratio and precipitation behavior.600Mpa yield strength is ...Various hot rolling schedules were applied to a Nb,V,Ti contained HSLA steel.Coiling temperature had crucial effects on not only yield strength,but also yield ratio and precipitation behavior.600Mpa yield strength is achieved when coiled at 450℃,which is 100Mpa higher than those coiled at 570℃.However,the low coiling temperature had adverse effect to increase yield ratio,which increased from 0.78 to 0.88 as coiling temperature dropped from 570℃ to 450℃.High resolution SEM analysis shows that sizes of Nb,V,Ti precipitates are affected by coiling temperature.Coarse (Nb,Ti)(C,N) precipitates up to 5μm are observed at higher coiling temperature and to decrease tensile strength,where high coiling temperature corresponds to low cooling rate.With strong cooling and coiling capacity of Shasteel’s 1450mm width hot rolling mill,these results indicate that strength and formability of the steel can be balanced when coiling temperature has been optimized.Alloying and microalloying costs can be reduced by efficiently utilizing the capacity of rolling mill.Alumina inclusions are found to act as nucleus for Nb,V,Ti precipitates,contributing to coarsening of precipitates.展开更多
The effect of coiling temperatures on the evolution of texture in Ti-IF steel during ferritic hot rolling, cold rolling and annealing was studied. It was found that texture evolution at high temperature coiling is abs...The effect of coiling temperatures on the evolution of texture in Ti-IF steel during ferritic hot rolling, cold rolling and annealing was studied. It was found that texture evolution at high temperature coiling is absolutely different from that at low temperature one. The hot band texture includes a strong α-fiber as well as a weak γ-fiber after ferritic hot rolling and low temperature coiling. Both of them intensify after cold rolling and a γ-fiber with peak at {111}〈112〉 is the main texture of annealed samples. However, the main component of the hot band texture after high temperature coiling is v-fiber. After cold rolling, the intensity of γ texture reduces; α fiber （except {111}〈110〉 component） intensifies and a strong and well-proportioned γ-fiber forms in the annealed samples.展开更多
The effects of cooling rate and coiling temperature on microstructure and mechanical properties of a plain carbon steel were investigated by combining metallography and tensile experiments. The results indicate that f...The effects of cooling rate and coiling temperature on microstructure and mechanical properties of a plain carbon steel were investigated by combining metallography and tensile experiments. The results indicate that ferrite grain size is refined and bainite transformation occurs to ensure high strength and elongation, as the cooling rate is quick enough. Yield strength and tensite strength improve with the decreased finish cooling temperature, but the elongation decreases too significantly to meet the requirements. Thus, the cooling rate must be quick enough, and the appropriate coiling temperature should be carefully selected to obtain refined ferrite and a small amount of bainite to improve the strength while the plasticity is also ensured. Under this condition, the Mn element concentration can be reduced to save cost or produce higher strength steel with same chemical composition.展开更多
A new intelligent control scheme for hot strip coiling temperature is presented. In this scheme, the prediction mode1 of finishing temperature and the presetting model of main cooling zone are establish based on BP ne...A new intelligent control scheme for hot strip coiling temperature is presented. In this scheme, the prediction mode1 of finishing temperature and the presetting model of main cooling zone are establish based on BP neural network, the feed-forward open-loop control model of main cooling zone is constructed based on T-S fuzzy neural network, a new improved structure of T-S fuzzy neural network is developed, and the feedback close-loop control model of precision cooling zone is obtained based on fuzzy control. The effectiveness of the proposed scheme has been demonstrated by computer simulation with a satisfactory result.展开更多
In this paper, the effect of hot-rolling processing parameters on the post-rolling transformation behavior of C-Mn-Cr-Cu weather-resistant martensitic steel was investigated.Results indicate that the post-rolling tran...In this paper, the effect of hot-rolling processing parameters on the post-rolling transformation behavior of C-Mn-Cr-Cu weather-resistant martensitic steel was investigated.Results indicate that the post-rolling transformation behavior, particularly the post-coiling transformation behavior, strongly depends on the coiling temperature.Under a high coiling temperature, ferrite/pearlite transformation was mainly observed with a low trans-formation speed and transformation dilation after coiling.With decreasing coiling temperature, the proportion of bainite transformation increased with an increased transformation speed and transformation dilation.The dependence of transformation behavior on the coiling temperature could be one of the most important reasons behind the coil collapse of the experimental steel.The optimization of hot-rolling and coiling processing parameters of the steel strip, including laminar flow cooling, coiling temperature, and suspension time on the winding machine, can signi-ficantly reduce the transformation dilation of the steel after hot rolling, thus effectively controlling the coil collapse of the steel.展开更多
To improve the precision of the coiling temperature and the performance of the feedback control system with long pure time delay on hot strip mills, we analyzed the design process of the Dahlin algorithm in detail. Th...To improve the precision of the coiling temperature and the performance of the feedback control system with long pure time delay on hot strip mills, we analyzed the design process of the Dahlin algorithm in detail. The coiling temperature curves controlled by the PID algorithm and Dahlin algorithm were simulated and compared, which showed that the control precision with the Dahlin algorithm was higher than that with the PID algorithm. That was further verified by the production practice.展开更多
A measure called the Uncertainty in Unruptured Intracranial Aneurysm Patients Undergoing Endovascular Coiling Scale (UUIACS) was developed and its validity and reliability were examined. The 49 questions that comprise...A measure called the Uncertainty in Unruptured Intracranial Aneurysm Patients Undergoing Endovascular Coiling Scale (UUIACS) was developed and its validity and reliability were examined. The 49 questions that comprised the original draft of the UUIACS were created based on interview data. Based on data from 172 participants, exploratory and confirmatory factor analyses were conducted. As a result of exploratory factor analysis, the UUIACS e retained 17 items and extracted four factors (“Lack of decision-making cues”, “Lack of information and complexity of information interpretation”, “The ambiguous nature of the disease”, and “The unpredictable living with UIA”). All of the UUIACS items showed adequate internal consistency. Between the UUIAC scale and the Universal Uncertainty in Illness Scale (UUIS), the Health Locus of Control (HLC) scale, and the SF-36v2® (Japanese version), positive correlations were found between the UUIACS and UUIS, and the HLC scale at a 1% significance level indicating concurrent validity. According to confirmatory factor analysis, the UUIACS had an acceptable goodness of fit. Given these findings, the UUIACS was judged to have satisfied the criteria for use in a clinical setting, although further investigation was required.展开更多
Background: Potentially lethal, aneurysmal subarachnoid hemorrhage has a bad prognosis for many individuals. Over the past few decades, endovascular and surgical interventions have been developed, including surgical c...Background: Potentially lethal, aneurysmal subarachnoid hemorrhage has a bad prognosis for many individuals. Over the past few decades, endovascular and surgical interventions have been developed, including surgical clipping, and endovascular coiling. Patients who have aSAH are also susceptible to delayed cerebral ischemia and cerebral vasospasm. The aim of this study is to compare the outcome of endovascular coiling with surgical clipping in patients with SAH, specifically in relation to prevalence of vasospasm, in the country of Georgia. Method: In this study, we present a retrospective review of the outcomes of 217 patients with acute subarachnoid hemorrhage who underwent endovascular coiling or surgical clipping. The data were gathered from patients who are admitted to New Vision University Hospital and Caucasus Medical Center in Tbilisi, Georgia, between 2017 and 2022. Results: Vasospasm was prevalent in 217 of the patients who had aneurysmal rupture when they first appeared. Endovascular coiling or surgical clipping was used to treat aneurysmal rupture. In our sample, 24.81 percent of patients who underwent coiling experienced vasospasm after 14 days, compared to 31.25 percent of patients who underwent clipping. After endovascular coiling and surgical clipping, the severity of vasospasm was only slightly different, according to Lindegaard ratios. Finally, 32 patients (23.35 percent) died after coiling whereas 55 patients (68.75 percent) died within three decades of clipping. Conclusion: After 5 years of data collection, this study has demonstrated the most favorable option for treatment is endovascular coiling. However, the treatment choice takes multiple factors into account, and clipping is not ideal for some ruptured aneurysms. Despite the fact that endovascular coiling is usually successful and minimally invasive, complications can occur and additional monitoring and potential surgical intervention are indicated.展开更多
文摘Objective To compare the differences of therapeutic effect of chronic fatigue syndrome （CFS） treated with the combined therapy of Panlongci （coiling dragon needling） and cupping on back and the western medicine therapy with prednisone. Methods Seventy-two cases were randomly divided into 2 groups of acupuncture-cupping group （37 cases） and prednisone group （35 cases）. In acupuncture-cupping group, Jiaji points （夹脊 EX-B 2） of the level of T1–L5 were applied with coiling dragon needling once a day, combining with moving cupping on back once every two days. In prednisone group, prednisone tablets of 10 mg were orally taken at 8：00 am everyday. Seven days were counted as one treatment course, and 2 courses were carried on totally. FS-14 scale and BELL’s CFS integral table were applied to evaluate the fatigue degree of patients before and after the treatment, and the therapeutic effects of both groups were compared. Results After one course of treatment, the BELL’s scores of both groups were obviously improved （both P0.01）, but there was no significant difference between the 2 groups （P0.05）; after 2 courses of treatment, the BELL’s score in acupuncture-cupping group improved more obviously than that of the prednisone group （P0.05）, and the total effective rate of 91.9% （34/37） in acupuncture-cupping group was superior to that of 71.4% （25/35） in prednisone group （P0.05）. Conclusion The therapeutic effect of chronic fatigue syndrome treated with coiling dragon needling and moving cupping on back is positive, which is superior to that of prednisone with oral administration.
文摘Many strip materials are coiled after rolling process. The stresses are imposed on the material wound on the automatically controlled collapse mandrel under the coiling tension. The coiling process can be described by three typical cases: winding without automatic adjustment, winding with automatic adjustment and after mandrel removal. A new model of equations for predicting the stresses during the strip coiling process is built by consideration of the three cases respectively. By solving the equations of different typical cases, the radial stresses and tangential stress of the layers of coil can be calculated. Also, the coiling parameters, such as strip thickness, coiling tension and necking critical pressure, affecting the coil performance are investigated. It is believed that the present model can be used for design and control of the automatically controlled collapse mandrel.
基金supported by the National Key R&D Program of China(No.2017 YFB0305100)the Key Research and Development Program of Hubei Province(No.2020BAB057)the Natural Science Foundation and Major Technology Innovation of Hubei Province(No.2017AAA113).
文摘Influence of coiling temperature(CT)on the microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V was elucidated.The precipitation behavior of nano-sized particles was investigated by theoretical calculation and quantitative analysis.And the results revealed that V-enriched(Ti,Mo,V)C precipitated in the ferrite matrix.As the CT decreased,the site fractions of Ti in(Ti,Mo,V)C changed little,the site fractions of Mo increased,and the site fractions of V decreased accordingly.Moreover,the low CT could refine the microstructure and precipitated particles but suppress the precipitation of(Ti,Mo,V)C particles simultaneously,leading to the volume fraction of(Ti,Mo,V)C significantly decreasing,consequently causing an increment of grain refinement strengthening and a reduction in precipitation hardening.When the CT was 600℃,the steel characterized by fine polygonal ferrite,a small amount of bainite and nano-sized(Ti,Mo,V)C precipitates exhibited the optimum mechanical properties with the ultimate tensile strength of 870 MPa,yield strength of 807 MPa and elongation to fracture of 17%.
基金Item Sponsored by National Natural Science Foundation of China(51204047)National High Technology Research and Development Program of China(2011BAE13B04)Fundamental Research Funds for the Central Universities of China(N130407004)
文摘The influences of coiling temperature and cooling condition on structural transformation of the hot-rolled tertiary oxide scale formed under continuous cooling conditions were studied by thermal gravimetric analyzer. The fourth oxide scale formed under different conditions were classified and plotted. Because the oxide scale structure transformation is diffusion-controlled and the transformation law is similar to ＂C＂ curve, the eutectoid transformation nose temperature is 450 ℃. Under condition of low temperature and high cooling rate, ion diffusion behavior is restricted so that the eutectoid reaction is suppressed, resulting in that the fourth oxide scale is mainly made up of pre-eutectoid Fe304 and FeO without eu- tectoid products. From scale structure transition diagram, the eutectoid reaction process was affected by coiling temperature and cooling rate, leading to various scale structures.
基金This work was supported by the Foundation of China Electric Power Research Institute(No.51601174).
文摘The microstructure characteristics and properties(especially hole expansion property)of 800 MPa hot-rolled complex phase steel with different coiling temperatures were studied.The microstructure consisted of polygonal ferrite and precipitates when the steel was coiled at 550℃,and when the steel was coiled between 460–520℃,the microstructure was composed of granular bainite and martensite and austenite(M/A)islands.The morphology of the crack was analyzed by scanning electron microscopy,and the in situ scanning electron microscope tensile test was used to find out the fracture mechanism and deformation behavior of the steel with different coiling temperatures.When the steel was coiled at 550℃,the cracks initiated at the ferrite grain boundary and propagated through the grains or along the grain boundaries.When the steel was coiled at 520℃,the cracks first initiated at the junction of ferrite and M/A island and then propagated through the grains.The steel coiled at 520℃ has quite good mechanical properties and relatively high hole expansion ratio.
文摘Mice deficient in the transcription factor pleomorphic adenoma gene 1(PLAG1)exhibit reproductive issues that are characterized,in part,by decreased progressive sperm motility in the male.However,the underlying cause of this impairment is unknown.As epididymal transit is critical for sperm maturation and motility,the morphology of the epididymis of Plag1-deficient mice was investigated and the spatial expression patterns of PLAG1 protein and mRNA were identified.Using X-gal staining and in situ hybridization,PLAG1 was shown to be widely expressed in both the epithelium and stroma in all regions of the mouse epididymis.Interestingly,the X-gal staining pattern was markedly different in the cauda,where it could be suggestive of PLAG1 secretion into the epididymal lumen.At all ages investigated,the morphology of epididymides from Plag1 knockout(KO)mice was aberrant;the tubule failed to elongate and coil,particularly in the corpus and cauda,and the cauda was malformed,lacking its usual bulbous shape.Moreover,the epididymides from Plag1 KO mice were significantly reduced in size relative to body weight.In 20%of Plag1-deficient mice,the left testicle and epididymis were lacking.The impaired morphogenesis of the epididymal tubule is likely to be a major contributing factor to the fertility problems observed in male Plag1-deficient mice.These results also establish PLAG1 as an important regulator of male reproduction,not only through its involvement in testicular sperm production,but also via its role in the development and function of the epididymis.
基金supported by Science and Technology Innovation Cooperation Project between China and South Africa(2017YFE0113400).
文摘The strength-to-weight ratio is an important property of high-strength low-alloy(HSLA)steel in pipeline,whose precipitation strengthening can be improved.The final rolling temperature(FRT)and coiling temperature(CT)are the key process parameters in the control of precipitates and microstructure.Continuous cooling rate was fixed at 10℃/s,and the effects of deformation and coiling temperatures on precipitates and microstructure of Ti-Nb microalloyed HSLA steel were investigated through thermo-mechanical controlled processing on Gleeble 3500.The microstructure is mainly acicular ferrite with high density dislocation and several microns scale.The size and volume fraction of the precipitates were studied under transmission electron microscopy.The results showed that the diameter of the precipitates was in the range between 4 and 240 nm.The optimized combination of parameters is FRT of 820℃and CT of 550℃,and the volume fraction of precipitates obtained under this process is 0.59%.
基金supported by grant of Changzhou science and technology projects of social development (No. CS2007203)
文摘Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.
基金Funded by the National Natural Science Foundation of China(No.51501056)Natural Science Foundation of Hebei Province(No.E2016209341)+2 种基金Educational Commission of Hebei Province(No.BJ2014031)Project of Science and Technology of Tangshan(Nos.14130243B and 15130202C)Foundation of North China University of Science and Technology(No.JP201510)
文摘The effects of hot-strip coiling temperature on Ti（C,N） precipitation, texture and hydrogen permeation behavior in DC06 EK enamel steel were investigated by TEM, EBSD test and electrochemical hydrogen permeation experiment. It was found that the Ti（C,N） particles in hot-strip coarsened with increasing coiling temperature, whereas after cold-rolling and annealing, the size difference of Ti（C,N） particles was lessened. The hot-strip coiling temperature has a significant impact on the recrystallized texture in the subsequent cold-rolled and annealed sheet. Hot-strip using high temperature（700 ℃） coiling leads to strong {111} recrystallized texture in annealed sheet, with peak intensity 9.2. On the contrary, in annealed sheets using hot-strip coiling at 650 ℃, their {111} recrystallized textures were weaker, which was also reflected in their rmvalues. Even though the hydrogen diffusion coefficient is slightly lower（7.76×10^（-5） mm^2/s） in annealed sheet using low temperature coiling（600 ℃）, appropriately higher coiling temperature is more suitable for DC06 EK enamel steel combining both good drawability and fish-scale resistance.
基金This work was financially supported by the Joint Fund of Iron and Steel Research(No.U1660103)National Natural Science Foundation of China(No.51574162)+2 种基金the National Key R&D Program of China(No.2018YFE0306102)3DAP measurements were made in the Instrumental Analysis and Research Center at Shanghai UniversityThe authors would like to express sincere thanks for their support.
文摘Low-carbon steel is widely used for household appliance and automotive panel steel because of its excellent plasticity.Unfortunately,yield point phenomena easily appear in the low-carbon steel produced by a continuous annealing process and cause degradation to the surface quality during processing.The effect of the coiling temperature(600-750℃)and annealing temperature(740-820℃)on the yield point behavior is studied.Tensile tests show that coiling temperature has a greater effect on yield point elongation(YPE)and aging index(AI)than the annealing temperature.Microstructure observations show that coiling temperature at 750℃would make the micron-sized carbides appearing at the grain boundary disappear and a number of dispersed nanoscale carbides precipitate in grain interior,corresponding to the highest solid solution carbon content in the matrix of 750℃coiled sample.The experimental results suggest that AI rather than YPE has a positive relationship with the solid solution carbon content of the low-carbon steel.And YPE has a positive relationship with the upper/lower yield strength.
基金supported by grants from the National Natural Science Foundation of China,grant no. 81370041, 81771233, 81671655the Outstanding Clinical Discipline Project of Shanghai Pudonggrant no.PWYgy2018-04.
文摘Background:To evaluate the efficacy of stent-assisted coiling(SAC)for the treatment of carotid ophthalmic segment aneurysm segment aneurysms(OSAs)of the internal carotid artery(ICA)through detailed long-term follow-up of a large patient cohort.Methods:We retrospectively analyzed 88 consecutive patients with OSAs between January 2009 and January 2020 at our center.Angiographic results were evaluated using the modified Raymond grading system and clinical outcomes were evaluated using the mRS scale.The primary endpoints were major aneurysm recurrence and poor clinical outcomes for at least 18 months of follow-up.The patients were asked to attend clinical follow-up assessments and possibly undergo DSA or MR via telephone.Results:We enrolled 88 patients with 99 OSAs treated with coiling,of whom 76 were treated with SAC.The coiling procedures were successful in all 88 patients.Overall,complications occurred in 8 patients(9.1%).No procedure-related mortality was observed.67(76.1%)experienced immediate aneurysm occlusion at the end of the procedure.Long-term angiographic follow-up(18 months)was available in 45/88 aneurysms(51%)(average 18.7±5.2 months).Four patients continued their follow-up for 5 years after initial aneurysm treatment.After a clinical follow-up time of 28.7 months(range,12-51 months),85 patients(95.5%)achieved favorable clinical outcomes(mRS scores of 0-2).Conclusions:This study indicates that SAC treatment is a safe and effective therapeutic alternative for ruptured and unruptured OSAs.The procedural risks are low with relatively long-term effectiveness.
文摘Various hot rolling schedules were applied to a Nb,V,Ti contained HSLA steel.Coiling temperature had crucial effects on not only yield strength,but also yield ratio and precipitation behavior.600Mpa yield strength is achieved when coiled at 450℃,which is 100Mpa higher than those coiled at 570℃.However,the low coiling temperature had adverse effect to increase yield ratio,which increased from 0.78 to 0.88 as coiling temperature dropped from 570℃ to 450℃.High resolution SEM analysis shows that sizes of Nb,V,Ti precipitates are affected by coiling temperature.Coarse (Nb,Ti)(C,N) precipitates up to 5μm are observed at higher coiling temperature and to decrease tensile strength,where high coiling temperature corresponds to low cooling rate.With strong cooling and coiling capacity of Shasteel’s 1450mm width hot rolling mill,these results indicate that strength and formability of the steel can be balanced when coiling temperature has been optimized.Alloying and microalloying costs can be reduced by efficiently utilizing the capacity of rolling mill.Alumina inclusions are found to act as nucleus for Nb,V,Ti precipitates,contributing to coarsening of precipitates.
基金National Natural Science Foundation of China for financial support, under Grant No. 50104004.
文摘The effect of coiling temperatures on the evolution of texture in Ti-IF steel during ferritic hot rolling, cold rolling and annealing was studied. It was found that texture evolution at high temperature coiling is absolutely different from that at low temperature one. The hot band texture includes a strong α-fiber as well as a weak γ-fiber after ferritic hot rolling and low temperature coiling. Both of them intensify after cold rolling and a γ-fiber with peak at {111}〈112〉 is the main texture of annealed samples. However, the main component of the hot band texture after high temperature coiling is v-fiber. After cold rolling, the intensity of γ texture reduces; α fiber （except {111}〈110〉 component） intensifies and a strong and well-proportioned γ-fiber forms in the annealed samples.
文摘The effects of cooling rate and coiling temperature on microstructure and mechanical properties of a plain carbon steel were investigated by combining metallography and tensile experiments. The results indicate that ferrite grain size is refined and bainite transformation occurs to ensure high strength and elongation, as the cooling rate is quick enough. Yield strength and tensite strength improve with the decreased finish cooling temperature, but the elongation decreases too significantly to meet the requirements. Thus, the cooling rate must be quick enough, and the appropriate coiling temperature should be carefully selected to obtain refined ferrite and a small amount of bainite to improve the strength while the plasticity is also ensured. Under this condition, the Mn element concentration can be reduced to save cost or produce higher strength steel with same chemical composition.
文摘A new intelligent control scheme for hot strip coiling temperature is presented. In this scheme, the prediction mode1 of finishing temperature and the presetting model of main cooling zone are establish based on BP neural network, the feed-forward open-loop control model of main cooling zone is constructed based on T-S fuzzy neural network, a new improved structure of T-S fuzzy neural network is developed, and the feedback close-loop control model of precision cooling zone is obtained based on fuzzy control. The effectiveness of the proposed scheme has been demonstrated by computer simulation with a satisfactory result.
文摘In this paper, the effect of hot-rolling processing parameters on the post-rolling transformation behavior of C-Mn-Cr-Cu weather-resistant martensitic steel was investigated.Results indicate that the post-rolling transformation behavior, particularly the post-coiling transformation behavior, strongly depends on the coiling temperature.Under a high coiling temperature, ferrite/pearlite transformation was mainly observed with a low trans-formation speed and transformation dilation after coiling.With decreasing coiling temperature, the proportion of bainite transformation increased with an increased transformation speed and transformation dilation.The dependence of transformation behavior on the coiling temperature could be one of the most important reasons behind the coil collapse of the experimental steel.The optimization of hot-rolling and coiling processing parameters of the steel strip, including laminar flow cooling, coiling temperature, and suspension time on the winding machine, can signi-ficantly reduce the transformation dilation of the steel after hot rolling, thus effectively controlling the coil collapse of the steel.
文摘To improve the precision of the coiling temperature and the performance of the feedback control system with long pure time delay on hot strip mills, we analyzed the design process of the Dahlin algorithm in detail. The coiling temperature curves controlled by the PID algorithm and Dahlin algorithm were simulated and compared, which showed that the control precision with the Dahlin algorithm was higher than that with the PID algorithm. That was further verified by the production practice.
文摘A measure called the Uncertainty in Unruptured Intracranial Aneurysm Patients Undergoing Endovascular Coiling Scale (UUIACS) was developed and its validity and reliability were examined. The 49 questions that comprised the original draft of the UUIACS were created based on interview data. Based on data from 172 participants, exploratory and confirmatory factor analyses were conducted. As a result of exploratory factor analysis, the UUIACS e retained 17 items and extracted four factors (“Lack of decision-making cues”, “Lack of information and complexity of information interpretation”, “The ambiguous nature of the disease”, and “The unpredictable living with UIA”). All of the UUIACS items showed adequate internal consistency. Between the UUIAC scale and the Universal Uncertainty in Illness Scale (UUIS), the Health Locus of Control (HLC) scale, and the SF-36v2® (Japanese version), positive correlations were found between the UUIACS and UUIS, and the HLC scale at a 1% significance level indicating concurrent validity. According to confirmatory factor analysis, the UUIACS had an acceptable goodness of fit. Given these findings, the UUIACS was judged to have satisfied the criteria for use in a clinical setting, although further investigation was required.
文摘Background: Potentially lethal, aneurysmal subarachnoid hemorrhage has a bad prognosis for many individuals. Over the past few decades, endovascular and surgical interventions have been developed, including surgical clipping, and endovascular coiling. Patients who have aSAH are also susceptible to delayed cerebral ischemia and cerebral vasospasm. The aim of this study is to compare the outcome of endovascular coiling with surgical clipping in patients with SAH, specifically in relation to prevalence of vasospasm, in the country of Georgia. Method: In this study, we present a retrospective review of the outcomes of 217 patients with acute subarachnoid hemorrhage who underwent endovascular coiling or surgical clipping. The data were gathered from patients who are admitted to New Vision University Hospital and Caucasus Medical Center in Tbilisi, Georgia, between 2017 and 2022. Results: Vasospasm was prevalent in 217 of the patients who had aneurysmal rupture when they first appeared. Endovascular coiling or surgical clipping was used to treat aneurysmal rupture. In our sample, 24.81 percent of patients who underwent coiling experienced vasospasm after 14 days, compared to 31.25 percent of patients who underwent clipping. After endovascular coiling and surgical clipping, the severity of vasospasm was only slightly different, according to Lindegaard ratios. Finally, 32 patients (23.35 percent) died after coiling whereas 55 patients (68.75 percent) died within three decades of clipping. Conclusion: After 5 years of data collection, this study has demonstrated the most favorable option for treatment is endovascular coiling. However, the treatment choice takes multiple factors into account, and clipping is not ideal for some ruptured aneurysms. Despite the fact that endovascular coiling is usually successful and minimally invasive, complications can occur and additional monitoring and potential surgical intervention are indicated.
