Cold compression deformation method for reducing residual stress and uniformizing micro-property in ferrite steel

To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray diffraction and nanoindentation test have been used to detect the residual stress and micro-property.The samples with deformation rate of 0-5.59%or annealing at 550℃ are analyzed.The results show that,due to the coupling effect of thermal expansion and cold contraction and the volume expansion of microstructural transformation from austenite to ferrite,compressive residual stress was found inside the hot-rolled samples.With the increase in cold compression deformation,the dislocation density increased and the microhardness increased gradually,and there is no obvious rule for the change of mean nano-hardness in micro-zone for the center of samples.However,the uniformity of nano-hardness in the micro-zone increased first and then decreased,and the value of residual stress has obvious corresponding relationship with the uniformity of micro-zone property.The cold compression deformation with appropriate reduction rate can reduce residual stress and improve nano-hardness uniformity of the hot-rolled samples,but more deformation(such as reduction rateε=5.59%)makes residual stress increase and makes uniformity of nano-hardness deteriorate.

Reduction of the residual stresses in cold expanded thick-walled cylinders by plastic compression

We suppose that in order to maintain high accuracy of holes and to lower residual stresses after cold expansion of thick-walled cylinders, which undergo cross-section plastic deformation, it is necessary to perform axial plastic compression and subsequent cold expansion with small interferences. To test this hypothesis, we studied hoop, radial and axial residual stresses in cylinders made of carbon steel AISI 1050 with hole diameter of 5 mm, outer diameter of 15 mm and length of 30 mm by Sachs method as well as accuracy of expanded holes. It is found that double cold expansion with total interference equal to 5.1% generates hoop residual stresses with largest absolute value equal to 284 MPa and ensures high holes accuracy(IT7). After plastic compression with strain equal to 0.5 and 1% the mentioned stresses reduced to 120 and 75 MPa respectively,and accuracy of the holes reduced as well. Subsequent cold expansion with small interference equal to 0.9% helps to restore holes accuracy(IT7)gained by double cold expansion and ensure that absolute value of hoop residual stresses(177 MPa) is lower compared to double cold expansion.

An Experimental Investigation on Low Load Combustion Stability and Cold-Firing Capacity of a Gasoline Compression Ignition Engine

Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations are two major challenges for GCI combustion. Strategies including negative valve overlap (NVO), advanced injection strategies, fuel reforming, and intake preheating have been proposed in order to solve these difficulties;however, the cold start is still an obstacle. The objective of this work is to study effective methods to achieve GCI engine cold start-up. This work combines NVO, in-cylinder fuel reforming, and intake preheating to achieve quick firing under cold-start conditions and the subsequent warmup conditions. The results show that start of injection (SOI) during the intake stroke yields the best fuel economy, and injection during the compression stroke has the potential to extend the low load limit. Furthermore, SOI during the NVO period grants the ability to operate under engine conditions with cold intake air and coolant. With highly reactive products made by in-cylinder fuel reforming and fast heat accumulation in the combustion chamber, the NVO injection strategy is highly appropriate for GCI firing. An additional assisted technical method, such as intake preheating, is required to ignite the first firing cycle for a cold-start process. With the combination of NVO, in-cylinder fuel reforming, and intake preheating, the GCI engine successfully started within five combustion cycles in the experiment. After the firing process, the engine could stably operate without further intake preheating;thus, this method is appropriate for engine cold-start and warm-up.

The effect of the application of cold on hematoma, ecchymosis, and pain at the catheter site in patients undergoing percutaneous coronary intervention

Objective: This study was conducted to determine the effect of the application of cold on hematoma,ecchymosis,and pain in patients undergoing percutaneous coronary intervention.Methods: It is a quasi-experimental study with a control group.A total of 200 patients (100 in the control group and 100 in the experimental group) were included in the research.In the experimental group,a cold pack was applied to the bottom of the sandbag for the first 15 min after withdrawing the femoral arterial catheter.Both groups were assessed and followed up at the first 15th minute and 4th,48th and 72 nd h.Results: After the femoral arterial catheter was withdrawn,ecchymosis and hematoma were smaller and pain was less in the experimental group at the catheter entry site compared to the control group,and the difference was statistically significant (P < 0.01).Conclusion: It was determined that the application of cold reduced the formation of hematomas,ecchymoses and pain in patients after the withdrawal of the femoral arterial catheter.

手足低温法预防盐酸多柔比星脂质体致手足综合征的效果

目的 从临床角度探究局部冷敷法在盐酸多柔比星脂质体(PLD)致相关手足综合征(HFS)中的应用效果。方法 采取非同期随机对照试验,选取2021年6月至2023年6月河北工程大学附属医院乳腺外科已治疗的乳腺癌患者为研究对象,以2021年6月至2022年5月化疗的乳腺癌患者为常规护理组(n=58),2022年6月至2023年6月化疗的乳腺癌患者为局部冷敷法组(n=55)。比较两组在4次PLD化疗阶段HFS的发生率、患者治疗依从性、诊疗满意度及患者就医体验感。结果 局部冷敷法组HFS发生率为23.6%(13/55),常规护理组为44.8%(26/58);局部冷敷法组HFS发生率低于常规护理组(χ^(2)=5.609,P=0.018)。局部冷敷法组HFS严重程度轻于对照组(P<0.05)。局部冷敷法组Ⅱ级及以上HFS发生率为10.9%、常规护理组为25.9%;局部冷敷法组Ⅱ级及以上HFS发生率低于常规护理组(P<0.05)。局部冷敷法组治疗依从性及满意度均高于常规护理组(P<0.05)。结论 局部冷敷法可有效预防和降低PLD化疗过程中HFS的发生率和严重程度、提高患者护理干预的依从性、患者满意度较高。

“FENG QI AI” HOT COMPRESS TREATMENT

Hot medicated cornpress treatment belongs to an external treatment and is a kindof moxibustion. ″Feng Qi Ai″ prescription was recorded in Yi Fang Lei Ju. Zhu Xu Men, Rui ZhuTang Fang. In the treatment, pain in the loin and the knees, cold-pain around the navel and in theabdornen,diarrhea due to deficiency and cold and other diseases are treated by combination of drugswith hot compress- We have irnproved the treatment and extended the range of its indication. It wasused for treatment 0f menorrhalgia due to cold uterine, gastralgia due to coId of rniddle-jiao, sciatica’periarthritis of shoulder, systremma,piriformis syndrome with good results.

自制工形鼻额部冷敷包与传统冰袋在鼻中隔偏曲矫正术后的应用比较

目的比较工形鼻额部冷敷包和传统冰袋在鼻中隔偏曲矫正术后的冰敷效果,以期为鼻部手术患者提供一种更加有效的冰敷方案。方法本研究以2021年1月~2022年6月间在宜昌市中心人民医院西陵院区接受鼻中隔偏曲矫正术的患者为研究对象,共计124例。随机分为两组,每组62例。两组分别采用自制工形鼻额部冷敷包(实验组)与传统冰袋(对照组)冰敷。比较两组患者术后24 h、48 h疼痛情况的视觉模拟量表(VAS)评分、肿胀程度评分和舒适度。结果鼻中隔偏曲矫正术冷敷24 h和48 h后,实验组的VAS评分及肿胀程度评分均低于对照组,差异有统计学意义(P<0.05);实验组患者的舒适感明显高于对照组,差异有统计学意义(P<0.05)。结论工形鼻额冷敷包能够减轻鼻中隔偏曲矫正术后鼻腔填塞引起的疼痛和鼻部肿胀,能提高患者舒适度,有利于加速患者的术后康复。

磷矿粉球团冷固结成型试验及机械性能的影响因素

针对磷矿粉矿无法直接入炉冶炼黄磷的问题,本文采用磷矿粉冷固结成型方法来制备磷矿粉球团,研究黏结剂用量、水分添加量、成型压力和烧结温度对磷矿粉球团落下强度和抗压强度的影响。研究结果表明:球团的抗压强度和落下强度随黏结剂用量的增加而升高,随成型压力的增加呈现先升高后降低,随水分质量分数的增加呈现先升高后降低,抗压强度随着烧结温度的升高而升高;在黏结剂用量为0.4%、水分质量分数为8%、成型压力为11 MPa条件下制备的磷矿粉生球团的抗压强度可达148.46 N/P,落下强度达46次/(0.5 m);在1200℃下烧结2 h后,磷矿球团的抗压强度可达966 N/P,且经跌落破碎后无粉化现象。本文旨在弥补富磷矿块矿资源的不足,并为进一步促进磷矿粉矿在黄磷生产中的应用提供参考。

Performance of RAP in the System of Cold Inplace Recycling of Asphalt Pavement

The property of reclaimed asphalt pavement（RAP） mixture will be affected mainly by composition of old asphalt/soil and cement content in CIR system. We studied the relationship between A/S and cementitious materials. It showed that if there was no soil in RAP, the unconfined compressive strength was only from 0.18 MPa to 1.07 MPa even if adding cement was from 2% to 6%, and RAP samples collapsed during conserving in water. The optimum water content rose from 6.5% to 11% with the declining of A/S from S=0 to A/S=1/5. Five RAP samples all got the maximum compressive strength when A/S=5/5, and the maximum compressive strength of the samples adding 6% cement was 3.17 MPa. It showed that the capacity of RAP was not only affected by A/S, but also by the content of cement. The dynamic modulus of RAP will increase with the rise of loading frequency and decrease with the temperature rising. SEM test showed that C-S-H interlacing formed the netted structure, and it enwrapped the aggregate and improved the strength of RAP.

超微细氧化铅锌烟灰制团工艺技术研究

超微细氧化铅锌烟灰含Pb 12.77%、Zn 38.12%,铅矿物主要是硫酸铅和铅硅酸盐,锌矿物主要是ZnO。物料具有粒度超微细、堆密度小、亲水性差、颗粒表面荷电等特点。冷压制团工艺技术研究结果表明:采用西北矿冶研究院自主研发的新型无机粘结剂T10可有效提高团块干燥速度、湿团落下强度及干团抗压强度等技术指标。在水分配比14%,压力15 MPa条件下,使用T10作为粘结剂,所制团块经220℃干燥12 h,抗压强度20.45 MPa。

冷弯厚壁压弯构件抗震性能影响参数分析

冷弯厚壁型钢作为一种广泛应用于现代建筑结构中的材料,其在设计中展现出独特的优势,但其在地震荷载下的行为特性仍需进一步明确。通过数值分析研究宽厚比、长细比和轴压比等参数对冷弯厚壁压弯构件抗震性能的影响。研究结果表明,所有骨架曲线在第一和第三象限呈现出非对称形态,这表明冷弯厚壁压弯构件在加载与卸载过程中的力学行为存在明显差异。宽厚比、长细比和轴压比3个参数对冷弯厚壁压弯构件抗震性能均有影响,不同破坏模式又影响着构件的抗震性能。研究结果揭示了各参数与抗震性能之间的关系,强调了设计中需特别关注的关键点,以确保结构既安全又经济。

冷热-荷载耦合下纤维锂渣混凝土柱偏心受压性能

为研究冷热循环作用及耦合应力对纤维锂渣混凝土(PLiC)柱偏心受压性能的影响,制作6根PLiC柱和2根对照柱,将其施加0、0.10、0.20、0.35的耦合应力之后,经历0次、100次、200次、300次冷热循环作用后进行偏心受压静力试验,研究冷热循环次数、耦合应力比对PLiC柱偏心受压性能的影响。结果表明:单掺锂渣对试验柱的破坏形态、延性、开裂荷载和极限荷载影响均较小,而掺入1.2 kg/m^(3)的PLiC柱受压破坏时无明显混凝土压溃现象,且变形性能更好,延性提高24.7%、开裂荷载提高3.5倍、极限荷载提高24.73%;耦合应力比不变,冷热循环次数从100次增加到300次时,PLiC柱裂缝数量增加且呈现多而密的特点,延性系数提高8.6%,极限承载力下降33.56%;冷热循环200次时,耦合应力比从0.10增加到0.35,构件延性系数变化较小,极限承载力下降34.55%。试验中冷热循环温差为58℃,可为中国西部地区大温差环境下混凝土结构设计提供一定参考。

混料工艺对铝锆碳耐火材料生坯性能的影响

针对铝锆碳耐火材料生坯显微结构和力学性能的调控与优化,以板状刚玉、锆莫来石、锆刚玉为骨料,α-Al_(2)O_(3)微粉、鳞片石墨、添加剂为细粉,木质素磺酸盐为结合剂,机压成型制备铝锆碳耐火材料试样和基质试样。研究了细粉的混料工艺(手动混料0.5 h、未混料、球磨混料2和5 h)对基质试样和耐火材料试样体积密度、显气孔率、常温耐压强度和显微结构的影响。结果表明:细粉的混料工艺对试样显气孔率和体积密度的影响较小,但对显微结构和常温耐压强度影响显著。球磨混合使得原料分布均匀,显著减少气孔、裂纹等缺陷,并使得基质原料的粒度均匀性提高和比表面积增加,有利于木质素磺酸盐溶液结合剂的吸附和黏结,从而保证强度的明显提升。但过长的球磨时间可能会导致原料颗粒过细,团聚增多,反而降低了强度。当细粉经2 h球磨混合时,试样中基质与骨料结合较为紧密,常温耐压强度最高。

压合衬套冷挤压强化的残余应力的数值模拟

孔用衬套冷挤压强化的残余应力分布对实现优异的挤压效果起到重要的作用,而被挤压件材料和挤压量对挤压残余应力分布的影响显著。根据非线性接触摩擦理论,建立了基于压合衬套冷挤压强化的三维有限元模型,模拟获得了TB6钛合金、7050铝合金及TC4钛合金材料耳片孔强化的切向残余应力分布情况,并通过残余应力检测实验验证了有限元模拟的有效性;同时,研究了挤压量对耳片孔冷挤压强化残余应力状态的影响,揭示了切向残余应力沿着挤入面、中间面、挤出面以及衬套厚度方向的分布规律。研究结果表明:冷挤压孔强化后的残余应力在沿孔壁厚度方向上分布不均匀,切向残余压应力在中间面的分布区域最广;增大挤压量可以在一定程度上扩大压应力的分布范围,且能够提高区域压应力数值,但是也会引入部分拉应力,易产生褶皱现象;在相同的挤压条件下,TB6钛合金耳片冷挤压后所产生的切向残余压应力在应力数值和分布区域上都具有明显的优势。

The Characteristics of Asphalt Mixture in the System of Full Thickness Cold In-place Recycling

A new research method was proposed（A/S method） to study the components and properties of reclained asphalt mixture（RAP）. The RAP was divided into two main parts, one was marked with A that included all the reclaimed old asphalt materials（including some parts of particle materials covered by asphalt）, the other was marked with S which mainly included works soil in the road structure. The actual working conditions were simulated by this kind of new method, and the adaption between the RAP properties, A/S, and the content of cementitious materials were studied. The research indicated that the real working condition could be simulated effectively by means of A/S method. It was also showed that high content of cement could improve the overall performance of RAP significantly, but it would have a negative effect on the properties of RAP if the types and sizes of aggregate particles in RAP mixture were too single. The optimum water content and maximum dry density could not be regarded as the primary basis to evaluate the overall performance of RAP, when S=0 in the experiments, although the maximum density of samples was bigger than that with A/S=1/1, the samples were not strong enough and they were easy to collapse, which indicated that component design of RAP played a great role in improving the overall properties of RAP and the comprehensive tests should be considered to evaluate the stability of RAP. Low frequency load in high temperature environment had the negative effect on the overall stability of RAP, and factors such as the loading state of the materials, the hydration degree of cementitious materials, and the aggregate gradation in the mixture were the determining factors for improving the overall performance of RAP.

苍夷明目汤内服联合眼部冷湿敷治疗过敏性结膜炎临床研究

目的:观察苍夷明目汤内服联合眼部冷湿敷对过敏性结膜炎患者临床症状及泪液因子的影响。方法:选取68例过敏性结膜炎患者为研究对象,按随机数字表法分为对照组及研究组各34例,对照组给予0.05%氮卓斯汀滴眼液治疗,研究组给予苍夷明目汤内服联合眼部冷湿敷治疗。2组均治疗2周。比较2组临床疗效及不良反应发生率,比较2组治疗前后症状体征积分、泪液生化因子[嗜酸性粒细胞阳离子蛋白(ECP)、组胺(HA)、白三烯B4(LTB4)]、泪膜稳定性指标值[泪液分泌试验(SIT)、泪膜破裂时间(BUT)]、泪河参数、血清免疫球蛋白E(IgE)水平的变化。结果:治疗2周后,2组症状积分、体征积分均较治疗前下降(P<0.05),研究组症状积分、体征积分均低于对照组(P<0.05)。研究组临床疗效总有效率为94.12%,对照组为76.47%,2组比较,差异有统计学意义(P<0.05)。治疗2周后,2组ECP、HA、LTB4水平均较治疗前下降(P<0.05),研究组上述3项水平均低于对照组(P<0.05)。治疗2周后,2组SIT、BUT指标值均较治疗前增加,研究组SIT、BUT指标值均大于对照组(P<0.05)。治疗2周后,2组泪河高度、泪河深度、泪河横截面面积均较治疗前增加(P<0.05),血清IgE水平均较治疗前下降(P<0.05);研究组泪河高度、泪河深度、泪河横截面面积均高于对照组,血清IgE水平低于对照组(P<0.05)。研究组不良反应发生率为8.82%,对照组为14.71%,2组不良反应发生率比较,差异无统计学意义(P>0.05)。结论:苍夷明目汤内服联合眼部冷湿敷治疗过敏性结膜炎可改善症状及体征,提升泪膜稳定性,降低泪液炎性介质水平,缓解过敏反应,促进泪膜功能恢复,用药安全性高。

新伤续断汤加减联合冷热敷及按摩治疗四肢骨折后急性疼痛肿胀的效果

目的观察新伤续断汤加减联合冷热敷及按摩治疗四肢骨折后急性疼痛肿胀的效果。方法选取2021年1月—2022年12月泉州市中医院收治的四肢骨折后急性疼痛肿胀患者60例,病例分组方法为随机数字表法,常规西医治疗组30例采用常规西医治疗,新伤续断汤组30例在常规西医治疗组基础上采用新伤续断汤加减联合冷热敷及按摩治疗,2组均治疗30 d。比较2组治疗前后中医证候积分、视觉模拟评分法(VAS)评分、肿胀程度及骨折愈合指标[骨形态发生蛋白(BMP)、Ⅰ型前胶原羧基端肽(PⅠCP)、胰岛素生长因子(IGF)、骨碱性磷酸酶(ALP)]。结果治疗30 d后,2组各项中医证候积分均较治疗前降低,且与常规西医治疗组各项中医证候积分相比,新伤续断汤组明显更低(P<0.01);2组VAS评分及肿胀程度均较治疗前降低,且与常规西医治疗组上述指标相比,新伤续断汤组明显更低(P<0.01);2组BMP、PⅠCP、IGF及ALP水平均较治疗前升高,且与常规西医治疗组上述指标相比,新伤续断汤组明显更高(P<0.01)。结论四肢骨折后急性疼痛肿胀患者采用新伤续断汤加减联合冷热敷及按摩治疗的效果较好,可有效改善中医证候,减轻疼痛和肿胀程度,促进骨折愈合。

新型粉煤灰泡沫混凝土墙体轴心受压性能试验研究

利用工业固废粉煤灰制备节能与承重一体的新型墙体,对无冷弯薄壁C型钢外包内置钢丝网片固废粉煤灰泡沫混凝土墙体FW、外包1mm厚冷弯薄壁C型钢内置钢丝网片固废粉煤灰泡沫混凝土墙体CW1、外包2mm厚冷弯薄壁C型钢内置钢丝网片固废粉煤灰泡沫混凝土墙体CW2分别在轴压作用下的破坏形态、荷载-位移曲线及墙体极限承载力进行试验研究。研究结果表明:从破坏形态度角度,FW、CW1及CW2在破坏时,冷拔钢丝、冷弯薄壁C型钢发生屈服,泡沫混凝土破裂;FW大面积泡沫混凝土挤压破碎剥落,破坏严重;CW2破坏时完整性优于FW、CW1。从变形角度,CW1、CW2外包的C型钢能够对墙体内部的泡沫混凝土起到约束作用,墙体的刚度得到提升。从承载力角度,CW2较CW1提升了17.4%,较FW提升了23.7%。对墙体的轴压承载力进行理论计算,与墙体轴心受压试验的实测值相比,二者误差在10%以内且小于实测值,满足国家现行规范、行业技术标准相关要求。

型煤强度重复测试波动情况统计分析

分别利用无机黏结剂和有机黏结剂,在相同的实验条件下制备5种型煤,利用t分布对型煤的冷压强度、浸水强度、耐磨强度、热稳定性和落下强度的测值波动进行了统计分析。结果发现,型煤强度测试结果之间并无显著性差异,质量稳定性较好。无机黏结剂和有机黏结剂制备型煤的冷压强度的最大相对误差分别在4.11%和4.30%以内,浸水强度的最大相对误差分别在5.30%和5.68%以内。无机黏结剂制备型煤的落下强度、耐磨强度、热稳定性的最大相对误差分别在3.26%、2.76%和4.11%以内。型煤浸水强度的质量波动大于型煤的冷压强度,热稳定性比耐磨性测试的最大相对误差高,这与型煤强度测试流程长、测试干扰因素多有关。

额部冷敷联合同理心责任护理对耳鼻喉患者自我效能的影响研究

目的:探讨额部冷敷联合同理心责任护理对耳鼻喉患者自我效能的影响。方法:选取医院耳鼻喉头颈外科收治的66例耳鼻喉患者,通过随机数表法分为对照组(33例)和观察组(33例)。对照组患者予以常规护理,观察组患者采用额部冷敷联合同理心责任护理。比较两组患者护理效果。结果:观察组患者治疗依从性高于对照组(P<0.05)。较护理前,两组患者护理后焦虑自评量表(SAS)、抑郁自评量表(SDS)评分均降低(P<0.05),观察组更低(P<0.05);两组患者护理后一般效能感量表(GSES)、自我护理能力测定量表(ESCA)评分均升高(P<0.05),观察组更高(P<0.05)。结论:额部冷敷联合同理心责任护理可改善耳鼻喉患者的不良情绪,提升患者治疗依从性、自我效能及自我护理能力,值得推广。