期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
关于课堂小组合作探究学习的研究 被引量:1
1
作者 李军会 《教育教学论坛》 2014年第13期171-172,共2页
小组合作探究学习是一种以学生为中心,以小组为形式,为了共同的学习目标,共同学习,相互促进,共同提高的一种教学策略。小组合作学习是与"个体学习"相对应的一种教学策略和学习组织形式,是一种学生在小组中通过合作探究学习,... 小组合作探究学习是一种以学生为中心,以小组为形式,为了共同的学习目标,共同学习,相互促进,共同提高的一种教学策略。小组合作学习是与"个体学习"相对应的一种教学策略和学习组织形式,是一种学生在小组中通过合作探究学习,完成学习目标并获得知识的学习方法。下面我就结合课堂教学实践谈谈我的一点心得。 展开更多
关键词 科学分组 独立思考 时机组织
下载PDF
Enhanced strengthening by two-step progressive solution and aging treatment in AM50-4%(Zn,Y) magnesium alloy 被引量:1
2
作者 Shuai DAI Feng WANG +3 位作者 De-zhi MA Zhi WANG Zheng LIU Ping-li MAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第12期2419-2426,共8页
AM50-4%(Zn,Y)alloy with a Zn/Y mole ratio of6:1was subjected to thermal analysis,and the results were used for designing a two-step progressive solution treatment process.The effects of solution and aging treatments o... AM50-4%(Zn,Y)alloy with a Zn/Y mole ratio of6:1was subjected to thermal analysis,and the results were used for designing a two-step progressive solution treatment process.The effects of solution and aging treatments on the microstructure and mechanical properties of the AM50-4%(Zn,Y)alloy were investigated using OM,XRD,SEM/EDS,TEM,tensile test and hardness test.The experimental results demonstrated that the two-step progressive solution treatment could make theΦandβphases sufficiently dissolve into the matrix which possessed higher supersaturated degree of the dissolved solute compared with the one-step solution treatment.This resulted in a certain enhancement of the precipitation strengthening effect during the subsequent aging process.The precipitation of theФphase had a greater impact on the comprehensive mechanical properties of the alloy thanβphase precipitation when the aging treatment was performed at180℃.The peak aging strength of the AM50-4%(Zn,Y)alloy which was subjected to the two-step progressive solution treatment process(345℃for16h and375℃for6h)was obtained after the aging treatment at180℃for12h. 展开更多
关键词 AM50-4%(Zn Y) alloy thermal analysis solution aging treatment microstructure strengthening mechanism
下载PDF
Metachronous penile metastasis from rectal cancer after total pelvic exenteration 被引量:2
3
作者 Yuta Kimura Keiichi Nasu +2 位作者 Hiroki Matsunaga Masahiro Warabi Satoru Inoue 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第38期5476-5478,共3页
Despite its abundant vascularization and extensive circulatory communication with neighboring organs, metastases to the penis are a rare event. A 57-yearold male, who had undergone total pelvic exenteration for rectal... Despite its abundant vascularization and extensive circulatory communication with neighboring organs, metastases to the penis are a rare event. A 57-yearold male, who had undergone total pelvic exenteration for rectal cancer sixteen months earlier, demonstrated an abnormal uptake within his penis by positron emission tomography/computed tomography. A single elastic nodule of the middle penis shaft was noted deep within Bucks fascia. No other obvious recurrent site was noted except the penile lesion. Total penectomy was performed as a curative resection based on a diagnosis of isolated penile metastasis from rectal cancer. A histopathological examination revealed an increase of well differentiated adenocarcinoma in the corpus spongiosum consistent with his primary rectal tumor. The immunohistochemistry of the tumor cells demonstrated positive staining for cytokeratin 20 and negative staining for cytokeratin 7, which strongly supported a diagnosis of penile metastasis from the rectum. The patient is alive more than two years without any recurrence. 展开更多
关键词 Penile metastasis Rectal cancer Corpus spongiosum
下载PDF
Effects of Mg content on microstructure and mechanical properties of low Zn-containing Al-xMg-3Zn-1Cu cast alloys 被引量:1
4
作者 Chuan LEI Qu-dong WANG +5 位作者 Hua-ping TANG Tian-wen LIU Zhong-yang LI Hai-yan JIANG Kui WANG Wen-jiang DING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第3期721-738,共18页
Effects of Mg content on the microstructure and mechanical properties of low Zn-containing Al−xMg−3Zn−1Cu cast alloys(x=3−5,wt.%)were investigated.As Mg content increased in the as-cast alloys,the grains were refined ... Effects of Mg content on the microstructure and mechanical properties of low Zn-containing Al−xMg−3Zn−1Cu cast alloys(x=3−5,wt.%)were investigated.As Mg content increased in the as-cast alloys,the grains were refined due to enhanced growth restriction,and the formation ofη-Mg(AlZnCu)_(2) and S-Al_(2)CuMg phases was inhibited while the formation of T-Mg_(32)(AlZnCu)_(49 )phase was promoted when Mg content exceeded 4 wt.%.The increase of Mg content encumbered the solution kinetics by increasing the size of eutectic phase but accelerated and enhanced the age-hardening through expediting precipitation kinetics and elevating the number density of the precipitates.As Mg content increased,the yield strength and tensile strength of the as-cast,solution-treated and peak-aged alloys were severally improved,while the elongation of the alloys decreased.The tensile strength and elongation of the peak-aged Al−5Mg−3Zn−1Cu alloy exceed 500 MPa and 5%,respectively.Precipitation strengthening implemented by T′precipitates is the predominant strengthening mechanism in the peak-aged alloys and is enhanced by increasing Mg content. 展开更多
关键词 Mg content low Zn-containing Al-x Mg-3Zn-1Cu cast alloys microstructure aging response strengthening mechanism
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部