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西藏桑日县程巴铜钼多金属矿地质特征及矿床成因分析
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作者 曾海良 龚兴 《世界有色金属》 2024年第8期135-137,共3页
冈底斯成矿带是西藏乃至我国的一条重要的铜多金属成矿带,区内已发现厅宫、驱龙、甲马等大型特大型斑岩铜矿及克鲁、冲木达等中型以上铜矿;矿床类型有斑岩型、火山热液型、接触交代(夕卡岩)型等。桑日县程巴铜钼多金属矿就处在西藏南冈... 冈底斯成矿带是西藏乃至我国的一条重要的铜多金属成矿带,区内已发现厅宫、驱龙、甲马等大型特大型斑岩铜矿及克鲁、冲木达等中型以上铜矿;矿床类型有斑岩型、火山热液型、接触交代(夕卡岩)型等。桑日县程巴铜钼多金属矿就处在西藏南冈底斯克鲁-冲木达一带远景区内,矿床成因为矽卡岩+斑岩复合型钼铜矿床。 展开更多
关键词 程巴铜钼多金属矿 地质特征 矿床成因 西藏桑日县
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西藏努日、程巴铜-钼-钨矿床硫铅同位素地球化学 被引量:16
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作者 王立强 唐菊兴 +3 位作者 陈伟 罗茂澄 江化寨 张凯 《地球学报》 EI CAS CSCD 北大核心 2014年第1期39-48,共10页
努日、程巴矿床是冈底斯成矿带东段南缘紧邻雅鲁藏布江缝合带产出的两个斑岩-矽卡岩矿床,两矿床矿化元素组合分别为Cu-Mo-W和Mo-Cu。文章以努日和程巴矿床中主要金属硫化物为研究对象,采用S、Pb同位素研究方法对矿床成矿物质来源进行探... 努日、程巴矿床是冈底斯成矿带东段南缘紧邻雅鲁藏布江缝合带产出的两个斑岩-矽卡岩矿床,两矿床矿化元素组合分别为Cu-Mo-W和Mo-Cu。文章以努日和程巴矿床中主要金属硫化物为研究对象,采用S、Pb同位素研究方法对矿床成矿物质来源进行探讨。硫同位素研究结果表明,两矿床硫同位素组成δ34S值范围均较窄,具明显塔式分布特征,矿床硫主要来自于深源岩浆;努日矿床硫同位素组成在空间上具有一定的变化规律,指示矿区41线附近存在隐伏岩体。矿石铅同位素组成表明,两矿床成矿物质中均有幔源和壳源物质的参与,不同的是壳源物质源区存在差异,努日矿床壳源物质源区为拉萨地块结晶基底,而程巴矿床壳源物质则可能来源于印度—亚洲大陆碰撞过程中的印度大陆岩石圈物质。努日和程巴矿床的矿化元素组合与其成矿物质源区特征是相对应的,冈底斯成矿带矿化元素组合由南向北的分带性系不同的壳源物质基础加之不同程度的幔源物质混染造成的。 展开更多
关键词 硫同位素 铅同位素 矿化元素组合 成矿物质来源 努日 程巴
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西藏冈底斯北带首例主碰撞造山期铜矿——林周县程巴矽卡岩型铜矿床地质特征、辉钼矿Re-Os同位素年龄及成矿意义 被引量:7
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作者 郑文宝 丁帅 +5 位作者 李盛俊 冷秋锋 李超 王豪 李茂田 戴成龙 《地质学报》 EI CAS CSCD 北大核心 2019年第2期459-469,共11页
通过近十年的地质勘查,在冈底斯北带多座具有经济价值的矿床得到开发利用,该带已经成为西藏地区矿床勘查与研究的又一热点地区。程巴铜矿是冈底斯北带近年来新发现的唯一一例中-大型规模的富铜矿床。矿床为典型的富含石榴子石的矽卡岩... 通过近十年的地质勘查,在冈底斯北带多座具有经济价值的矿床得到开发利用,该带已经成为西藏地区矿床勘查与研究的又一热点地区。程巴铜矿是冈底斯北带近年来新发现的唯一一例中-大型规模的富铜矿床。矿床为典型的富含石榴子石的矽卡岩型矿床,铜矿体主要呈似层状、脉状产于林布宗组角岩和多底沟组大理岩的层间构造带内,矿石中富铜,伴生钼、锌、金、银、铋。本文在矿床成矿地质背景和矿床地质特征研究的基础上,用Re-Os同位素方法测试辉钼矿,获得等时线年龄为58.49±0.43 Ma(MSWD=0.61),模式年龄加权平均为58.49±0.33Ma(MSWD=0.25),确定程巴铜矿是主碰撞期成矿作用的产物,程巴铜矿的发现证明在冈底斯成矿带主碰撞造山过程能够形成铜矿床。因此,主碰撞成矿阶段由深变浅的矿床组合模型应在前人研究的基础上修改为矽卡岩型Cu(Mo)矿+矽卡岩型Fe-Pb-Zn-Mo(Cu)矿+斑岩型Mo(W)矿。此外,辉钼矿中Re含量介于84.6×10^(-6)~461.3×10^(-6)之间,平均值为252×10^(-6),暗示程巴矿区物源具有壳幔混合的特征。 展开更多
关键词 地质特征 辉钼矿RE-OS年龄 主碰撞造山 冈底斯北带 程巴铜矿
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冈底斯成矿带林周县程巴矽卡岩铜多金属矿床特征:对藏南区域古新世铜矿床的找矿启示 被引量:4
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作者 谢桂青 陈小龙 +3 位作者 马龙敬 高坡 左俊增 王晓青 《矿床地质》 CAS CSCD 北大核心 2021年第3期625-630,共6页
冈底斯是全球重要的斑岩-矽卡岩铜矿床的成矿带之一,发育侏罗纪(173~160 Ma)和中新世(26~12 Ma)两期矿化事件。印度与亚洲大陆主碰撞期(65~50 Ma)形成了该带规模最大的壳幔混源岩浆岩,而藏南能否形成大中型规模的斑岩-矽卡岩铜矿床一直... 冈底斯是全球重要的斑岩-矽卡岩铜矿床的成矿带之一,发育侏罗纪(173~160 Ma)和中新世(26~12 Ma)两期矿化事件。印度与亚洲大陆主碰撞期(65~50 Ma)形成了该带规模最大的壳幔混源岩浆岩,而藏南能否形成大中型规模的斑岩-矽卡岩铜矿床一直是个未解之谜。文章获得冈底斯带东部程巴大型矽卡岩铜多金属矿床中与黄铜矿共生的辉钼矿Re-Os模式年龄和含矿花岗闪长岩U-Pb年龄分别为(58.9±0.9)Ma、(57.6±0.4)Ma,认为它是主碰撞期首例矽卡岩铜矿床。含矿岩体可见自形角闪石早于斜长石,与甲玛超大型斑岩-矽卡岩型铜矿床具有类似的含矿地层、矽卡岩矿物组合和成矿元素分带特征。结合区域构造背景的资料,笔者提出冈底斯成矿带东部具有寻找古新世斑岩-矽卡岩铜矿床的潜力。 展开更多
关键词 地球化学 主碰撞期 古新世 程巴矽卡岩铜多金属矿床 冈底斯成矿带
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西藏程巴钼矿床地质特征与成因分析
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作者 汪东 钟康惠 +1 位作者 刘堂 张文磊 《四川建材》 2016年第5期170-172,共3页
程巴斑岩型铜钼矿床位于雅江结合带边缘、拉达克-南冈底斯-下察隅岩浆弧带上。矿区主要出露上三叠统姐德秀组(T_3j)、下白垩统比马组第四段(K_1b^4)、下白垩统比马组第五段(K_1b^5)及古新统罗布莎群(E_1b)。岩浆活动强烈,岩石类型主要... 程巴斑岩型铜钼矿床位于雅江结合带边缘、拉达克-南冈底斯-下察隅岩浆弧带上。矿区主要出露上三叠统姐德秀组(T_3j)、下白垩统比马组第四段(K_1b^4)、下白垩统比马组第五段(K_1b^5)及古新统罗布莎群(E_1b)。岩浆活动强烈,岩石类型主要为古新世石英闪长岩(δοE_1)、始新世二长花岗岩(ηγE_2)、渐新世正长花岗岩(ζγE_3)。岩浆活动强烈,岩石类型主要为石英闪长岩、二长花岗岩、正长花岗岩,正长花岗岩为赋矿岩体。结合区域地质背景、矿区地质特征、矿体特征及成矿时代,初步分析了程巴钼矿床的类型和矿床成因。 展开更多
关键词 程巴钼矿 斑岩型 地质特征
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西藏乃东县程巴钼矿床地质特征及成矿作用分析
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作者 张磊 钟康惠 +1 位作者 于涛 白荣龙 《四川有色金属》 2016年第2期27-30,共4页
通过介绍西藏程巴钼矿床的地质特征,对矿床的成矿作用做简单分析。研究结果表明,在印度—欧亚大陆板块碰撞晚期,渐新世正长花岗岩沿断裂侵入到古新统罗布莎群地层和始新世二长花岗岩中,产生围岩蚀变,从而形成铜钼矿床。期后的含矿热液... 通过介绍西藏程巴钼矿床的地质特征,对矿床的成矿作用做简单分析。研究结果表明,在印度—欧亚大陆板块碰撞晚期,渐新世正长花岗岩沿断裂侵入到古新统罗布莎群地层和始新世二长花岗岩中,产生围岩蚀变,从而形成铜钼矿床。期后的含矿热液作用不仅提供了新的成矿物质来源,而且形成了新矿化叠加,进一步富集成矿。 展开更多
关键词 程巴 钼矿 地质特征 成矿作用
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X射线荧光方法在西藏山南地区程巴铜多金属矿上的应用 被引量:1
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作者 陈小红 刘国安 +1 位作者 郑秀红 曹发明 《四川有色金属》 2014年第1期28-30,34,共4页
结合程巴铜多金属矿区的地质特点,应用X射线荧光方法对程巴矿区岩石露头进行测量,在勘测区北端出现的Cu元素异常与已知铜多金属矿体位置基本一致,得出在矿体露头及矿体埋深比较浅的情况下,相应的成矿元素或与成矿有关的元素原生晕均显示... 结合程巴铜多金属矿区的地质特点,应用X射线荧光方法对程巴矿区岩石露头进行测量,在勘测区北端出现的Cu元素异常与已知铜多金属矿体位置基本一致,得出在矿体露头及矿体埋深比较浅的情况下,相应的成矿元素或与成矿有关的元素原生晕均显示X荧光异常,说明应用岩石X荧光测量地表矿体露头及浅埋深矿体所形成的原生晕异常是非常有效的;在勘查区南部蛇绿岩套,形成W元素异常、Cr元素高异常产出。建议着重在程巴勘查区南部5条测线的800m-1300m所组成的区域开展下一步的工作。 展开更多
关键词 X射线荧光 程巴矿区 岩石测量
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西藏程巴铜钼多金属矿地质特征及成因浅析 被引量:1
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作者 何永海 《云南地质》 2016年第1期69-72,共4页
程巴铜钼多金属矿床位于冈底斯成矿带东段南缘。矿体呈似层状、透镜状产出于似斑状二长花岗岩及石英钠长斑岩外接触带的矽卡岩、大理岩之中,为典型斑岩-矽卡岩型矿床。近几年勘查工作表明矿区深部具有较大的找矿空间。
关键词 矽卡岩 铜钼矿床 西藏程巴
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Surgical treatment of intrahepatic cholangiocarcinoma: a retrospective study of 104 cases 被引量:1
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作者 Xiao-Dong Xun Qiang Li 《Cancer Biology & Medicine》 SCIE CAS CSCD 2016年第4期469-473,共5页
Objective: To explore the clinicopathological features, surgical treatment techniques, and prognostic risk factors of intrahepatic cholangiocarcinoma(ICC).Methods: A total of 104 ICC cases were collected from January ... Objective: To explore the clinicopathological features, surgical treatment techniques, and prognostic risk factors of intrahepatic cholangiocarcinoma(ICC).Methods: A total of 104 ICC cases were collected from January 2008 to December 2013 at Tianjin Medical University Cancer Institute and Hospital and divided into the hepatic hilum lymphadenectomy(HLL, 21 cases), extended hepatic hilum lymphadenectomy(EHLL, 12 cases), and non-lymphadenectomy(NL, 71 cases) groups. The clinical data of the patients were retrospectively analyzed, and the prognostic differences were compared among different groups.Results: The 1-, 2-, and 3-year overall survival(OS) rates of all cases were 72.1%, 56.1%, and 43.7%, respectively. The median survival duration was 34 months. The 1-, 2-, and 3-year OS rates of the HLL group(42.9%, 28.6%, and 28.6%, respectively) were significantly lower than those of the NL group(78.9%, 62.5%, and 47.8%, respectively). Meanwhile, the 1-, 2-, and 3-year OS rates of the EHLL group(75.0%, 56.1%, and 33.3%, respectively) were not significantly different from those of the other two groups.Univariate analysis showed that age, gender, American Joint Committee on Cancer(AJCC) stage, differentiation, ferritin(Fer),carbohydrate antigen19-9(CA19-9) and carcinoembryonicantigen(CEA) levels, lymph node metastasis(LNM), and lymph node dissection(LND) were prognostic factors for the long-term survival of ICC. Meanwhile, multivariate analysis revealed that age,AJCC stage, differentiation, Fer levels, and LNM were independent risk factors for survival.Conclusions: ICC patients will not benefit from lymphadenectomy in the absence of LNM. However, systematic lymphadenectomy may improve ICC outcomes if the location of lymphatic metastasis is known. Age, AJCC stage, differentiation,Fer level, and LNM are independent risk factors for survival in ICC. 展开更多
关键词 Intrahepatic cholangiocarcinoma surgical treatment lymph node dissection PROGNOSIS
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Interleukin-24 is correlated with differentiation and lymph node numbers in rectal cancer 被引量:3
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作者 Youngmin Choi Mee-Sook Roh +2 位作者 Young-Seoub Hong Hyung-Sik Lee Won-Joo Hur 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第9期1167-1173,共7页
AIM:To assess the significance of interleukin(IL)-24 and vascular endothelial growth factor(VEGF)expression in lymph-node-positive rectal cancer. METHODS:Between 1998 and 2005,90 rectal adenocarcinoma patients with ly... AIM:To assess the significance of interleukin(IL)-24 and vascular endothelial growth factor(VEGF)expression in lymph-node-positive rectal cancer. METHODS:Between 1998 and 2005,90 rectal adenocarcinoma patients with lymph node involvement were enrolled.All patients received radical surgery and postoperative pelvic chemoradiotherapy of 50.4-54.0 Gy.Chemotherapy of 5-fluorouracil and leucovorin or levamisole was given intravenously during the first and last week of radiotherapy,and then monthly for about 6 mo.Expression of IL-24 and VEGF was evaluated by immunohistochemical staining of surgical specimens, and their relations with patient characteristics and survival were analyzed.The median follow-up of surviving patients was 73 mo(range:52-122 mo). RESULTS:IL-24 expression was found in 81 out of 90 patients;31 showed weak intensity and 50 showedstrong intensity.VEGF expression was found in 64 out of 90 patients.Negative and weak intensities of IL-24 expression were classified as negative expression for analysis.IL-24 expression was significantly reduced in poorly differentiated tumors in comparison with well or moderately differentiated tumors(P=0.004),N2b to earlier N stages(P=0.016),and stageⅢc to stageⅢ a orⅢb(P=0.028).The number of involved lymph nodes was also significantly reduced in IL-24-positive patients in comparison with IL-24-negative ones. There was no correlation between VEGF expression and patient characteristics.Expression of IL-24 and VEGF was not correlated with survival,but N stage and stages were significantly correlated with survival. CONCLUSION:IL-24 expression was significantly correlated with histological differentiation,and inversely correlated with the degree of lymph node involvement in stageⅢrectal cancer. 展开更多
关键词 INTERLEUKIN-24 Rectal cancer Lymph node Histological differentiation Vascular endothelial growth factor
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AN EQUIVALENT PROPOSITION TO THE CONJECTURE OF GOLDBACH
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作者 王友菁 刘宗杰 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第1期93-95,共3页
In this paper,a formula is given. The formula gives the number of prime number solutions of the indefinite equation p 1+p 2=2n , and based on it, an equivalent proposition to the conjecture of Goldbach is obtained.
关键词 prime numbers indefinite equation prime number solution conjecture of Goldbach equivalent proposition
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The Fallacy of Participation in Behaviour Change Programming: The Case of Gweru Women AIDS Prevention Association (GWAPA), Zimbabwe
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作者 Patience Priscilla Mushuku 《Journalism and Mass Communication》 2013年第11期733-747,共15页
Gweru Women AIDS Prevention Association (GWAPA) is an organization that works with commercial sex-workers in the Midlands Province to try and stymie the tide of HIV/AIDS. The organization premises its activities upo... Gweru Women AIDS Prevention Association (GWAPA) is an organization that works with commercial sex-workers in the Midlands Province to try and stymie the tide of HIV/AIDS. The organization premises its activities upon the belief that sex workers are forced into prostitution by poverty and thus offers them alternative livelihood strategies such as piggery projects, chicken rearing, and vegetable vending projects as well as seed money with which to start flea market projects. The organization also runs a condom promotion project, a legal literacy project, and an advocacy project, all in a bid to empower the sex workers cognitively. The study was carried out between April and October 2008, using bar-based observations, interviews, focus group discussions, and documentary evidence. The study found participation to have been more of a fallacy in as far as programming depended more on the whims of donor funders than the actual needs of programme beneficiaries. In the top-down manner that is typical of development communication, the organization would engage donors and secure funding for certain projects which they would then try to convince the sex workers to take up, with mixed results. The research also found limited evidence of real empowerment of beneficiaries in the long run, with the sex workers themselves insisting that the "piece-meal" efforts of the organization were not sustainable enough to induce them to abandon sex work altogether. The study did, however, find that the organization and its programming had actually managed to score notable success in promoting safer sex within the context of prostitution, albeit without eradicating sex work altogether. 展开更多
关键词 PARTICIPATION commercial sex work EMPOWERMENT
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Applications of Power Rail Track Program to Tracings of Brazilian Railways
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作者 Sonia Janneth Rosero Munoz Mhileizer Arielys Toledo Arenas +1 位作者 Diogenes Cortijo Cost Cassio EduardoLima de Paiva 《Journal of Civil Engineering and Architecture》 2016年第4期501-512,共12页
In Brazil, the use of software and applications in railway geometric designs is rare. Currently, after the division and privatization of the national rail network, the concessionaires who assumed the administration, a... In Brazil, the use of software and applications in railway geometric designs is rare. Currently, after the division and privatization of the national rail network, the concessionaires who assumed the administration, are investing in modernization, recovery and extension of this transport model to make it more efficient. The PIL (Program of Investment in Logistics) has generated growth of the sector in response to the amount of investments, greatly enhancing the load capacity and optimizing the geometric design, which would allow speed of 80 km/h. Based on this information, the objective of this research is to verify the software applications of Power Rail Track Program of Bentley Systems, Inc. for geometric designs in future deployments of railways in Brazil. This software is based on numerical calculations, including roller adjustment by the least squares method to calculate and choose the best alignments, and regression tools, to a fast and effectively optimization of various parameters of the geometry for a future or existing railway. Different variables that allow you to optimize the geometric design are analyzed, considering several optional alignments and complex restrictions present in geometric design, taking into account variables such as circular curves, transition, tangents and rays. The software regression tools include curvature diagrams identifying points and curves, tangent and spirals. The analysis results are presented quickly and points can be added or deleted from the regression analysis, providing improved tracing. The software also allows to detail the elements of the executive project of the railway line such as rails, joints, turning points, waypoints and others. The result of this study has shown that the application of the Power Rail Track Program generates significant cost savings in time and increases in productivity, providing greater opportunity to optimize the geometry and reducing geometric design costs. 展开更多
关键词 Geometric design railways optimization software geometric tracing.
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Initial Value Problems for Second Order Impulsive Integro-Differential Equation in Banach Spaces
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作者 陈芳启 张海燕 《Transactions of Tianjin University》 EI CAS 2005年第1期73-78,共6页
By an established comparison result and using the upper and lower solutions,one sufficient condition of existence of minimal and maximal solutions to initial value problem for second order impulsive integro-differenti... By an established comparison result and using the upper and lower solutions,one sufficient condition of existence of minimal and maximal solutions to initial value problem for second order impulsive integro-differential equation in Banach spaces is obtained and the related results are essentially improved.At the same time, another sufficient condition of existence of minimal and maximal solutions based on the Kuratowski measure of noncompactness is given. 展开更多
关键词 impulsive integro-differential equation initial value problem comparison result
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Labelling of the Energetic Efficiency on a Case Study in Passo Fundo, RS, Brazil, in Accordance with the Mentioned Methods under the Respective Brazilian Regulation-RTQ-C
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作者 Letiane Beninca Grace Tibério Cardoso Cristiana Rodrigues 《Journal of Civil Engineering and Architecture》 2018年第5期355-361,共7页
Having as a starting point of the problematic energy consumption of buildings, it studied the panorama of energy efficiency, emphasizing the Brazilian program of the INMETRO (Instituto Nacional de Metrologia, Normali... Having as a starting point of the problematic energy consumption of buildings, it studied the panorama of energy efficiency, emphasizing the Brazilian program of the INMETRO (Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial), PROCEL “Edifica” (national program for energy efficiency in buildings), contained in the norm RTQ-C (technical requirements of the quality for the level of energetic efficiency of commercial, service, and public buildings). For a better understanding of the regulation, it elected a building, emblematic in the city of Passo Fundo, RS, Brazil, illustrating the perspective of the program. The building was classified in accordance with the two methodologies presented by the program: prescriptive and simulation, so it was possible to investigate the peculiarities of each methodology and the own regulation. After the application of the methodologies, we came to the conclusion that the prescriptive method is less accurate and requires more dedication by the evaluator to do all the calculations and surveys required, however, it is the fastest tool and accessible to the field professionals. The simulation on the other hand, is a more accurate methodology and reaches levels of analysis that the prescriptive method does not reach, but still is a tool that needs large initial financial contribution and prior knowledge. 展开更多
关键词 Energy efficiency labelling Brazilian regulation.
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The Scenario of Lean Product Development in Brazilian Auto-industry
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作者 Ana Julia Dal Fomo Fernando Antonio Forcellini +2 位作者 Henrique Rozenfeld Liane Mahlmann Kipper Femando Augusto Pereira 《Chinese Business Review》 2014年第11期692-706,共15页
The purpose of this paper is to evaluate the impact of lean product development (LPD) in the Brazilian automotive sector. A mailed-questionnaire survey was used to examine 23 questions about LPD principles and pract... The purpose of this paper is to evaluate the impact of lean product development (LPD) in the Brazilian automotive sector. A mailed-questionnaire survey was used to examine 23 questions about LPD principles and practices. The target population for the study was Brazil's largest product development and design companies. The study identified that although the automobile sector is seen as a reference in the adoption of lean practices, there is still potential for improvement by establishing partnership relations with suppliers, and with those on the other points of the chain by identifying what provides value to clients. Set-based concurrent engineering is also a practice that needs to be better developed, as well as the value stream mapping tool to identify waste and activities that add value to the product development process. There has been no previous study of this nature in Brazil that characterizes the sector and highlights its importance in relation to the global scene, providing incentives to international investors. The value of the work is in the results that allow diagnosing the lean development practices that are most used in the automotive sector. Moreover, the survey questions can be applied in other economic sectors and at companies of other sizes. The study contributed to providing a systematic view of the product development process from the perspective of people, processes, and technology, and assists companies and academics manage change. 展开更多
关键词 auto-industry LEAN product development process PRACTICES
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Stress evolution and failure process of Brazilian disc under impact 被引量:6
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作者 周子龙 邹洋 +1 位作者 李夕兵 江益辉 《Journal of Central South University》 SCIE EI CAS 2013年第1期172-177,共6页
To reveal stress distribution and crack propagation of Brazilian discs under impact loads, dynamic tests were conducted with SHPB (split Hopkinson pressure bar) device. Stress states of specimens were monitored with... To reveal stress distribution and crack propagation of Brazilian discs under impact loads, dynamic tests were conducted with SHPB (split Hopkinson pressure bar) device. Stress states of specimens were monitored with strain gauges on specimen surface and SHPB bars. The failure process of specimen was recorded by ultra speed camera FASTCAM SAI.1 (675 000 fps). Stress histories from strain gauges offer comprehensive information to evaluate the stress equilibrium of specimen in time and space. When a slowly rising load (with loading rates less than 1 200 N/s for d 50 mm bar) is applied, there is usually good stress equilibrium in specimen. The stress distribution after equilibrium is similar to its static counterpart. And the first crack initiates at the disc center and propagates along the load direction. But with the front of incident wave becoming steep, it is hard for specimens to get to stress equilibrium. The first crack may appear anywhere on the specimen together with multiple randomly distributed secondary cracks. For a valid dynamic Brazil test with stress equilibrium, the specimen will break into two halves neatly. While for tests with stress disequilibrium, missing strap may be found when broken halves of specimens are put together. For those specimens broken up neatly at center but having missing wedges at the loading areas, it is usually subjected to local buckling from SHPB bars. 展开更多
关键词 dynamic Brazil test Brazilian disc stress evolution failure pattern
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Differential effects of energy balance on experimentally-induced colitis
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作者 Sarah J McCaskey Elizabeth A Rondini +1 位作者 Ingeborg M Langohr Jenifer I Fenton 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第7期627-636,共10页
AIM: To characterize the influence of diet-induced changes in body fat on colitis severity in SlVlAD3-/- mice.METHODS: SMAD3-/- mice (6-8 wk of age) were ran- domly assigned to receive a calorie restricted (30% o... AIM: To characterize the influence of diet-induced changes in body fat on colitis severity in SlVlAD3-/- mice.METHODS: SMAD3-/- mice (6-8 wk of age) were ran- domly assigned to receive a calorie restricted (30% of control; CR), control (CON), or high fat (HF) diet for 20 wk and were gavaged with sterile broth or with Helicobacter hepaticus (H. hepaticus) to induce colitis. Four weeks after infection, mice were sacrificed and the cecum and colons were processed for histological evaluation.RESULTS: Dietary treatment significantly influenced body composition prior to infection (P 〈 0.05), with CR mice having less (14%±2%) and HF-fed mice more body fat (32% ± 7%) compared to controls (22%±4%). Differences in body composition were associated with alterations in plasma levels of leptin (HF 〉 CON 〉 CR) and adiponectin (CON 〉 HF 〉/ CR) (P 〈 0.05). There were no significant differences in colitis scores between CON and HF-fed mice 4 wk post-infection. Consistent with this, differences in proliferation and in- flammation markers (COX-2, iNOS), and infiltrating cell types (CD3^+ T lymphocytes, macrophages) were not observed. Unexpectedly, only 40% of CR mice survived infection with H. hepaticus, with mortality observed as early as I wk following induction of colitis.CONCLUSION: Increased adiposity does not influence colitis severity in SMAD3-/- mice. Importantly, caloric restriction negatively impacts survival following pathogen challenge, potentially due to an impaired immune response. 展开更多
关键词 SMAD3 COLITIS ADIPOKINE OBESITY Calorierestriction
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Large Deviations for a Generalized Compound Renewal Risk Model
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作者 GA O Shan 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第3期399-406,共8页
This paper extends the ordinary renewal risk model to the case where the premium income process,based on a renewal counting process,is no longer a linear function;and the total claim amount process is described by a c... This paper extends the ordinary renewal risk model to the case where the premium income process,based on a renewal counting process,is no longer a linear function;and the total claim amount process is described by a compound renewal process.For this realistic risk model,the large deviations for the claim surplus process is investigated. 展开更多
关键词 heavy-tailed distribution renewal counting process large deviation
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Roles Portrayed by Women: A Content Analysis in Brazilian Television Advertisements
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作者 Claudia Rosa Acevedo Helenita Tamashiro +1 位作者 Jouliana Jordan Nohara Julio Cunha 《Journalism and Mass Communication》 2013年第7期409-421,共13页
The main purpose of this paper was to examine female roles portrayed by advertising. More specifically, the questions that motivated this research project were "What messages about women have been given to society th... The main purpose of this paper was to examine female roles portrayed by advertising. More specifically, the questions that motivated this research project were "What messages about women have been given to society through advertisement?" and "Have these portrayals been changed during the past decades?" The study consisted of a systematic content analysis of Brazilian commercials from 1973 to 2000. The population from which this sample was drawn consisted of Brazilian commercials which got an award in international and national festivals. A probabilistic sample procedure was employed. Ninety five pieces were selected. The categories and operational rules used in the study were developed based on previous research. This study has proposed that female images in advertising are depicted in three different ways: stereotyped, idealized, and plural portrayals. Our results have revealed that some specific images have changed, however, they continued to be stereotyped and idealized. 展开更多
关键词 roles in advertising gender representations mass communication female roles content analysis inmedia
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