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金属油气管道点蚀缺陷安全评估及预警系统研究 被引量:5
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作者 hoang van thanh 龙伟 +2 位作者 李炎炎 黄仕磊 胥鑫 《工程科学与技术》 EI CAS CSCD 北大核心 2021年第1期162-169,共8页
在油气输送过程中,因为载荷和腐蚀介质等因素的影响,油气金属管道很容易萌生缺陷而引发重大安全事故。点蚀与多点蚀缺陷是存在周期最长、最普遍、最有可能产生穿孔的高危缺陷,因此对金属管道工作过程中的在线检测与安全评估一直是油气... 在油气输送过程中,因为载荷和腐蚀介质等因素的影响,油气金属管道很容易萌生缺陷而引发重大安全事故。点蚀与多点蚀缺陷是存在周期最长、最普遍、最有可能产生穿孔的高危缺陷,因此对金属管道工作过程中的在线检测与安全评估一直是油气输送技术领域研究的重点和热点。作者考虑了多个点蚀及点蚀之间的相互作用,根据美国石油协会的API-579的技术标准,研究点蚀占比对剩余强度的影响,建立对金属管道点蚀缺陷剩余强度的统一评价模型,也称无缝表征评价函数;然后,将无缝表征模型与场指纹法(FSM)管道腐蚀监测技术相结合,运用基于FSM技术的管道腐蚀3维模型获取点蚀占比、剩余壁厚等在役管道参数,通过无缝表征模型评价管道安全并构建面向全域生产管线的安全评估决策及安全预警系统。该评估系统完善了FSM技术对点蚀缺陷的安全评估,同时也实现了无缝表征模型计算中的在线评估。油气田现场试验表明这个安全评估系统具有一定的实际应用价值。 展开更多
关键词 安全评估 点蚀缺陷 场指纹法 无缝表征模型 缺陷监测
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Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests 被引量:1
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作者 Tran van Do Mamoru Yamamoto +42 位作者 Osamu Kozan Vo Dai Hai Phung Dinh Trung Nguyen Toan Thang Lai thanh Hai Vu thanh Nam Trieu Thai Hung hoang van Thang Tran Duc Manh Cao Chi Khiem Vu Tien Lam Nguyen Quang Hung Tran hoang Quy Pham Quang Tuyen Trinh Ngoc Bon Nguyen Thi Thu Phuong Ninh Viet Khuong Nguyen van Tuan Dang Thi Hai Ha Tran Hai Long Dang van Thuyet Dang Thinh Trieu Nguyen van Thinh Tran Anh Hai Duong Quang Trung Nguyen van Bich Dinh Hai Dang Pham Tien Dung Nguyen Huy hoang Le Thi Hanh Phan Minh Quang Nguyen Thi Thuy Huong hoang thanh Son Nguyen thanh Son Nguyen Thi van Anh Nguyen Thi Hoai Anh Pham Dinh Sam hoang Thi Nhung hoang van thanh Nguyen Huu Thinh Tran Hong van Ho Trung Luong Bui Kieu Hung 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第5期1713-1722,共10页
Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest ecosystems.This study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of V... Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest ecosystems.This study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was developed.The results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of sunshine.Basal area and AGB are positively correlated with trees>30 cm DBH.Most areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-1.Seventy percent of the areas surveyed had stand densities of 300–600 ind.ha^-1,and 64%had basal areas of 20–40 m^2 ha^-1.Precipitation is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in Vietnam.Disturbances causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density. 展开更多
关键词 Aboveground biomass Carbon storage Climatic variables ECOREGION Edaphic variables Oldgrowth forest
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