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Study of Neutron Cross Talk Rejection Based on Testing Experiment and Simulation
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作者 游海波 宋玉收 +1 位作者 肖军 叶沿林 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第6期473-477,共5页
Experimental data analysis and simulation calculations were performed in order to evaluate the cross-talk rejection performance of a typical neutron detection array. For very closely packed scintillation bars, the CT ... Experimental data analysis and simulation calculations were performed in order to evaluate the cross-talk rejection performance of a typical neutron detection array. For very closely packed scintillation bars, the CT rejection may rely on the position relation between the two signals. The criteria |△x|≤ 15 cm and |△y|≤12 cm are currently proposed for a rejection rate higher than 90%. For signals coming from distanced bars, the energy conservation relationship can be applied to reject the CT events with a similar performance. In both cases the results of simulation agree very well with the experimental data, assuring their applicability to other detection systems and physics problems. 展开更多
关键词 test experiment GEANT4 simulation cross talk neutron detection
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On the Analysis Method of the Triple Test Cross Design
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作者 Jin Yi(Northeast Agricultural University, Harbin 1 50030, P R C) 《Journal of Northeast Agricultural University(English Edition)》 CAS 1995年第1期66-74,共9页
The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different f... The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different from the previous reports have been concluded: (1)both the degrees of freedom of the orthogonal terms C2 and C3 are m, (2)the denominator in the F test to C2 and C3 is the error mean of square between plots. 展开更多
关键词 Triple test cross design Additive-dominant model Epistasis model Genetic parameter estimate.
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Characteristics of the Variation of Cross Fault Short-Baseline and Short-Range Leveling in Western Yunnan Earthquake Test Site Before Lijiang M_S7.0 Earthquake
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作者 Li Zhonghua, Su Youjing, and Liu ZhuyinSeismological Bureau of Yunnan Province, Kunming 650041, China 《Earthquake Research in China》 1998年第4期46-56,共11页
Results of analysis of variation of cross fault short-baseline and short-range leveling in Western Yunnan Earthquake Test Site (WYETS), results show that among five observation stations of cross fault short-baseline a... Results of analysis of variation of cross fault short-baseline and short-range leveling in Western Yunnan Earthquake Test Site (WYETS), results show that among five observation stations of cross fault short-baseline and short-range leveling in WYETS before the Lijiang MS7.0 Earthquake occurred in February 1996 only Yongsheng observation station (epicentral distance 82 km) located at Chenghai fault shows great variation about one year before the earthquake. And the nearest observation station, Lijiang (epicentral distance 42 km); presents great coseismic variation, but does not show obvious anomalous variation before the earthquake. There are no significant variations related to the earthquake at the other three observation stations. Two methods are used in analysis of the observed data and some valuable results have been obtained. 展开更多
关键词 cross FAULT measurement Lijiang MS7.0 EARTHQUAKE Western Yunnan EARTHQUAKE test Site.
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Research and application of cross-test strategy based on component
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作者 SONG Yu TIAN Hua CAO Yong-feng 《通讯和计算机(中英文版)》 2007年第8期40-43,共4页
关键词 交叉测试策略 软件测试 组成 应用 软件开发
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Self-Cross-Linked Tannin-Aminated Tannin Surface Coatings for Particleboard
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作者 Bengang Zhang Antonio Pizzi +2 位作者 Mathieu Petrissans Anelie Petrissans Colin Baptiste 《Journal of Renewable Materials》 EI 2023年第12期4097-4121,共25页
Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many,if not all of the tannin hydroxyl groups with–NH_(2)groups.A tannin-aminated tannin(ATT)partic... Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many,if not all of the tannin hydroxyl groups with–NH_(2)groups.A tannin-aminated tannin(ATT)particleboard coating was then prepared by reacting raw tannin extract with aminated tannin extract and thus cross-linking the two by substituting tannin’s hydroxyl groups with the–NH_(2)groups on the aminated tannin to form–NH-bridges between the two.The resulting particleboard coating gave encouraging results when pressed at 180℃for 3 min.Conversely,the system in which tannin was reacted/cross-liked with urea(ATU)by a similar amination reaction did not perform as well as the ATT system,and this even when a higher curing temperature and longer hot press time were used.In particular its water repellence was worse probably due to the presence of urea and such a system with lower reactivity.Nonetheless,substituting the tannin–OHs with the urea–NH_(2)groups appeared to also take place.ATT gave better results than ATU as regards water repellence and mechanical resistance as shown by the cross cut test.The ATT system was shown to be between 95%and 98%biosourced.The difference appeared to be due,by TMA analysis,to the much faster formation of the ATT hardened network leading to a better cross-linked polymer coating.The chemical species formed for both the ATT and ATU system were studied by MALDI ToF and CP MAS^(13)C NMR. 展开更多
关键词 Biocoatings PARTICLEBOARD aminated tannin cross-linked tannin-aminated tannin tannin-urea cross links water repellence cross cut test MALDI ToF ^(13)C NMR
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The “Colour Family Drawing Test”: Assessing Children’s Perception of Family Relationships. Studies on Mental Health and Cross-Cultural Comparisons
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作者 Valeria Biasi Paolo Bonaiuto James M. Levin 《Health》 2015年第3期300-307,共8页
We apply the Colour Family Drawing Test, as a development of the traditional black and white test, for cross-cultural comparison. The participants, aged 7 - 10 years, both genders, were examined individually. Each sub... We apply the Colour Family Drawing Test, as a development of the traditional black and white test, for cross-cultural comparison. The participants, aged 7 - 10 years, both genders, were examined individually. Each subject sat at a single table with a white rectangular card of standard size, 24 well-sharpened colour pencils, a black pencil, an eraser and other appropriate tools. S/he received this verbal instruction: “Draw your family”. The procedure was firstly applied to 120 participants attending primary schools of Rome (Biasi, Bonaiuto and Levin, 2014). The families were evaluated through a semi-structural interview conducted with the children’s teachers and divided into: Harmonious versus Very Conflictual Families. The drawings made by children of Harmonious Families consistently used “Reassuring and Playful Colours” (Pink, Orange, Sky Blue, Light Green, Light Yellow, other pastel colours);and were larger, tidier and more proportioned to respect the opposite group. Children belonging to Conflictual Families used mostly “Alarming and Serious Colours” (Grey, Black, Dark Bleu, Violet, Olive Green) and their drawings were less extended, more often disordered and had typical deformations such as figures too thin. A second investigation examined 120 participants belonging to Asian immigrant families residing in Italy. A third investigation examined 120 participants belonging to Russian families of Moscow. Both last two investigations obtained very similar results on the use of colours, and gave a confirmation of the relevance of the Colour Family Drawing Test. 展开更多
关键词 COLOUR Conflictual FAMILY cross-Cultural Comparison COLOUR DRAWING FAMILY test EXPRESSIVENESS
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Testing for Cross-Sectional Dependence in a RandomEffects Model
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作者 Afees Salisu Sam Olofin Eugene Kouassi 《Open Journal of Statistics》 2012年第1期88-97,共10页
This paper extends and generalizes the works of [1,2] to allow for cross-sectional dependence in the context of a two-way error components model and consequently develops LM test. The cross-sectional dependence follow... This paper extends and generalizes the works of [1,2] to allow for cross-sectional dependence in the context of a two-way error components model and consequently develops LM test. The cross-sectional dependence follows the first order spatial autoregressive error (SAE) process and is imposed on the remainder disturbances. It is important to note that this paper does not consider alternative forms of spatial lag dependence other than SAE. It also does not allow for endogeneity of the regressors and requires the normality assumption to derive the LM test. 展开更多
关键词 cross-SECTIONAL DEPENDENCE Error Components MODEL LAGRANGIAN MULTIPLIER (LM) tests
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Research on Well Testing Interpretation of Low Permeability Deformed Dual Medium Reservoir
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作者 Meinan Wang Yue Xie +2 位作者 Rui Zhang Guohao Zhang Jianguo Liu 《Open Journal of Applied Sciences》 2023年第11期2141-2148,共8页
Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and esta... Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and established. The difference method was used to solve the problem, and pressure and pressure derivative double logarithmic curves were drawn to analyze the seepage law. The research results indicate that the influence of starting pressure gradient and medium deformation on the pressure characteristic curve is mainly manifested in the middle and late stages. The larger the value, the more obvious the upward warping of the pressure and pressure derivative curve;the parameter characterizing the dual medium is the crossflow coefficient. The channeling coefficient determines the time and location of the appearance of the “concave”. The smaller the value, the later the appearance of the “concave”, and the more to the right of the “concave”. 展开更多
关键词 Low Permeability Oil Reservoirs Deformation Medium Dual Media cross Flow Coefficient Well testing Interpretation Model
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复杂受荷下盾构隧道原型结构试验平台的研发与实证 被引量:1
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作者 柳献 刘震 +1 位作者 叶宇航 姚鸿梁 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第5期927-937,共11页
盾构隧道结构在全寿命周期中往往将面临诸多复杂荷载状态,如注浆、偏载、偏转等非对称偏不利工况。为验证结构在这些复杂荷载状态下的适用性,探究结构力学性能,开展足尺原型结构试验研究往往是最为直接而有效的手段。既有原型试验主要... 盾构隧道结构在全寿命周期中往往将面临诸多复杂荷载状态,如注浆、偏载、偏转等非对称偏不利工况。为验证结构在这些复杂荷载状态下的适用性,探究结构力学性能,开展足尺原型结构试验研究往往是最为直接而有效的手段。既有原型试验主要关注隧道结构在简单对称荷载条件下的力学性能,鲜有关注复杂非对称荷载状态。为拓展原型试验的适用范围,提出了适用于不同断面盾构隧道结构的原型试验平台和用于模拟复杂荷载状态的试验荷载设计方法。该方法适用于任意加载点布置和液压站分组的试验系统,可对注浆、偏载、偏转等复杂荷载状态下结构响应进行精确模拟。通过类矩形盾构隧道、双圆隧道和圆形隧道的偏载原型结构试验研究,验证了试验平台和试验荷载设计方法的适用性。进一步针对试验关键参数的分析表明,控制目标权重系数的调整能有效满足不同的试验模拟要求;基于试验荷载设计方法优化的迭代算法能有效考虑计算模型或边界支承条件的非线性;环箍钢绞线和千斤顶的组合加载模式能将拟合误差水平降低至千斤顶加载模式的1/5,但需要删去部分加载点使试验荷载合理且适用;对于越复杂的结构和荷载,精确模拟结构状态需要的试验系统独立荷载组数越高,对试验平台的要求也越高。 展开更多
关键词 复杂受荷状态 原型试验 试验平台 试验荷载设计 断面形式
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液化场地大直径变截面单桩动力响应研究 被引量:1
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作者 冯忠居 段久琴 +3 位作者 张聪 林立华 赵瑞欣 王逸然 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第5期56-67,共12页
为研究不同地震动强度下液化场地大直径变截面单桩的动力响应规律,基于振动台试验,选取5010波,在地震动强度0.10g~0.45g作用下,研究液化场地砂土孔压比和大直径变截面单桩桩顶水平位移、桩身弯矩、桩身加速度时程响应及桩基损伤等变化规... 为研究不同地震动强度下液化场地大直径变截面单桩的动力响应规律,基于振动台试验,选取5010波,在地震动强度0.10g~0.45g作用下,研究液化场地砂土孔压比和大直径变截面单桩桩顶水平位移、桩身弯矩、桩身加速度时程响应及桩基损伤等变化规律.试验结果表明:饱和砂土孔压比随着地震动强度的增大上升明显,地震动强度≥0.30g时,饱和砂土孔压比稳定值在0.9附近,此时砂土完全液化;在0.45g地震动强度作用下,桩身加速度、桩顶水平位移及桩身弯矩均达到最大;桩身不同位置处加速度峰值出现时刻均滞后于输入地震波加速度峰值出现时刻,且桩顶及变截面的加速度响应比桩端的响应更弱;不同地震动强度作用下,桩身弯矩最大值均出现在液化土层和非液化土层分界处,且变截面处弯矩小于土层分界面处;地震动强度达到0.30g时,大直径变截面单桩桩身发生损伤.因此,液化场地下大直径变截面桥梁单桩基础抗震设计时,应该重点考虑饱和砂土层分界处、变截面处的抗弯能力,以确保单桩桩身强度满足抗震要求. 展开更多
关键词 岩土工程 变截面单桩 液化场地 动力响应 振动台试验 抗震设计
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基于BP神经网络的高分辨率海底地形跨层生成模型 被引量:1
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作者 王振 张锡亭 王建华 《应用科技》 CAS 2024年第1期143-150,176,共9页
为了满足海底地形的高分辨率需求及解决测量数据的有限性问题,基于多层前馈神经网络(back propagation,BP)和跨层网格生成策略,建立了兼顾海底区域地形整体特征和局部地形信息的海底地形跨层生成模型,实现对海底地形数据生成填充。以南... 为了满足海底地形的高分辨率需求及解决测量数据的有限性问题,基于多层前馈神经网络(back propagation,BP)和跨层网格生成策略,建立了兼顾海底区域地形整体特征和局部地形信息的海底地形跨层生成模型,实现对海底地形数据生成填充。以南海海底地形为例,通过误差对比、假设检验以及海底地形云图的图像清晰度对本文模型生成数据进行有效性验证。结果显示所建立的模型在保证与原始数据之间误差小和数据特征相同的前提下完成了对地形云图的图像清晰度的提升,并且结果优于传统克里金插值方法。本文分析结果可为地形数据相关研究提供参考。 展开更多
关键词 高分辨率海底地形 跨层网格 BP神经网络 克里金插值 Mann-Whitney U检验 Levene检验 图像清晰度 误差
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一种基于函数依赖的跨合约模糊测试方案
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作者 张立强 路梦君 严飞 《信息网络安全》 CSCD 北大核心 2024年第7期1038-1049,共12页
随着区块链应用的快速发展和智能合约的广泛使用,由智能合约引发的安全事件急剧增多,导致基于区块链的数字资产产生了巨大损失。目前,虽然部分工具可以检测智能合约安全漏洞,但是它们主要针对单个智能合约进行检测,未考虑跨合约之间的... 随着区块链应用的快速发展和智能合约的广泛使用,由智能合约引发的安全事件急剧增多,导致基于区块链的数字资产产生了巨大损失。目前,虽然部分工具可以检测智能合约安全漏洞,但是它们主要针对单个智能合约进行检测,未考虑跨合约之间的交互依赖关系,因此会产生较多的误报。针对上述智能合约漏洞检测工具在跨合约场景下误报率较高和性能消耗过大的问题,文章提出一种基于函数依赖的跨合约模糊测试方案FIFuzz。该方案提出ContractRank算法进行合约间依赖关系建模,采用函数重要度来表征函数在合约间交互过程中的重要程度,并在后续模糊测试模块中加以利用。模糊测试通过基于函数重要度的交易序列生成策略和基于合约地址映射关系的地址类型数据生成策略来提高检测效率,缩减跨合约漏洞检测的搜索空间。另外,通过合约调用模拟来降低漏洞检测的假阳性率。与相关工具的对比实验表明,FIFuzz的漏洞检测时间相对其他工具缩短了80%,检测到的漏洞数量是其他工具的两倍,检测跨合约漏洞的准确率也明显高于其他工具。实验结果表明,FIFuzz能够有效提升跨合约漏洞的检测准确率,降低误报率,并减小时间开销。 展开更多
关键词 智能合约 模糊测试 跨合约漏洞
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Lung Function Impairment among Gasoline Attendants: A Cross-Sectional Study
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作者 Emmanuel Obazee Henry Aiwuyo +8 位作者 Anthony Kweki Tinuade Obazee Tinuade Obazee John Osarenkhoe Uche Agboje Beatrice Torere Nosakhare Ilerhunmwuwa Uchenna Amaechi Gabriel Alugba 《Open Journal of Ecology》 2023年第3期48-63,共16页
Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly ... Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries. 展开更多
关键词 Lung Function test Lung Impairment Lung Impairment Pattern Gasoline Attendants Occupational Hazards cross-Sectional Study
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NPR锚索对跨断层软岩大变形隧道控制技术研究
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作者 陶志刚 林伟军 +3 位作者 李勇 孙滢滢 熊弋文 陈明亮 《隧道建设(中英文)》 CSCD 北大核心 2024年第S01期113-123,共11页
为探究NPR锚索对东马场跨断层软岩大变形隧道控制效果,首先对NPR锚索进行静力拉伸试验,验证其恒阻大变形的能力和具有良好的抵御外力的效果;随后开展NPR锚索对东马场隧道围岩变形控制的三维物理模型试验。试验现象和数据表明:在开挖过程... 为探究NPR锚索对东马场跨断层软岩大变形隧道控制效果,首先对NPR锚索进行静力拉伸试验,验证其恒阻大变形的能力和具有良好的抵御外力的效果;随后开展NPR锚索对东马场隧道围岩变形控制的三维物理模型试验。试验现象和数据表明:在开挖过程中,隧道围岩也没有出现较大垮落和坍塌,NPR锚索对软岩隧道围岩有较好的支护效果。在加载完成后,NPR锚索对非断层处的隧道围岩最大位移约为14 mm,断层处的围岩最大位移约为21 mm,隧道区域所受应力分布的不规律性,导致隧道围岩出现挤压变形,位移曲线呈振荡状。在NPR锚索的支护下,围岩应力最大发生在左拱肩,围岩临空面3 cm处切应力最大(0.3 MPa),隧道未出现大规模的不对称破坏现象,隧道总体呈现出“小塌而不垮”,变形总体可控。 展开更多
关键词 断层隧道 软岩大变形 NPR锚索 物理模型试验
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Lung Function Impairment among Gasoline Attendants: A Cross-Sectional Study
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作者 Emmanuel Obazee Henry Aiwuyo +8 位作者 Anthony Kweki Tinuade Obazee Tinuade Obazee John Osarenkhoe Uche Agboje Beatrice Torere Nosakhare Ilerhunmwuwa Uchenna Amaechi Gabriel Alugba 《Open Journal of Respiratory Diseases》 2023年第3期48-63,共16页
Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly ... Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries. 展开更多
关键词 Lung Function test Lung Impairment Lung Impairment Pattern Gasoline Attendants Occupational Hazards cross-Sectional Study
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胀锁型锚索双向加固窄煤柱试验研究与工程应用
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作者 王军 吕顺章 +3 位作者 杨光 王波 谷长宛 王港 《矿业科学学报》 CSCD 北大核心 2024年第2期258-269,共12页
针对沿空掘巷窄煤柱非对称变形问题,提出了对穿锚索双向加固窄煤柱技术,设计了伸长型和胀锁型两种对穿锚索结构及工艺,开展了对穿锚索拉拔试验,试验表明两种锚索结构均满足抗拉要求,从锚索破坏形态、施工便捷性和材料经济性等方面对比分... 针对沿空掘巷窄煤柱非对称变形问题,提出了对穿锚索双向加固窄煤柱技术,设计了伸长型和胀锁型两种对穿锚索结构及工艺,开展了对穿锚索拉拔试验,试验表明两种锚索结构均满足抗拉要求,从锚索破坏形态、施工便捷性和材料经济性等方面对比分析,确定胀锁型对穿锚索为窄煤柱双向加固的首选。进一步通过相似模型试验与数值模拟研究了不同加固方式下煤柱承载变形规律和对穿锚索受力特征。结果表明:双排紧密型对穿锚索加固试件较未加固试件峰值荷载提高了96.04%,且随着锚索排数及数量的增加,窄煤柱双向加固稳定性越来越高,胀锁型对穿锚索提高了煤柱破坏前的能量储存量和临界破坏点。最后,在济宁三号煤矿123_(下)04工作面运输巷开展胀锁式对穿锚索加固窄煤柱工程试验,监测显示对穿锚索锚固力超过220 kN,锚索加固区煤柱帮鼓量降低70%,窄煤柱整体稳定性好,窄煤柱双向加固技术可行,为沿空掘巷工程提供了新技术途径。 展开更多
关键词 沿空掘巷 双向加固 窄煤柱 胀锁型对穿锚索 拉拔试验 承压性能
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地震-波浪联合作用下考虑冲刷效应的跨海斜拉桥振动台试验研究
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作者 李忠献 郑庆涛 +1 位作者 苏俊省 赵博 《土木工程学报》 EI CSCD 北大核心 2024年第10期71-81,共11页
针对跨海桥梁服役期内可能遭受地震、波浪以及冲刷效应影响的问题,开展地震与波浪联合作用下考虑冲刷效应的跨海斜拉桥振动台试验,研究地震与波浪联合作用下冲刷效应对斜拉桥动力特性及关键截面动力响应(加速度、位移和应变)的影响规律... 针对跨海桥梁服役期内可能遭受地震、波浪以及冲刷效应影响的问题,开展地震与波浪联合作用下考虑冲刷效应的跨海斜拉桥振动台试验,研究地震与波浪联合作用下冲刷效应对斜拉桥动力特性及关键截面动力响应(加速度、位移和应变)的影响规律。研究表明:随着冲刷深度的增加,斜拉桥自振频率逐渐降低;冲刷深度的增加,降低了桥塔桩基础侧向约束,引起地震与波浪联合作用下桩顶动力响应明显增大,且增幅比其他位置更为显著;边墩墩顶加速度和相对位移均大于辅助墩墩顶,桥墩抗震设计时,应采用不同配筋率和不同的截面尺寸对边墩和辅助墩开展差异化设计;考虑冲刷效应明显增大了地震与波浪联合作用下塔底、边墩和辅助墩墩底等关键截面的应变,相较于无冲刷工况,大冲刷工况下塔底、边墩及辅助墩墩底应变分别增加39%、36%和42%,抗震设计时应高度重视。 展开更多
关键词 跨海斜拉桥 振动台试验 地震-波浪联合作用 冲刷效应 动力响应
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输电铁塔装配式基础抗剪键连接的剪切性能
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作者 吕庆 胡嘉飞 +2 位作者 麻坚 华献宏 徐刚 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2024年第6期1153-1160,共8页
预制构件连接方法及其界面剪切性能影响整个输电铁塔装配式基础的受力和变形.针对螺栓连接易松动、变形大之类的问题,提出采用高强灌浆料灌注成形的十字形抗剪键作为输电铁塔装配式基础连接方案.采用室内剪切试验和数值模拟,研究该抗剪... 预制构件连接方法及其界面剪切性能影响整个输电铁塔装配式基础的受力和变形.针对螺栓连接易松动、变形大之类的问题,提出采用高强灌浆料灌注成形的十字形抗剪键作为输电铁塔装配式基础连接方案.采用室内剪切试验和数值模拟,研究该抗剪键连接的剪切性能,并与常用的螺栓连接进行对比分析.结果表明:十字形抗剪键剪切破坏模式为剪断型脆性破坏,破坏形态表现为以抗剪键为中心向外略有扩展成菱形.和螺栓连接相比,抗剪键连接的剪切强度略低,但剪切刚度显著提高.浇筑过程中灌浆料外溢对界面抗剪强度有提高作用.抗剪键的抗剪性能与灌浆料强度正相关,但提高灌浆料强度对抗剪性能提升并不明显.抗剪键深度对抗剪性能有影响,但在抗剪键深度超过20 mm后,抗剪键的抗剪性能不再提高.根据剪切试验和数值模拟结果,建议十字形抗剪键设计为长200 mm、宽20 mm、深20 mm. 展开更多
关键词 输电铁塔 装配式基础 十字形抗剪键 剪切性能 剪切试验
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10 kV配网耐张型复合绝缘横担研究综述
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作者 刘云鹏 李浩义 +4 位作者 周松松 唐力 李乐 宗强 张配斯 《华北电力大学学报(自然科学版)》 CAS 北大核心 2024年第5期21-34,共14页
复合绝缘横担具有轻质高强、绝缘可靠性高且防雷效果优异等特点,正逐步在10 kV配电线路中得到推广应用。围绕配网耐张型复合绝缘横担结构设计、耐久性研究及性能测试三个问题,首先综述10 kV配网耐张型复合绝缘横担的发展现状,指出研究... 复合绝缘横担具有轻质高强、绝缘可靠性高且防雷效果优异等特点,正逐步在10 kV配电线路中得到推广应用。围绕配网耐张型复合绝缘横担结构设计、耐久性研究及性能测试三个问题,首先综述10 kV配网耐张型复合绝缘横担的发展现状,指出研究必要性,进而针对其设计依据、现有设计型式、以疲劳振动老化为代表的耐久性研究进展及关键性能测试与评估展开论述,同时分析目前存在的问题及有待解决的困难,最后结合应用情况进行总结与展望,以期为配网耐张型复合绝缘横担的结构优化、性能提升以及后续大规模应用提供参考。 展开更多
关键词 复合绝缘横担 耐张结构 10 kV配网 疲劳振动老化 结构设计 性能测试
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抽蓄电站无压隧洞交叉区体型优化试验研究
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作者 田静 顾长宽 +1 位作者 郭汉驰 薛海 《水电能源科学》 北大核心 2024年第10期115-117,38,共4页
交叉无压隧洞交汇区域水流的水力特性复杂,无压隧洞交叉区体型及交汇口水流水力特性的研究对确保水利枢纽的安全运行具有重要的工程意义。基于物理模型试验,对某抽水蓄能电站下水库高落差泄洪排沙洞和放空洞交叉区体型进行优化,最终确... 交叉无压隧洞交汇区域水流的水力特性复杂,无压隧洞交叉区体型及交汇口水流水力特性的研究对确保水利枢纽的安全运行具有重要的工程意义。基于物理模型试验,对某抽水蓄能电站下水库高落差泄洪排沙洞和放空洞交叉区体型进行优化,最终确定圆弧连接+交叉角21°的交叉区体型。对比分析圆弧连接+交叉角21°的交叉区优化体型下特征试验工况的水力特性。结果表明,6种特征试验工况下,泄洪排沙洞和放空洞交叉口及下游均为急流,明流泄洪且流态较稳定,均在交汇口下游右边直墙处形成最大水深,水深低于直墙高度,满足水面线不宜超过直墙范围的要求。 展开更多
关键词 交叉无压隧洞 体型优化 交汇水流 抽水蓄能电站 模型试验
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