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Coseismic site response and slope instability using periodic boundary conditions in the material point method
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作者 Abdelrahman Alsardi Alba Yerro 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第3期641-658,共18页
This paper proposed the explicit generalized-a time scheme and periodic boundary conditions in the material point method(MPM)for the simulation of coseismic site response.The proposed boundary condition uses an intuit... This paper proposed the explicit generalized-a time scheme and periodic boundary conditions in the material point method(MPM)for the simulation of coseismic site response.The proposed boundary condition uses an intuitive particle-relocation algorithm ensuring material points always remain within the computational mesh.The explicit generalized-a time scheme was implemented in MPM to enable the damping of spurious high frequency oscillations.Firstly,the MPM was verified against finite element method(FEM).Secondly,ability of the MPM in capturing the analytical transfer function was investigated.Thirdly,a symmetric embankment was adopted to investigate the effects of ground motion arias intensity(I_(a)),geometry dimensions,and constitutive models.The results show that the larger the model size,the higher the crest runout and settlement for the same ground motion.When using a Mohr-Coulomb model,the crest runout increases with increasing I_(a).However,if the strain-softening law is activated,the results are less influenced by the ground motion.Finally,the MPM results were compared with the Newmark sliding block solution.The simplified analysis herein highlights the capabilities of MPM to capture the full deformation process for earthquake engineering applications,the importance of geometry characterization,and the selection of appropriate constitutive models when simulating coseismic site response and subsequent large deformations. 展开更多
关键词 Coseismic site response Periodic conditions Time integration Material point method(MPM)
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Quantitative Analysis of Seeing with Height and Time at Muztagh-Ata Site Based on ERA5 Database
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作者 Xiao-Qi Wu Cun-Ying Xiao +3 位作者 Ali Esamdin Jing Xu Ze-Wei Wang Luo Xiao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期87-95,共9页
Seeing is an important index to evaluate the quality of an astronomical site.To estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanal... Seeing is an important index to evaluate the quality of an astronomical site.To estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanalysis database(ERA5)is used.Seeing calculated from ERA5 is compared consistently with the Differential Image Motion Monitor seeing at the height of 12 m.Results show that seeing decays exponentially with height at the Muztagh-Ata site.Seeing decays the fastest in fall in 2021 and most slowly with height in summer.The seeing condition is better in fall than in summer.The median value of seeing at 12 m is 0.89 arcsec,the maximum value is1.21 arcsec in August and the minimum is 0.66 arcsec in October.The median value of seeing at 12 m is 0.72arcsec in the nighttime and 1.08 arcsec in the daytime.Seeing is a combination of annual and about biannual variations with the same phase as temperature and wind speed indicating that seeing variation with time is influenced by temperature and wind speed.The Richardson number Ri is used to analyze the atmospheric stability and the variations of seeing are consistent with Ri between layers.These quantitative results can provide an important reference for a telescopic observation strategy. 展开更多
关键词 site testing atmospheric effects methods:data analysis telescopes EARTH
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A new abdominal drainage tube fixation method for 3-port laparoscopic cholecystectomy improves patients’postoperative quality of life
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作者 Fenghua Zhang Lin Lin +2 位作者 Huan Zhang Jinghua Liu Rui Wang 《Laparoscopic, Endoscopic and Robotic Surgery》 2024年第3期107-112,共6页
Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention ... Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention from medical staff.The aim of this study was to explore the influence of a new abdominal drainage tube fixation method for 3-port laparoscopic cholecystectomy(LC)on patients’postoperative quality of life.Methods Patients who underwent 3-port LC with abdominal drainage tubes in the Department of Hepatobiliary Surgery of Linyi People’s Hospital from March 1,2023 to October 31,2023 due to gallstones with chronic cholecystitis were selected for this study.The patients were randomly divided into an experimental group and a control group.In the experimental group,the new abdominal drainage tube fixation method was used,while in the control group,the traditional method was used.Afterward,the quality of life of patient in terms of pain,activity,recovery time,and mental health status was evaluated.The exudate around the patient’s drainage tube was collected for bacterial culture and analysis.Results A total of 139 patients were randomly divided into an experimental group(70 patients)and a control group(69 patients).The patients’baseline characteristics were not significantly different.The patients in the experimental group had better outcomes in quality of life,with higher pain scores(24.03±2.37 vs.15.48±2.29,p<0.001)and activity scores(20.57±1.78 vs.14.13±1.43,p<0.001),and a shorter postoperative recovery time(2.36±0.68 d vs.2.96±1.34 d,p<0.001).The same results were shown in linear regression analysis scores of the 2 groups.The positive rate of bacterial culture in the exudate around the patient’s drainage tube in the experimental group was significantly lower than that in the control group(12.9%vs.43.5%,p<0.001);and furthermore,the positive rate of conditional pathogenic bacteria was even lower(7.1%vs.33.3%,p<0.001)in the experimental group than in the control group.Conclusion This new abdominal drainage tube fixation method can effectively promote patient rehabilitation and improve the quality of life for patient following 3-port LC with abdominal drainage tubes. 展开更多
关键词 Abdominal drainage tube Surgical site infection Quality of life Fixation method Laparoscopic cholecystectomy
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Preserving environmental quality of ecotourism sites through community participation in Purulia District of West Bengal,India
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作者 Piyall CHATTERJEE Soumyendra Kishore DATTA 《Regional Sustainability》 2024年第3期111-123,共13页
The importance of valuing environmental resources,especially in ecotourism sites,has become increasingly important over the last two decades.Ecotourism is now considered as an important source of livelihood of local s... The importance of valuing environmental resources,especially in ecotourism sites,has become increasingly important over the last two decades.Ecotourism is now considered as an important source of livelihood of local stakeholders in backward regions.Therefore,the preservation of ecotourism sites through community participation seems very important to maintain continued flow of tourists.This study aimed at recognizing the importance of community participation for the preservation of ecotourism sites.For this,this study executed a survey based on non-probability sampling in two ecotourism sites(Garpanchkot and Baranti)covering 100 respondents in Purulia District,West Bengal of India.The central issue of this study was to assess the tendency of community participation for the conservation of ecotourism sites and find the optimum condition for offering participatory labour time.This study showed that the participation of young people is high,and the majority of respondents are aware of the importance in protecting ecotourism sites.Because respondents were too poor to offer money,the contingent valuation method(CVM)was used to elicit their willingness to pay(WTP)participatory labour time for the conservation of ecotourism sites.Respondents’age,income,education level,caste,and their perceived environmental quality had significant relationship with their WTP participatory labour time by applying the ordinary least square(OLS)model.It was found that the mean WTP participatory labour time of each respondent in a month is approximately 3.64 h.The significance of this study is that community participation can improve the sense of belonging,trust,and credibility of ecotourism sites,making them more appreciative of the value and protection of these sites. 展开更多
关键词 Ecotourism site conservation Community participation Local stakeholders Willingness to pay Participatory labour time Ordinary least square(OLS)model Contingent valuation method(CVM)
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A method to obtain the wind field characteristics of super-large aperture radio telescope site based on single-point wind tower and numerical simulation 被引量:4
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作者 Fei-Long He Qian Xu +1 位作者 Na Wang Chun-Hua Zhu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2020年第12期270-278,共9页
The influence of wind on the pointing accuracy of large aperture radio telescopes is becoming increasingly serious, especially at high observing frequency. Obtaining the wind field characteristics efficiently is very ... The influence of wind on the pointing accuracy of large aperture radio telescopes is becoming increasingly serious, especially at high observing frequency. Obtaining the wind field characteristics efficiently is very important to reduce the wind disturbance on antenna structure. In this paper, an error evaluation of numerical simulation method is established based on the measured data of single point wind tower, and the wind field characteristics are obtained from the evaluated numerical simulation results combined with the measured data for the 110 m aperture Qi Tai radio Telescope(QTT) site. According to the simulation results, compared with the measured data, the root mean square error(RMSE) of wind speed is less than 1 m s^-1, and the minimum wind speed RMSE is 0.2 m s^-1. An analysis of the wind field characteristics of the QTT site suggests that the active wind resistance design of the antenna periphery should focus on the SSW(south-south-west) direction. 展开更多
关键词 telescopes site testing methods:data analysis
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Introducing an effective coherence function to generate non-uniform ground motion on topographic site using time-domain boundary element method 被引量:3
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作者 Mohsen Isari Reza Tarinejad 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第1期89-100,共12页
In this study,a comprehensive parametric analysis was performed on non-uniform excitation of V-shaped topography using the boundary element method in time domain.For this purpose,wave scattering analysis was carried o... In this study,a comprehensive parametric analysis was performed on non-uniform excitation of V-shaped topography using the boundary element method in time domain.For this purpose,wave scattering analysis was carried out on a topography subjected to the SV-wave for different predominant frequencies and shape ratios.Based on the numerical results,new coherence and time delay functions are proposed to generate non-uniform ground motion for topographic irregularities.The efficiency and accuracy of the proposed functions for real engineering problems are indicated by comparison with observations reported in previous literature. 展开更多
关键词 site effect time delay boundary element method AMPLIFICATION coherence function
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Optimizing the atmospheric sampling sites using fuzzy mathe-matic methods
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作者 FANG Chun sheng WANG Ju +1 位作者 DONG De ming YU Lian sheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第4期464-468,共5页
A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental samp... A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental sampling sites. According to its basis, an application in the optimization of sampling sites in the atmospheric environmental monitoring was discussed. The method was proven to be suitable and effective. The results were admitted and applied by the Environmental Protection Bureau (EPB) of many cities of China. A set of computer software of this approach was also completely compiled and used. 展开更多
关键词 fuzzy set primary matrix element theorem fisher classification method optimization of sampling sites
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The Measurement and Uncertainty Analysis of Antenna Factor of Microwave Antennas Based on Standard Site Method
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作者 Chaochan Chen Hong Shi +1 位作者 Yi Miao Yu Sang 《International Journal of Communications, Network and System Sciences》 2017年第5期138-145,共8页
A method of Standard Site Method (SSM) in the American National Standards Institute’s ANSI C63.5 is described in the frequency ranges from 30 MHz to 1000 MHz. And a measurement system is set up for determining antenn... A method of Standard Site Method (SSM) in the American National Standards Institute’s ANSI C63.5 is described in the frequency ranges from 30 MHz to 1000 MHz. And a measurement system is set up for determining antenna factors (AF) of antennas on an Open Area Test Sites (OATS). AF of antennas including log-periodic antenna and biconical antenna is measured with SSM method by Shanghai Institute of Measurement and Testing Technology (SIMT), which shows good agreement to data measured by National Institute of Metrology (NIM). In the end, it analyzes the measurement uncertainty of SIMT in the 30 MHz to 1000 MHz frequency band and does comparison to that of NIM. 展开更多
关键词 ANTENNA FACTORS Standard site method (SSM) MEASUREMENT UNCERTAINTY
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Tip-Nanoparticle Near-Field Coupling in Scanning Near-Field Microscopy by Coupled Dipole Method
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作者 Yi Ruan Kan Li +1 位作者 Qiang Lin Ting Zhang 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第4期42-45,共4页
We use the couple dipole method to investigate the scanning near-field optical microscopy metallic tip-nanoparticle near-field interaction. Dependences of the local field intensity inside the nanoparticle on the nanos... We use the couple dipole method to investigate the scanning near-field optical microscopy metallic tip-nanoparticle near-field interaction. Dependences of the local field intensity inside the nanoparticle on the nanosized tip shape,the tip open angle and the illumination angle are revealed. In combination with the previous results, we establish a complete model to understand the tip-nanoparticle near-field coupling mechanism. 展开更多
关键词 Tip-Nanoparticle near-field Coupling in Scanning near-field Microscopy by Coupled Dipole method
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Landfill Site Selection Using GIS and Multi-Criteria Decision-Making AHP and SAW Methods: A Case Study in Sulaimaniyah Governorate, Iraq
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作者 Karwan Alkaradaghi Salahalddin S. Ali +1 位作者 Nadhir Al-Ansari Jan Laue 《Engineering(科研)》 2020年第4期254-268,共15页
Lack of land for waste disposal is one of the main problems facing urban areas in developing countries. The Sulaimaniyah Governorate, located in northern Iraq, is one of the main cities of the country in the Kurdistan... Lack of land for waste disposal is one of the main problems facing urban areas in developing countries. The Sulaimaniyah Governorate, located in northern Iraq, is one of the main cities of the country in the Kurdistan Region, covering an area of 2400 km2. Currently, there is no landfill site in the study region that meets scientific and environmental requirements, inappropriate dumping of solid waste causes adverse effects on the environment, economic and urban aesthetic. To overcome with this phenomenon, it is very crucial to suggest a landfill site, even in countries that recycle or burn their waste to protect the environment. Landfill sites should be carefully selected by considering all regulations and other restrictions. The integration of geographic information systems and multi-criteria decision analysis is used in this study to select suitable landfill locations in the region, for this purpose, thirteen layers are prepared according to their importance including urban area, villages, rivers, groundwater depth, slope, elevation, soil types, geological formations, roads, oil and gas field, land use classification, archaeological site and power lines. Two different methods (simple additive weighting and analytic hierarchy process) are implemented in a geographical information system to obtain the suitability index map for candidate landfill sites, where all these sites satisfied the scientific and environmental criteria which were adopted in this study. The comparison of the maps resulting from these two different methods demonstrates that both methods produced consistent results. 展开更多
关键词 LANDFILL site Criteria WEIGHTS GIS Software ANALYTIC Hierarchy Process (AHP) Simple Additive Weighting (SAW) method
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Estimation of Site Effects on Stations in the Capital Circle Region Using the Generalized Inversion Method
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作者 Shi Haixia Xiu Jigang +2 位作者 Chen Zhangli Wang Qincai Hua Wei 《Earthquake Research in China》 2010年第2期198-210,共13页
Generalized Inversion Method has been used to estimate the spatial variation of site effects,using the digital data of SH-waves recorded by 63 stations in the Capital Circle Region of China from 2001 to 2006.We gained... Generalized Inversion Method has been used to estimate the spatial variation of site effects,using the digital data of SH-waves recorded by 63 stations in the Capital Circle Region of China from 2001 to 2006.We gained the site effects of all stations participating in the calculation.We found that the site effect of rock was stabile and about 1.0 from 1.0Hz to 10.0Hz,while the site effect of deposit was high in low frequencies,about 3 ~ 7 from 1.0Hz to 8.0Hz,and the site effect was protuberant at about 5.0Hz,then fell as the frequency increased.The result shows the shape and intensity of station site effects are mainly influenced by the lithology below the station,and possibly also by the local geological structure. 展开更多
关键词 Capital Circle Region site effects Generalized inversion method SH-wave Weighting factor
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Application of high-density resistivity method in archaeological investigation of Sumicheng ancient city site
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作者 XIN Zhonghua HAN Jiangtao +2 位作者 WANG Zhigang LIU Lijia LI Zhuoyang 《Global Geology》 2021年第1期58-63,共6页
The authors employ the high-density resistivity method during an archaeological investigation of Sumicheng site,an ancient city of the Tang Dynasty,to find evidence of human activities and locate a favorable target fo... The authors employ the high-density resistivity method during an archaeological investigation of Sumicheng site,an ancient city of the Tang Dynasty,to find evidence of human activities and locate a favorable target for archaeological excavation in the southern part of the outer city.There are two obvious high-resistivity structures,the south wall of the inner city and an ancient building near the south gate along the outer city wall,of which the resistivities are indicative of rammed soil foundations.The south wall of the inner city is continuous but is cut off abruptly to the east,which we suggest it is due to either wall damage or destruction.The resistivity signature of the target area is verified by archaeological excavation,proving the feasibility and effectiveness of implementing the high-density resistivity method for archaeological exploration. 展开更多
关键词 Sumicheng ancient city site high-density resistivity method archaeological exploration electrical resistivity structure
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The AIMS Site Survey
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作者 Xing-Ming Bao Jian Wang +2 位作者 Shuai Jing Yuan-Yong Deng Dong-Guang Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第11期14-24,共11页
This paper reports site survey results for the Infrared System for the Accurate Measurement of Solar Magnetic Field, especially in Saishiteng Mountain, Qinghai, China. Since 2017, we have installed a weather station,s... This paper reports site survey results for the Infrared System for the Accurate Measurement of Solar Magnetic Field, especially in Saishiteng Mountain, Qinghai, China. Since 2017, we have installed a weather station,spectrometers for precipitable water vapor, and Solar Differential Image Motion Monitor, and have carried out observations on weather elements, precipitable water vapor, and daytime seeing conditions for more than one year in almost all candidates. At Mt. Saishiteng, the median value of daytime precipitable water vapor is 5.25 mm and its median value in winter season is 2.1 mm. The median value of the Fried parameter of daytime seeing observation at Saishiteng Mountain is 3.42 cm. Its solar direct radiation data show that solar average observable time is 446 minutes per day and premium time is 401 minutes per day in 2019 August. 展开更多
关键词 site testing atmospheric effects methods:analytical
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考虑淹没区域危险度的溃坝洪灾避难场所选址评价
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作者 李宗坤 张开楷 +3 位作者 葛巍 朱俊宇 焦余铁 张亚东 《郑州大学学报(工学版)》 CAS 北大核心 2024年第6期1-8,共8页
针对溃坝洪灾避难场所选址中对潜在淹没区域危险程度重视不足的问题,提出了一种新的溃坝洪灾避难场所选址评价模型。首先,在构建危险度评价指标体系的基础上,运用改进突变评价法对潜在淹没区域进行危险度评价和危险等级划分;其次,将避... 针对溃坝洪灾避难场所选址中对潜在淹没区域危险程度重视不足的问题,提出了一种新的溃坝洪灾避难场所选址评价模型。首先,在构建危险度评价指标体系的基础上,运用改进突变评价法对潜在淹没区域进行危险度评价和危险等级划分;其次,将避难场所与高级别危险区的距离作为选址评价指标,并考虑避难场所的灾害风险、位置规模、应急保障等条件,通过层次分析法确定权重,运用TOPSIS法对避难场所进行选址评价;最后,以我国陆浑水库下游13个潜在淹没区域和10个备选避难场所为例进行验证。结果表明:危险等级较高的潜在淹没区域中,白元镇为Ⅰ级危险区,彭婆镇、鸣皋镇、城关街道、龙门镇为Ⅱ级危险区,评价较优的备选避难场所能够满足重视高危险度潜在淹没区域的要求。 展开更多
关键词 溃坝洪水 避难场所 危险度 选址 TOPSIS法
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全脑血管造影术后即刻采用轴线翻身法的临床效果
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作者 王宁 王君 +2 位作者 于英男 王瑜 边洋 《中国医药导报》 CAS 2024年第17期75-77,81,共4页
目的 探讨全脑血管造影术后即刻采用轴线翻身法对患者穿刺点出血情况、腰背部疼痛及满意度的影响。方法 选取2021年6月至2022年6月解放军总医院第一医学中心神经内科医学部收治的236例行全脑血管造影术患者为研究对象,按照随机数字表法... 目的 探讨全脑血管造影术后即刻采用轴线翻身法对患者穿刺点出血情况、腰背部疼痛及满意度的影响。方法 选取2021年6月至2022年6月解放军总医院第一医学中心神经内科医学部收治的236例行全脑血管造影术患者为研究对象,按照随机数字表法将其分为对照组和观察组,每组118例。对照组术后采用常规护理,平卧6 h后进行轴线翻身;观察组术后即刻采用轴线翻身法翻身。比较两组穿刺点出血情况、腰背部疼痛程度及满意度。结果 两组穿刺点皮下血肿、少量渗血、明显出血发生率比较,差异无统计学意义(P>0.05)。观察组腰背部视觉模拟评分法评分低于对照组,满意度高于对照组,差异有统计学意义(P<0.05)。结论 全脑血管造影术后即刻采用轴线翻身法,可降低患者腰背部疼痛程度,改善术后舒适度,提高满意度,且即刻轴线翻身法并不增加穿刺点出血发生率。 展开更多
关键词 全脑血管造影术 轴线翻身法 穿刺点出血
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良渚古城老虎岭水坝遗址考古剖面保护研究与工程实践
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作者 张秉坚 孙海波 郭青林 《文物保护与考古科学》 北大核心 2024年第3期143-151,共9页
良渚古城老虎岭水坝遗址是我国迄今发现最早的大型水利工程系统中的一处典型遗存,对中国文明起源和世界文明史的研究具有重要意义。为清晰地展示老虎岭水坝土遗址上“草裹泥”筑坝工艺的痕迹,针对温热、潮湿、多雨环境土遗址保护的难题... 良渚古城老虎岭水坝遗址是我国迄今发现最早的大型水利工程系统中的一处典型遗存,对中国文明起源和世界文明史的研究具有重要意义。为清晰地展示老虎岭水坝土遗址上“草裹泥”筑坝工艺的痕迹,针对温热、潮湿、多雨环境土遗址保护的难题,在总结吸取国内土遗址保护经验教训的基础上,借助浙江大学的研究成果和敦煌研究院的工程经验,提出了一套避免使用化学材料加固,而以“黑屋+隔水+控湿”为主的小环境控制工程策略,包括:构建遮光大棚以避雨和抑制绿色生物生长;铺设防水毯以防止坝体渗水;设置电加热玻璃罩以保湿和封闭展示面;采用气相补水以调控空气湿度和土体含水率;采用植物精油等绿色环保技术防治微生物;同时做好遗址实时监测和管护等。这套综合保护措施是土遗址保护理念和工程实践的一次新的尝试。 展开更多
关键词 潮湿环境土遗址 湿法保护 小环境控制 考古剖面 老虎岭水坝遗址 良渚古城
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三级综合医院紧密型多院区手术部位感染防控管理指标体系构建研究
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作者 李丽 谢多双 +4 位作者 彭民金 胡荍 来瑞平 孟昆 唐以军 《中国医院》 北大核心 2024年第7期47-49,共3页
目的:以系统管理理论为指导,采用德尔菲专家咨询法构建三级综合医院紧密型多院区手术部位感染防控管理指标体系,旨在通过探索与实践,将该指标体系推广至其他同类型医院,成为手术部位感染防控部门参照执行的管理范本。方法:通过检索文献... 目的:以系统管理理论为指导,采用德尔菲专家咨询法构建三级综合医院紧密型多院区手术部位感染防控管理指标体系,旨在通过探索与实践,将该指标体系推广至其他同类型医院,成为手术部位感染防控部门参照执行的管理范本。方法:通过检索文献、专家小组讨论形成指标体系框架,将咨询问卷发放给20位专家,进行两轮咨询,最终构建出多院区手术部位感染防控管理指标体系。结果:两轮专家咨询的积极系数均为100%,权威系数为0.93,协调系数均值第一轮为0.07、第二轮为0.32。根据得分情况及专家修改意见,最终形成6个一级指标、20个二级指标和53个三级指标。结论:本研究咨询的专家具有较高的积极性和较好的代表性,且协调性逐步提高,拟定了一套三级综合医院紧密型多院区手术部位感染防控管理指标,为同类型医院手术部位感控防控管理提供了参考依据。 展开更多
关键词 德尔菲法 多院区 手术部位 感染防控 管理指标
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物联网国家标准验证点建设研究
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作者 杨宏 王晓春 +1 位作者 苏静茹 卓兰 《中国标准化》 2024年第14期53-57,共5页
本文梳理了国家标准化主管部门在标准验证方面的政策部署和批准标准验证点建设的举措,总结了在行业主管部门的推动下,物联网技术、产业、标准发展的情况。介绍了物联网标准验证的基础以及取得的成效,分析了物联网标准验证的重点、难点... 本文梳理了国家标准化主管部门在标准验证方面的政策部署和批准标准验证点建设的举措,总结了在行业主管部门的推动下,物联网技术、产业、标准发展的情况。介绍了物联网标准验证的基础以及取得的成效,分析了物联网标准验证的重点、难点以及物联网标准验证点建设思路、技术路线,提出了物联网标准验证方法。本文提出的标准验证点建设思路以及标准全生命周期验证方法,对于其他类似领域的标准验证工作开展、标准验证点建设将具有参考价值和借鉴意义。 展开更多
关键词 国家标准验证点 标准验证方法 物联网 国家标准
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基于离散单元法的石峁遗址东门城墙稳定性及加固方法研究
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作者 秦立科 韦坤 +5 位作者 王磊 庞磊 王霁竹 毛迪 李婉茹 陈立杰 《文物保护与考古科学》 北大核心 2024年第4期1-12,共12页
石峁遗址外城东门城墙出现了严重的外倾变形,面临倒塌风险,为对其进行科学保护,进行了城墙稳定性及加固方法的研究。提出风化折减系数表征灰缝的风化程度,利用离散单元法建立城墙模型,并验证其有效性,通过强度折减法研究在风化作用下城... 石峁遗址外城东门城墙出现了严重的外倾变形,面临倒塌风险,为对其进行科学保护,进行了城墙稳定性及加固方法的研究。提出风化折减系数表征灰缝的风化程度,利用离散单元法建立城墙模型,并验证其有效性,通过强度折减法研究在风化作用下城墙的变形及稳定性,通过反演分析法确定城墙的风化程度和灰缝的力学参数。研究结果表明:灰缝强度降低是城墙变形失稳的主要原因;在土压力作用下,城墙破坏呈滑移-倾覆模式;城墙目前处于欠稳定状态,风化系数为0.45~0.48,灰缝强度粘聚力和内摩擦角分别为21 kPa和14°。在此基础上,提出了灰缝灌浆和外侧支撑两种加固方法并进行了比选,最终加固取得了良好的效果。研究结果可为石峁城墙的后续的加固保护提供借鉴和参考。 展开更多
关键词 石峁遗址 城墙 离散元法 强度折减法 稳定性 风化
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盐益智仁-盐小茴香药对止泻活性部位筛选及“谱效”关系研究
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作者 李红伟 徐若颖 +4 位作者 周宁 曹彦刚 田连起 石延榜 李凯 《中国比较医学杂志》 CAS 北大核心 2024年第7期48-59,共12页
目的筛选盐益智仁-盐小茴香药对(YZYH)止泻活性部位,并通过“谱效”关系研究推测其药效物质基础和质量标志物。方法制备大鼠脾肾阳虚泄泻模型,测定盐益智仁-盐小茴香药对石油醚(YZYH⁃L)、乙酸乙酯(YZYH⁃M)、水(YZYH⁃H)3部位药效指标,包... 目的筛选盐益智仁-盐小茴香药对(YZYH)止泻活性部位,并通过“谱效”关系研究推测其药效物质基础和质量标志物。方法制备大鼠脾肾阳虚泄泻模型,测定盐益智仁-盐小茴香药对石油醚(YZYH⁃L)、乙酸乙酯(YZYH⁃M)、水(YZYH⁃H)3部位药效指标,包括体重、肛温、腹泻潜伏期(diarrhea incubation period,DIP)、腹泻指数(diarrheal index,DI)等行为学指标及一氧化氮合成酶(nitric oxide synthetase,NOS)、环磷酸鸟苷(cyclic guanosine monophosphate,cGMP)、磷酸肌酸激酶(creatine phosphate kinase,CPK)等生化指标;建立不同部位高效液相色谱(high performance liquid chromatography,HPLC)图谱,采用灰色关联法分析各部位化学成分与止泻药效指标间的“谱效”关系。结果与空白对照组大鼠相比,15 d后,模型组大鼠出现泄泻证主症关键病理指标—水样便,同时,伴随食后腹胀、食欲不振和弓背等脾阳和肾阳虚泄泻的次症典型特征;给与治疗药物后,泄泻主症和次症均有不同程度的改善,其中阳性药、YZYH⁃M部位第28天后泄泻模型大鼠关键指标DIP极显著延长(P<0.01)、DI极显著降低(P<0.01),以及脾、肾阳虚泄泻的次症典型特征代表性指标体重、24 h摄食、饮水量、肛温和血清生化指标NOS、cGMP、CPK等活性的调节作用均较其它给药组好;“谱效”关系研究表明茴香醛、4号色谱峰等成分与DIP、DI、NOS、cGMP、CPK 5个药效指标的关联度重要。结论YZYH⁃M部位为药对止泻活性部位,其作用机制与抑制胃肠功能亢进和调节机体能量代谢与免疫相关;茴香醛及4号峰作为药对的质量标志物。 展开更多
关键词 盐益智仁-盐小茴香药对 止泻作用 活性部位 “谱效”关系 灰色关联法 茴香醛
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