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The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 269-278 doi: 10.1007/s11783-014-0672-y

摘要： Soil moisture variability in natural landscapes has been widely studied; however, less attention has been paid to its variability in the urban landscapes with respect to the possible influence of texture stratification and irrigation management. Therefore, a case study was carried out in the Beijing Olympic Forest Park to continuously monitor the soil in three typical profiles from 26 April to 11 November 2010. The texture stratification significantly affected the vertical distribution of moisture in the non-irrigated profile where moisture was mostly below field capacity. In the profile where irrigation was sufficient to maintain moisture above field capacity, gravity flow led to increased moisture with depth and thus eliminated the influence of texture. In the non-irrigated sites, the upper layer (above 80 cm) exhibited long-term moisture persistence with the time scale approximating the average rainfall interval. However, a coarse-textured layer weakened the influence of rainfall, and a fine-textured layer weakened the influence of evapotranspiration, both of which resulted in random noise-like moisture series in the deeper layers. At the irrigated site, frequent irrigation neutralized the influence of evapotranspiration in the upper layer (above 60 cm) and overshadowed the influence of rainfall in the deeper layer. As a result, the moisture level in the upper layer also behaved as a random noise-like series; whereas due to deep transpiration, the moisture of the deep layer had a persistence time-scale longer than a month, consistent with characteristic time-scales found for deep transpiration.

关键词： moisture vertical distribution     moisture temporal variation     texture stratification     irrigation     meteorological forcing     urban landscape    

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Removal, distribution and plant uptake of perfluorooctane sulfonate (PFOS) in a simulated constructed

Weichuan Qiao, Rong Li, Tianhao Tang, Achuo Anitta Zuh

《环境科学与工程前沿（英文）》 2021年 第15卷 第2期 doi: 10.1007/s11783-020-1312-3

摘要： Abstract • PFOS was removed by soil adsorption and plant uptake in the VFCW. • Uptake of PFOS by E. crassipes was more than that of C. alternifolius. • PFOS in wastewater can inhibit the removal of nutrients. • Dosing with PFOS changed the soil microbial community in the VFCW. A vertical-flow constructed wetland (VFCW) was used to treat simulated domestic sewage containing perfluorooctane sulfonate (PFOS). The removal rate of PFOS in the domestic sewage was 93%–98%, through soil adsorption and plant uptake, suggesting that VFCWs can remove PFOS efficiently from wastewater. The removal of PFOS in the VFCW was dependent on soil adsorption and plant uptake; moreover, the percentage of soil adsorption was 61%–89%, and was higher than that of the plants uptake (5%–31%). The absorption capacity of Eichhornia crassipes (E. crassipes) (1186.71 mg/kg) was higher than that of Cyperus alternifolius (C. alternifolius) (162.77 mg/kg) under 10 mg/L PFOS, and the transfer factor of PFOS in E. crassipes and C. alternifolius was 0.04 and 0.58, respectively, indicating that PFOS is not easily translocated to leaves from roots of wetland plants; moreover, uptake of PFOS by E. crassipes was more than that of C. alternifolius because the biomass of E. crassipes was more than that of C. alternifolius and the roots of E. crassipes can take up PFOS directly from wastewater while C. alternifolius needs to do so via its roots in the soil. The concentration of 10 mg/L PFOS had an obvious inhibitory effect on the removal rate of total nitrogen, total phosphorus, chemical oxygen demand, and ammonia nitrogen in the VFCW, which decreased by 15%, 10%, 10% and 12%, respectively. Dosing with PFOS in the wastewater reduced the bacterial richness but increased the diversity in soil because PFOS stimulated the growth of PFOS-tolerant strains.

关键词： Vertical-flow constructed wetland     Perfluorooctane sulfonate     Wetland plants     Soil microbial community     Effect     Speciality: Wetlands     Transformation     Organic pollutants     Phytoremediation     Exposure assessment     Sewage    

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Effects of sucrose crystallization and moisture migration on the structural changes of a coated intermediatemoisture food

Tiancheng LI, Peng ZHOU, Theodore P. LABUZA

《化学科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 346-350 doi: 10.1007/s11705-009-0256-8

摘要： The purpose of this study was to investigate whether moisture migration and sugar crystallization play an important role in the changes of IMF matrix structure. The migration of water was monitored with changes of water activity in different physical domains of samples during storage, while the crystallization of sucrose was determined with X-ray powder diffraction (XRD). The formation of both a hard inner-layer and agglomerated particles in the inner matrix was observed during storage. Our results suggested that both moisture loss and sucrose crystallization were mainly responsible for the formation of the crusty intermediate inner layer, and the agglomerated matrix particles were the result of sucrose crystallization.

关键词： inner-layer     agglomerated     IMF     moisture migration     crystallization    

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Organophosphate esters in sediment from Taihu Lake, China: Bridging the gap between riverine sources and lake sinks

《环境科学与工程前沿（英文）》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1464-9

摘要：

• Eleven OPEs were detected in river sediment and lake sediment in Taihu Lake.

关键词： Organophosphate esters     Partition     Vertical distribution     Composition profile     Positive matrix factorization    

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Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

Jie HAN,Harihar Shiwakoti

《结构与土木工程前沿（英文）》 2016年 第10卷 第1期   页码 30-43 doi: 10.1007/s11709-016-0318-1

摘要： Existing test methods to determine moisture sensitivity in hot-mix asphalt (HMA) mixtures are time consuming and inconsistent. This research focused on wheel tracking devices to evaluate moisture sensitivity. The Asphalt Pavement Analyzer (APA) and the Hamburg Wheel Tracking Device (HWTD) were used for this research. Compacted cylindrical samples were fabricated using a Superpave Gyratory compactor. This study selected two most commonly used mixtures, SM-12.5A with PG 64-22 binder in overlay projects and SM-19A mixtures with PG 64-22 binder for major modification projects at Kansas Department of Transportation. Test results show that APA tests could induce stripping in most samples without any anti-stripping agent, which could be identified visually. However, APA results did not indicate any stripping inflection point while the HWTD results showed stripping inflection points, which are important to identify stripping potential of mixtures. The APA results show that wet tests are severe at lower temperatures. The HWTD results show improvement in the performance using anti-stripping agents at later stage. The HWTD test is more effective as a rapid test method in case of determining moisture sensitivity. Laboratory results from this study should be verified and correlated with field performance.

关键词： hot-mix asphalt     moisture sensitivity     rutting     wheel tracking test    

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Solvates and polymorphs of clindamycin phosphate: Structural, thermal stability and moisture stability

Junbo Gong, Dejiang Zhang, Yuanyuan Ran, Keke Zhang, Shichao Du

《化学科学与工程前沿（英文）》 2017年 第11卷 第2期   页码 220-230 doi: 10.1007/s11705-017-1624-4

摘要： Clindamycin phosphate (CP), an antibacterial agent, has been reported to form several solid-state forms. The crystal structures of two CP solvates, a dimethyl sulfoxide (DMSO) solvate and a methanol/water solvate (solvate V), have been determined by single crystal X-ray diffraction. The properties and transformations of these forms were characterized by powder X-ray diffraction, Single-crystal X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, hot-stage microscopy, and dynamic vapor sorption. Very different hydrogen bonding networks exist among the host-host and host-solvent molecules in the two crystal structures, resulting in different moisture stabilities. The thermal stabilities of the two solvates upon heating and desolvation were also studied. When the temperature was above the boiling point of methanol, solvate V converted to a polymorphic phase after a one step desolvation process, whereas the desolvation temperature of the DMSO solvate was below the boiling point of DMSO. At the relative humidity above 43%, the DMSO solvate transformed to a hydrate at 25 °C. In contrast, solvate V did not transform at any of the humidities studied.

关键词： clindamycin phosphate     solvate     crystal structure     thermal stability     moisture stability    

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Modeling temperature and moisture dependent emissions of carbon dioxide and methane from drying dairy

Enzhu HU, Pakorn SUTITARNNONTR, Markus TULLER, Scott B. JONES

《农业科学与工程前沿（英文）》 2018年 第5卷 第2期   页码 280-286 doi: 10.15302/J-FASE-2018215

摘要： Greenhouse gas emissions due to biological degradation processes of animal wastes are significant sources of air pollution from agricultural areas. The major environmental controls on these microbe-induced gas fluxes are temperature and moisture content. The objective of this study was to model the effects of temperature and moisture content on emissions of CO and CH during the ambient drying process of dairy manure under controlled conditions. Gas emissions were continuously recorded over 15 d with paired fully automated closed dynamic chambers coupled with a Fourier Transformed Infrared gas analyzer. Water content and temperature were measured and monitored with capacitance sensors. In addition, on days 0, 3, 6, 9, 12 and 15, pH, moisture content, dissolved organic carbon and total carbon (TC) were determined. An empirical model derived from the Arrhenius equation confirmed high dependency of carbon emissions on temperature and moisture content. Results indicate that for the investigated dairy manure, 6.83% of TC was lost in the form of CO and 0.047% of TC was emitted as CH . Neglecting the effect of temperature, the moisture contents associated with maximum gas emissions were estimated as 0.75 and 0.79 g·g for CO and CH , respectively.

关键词： carbon dioxide     dairy manure     methane     moisture     temperature    

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高温合金压气机盘锻件纵断面中铌分布的原位统计分布分析表征

王海舟,李美玲,庄景云

《中国工程科学》 2011年 第13卷 第10期   页码 19-27

摘要：

采用原位统计分布分析表征技术系统研究了GH169高温合金压气机盘纵断面不同部位铌分布的规律。以所得到的与样品原位置相对应的数以万计原始信号系统解析为基础，进而获得压气机盘锻件的纵断面不同部位铌的定量统计分布信息以及加工工艺过程中铌的迁移规律。准确计算判定了盘纵断面不同部位铌的最大偏析度，提出了95 %置信度时中位值置信扩展率,即统计偏析度（S）新参数，用以表征铌在压气机盘中分布的均匀度；提出了所有数据在特定含量区间（C0±R）的频度（权重）比率，即统计符合度（F）新参数，用以表征预设质量控制区间铌含量的一致性的概率。采用原位统计分布分析的表征方法，准确定量地评定了高温合金压气机盘件纵断面不同部位铌的分布均匀度和符合度，为加工后盘件的质量控制评估提供了参考。

关键词： 原位统计分布分析表征技术     高温合金压气机盘     铌     统计偏析度     统计符合度     质量控制    

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Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns

Hiruy ABDU, David A. ROBINSON, Janis BOETTINGER, Scott B. JONES

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 135-145 doi: 10.15302/J-FASE-2017143

摘要： Knowledge of the spatial distribution of soil textural properties is important for determining soil moisture storage and soil hydraulic transport properties. Capturing field heterogeneity without exhaustive sampling and costly sample analysis is difficult. Our objective was to employ electromagnetic induction (EMI) mapping in low apparent electrical conductivity (EC ) soils at varying soil water contents to capture time invariant properties such as soil texture. Georeferenced EC measurements were taken using a ground conductivity meter on six different days where volumetric water content ( ) varied from 0.11 to 0.23. The 50 m × 50 m field included a subsurface gravelly patch in an otherwise homogeneous silt-loam alluvial soil. Ordinary block kriging predicted EC at unsampled areas to produce 1-m resolution maps. Temporal stability analysis was used to divide the field into three distinct EC regions. Subsequent ground-truthing confirmed the lowest conductivity region correlated with coarse textured soil parent materials associated with a former high-energy alluvial depositional area. Combining maps using temporal stability analysis gives the clearest image of the textural difference. These maps could be informative for modeling, experimental design, sensor placement and targeted zone management strategies in soil science, ecology, hydrology, and agricultural applications.

关键词： soil electrical conductivity     soil texture mapping     temporal stability analysis    

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Reliability analysis of the control system of large-scale vertical mixing equipment

YANG Mingjin, LI Xiwen, LI Shaoping, YANG Shuzi

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 133-138 doi: 10.1007/s11465-008-0037-y

摘要： The control system of vertical mixing equipment is a concentrate distributed monitoring system (CDMS). A reliability analysis model was built and its analysis was conducted based on reliability modeling theories such as the graph theory, Markov process, and redundancy theory. Analysis and operational results show that the control system can meet all technical requirements for high energy composite solid propellant manufacturing. The reliability performance of the control system can be considerably improved by adopting a control strategy combined with the hot spared redundancy of the primary system and the cold spared redundancy of the emergent one. The reliability performance of the control system can be also improved by adopting the redundancy strategy or improving the quality of each component and cable of the system.

关键词： composite     redundancy     monitoring     vertical     technical    

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Performance of vertical axis water turbine with eye-shaped baffle for pico hydropower

Zhuohuan HU, Dongcheng WANG, Wei LU, Jian CHEN, Yuwen ZHANG

《能源前沿（英文）》 2022年 第16卷 第4期   页码 683-696 doi: 10.1007/s11708-020-0689-9

摘要： A series of inline pico hydropower systems, which could be used in confined space, especially for water distribution networks (WDNs), was designed and investigated. The turbine with an eye-shaped vertical water baffle was developed to evaluate the hydraulic performance. A three-dimensional dynamic mesh was employed and the inlet velocity was considered as the inlet boundary condition, whereas the outlet boundary was set as the outflow. Then, numerical simulations were conducted and the standard turbulence model was found to be the best capable of predicting flow features through the comparison with the experimental results. The effects of the opening diameter of the water baffle and installation angle of the rotor on the flow field in the turbine were investigated. The results suggested that the water baffle opening at = 30 mm and the rotor at a 52° angle could achieve the highest efficiency of 5.93%. The proper eye-shaped baffle not only accelerates the fluid flow and generates positive hydrodynamic torque, but also eliminates the flow separation. The scheme proposed in this paper can be exploited for practical applications in the water pipelines at various conditions and power requirements.

关键词： vertical axis water turbine     eye-shaped     vertical water baffle     pico hydropower    

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Effect of undercut on the lower bound stability of vertical rock escarpment using finite element and

Shuvankar DAS; Debarghya CHAKRABORTY

《结构与土木工程前沿（英文）》 2022年 第16卷 第8期   页码 1040-1055 doi: 10.1007/s11709-022-0841-1

摘要： In the present study, the stability of a vertical rock escarpment is determined by considering the influence of undercut. Lower bound finite element limit analysis in association with Power Cone Programming (PCP) is applied to incorporate the failure of rock mass with the help of the Generalized Hoek-Brown yield criterion. The change in stability due to the presence of undercut is expressed in terms of a non-dimensional stability number (σci/γH). The variations of the magnitude of σci/γH are presented as design charts by considering the different magnitudes of undercut offset (H/vu and wu/vu) from the vertical edge and different magnitudes of Hoek-Brown rock mass strength parameters (Geological Strength Index (GSI), rock parameter (mi,), Disturbance factor (D)). The obtained results indicate that undercut can cause a severe stability problem in rock mass having poor strength. With the help of regression analysis of the computed results, a simplified design equation is proposed for obtaining σci/γH. By performing sensitivity analysis for an undisturbed vertical rock escarpment, we have found that the undercut height ratio (H/vu) is the most sensitive parameter followed by GSI, undercut shape ratio (wu/vu), and mi. The developed design equation as well as design charts can be useful for practicing engineers to determine the stability of the vertical rock escarpment in the presence of undercut. Failure patterns are also presented to understand type of failure and extent of plastic state during collapse.

关键词： undercut     vertical escarpment     stability     Hoek-Brown yield criterion     PCP    

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Evacuation strategies for vertical ship lift during initial fire: Integrated application of stairs and

Shu CHEN, Menghan SHANG, Jianping WANG

《工程管理前沿（英文）》 2021年 第8卷 第1期   页码 135-147 doi: 10.1007/s42524-020-0125-1

摘要： Vertical ship lifts (VSLs) are widely used in navigation facilities worldwide because of their efficiency and low cost. Although several researchers have investigated fire evacuation strategies for reducing potential safety hazards in VSLs, an effective and integrated application of stairs and elevators when a fire occurs in a VSL is necessary. Several evacuation routes were analyzed according to VSL structure and evacuation times in this study. Objective function corresponding to the minimum vertical evacuation time and related simulation model was subsequently developed to obtain a cooperative evacuation plan considering different numbers of evacuees. The Three Gorges ship lift was used as an example, and simulation results indicate that number of evacuees and exit selection are the main influencing factors of the total evacuation time in the stair- and elevator-coordinated evacuation mode. Furthermore, the distance between people trapped in ship reception chamber and evacuation exits affects evacuees’ choice of exits. The proposed model can provide a theoretical reference for evacuation research during initial fire events in VSLs.

关键词： vertical ship lift     initial fire     fire evacuation     numerical simulation     stair     elevator    

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微波快速测定镁质硅酸镍矿水分的应用研究

范兴祥,杨晶晶,黄铭,汪云华,李柏榆

《中国工程科学》 2007年 第9卷 第11期   页码 200-203

摘要：

利用微波技术快速测定镁质硅酸镍矿的水分，并对不同含水量的镁质硅酸镍矿对检测结果的影响 进行了分析和讨论；对微波检测装置、特性及其操作方法做了说明。

关键词： 微波     测定     镁质硅酸镍矿     水分    

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Removal of arsenic by pilot-scale vertical flow constructed wetland

《环境科学与工程前沿（英文）》 2021年 第15卷 第4期 doi: 10.1007/s11783-021-1435-1

摘要：

• VFCWs are effective for the treatment of arsenic-containing wastewater.

关键词： Constructed wetland     Arsenic     Removal efficiency     Mass balance    

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标题 作者 时间 类型 操作

The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

期刊论文

Removal, distribution and plant uptake of perfluorooctane sulfonate (PFOS) in a simulated constructed

Weichuan Qiao, Rong Li, Tianhao Tang, Achuo Anitta Zuh

期刊论文

Effects of sucrose crystallization and moisture migration on the structural changes of a coated intermediatemoisture food

Tiancheng LI, Peng ZHOU, Theodore P. LABUZA

期刊论文

Organophosphate esters in sediment from Taihu Lake, China: Bridging the gap between riverine sources and lake sinks

期刊论文

Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

Jie HAN,Harihar Shiwakoti

期刊论文

Solvates and polymorphs of clindamycin phosphate: Structural, thermal stability and moisture stability

Junbo Gong, Dejiang Zhang, Yuanyuan Ran, Keke Zhang, Shichao Du

期刊论文

Modeling temperature and moisture dependent emissions of carbon dioxide and methane from drying dairy

Enzhu HU, Pakorn SUTITARNNONTR, Markus TULLER, Scott B. JONES

期刊论文

高温合金压气机盘锻件纵断面中铌分布的原位统计分布分析表征

王海舟,李美玲,庄景云

期刊论文

Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns

Hiruy ABDU, David A. ROBINSON, Janis BOETTINGER, Scott B. JONES

期刊论文

Reliability analysis of the control system of large-scale vertical mixing equipment

YANG Mingjin, LI Xiwen, LI Shaoping, YANG Shuzi

期刊论文

Performance of vertical axis water turbine with eye-shaped baffle for pico hydropower

Zhuohuan HU, Dongcheng WANG, Wei LU, Jian CHEN, Yuwen ZHANG

期刊论文

Effect of undercut on the lower bound stability of vertical rock escarpment using finite element and

Shuvankar DAS; Debarghya CHAKRABORTY

期刊论文

Evacuation strategies for vertical ship lift during initial fire: Integrated application of stairs and

Shu CHEN, Menghan SHANG, Jianping WANG

期刊论文

微波快速测定镁质硅酸镍矿水分的应用研究

范兴祥,杨晶晶,黄铭,汪云华,李柏榆

期刊论文

Removal of arsenic by pilot-scale vertical flow constructed wetland

期刊论文