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稳定性 11

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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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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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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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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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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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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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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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Influence of infiltration on energy consumption of a winery building

Hejiang SUN, Qingxia YANG

《能源前沿（英文）》 2014年第8卷第1期页码 110-118 doi: 10.1007/s11708-013-0293-3

摘要： With the wide use of light steel structure in industrial buildings, some problems such as air leakage, water dripping and condensation and so forth occur during the construction and operation phases. Through the onsite testing of a winery building in Huailai County, Hebei Province in China, the influence of infiltration on energy consumption in industrial buildings was studied. The pressurization test method and moisture condensation method were used to test the infiltration rates. The results show that the winery building is twice as leaky as normal Chinese buildings and five times as leaky as Canadian buildings. The energy use simulation demonstrates that the reduction of the infiltration rate of the exterior rooms to 1/3 and the interior rooms to 1/2 could help decrease a total energy consumption of approximately 20% and reduce a total energy cost of approximately $ 225000. Therefore, it has a great potential to reduce the energy consumption in this type of buildings. Enforcement of the appropriate design, construction and installation would play a significant role in improving the overall performance of the building.

关键词： industrial building air change rate pressurization test method moisture condensation method energy cost

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舌体水份含量测量仪的研制

贾贵玺,裴小娜,康英鹏,诸凯

《中国工程科学》 2007年第9卷第4期页码 41-44

摘要：

在中医理论里，舌体的水份含量是舌诊的重要参考依据。现有的测量方法在可重复性和测量精度上都不够理想。为此，提出了一种基于质传递速率方法的新型舌体水份含量测量仪，采用数字式温湿度传感器，详细阐明了检测原理、软硬件设计与实现方法。该测量仪有小型便携、操作简便、低功耗等优点，并通过实验证明比现有测量方法具有更好的性能，测量值标准偏差为2.9％，能快速准确地反映舌体干湿润燥程度。

关键词：舌体水份含量质传递速率数字式温湿度传感器

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不同微波遥感模态和不同数据组合的等湿度区域分布与土壤湿度的反演

袁苇,李宗谦,刘宁

《中国工程科学》 2004年第6卷第6期页码 50-56

摘要：

论述了主动、被动和主动被动相结合的3种微波遥感模态反演土壤湿度的方法和特点。为了采用人工神经网络方法反演出土壤湿度，在随机粗糙面双谱散射模型的基础上计算了裸土壤表面的散射系数和发射率，分析了3种不同的微波遥感模态和不同数据组合的等湿度区域分布的特点，从而确定了适合于各个微波遥感模态的输入数据组合。反演结果表明，只要选择适当的人工神经网络输入数据组合，采用3种模态中的任何一种微波遥感模态反演土壤湿度都是可行的，并具有较好的反演精度，结果对于微波遥感反演土壤湿度方案的选取具有指导意义。

关键词：微波遥感土壤湿度反演遥感模态和数据组合人工神经网络

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先验知识在被动微波遥感土壤湿度反演中的作用和影响

唐路,李宗谦,石长生,王薪

《中国工程科学》 2005年第7卷第3期页码 53-58

摘要：

利用微波遥感的发射率数据反演裸土壤湿度，不可避免需要结合地表面和土壤层的一些先验知识，而先验知识的准确度又将对反演结果的准确度产生一定的影响。文章讨论了地表的高度起伏相关函数形式、土壤温度和土壤质地等三类先验知识，定义了几种不同的土壤湿度反演误差，从而定量地给出三类先验知识的不确定性对土壤湿度反演的影响，指出：基于BSM散射模型和人工神经网络（ANN）的土壤湿度的反演方法是可行的，向ANN输入两种极化的裸土壤表面发射率数据便可反演出裸土壤的湿度，在上述三种先验知识具有一定的不确定性时仍可保证较好土壤湿度反演准确度。

关键词：微波遥感先验知识发射率土壤湿度双谱模型人工神经网络

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Evaluation and prediction of slope stability using machine learning approaches

《结构与土木工程前沿（英文）》 2021年第15卷第4期页码 821-833 doi: 10.1007/s11709-021-0742-8

摘要： In this paper, the machine learning (ML) model is built for slope stability evaluation and meets the high precision and rapidity requirements in slope engineering. Different ML methods for the factor of safety (FOS) prediction are studied and compared hoping to make the best use of the large variety of existing statistical and ML regression methods collected. The data set of this study includes six characteristics, namely unit weight, cohesion, internal friction angle, slope angle, slope height, and pore water pressure ratio. The whole ML model is primarily divided into data preprocessing, outlier processing, and model evaluation. In the data preprocessing, the duplicated data are first removed, then the outliers are filtered by the LocalOutlierFactor method and finally, the data are standardized. 11 ML methods are evaluated for their ability to learn the FOS based on different input parameter combinations. By analyzing the evaluation indicators R ², MAE, and MSE of these methods, SVM, GBR, and Bagging are considered to be the best regression methods. The performance and reliability of the nonlinear regression method are slightly better than that of the linear regression method. Also, the SVM-poly method is used to analyze the susceptibility of slope parameters.

关键词： slope stability factor of safety regression machine learning repeated cross-validation

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离聚物基封装胶膜的吸湿解吸——一种用于CIGS 薄膜光伏组件的自呼吸封装胶膜 Article

Miao Yang, Raymund Schäffler, Tobias Repmann, Kay Orgassa

《工程（英文）》 2020年第6卷第12期页码 1403-1407 doi: 10.1016/j.eng.2020.02.020

摘要：相对空气湿度是这些逆过程的热力学驱动力，并决定了其平衡含水率（equilibrium moisture content, EMC）。空气湿度越大，EMC也越大。

关键词：离聚物封装胶膜吸湿解吸 Cu(In Ga)Se₂光伏组件

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Predicting the elemental compositions of solid waste using ATR-FTIR and machine learning

《环境科学与工程前沿（英文）》 2023年第17卷第10期 doi: 10.1007/s11783-023-1721-1

摘要：

● A method based on ATR-FTIR and ML was developed to predict CHNS contents in waste.

关键词： Elemental composition Infrared spectroscopy Machine learning Moisture interference Solid waste Spectral noise

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Modified Bishop method for stability analysis of weakly sloped subgrade under centrifuge model test

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 727-741 doi: 10.1007/s11709-021-0730-z

摘要： The sliding forms of weak sloped and horizontal subgrades during the sliding process differ. In addition, the sliding form of weakly sloped subgrades exhibits considerable slippage and asymmetry. The accuracy of traditional slice methods for computing the stability safety factor of weakly sloped subgrades is insufficient for a subgrade design. In this study, a novel modified Bishop method was developed to improve the accuracy of the stability safety factor for different inclination angles. The instability mechanism of the weakly sloped subgrade was considered in the proposed method using the “influential force” and “additional force” concepts. The “additional force” reflected the weight effect of the embankment fill, whereas the “influential force” reflected the effect of the potential energy difference. Numerical simulations and experimental tests were conducted to evaluate the advantages of the proposed modified Bishop method. Compared with the traditional slice method, the error between the proposed method and the exact value is less than 32.3% in calculating the safety factor.

关键词： weakly sloped subgrade stability analysis additional force influential force modified Bishop method