官能团化刚性大环的超分子化学

重点介绍具有纳米尺寸的苯炔刚性大环的超分子化学:包括聚集效应,主客体化学、液晶行为及二维、三维超分子结构等.

印刷过程中控制润版液浓度的研究

提出了一种新的检测印刷过程中润版液的检测方法,分析和检测润版液的浓度是根据不同的润版液成分,用不同的方法,在不同的光区内进行的。这里给出了一些测量不同百分比浓度的酒精和酒精替代物的实验方法和结果,以便能发现合适的波长区域来检测和分析印刷过程中润版液的浓度,从而达到在实际印刷过程中控制润版液的浓度。

官能团化稠环芳香烃合成进展

对稠环芳香烃的合成方法、官能团化稠环芳香烃最新合成进展、官能团化稠环芳香烃构建的复杂分子体系(液晶、刚性线型和环状的大分子)及其超分子化学进行了评述.

超长六角多型纳米SiC晶须的光学性质

采用改进的PECVD技术首次制备出六角多型SiC纳米晶须.高分辨率电镜观察其直径在18～50 nm之间,长度为0.3μm～6mm.Raman光谱表明它是六角多型(4H)纳米SiC晶须.紫外光激发出现高强度蓝光发射.同时在550～620 nm和700～750 nm处分别出现两宽带发射,经计算其中蓝光发射带,4H-SiC带隙为3.98eV,这一发光现象与量子力学计算结果不符,说明了SiC晶须光学性质的特殊性.

关于南云道夫的一个定理的新改进

给出了 Ｂａｎａｃｈ 空间上的微分方程存在正不变集的一个充分条件。

Effect of Continuous Phase Viscosity on Membrane Emulsification

Oil-in-water(o/w) emulsions were produced with a membrane emulsification system. The effect of the continuous phase viscosity on the emulsification was studied. The theoretical analyses show that the continuous phase viscosity influences not only the flow field of the continuous phase but also the interfacial tension. The droplet size distribution and disperse phase flux for different continuous phase viscosity were investigated experimentally at constant wall shear stress and constant volume flow rate of the continuous phase respectively.

Assessment of Road Dust Contamination in India

The road dusts (RD) are fugitive in nature causing potential health hazards to people living in highways. They are generated from different sources on the roads and being a valuable archive of environmental information. In the present work, contamination assessment of 18 heavy metals and ions in road dusts of the country are described. Techniques i.e. ion selective, ion chromatography and atomic absorption spectrophotometers were used for analysis of the ions and metals. The content of F-, Cl-, , , , Na+, K+, Mg2+, Ca2+, As, Cr, Mn, Fe, Ni, Cu, Zn, Pb and Hg in the road dusts was ranged from 75 - 895, 276 - 12718, 48 - 1423, 243 - 10,580, 11 - 539, 290 - 46,484, 110 - 7716, 84 - 1771, 595 - 15,955, 24 - 42, 164 - 526, 1711 - 5218, 63,850 - 144,835, 47 - 62, 81 - 720, 166 - 450, 92 - 295 and 0.05 - 0.12 mg/kg with mean value of 224 ± 43, 3734 ± 895, 592 ± 895, 2859 ± 662, 143 ± 29, 4826 ± 2049, 1565 ± 411, 837 ± 121, 8545 ± 1288, 31 ± 4, 246 ± 82, 3002 ± 851, 91,331 ± 18,587, 54 ± 4, 206 ± 145, 241 ± 64, 171 ± 42 and 0.08 ± 0.02 mg/kg, respectively (at 95% probability). The enrichment, variation, correlation and sources of the contaminants are discussed.

Learn More about Your Data: A Symbolic Regression Knowledge Representation Framework

In this paper, we propose a flexible knowledge representation framework which utilizes Symbolic Regression to learn and mathematical expressions to represent the knowledge to be captured from data. In this approach, learning algorithms are used to generate new insights which can be added to domain knowledge bases supporting again symbolic regression. This is used for the generalization of the well-known regression analysis to fulfill supervised classification. The approach aims to produce a learning model which best separates the class members of a labeled training set. The class boundaries are given by a separation surface which is represented by the level set of a model function. The separation boundary is defined by the respective equation. In our symbolic approach, the learned knowledge model is represented by mathematical formulas and it is composed of an optimum set of expressions of a given superset. We show that this property gives human experts options to gain additional insights into the application domain. Furthermore, the representation in terms of mathematical formulas (e.g., the analytical model and its first and second derivative) adds additional value to the classifier and enables to answer questions, which sub-symbolic classifier approaches cannot. The symbolic representation of the models enables an interpretation by human experts. Existing and previously known expert knowledge can be added to the developed knowledge representation framework or it can be used as constraints. Additionally, the knowledge acquisition framework can be repeated several times. In each step, new insights from the search process can be added to the knowledge base to improve the overall performance of the proposed learning algorithms.

Heavy Metal Contamination of Tree Leaves

The study of heavy metal (HMs) contamination of environment is of great interest due to their serious health hazard. In this work, the contamination of tree leaves with the HMs in the most polluted industrial city, Korba, India is described. The leaves of common trees i.e. Azadirachta indica, Butea monosperma, Eucalyptus, Ficus religiosa, Mangifera indica and Tectona grandis were selected for assessment of the HMs contamination as bioindicator. The elevated concentration of HMs (i.e. As, Fe, Cr, Mn, Cu, Zn, Cd, Pb and Hg) in the tree leaves was observed, ranging from 2.8 - 43, 728 - 5182, 8.6 - 49, 48 - 1196, 43 - 406, 79 - 360, 1.12 - 1.65, 1.6 - 16.4 and 0.13 - 0.76 mg/kg, respectively. The concentration, enrichment and sources of the HMs in the leaves are described. Azadirachta indica leaves, accumulating higher concentration of the HMs, showed a higher efficiency as bioindicator for the urban pollution.

Transport Pollution in India

Road dusts contribute a large fraction of air pollution in urban environment of India. In the present work, contamination assessment of ions and elements i.e. F﹣, Cl﹣, NO-3, SO2-4, NH+4, Na+, K+, Mg2+, Ca2+, As, Cr, Mn, Fe, Ni, Cu, Zn, Pb and Hg in the road dusts of the most industrialized area of central India: Raipur (capital, Chhattisgarh state) is described during year: 2008-2013. In year 2008, the mean content of the element i.e. F﹣, Cl﹣, NO-3, SO2-4, NH+4, Na+, K+, Mg2+, Ca2+, As, Cr, Mn, Fe, Ni, Cu, Zn, Pb and Hgin the dust (n = 5) was found to be 292 ± 112, 5068 ± 2445, 927 ± 280, 3336 ± 1315, 155 ± 65, 4273 ± 1761, 1477 ± 626, 974 ± 243, 9809 ± 2370, 21.2 ± 2.4, 150 ± 30, 12,816 ± 12,522, 157,736 ± 61,542, 60 ± 7, 566 ± 608, 348 ± 154, 296 ± 163 and 0.10 ± 0.09 mg/kg, respectively. The enrichment, concentration variations and sources of the elements are discussed.

Contamination of Water, Dust, Soil, Rock and Urine with Fluoride in Central India

At least 15% of 0.1 million people residing in 117 villages of Tamnar block (Chhattisgarh, central India) are suffering from fluorosis diseases. In this work, the contamination of F- in the environment (i.e. water, soil, rock and urine) of the Tamnar block is described. The concentration variations of F-, Cl-, NO3-, SO42-, Na+, K+, Mg2+, Ca2+, Al, Mn, Fe and Zn in the groundwater are reported. The F- content in the water was ranged from 1.7 - 17 mg/L with mean value of 9.0 ± 3.7 mg/L. Fluoride was enriched up to 3-, 54-, 69- and 244-folds in the urine, soil, dust and rock, respectively. The cluster and factor analysis models were used to apportion sources of F- and other elements in the water.

Towards an enhanced understanding of the particle size effect on conversion/alloying lithium-ion anodes

Conversion/alloying materials(CAMs)represent a potential alternative to graphite as a Li-ion anode active material,especially for high-power applications.So far,however,essentially all studies on CAMs have been dealing with nano-sized particles,leaving the question of how the performance(and the de-/lithiation mechanism in general)is affected by the particle size.Herein,we comparatively investigate four different samples of Zn_(0.9)Co_(0.1)O with a particle size ranging from about 30 nm to a few micrometers.The results show that electrodes made of larger particles are more susceptible to fading due to particle displacement and particle cracking.The results also show that the conversion-type reaction in particular is affected by an increasing particle size,becoming less reversible due to the formation of relatively large transition metal(TM)and alloying metal nanograins upon lithiation,thus hindering an efficient electron transport within the initial particle,while the alloying contribution remains essentially unaffected.The generality of these findings is confirmed by also investigating Sn_(0.9)Fe_(0.1)O_(2) as a second CAM with a substantially greater contribution of the alloying reaction and employing Fe instead of Co as a TM dopant.

Digital twin of a droplet microarray platform:Evaporation behavior for multiple droplets on patterned chips for cell culture

Precise control of the evaporation of multiple droplets on patterned surfaces is crucial in many technological applications,such as anti‐icing,coating,and high‐throughput assays.Yet,the complex evaporation process of multiple droplets on well‐defined patterned surfaces is still poorly understood.Herein,we develop a digital twin system for real‐time monitoring of key processes on a droplet microarray(DMA),which is essential for parallelization and automation of the operations for cell culture.Specifically,we investigate the evaporation of multiple nanoliter droplets under different conditions via experiments and numerical simulations.We demonstrate that the evaporation rate is not only affected by the environmental humidity and temperature but is also strongly linked to the droplet distribution on the patterned surfaces,being significantly reduced when the droplets are densely distributed.Furthermore,we propose a theoretical method to aid in the experimental detection of volumes and pH variation of evaporating droplets on patterned substrates.This versatile and practical strategy allows us to achieve active maneuvering of the collective evaporation of droplets on a DMA,which provides essential implications for a wide range of applications including cell culture,heat management,microreactors,biochips,and so on.

Probabilistic simulation of electricity price scenarios using Conditional Generative Adversarial Networks

A novel approach for generative time series simulation of electricity price scenarios is presented.A"Time Series Simulation Conditional Generative Adversarial Network"(TSS-CGAN)generates short-term electricity price scenarios.In particular,the network is capable of generating a 24-dimensional output vector that corresponds to the expected behavior of electricity markets.The model can replace typical approaches from financial mathematics like statistical factor models to model the price distribution around a given forecast.The data cover a 3-year period from 2020 to 2023.Our empirical study is conducted on the EPEX SPOT market in Europe.An electricity price scenario includes the prices of the hourly contracts of a day-ahead auction at the EPEX SPOT power exchange.The model uses multivariate time series as input factors,consisting of point forecasts of electricity prices and fundamental data on generation and load profiles.The architecture of a CGAN TSS-is based on the idea of Conditional Generative Adversarial Networks combined with 1D Convolutional Neural Networks and Bidirectional Long Short-Term Memory.The model is evaluated using qualitative and quantitative criteria.For the evaluation,10,000 simulations of a test period are carried out.Qualitative criteria are whether the model follows certain electricity market-specific regularities and depicts them adequately.The quantitative analysis includes common error metric,compared to benchmark models,like DeepAR,Prophet and Temporal Fusion Transformer,the examination of the quantile ranges,the error distribution and a sensitivity analysis.The results show that the TSS-CGAN outperforms benchmark models such as DeepAR by reducing the continuous ranked probability score by 50%and considers market-specific circumstances such as the production of fluctuating energies and reacts correctly to changes in the corresponding variables.

Attitudes toward forest diversity and forest ecosystem services—a cross-cultural comparison between China and Switzerland

Aims Despite the current interest in services provided by ecosystems and the role of biodiversity,the relationship among human attitudes,biodiversity and ecosystem services has hardly been investigated.Moreover,few studies have examined attitudes toward nature in cross-cultural comparisons.This study investigates the attitudes of Chinese and Swiss people,both environmental experts and laypersons,toward forest biodiversity and ecosystem services.Methods Overall,640 people in China and Switzerland were interviewed with the help of a standardized questionnaire.In each country,the study population was equally divided into an urban(80 city dwellers and 80 environmental science students)and a rural(80 forest visitors and 80 farmers)study group.The 15-minute interviews took place in the cities of Beijing and Zurich and in the rural forested areas of Dujiangyan,Sichuan Province and Lake Sempach,canton Lucerne.Attitudes toward forest biodiversity were investigated with the help of color photographs that depicted both monocultures and speciesrich forests typical for China and Switzerland.Attitudes toward ecosystem services were investigated with the help of 13 statements on provisioning,regulating,cultural and supporting services of forests.Important Findings On average,Chinese participants showed no strong preferences for biodiversity,whereas the Swiss clearly preferred species-rich forests over monocultures.However,Chinese environmental science students did prefer species-rich forests and attributed to them a higher conservation value because of their higher biodiversity.Although there were no strong preferences for Chinese versus Swiss forests,all participants correctly answered that Chinese forests are more species rich in terms of plants and animals and thus found them less boring and more interesting,but also less managed,than Swiss forests.All participants highly valued the ecosystem services provided by forests;especially the regulating and supporting ones.Environmental science students and farmers placed more importance on the provisioning services,whereas city dwellers and forest visitors emphasized more on the regulating services.The disjuncture between the high ecological quality of species-rich forests and their low attractiveness to Chinese study participants points to a potential conflict between conservation policies and the public’s preferences.A better communication of ecosystem services provided by forest biodiversity to the public might change these preferences in favor of ecological quality,as already observed among Chinese environmental science students.

Multiphase-field modelling of concurrent grain growth and coarsening in complex multicomponent systems

Phase-field modelling of microstructural evolution in polycrystalline systems with phase-associated grains has largely been confined to continuum-field models.In this study,a multiphase-field approach,with a provision for introducing grain boundary and interphase diffusion,is extended to analyse concurrent grain growth and coarsening in multicomponent polycrystalline microstructures with chemically-distinct grains.The effect of the number of phases and components on the kinetics of evolution is investigated by considering binary and ternary systems of duplex and triplex microstructures,along with a single phase system.It is realised that the mere increase in the number of phases minimises the rate of concurrent grain growth and coarsening.However,the effect of components is substantially dependent on the respective kinetic coefficients.This work unravels that the disparity in the influence of phases and components is primarily due to the corresponding change introduced in the transformation mechanism.While the raise in number of phases convolutes the diffusion paths,the increase in number of component effects the rate of evolution through the interdiffusion,which introduces interdependency in the diffusing chemical-species.Additionally,the role of phase-fractions on the transformation rate of triplex microstructure is studied,and correspondingly,the interplay of interface-and diffusion-governed evolution is elucidated.A representative evolution of three-dimensional triplex microstructure with equal phase-fraction is comparatively analysed with the evolution of corresponding two-dimensional setup.

Experimental and Analytical Analysis of Perforated Plate Aerodynamics

Perforated walls and transpiration flow play an important role in aerodynamics due to an increasing interest in application of flow control by means of blowing and/or suction. An experimental study was carried out which has led to the determination of a transpiration flow characteristics in the form of a simple formula that is very useful in modelling such flows. In connection to this relation a method of 'aerodynamic porosity' determination has been proposed which is much more reliable than geometric description of the porosity. A theoretical analysis of the flow through a perforation hole was also carried out. The flow was considered as compressible and viscous. The gasdynamic analysis led us to a very similar result to the relation obtained from the experiment. The adequacy of the theoretical result is discussed in respect to the experiment.

Streamwise Vortex Interaction with a Horseshoe Vortex

How control in turbomachinery is very difficult because of the complexity of its fully 3-D flow structure. The authors propose to introduce streamwise vortices into the control of internal flows. A simple configuration of vortices was investigated in order to better understand the flow control methods by means of streamwise vortices. The research presented here concerns streamwise vortex interaction with a horseshoe vortex. The effects of such an interaction are significantly dependent on the relative location of the streamwise vortex in respect to the leading edge of the profile. The streamwise vortex is induced by an air jet. The horseshoe vortex is generated by the leading edge of a symmetric profile. Such a configuration gives possibility to investigate the interaction of these two vortices alone. The presented analysis is based on numerical simulations by means of N-S compressible solver with a two-equation turbulence model.

Morphological stability of three-dimensional cementite rods in polycrystalline system:A phase-field analysis

Transformations accompanying shape-instability govern the morphological configuration and distribution of the phases in a microstructure.Owing to the influence of the microstructure on the properties of a material,in the present work,the stability of three-dimensional rods in a‘representative'polycrystalline system is extensively analysed.A multiphase-field model,which recovers the physical laws and sharpinterface relations,and includes grain boundary diffusion,is adopted to investigate the morphological evolution of the precipitate.Moreover,the efficiency of the numerical approach is ensured by establishing the volume-preserving chemical equilibrium through the incorporation TCFe8(CALPHAD)data and solving phase-field evolution in the Allen-Cahn framework.The morphological evolution of the rod in the representative multiphase system exhibits a unique transformation mechanism which is significantly different from the evolution of an isolated finite-structure.It is realised that,in a polycrystalline arrangement,irrespective of the initial size of the rod,the shape-change begins with the energy-minimising events at the triple junctions.This early transformation renders a characteristic morphology at the longitudinal ends of the structure,which introduces sufficient driving-force through the curvature-difference for the subsequent morphological changes.The continued mass transfer to the terminations,ultimately,breaks-off the rod into separate entities that are entangled in the grain boundary.With increase in the aspect ratio of the rod,it is identified that the source of mass transfer,which turns into the ovulation site,shifts from the centre.This increases the number of fragmentation events and introduces satellite particle.The size of the satellite particle is dictated by a definite ovulation criterion,which is ascertained by examining the transformation of different-sized rods.A comprehensive understanding of the transformation kinetics and mechanism governing the morphological evolution of the rods in a polycrystalline system is rendered in this work.