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Detailed investigation of static and dynamic laser light scattering has been attempted in this work both theoretically and experimentally based on dilute water dispersions of two different homogenous spherical particles, polystyrene latexes and poly($N$-isopropylacrylamide) microgels. When Rayleigh-Gans-Debye approximation is valid, a new radius $R_{s}$, referred to as a static radius, can be obtained from the static light scattering $(SLS) $. If the absolute magnitude of the scattered intensity and some constants that are related to the instrument and samples are known, the average molar mass for large particles can be measured. The size information obtained from SLS is purely related to the optical properties of particles, i.e., to $R_{s}$ and its distribution $G(R_{s}) $. The size information obtained from dynamic light scattering $(DLS) $ is more complicated, the size distribution of which is a composite distribution that is not only related to the optical properties of particles, but also related to the hydrodynamic properties and the scattering vector. Strictly speaking, an apparent hydrodynamic radius $R_{h,app}$ is a composite size obtained from averaging the term $\exp (-q^{2}D\tau) $ in the static size distribution $G(R_{s}) $, with the weight $R_{s}^{6}P(q,R_{s}) $ that is also a function of both $R_{s}$ and the scattering vector $q$.

Detailed investigation of static and dynamic laser light scattering has been attempted in this work both theoretically and experimentally based on dilute water dispersions of two different homogenous spherical particles, polystyrene latexes and poly($N$-isopropylacrylamide) microgels. When Rayleigh-Gans-Debye approximation is valid, a new radius $R_{s}$, referred to as a static radius, can be obtained from the static light scattering $(SLS) $. If the absolute magnitude of the scattered intensity and some constants that are related to the instrument and samples are known, the average molar mass for large particles can be measured. The size information obtained from SLS is purely related to the optical properties of particles, i.e., to $R_{s}$ and its distribution $G(R_{s}) $. The size information obtained from dynamic light scattering $(DLS) $ is more complicated, the size distribution of which is a composite distribution that is not only related to the optical properties of particles, but also related to the hydrodynamic properties and the scattering vector. Strictly speaking, an apparent hydrodynamic radius $R_{h,app}$ is a composite size obtained from averaging the term $\exp (-q^{2}D\tau) $ in the static size distribution $G(R_{s}) $, with the weight $R_{s}^{6}P(q,R_{s}) $ that is also a function of both $R_{s}$ and the scattering vector $q$.

This article is from BMC Cancer , volume 14 . Abstract Background: The apparent diffusion coefficient (ADC) is a highly diagnostic factor in discriminating malignant and benign breast masses in diffusion-weighted magnetic resonance imaging (DW-MRI). The combination of ADC and other pictorial characteristics has improved lesion type identification accuracy. The objective of this study was to reassess the findings on an independent patient group by changing the magnetic field from 1.5-Tesla to 3.0-Tesla. Methods: This retrospective study consisted of a training group of 234 female patients, including 85 benign and 149 malignant lesions, imaged using 1.5-Tesla MRI, and a test group of 95 female patients, including 19 benign and 85 malignant lesions, imaged using 3.0-Tesla MRI. The lesion of interest was segmented from the raw image and four sets of measurements describing the morphology, kinetics, DW-MRI, and texture of the pictorial properties of each lesion were obtained. Each lesion was characterized by 28 features in total. Three classical machine-learning algorithms were used to build prediction models on the training group, which evaluated the prognostic performance of the multi-sided features in three scenarios. To reduce information redundancy, five highly diagnostic factors were selected to obtain a compact yet informative characterization of the lesion status. Results: Three classification models were built on the training of 1.5-Tesla patients and were tested on the independent 3.0-Tesla test group. The following results were found. i) Characterization of breast masses in a multi-sided way dramatically increased prediction performance. The usage of all features gave a higher performance in both sensitivity and specificity than any individual feature groups or their combinations. ii) ADC was a highly effective factor in improving the sensitivity in discriminating malignant from benign masses. iii) Five features, namely ADC, Sum Average, Entropy, Elongation, and Sum Variance, were selected to achieve the highest performance in diagnosis of the 3.0-Tesla patient group. Conclusions: The combination of ADC and other multi-sided characteristics can increase the capability of discriminating malignant and benign breast lesions, even under different imaging protocols. The selected compact feature subsets achieved a high diagnostic performance and thus are promising in clinical applications for discriminating lesion type and for personalized treatment planning.

By their great diversity and abundance Collembola represent a very significant component of soil fauna, which occupies a definite place in the processes of pedogenesis. For this reason, this group of small Apterygota has been drawing attention of the research workers during the last few years. Although, the role of Collembola in the process of organic matter decomposition has not been completely understood, for the present, it is known for certain that Collembola, by feeding on plant detritus as well as hyphae and spores of fungi, take part in the process of humification as initial humificators. Studies dealing with the problems of Collembolan distribution, taxonomy and ecology are numerous, but very few studies have been related to Collembola in sand soils, where their role, as initial humificators, is significant, especially during summer when the humification is extremely retarded (due to the high temperatures and the lack of moisture). For these reasons, we have undertaken to study the Collembolan fauna in different plant communities at the Deliblato Sand. Our aim was to study, in details, the qualitative and quantitative composition, as well as the seasonal dynamics of the Collenbolan fauna in different plant communities at the Deliblato Sand, which, according to Stepanovic-Veselicic ( 1953) represent the successive stages in the process of vegetation spreading over sand. In this way, it was possible for us to follow up the changes in the Collembolan fauna composition in different stages of vegetation succession, which were induced by the changes in plant cover and corresponding changes in edaphic and microclimatic factors. The present contribution has the characteristics of a fundamental research study, which ought to serve as a base for the understanding of the place and role of Collembola in the soil biocenosis. In the present work well known quantitative methods of study were used; e. g. monthly sampling of the 50 cm3 soil samples (with 10 repetitions) throughout the year. The separation of Collembola was achieved by means of a modified Tullgren apparatus, at the room temperature, during the period of 14 days. Barber traps with ethylene glycol were used, as an additional method for the sampling of atmobiontic forms. The following successive stages were investigated: bare sand dune; community Corispermeto-Polygonetum arenariae; community Festucetum vaginatae deliblaticum fumanetosum; community Festucetum vaginatae deliblaticum muscetosum; community Chrysopogonetum pannonicum typicum; association of Robinia pseudoacacia forest, habitat under Juniperus communis and association of Pinus nigra forest. In the studied communities we have found a total number of 44 species, of which Pseudachorutes subabdominalis, Orchesella albofasciata, Seira pallidipes, Sminthurus multipunctatus, Bourletiella virgulata and Arrhopalites terricola were found for the first time in Yugoslavia; Drepanura deliblatica and Bourletiella quadrangulata are new species, Subisotoma variabilis psammophila, Sinella pulcherrima jugoslavica and Bourletiella albanica angulipunctata are new subspecies described from the studied localities. Very unfavourable edaphic and climatic conditions, as well as the lack of vegetation, caused the complete absence of Collembola in the bare sand. In the pioneer community of Corispermeto-Polygonetum arenariae only two individuals of Collembola were found during our investigation. These species are characteristic for the surrounding, more developed communities, and, therefore, their appearance in the pioneer community can be attributed to the wind action. For the first time, during the vegetation successions, Collembola were found in the initial community of Festuca vaginata, solely in the patches of Festuca. The Collembolan fauna of this community is rather poor, it consists of only 9 species, more than half of which are atmobiontic. Lepidocyrtus paradoxus and Drepanura deliblatica are characteristic species of this community. In the terminal community of Festuca vaginata, the Collembolan fauna consists of 9 species also of which two, Seira pallidipes and Sminthurus multipunctatus, were not found in the initial community. In the steppe community of Chrysopogonetum pannonicum typicum the Collembolan fauna is characterised by far greater diversity. In this community 21 species of Collembola were found, of which 14 were not found in the above mentioned communities. More favourable edaphic and microclimatic conditions, as well as greater vegetation spreading, had influenced the composition of life forms too. Although the percentage ratio of the atmobiontic forms is also greater in this community the abundance of hemiedaphic species is increased in relation to the former community. Great qualitative changes of Collembolan fauna were observed in the association of Robinia and Pinus forests as well. Although the number of species is somewhat smaller (20 and 21), significant changes were found in the composition of life forms, e. g. the number of hemiedaphic and euedaphic species was increased. In the quantitative composition of the Collembolan fauna in the studied communities, the increase in abundance was found to be correlated to the increase in the vegetation spreading. It can be best seen in the initial succession stages if we compare the abundance of Collembola in the initial and the terminal Festuca vaginata community. The average abundance of Collembola in the initial community of Festuca vaginata was 1.981 ind./m2 while in the terminal it was 12.340 ind./m2. The increase in abundance between those two adjacent succession stages was for about six times, which rougly corresponds to the difference in vegetation spreading between those two communities. In the steppe community Chrysopogonetum pannonicum typicum we did not found higher abundance values as we had expected, because of quantitative impoverishement of the fauna due to the grazing of cattle. The mean abundance value of Collembola in this community was 770 ind./m2. The population density of Collembola in the Robinia forest was lower than the population density of these small Apterygot insects in forest habitats, in general. However, this phenomenon could be explained by the fact that Robinia forests are very xerothermic. During the investigation period, in all the studied plant communities significant fluctuations in abundance of the total Collembolan fauna, as well as single species, were found in different seasons. We did not find regular fluctuations in abundance in relation to the variations in climatic factors (moisture and temperature). In connection to this, we failed to found either characteristic spring and autumn maxima or summer and winter minima, as it was found by some authors for Collembola and other animals of soil mesofauna. Doubtless, climatic factors effect fluctuations of the Collembola abundance, but only on the base of fluctuations in climatic factors it is not possible to explain often sharp and unexpected changes in the abundance. Our findings, in comparision to the findings of other authors, show that the problem of seasonal dynamics of Collembolan abundance is a complex problem regulated by the interaction of the ecological factors. From the results of our study of the dynamics of Collembolan fauna at the Deliblato Sand the following facts can be emphasized: The succession of plant communities at the Deliblato Sand is followed by the succession of the Collembolan fauna in the ecosystems which are characteristic for these communities, so that lowest qualitative and quantitative values were found in the initial community of the Festuca vaginata and the highest in the antropogenous forests of Robinia pseudoacacia and Pinus nigra. In addition to this, with the more intensive covering and binding of sand by vegetation, the number of true soli Collembolan forms is in increase, while the percentage ratio of atmobiontic forms is in decrease.

Wind dynamic environment and wind-sand erosion and deposition processes on different surfaces along the Dunhuang–Golmud railway, China 作者： ZHANG Hongxue ZHANG Kecun AN Zhishan YU Yanping 作者单位： 1. Dunhuang Gobi Desert Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Gansu Agricultural University, Lanzhou 730000, China 提交时间： 2023-04-13 surface erosion and deposition wind environment three-dimensional (3D) laser scanner drift potential grain-size characteristic Dunhuang–Golmud railway 期刊： Journal of Arid Land 分类： 地球科学 >> 地理学 引用： ChinaXiv:202304.00941 (或此版本 ChinaXiv:202304.00941V1 ) DOI:10.1007/s40333-023-0099-z CSTR:32003.36.ChinaXiv.202304.00941.V1 推荐引用方式： ZHANG Hongxue,ZHANG Kecun,AN Zhishan,YU Yanping.(2023).Wind dynamic environment and wind-sand erosion and deposition processes on different surfaces along the Dunhuang–Golmud railway, China.Journal of Arid Land.doi:10.1007/s40333-023-0099-z 版本历史 [V1] 2023-04-13 13:18:27 ChinaXiv:202304.00941V1 下载全文

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Static and dynamic evolution of CO adsorption on γ-U (1 0 0) surface with different levels of Mo doping using DFT and AIMD calculations 作者： Li, Junwei 1,2 Jia Wei-min 2 Liu Chong 1 Lv Sha-Sha 3 Wang Jin-tao 2 Li Zheng-cao 1 作者单位： 1. School of Materials Science and Engineering, Tsinghua University 2. Xi’an Research Institute of High-Technology 3. College of Nuclear Science and Technology, Beijing Normal University 通讯作者： Li Zheng-cao Email:[email protected] 提交时间： 2023-08-14 摘要: Alloys of uranium and molybdenum are considered as the future of nuclear fuel and defense materials. However, surface corrosion is a fundamental problem in practical applications and storage. In this study, the static and dynamic evolution of carbon monoxide (CO) adsorption and dissociation on -U (1 0 0) surface with different Mo doping levels was investigated based on density functional theory and ab initio molecular dynamics. During the static calculation phase, parameters, such as adsorption energy, configuration, and Bader charge, were evaluated at all adsorption sites. Furthermore, the time-dependent behavior of CO molecule adsorption were investigated at the most favorable sites. The minimum energy paths for CO molecular dissociation and atom migration were investigated using the transition state search method. The results demonstrated that the CO on the uranium surface mainly manifests as chemical adsorption before dissociation of the CO molecule. The CO molecule exhibited a tendency to rotate and tilt upright adsorption. However, it is difficult for CO adsorption on the surface in one of the configurations with CO molecule in vertical direction but oxygen (O) is closer to the surface. Bader charge illustrates that the charge transfers from slab atoms to the 2* antibonding orbital of CO molecule and particularly occurs in carbon (C) atoms. The time is less than 100 fs for the adsorptions that forms embryos with tilt upright in dynamics evolution. The density of states elucidates that the overlapping hybridization of C and O 2p orbitals is mainly formed via the d orbitals of uranium and molybdenum (Mo) atoms in the dissociation and re-adsorption of CO molecule. In conclusion, Mo-doping of the surface can decelerate the adsorption and dissociation of CO molecules. A Mo-doped surface, created through ion injection, enhanced the resistance to uranium-induced surface corrosion. Adsorption and dissociation Uranium CO molecule Density functional theory ab-initio molecular dynamics 来自： 李俊炜 分类： 核科学技术 >> 核材料与工艺技术 投稿状态： 未投稿 引用： ChinaXiv:202308.00194 (或此版本 ChinaXiv:202308.00194V1 ) doi:10.12074/202308.00194 CSTR:32003.36.ChinaXiv.202308.00194.V1 推荐引用方式： Li, Junwei,Jia Wei-min,Liu Chong,Lv Sha-Sha,Wang Jin-tao,Li Zheng-cao.(2023).Static and dynamic evolution of CO adsorption on γ-U (1 0 0) surface with different levels of Mo doping using DFT and AIMD calculations.中国科学院科技论文预发布平台.[ChinaXiv:202308.00194] 版本历史 [V1] 2023-08-14 13:23:18 ChinaXiv:202308.00194V1 下载全文

This article is from Multidisciplinary Respiratory Medicine , volume 8 . Abstract Background: Tracheobronchomalacia (TBM) is a pathologic condition in which softening of tracheal and bronchial cartilage causes the dynamic narrowing of transverse or sagittal diameters of tracheobronchial lumen; an excessive dynamic airway collapse (EDAC) may also be associated, with a substantial invagination of the posterior membrane of trachebronchial tree.The aim of this study was to assess the prevalence of both TBM and EDAC in a population of asthmatics with different degrees of disease severity compared to a reference group of subjects without any bronchial obstruction. Methods: A cohort of 202 asthmatics was investigated by means of a dynamic flexible videobronchoscopy: 74 mild persistent (MPA - age 18–68 ys; 35 males; mean FEV1 = 88.6% pred. ± 8.3 sd); 63 moderate (MA - age 21–71 ys; 30 males; mean FEV1 = 71.3% pred. ± 9.1 sd), 65 severe asthmatics (SA - age 33–70 ys; 25 males; mean FEV1 = 48.5% pred. ± 7.6 sd), and 62 non obstructed subjects (NO - age 18–71 ys; 38 males; mean FEV1 98.6% pred. ± 2.7 sd). TBM and EDAC were classified according to FEMOS classification. Results: TBM and EDAC were observed in only 1/62 subjects (both 1.61%) of NO group, while their prevalence was 2.70% and 6.75% in MPA group; 7.93% and 19.04% in MA group; 18.46% and 69.23% in SA group, respectively. The crude prevalence of thyroid disorders in the population was 12.9%. In particular, the prevalence of thyroid disorders was significantly higher in females than in men, but 54-fold higher in females than in men in the presence of EDAC. Conclusions: 1) The prevalence of both TBM and EDAC is directly related to age, gender (females), and asthma severity; 2) EDAC is much more frequent than TBM in all asthma patients; 3) both tracheal abnormalities proved to be more represented in asthmatics with thyroid disorders, and particularly in female asthmatics with EDAC.

Improving our understanding of how symptoms interact in early clinical stages that represent different levels of risk for psychosis may reveal important insights in underlying mechanisms in early illness development. When studying these dynamics, it is important to acknowledge the heterogeneity in the population. One way of doing so is by assessing the extent to which dynamics between symptoms reflect a universal, clinical stage-specific or person-specific process. To this end we aim to answer three research questions: Research question 1: which connections between daily reports of psychological symptoms and resilience are stage independent (i.e., are found at group-level), which connections are stage specific (i.e, are found at subgroup-level) and which reflect heterogeneity in the sample (i.e., are found at the individual-level) in a sample of individuals at different levels of risk for psychosis? Research question 2: To what extent are subgroups defined by the clinical staging model, with subgroup membership determined mostly on severity of psychotic symptomatology, similar to subgroups when subgroup membership is determined based on symptom dynamics (i.e. connections between symptoms)? Research question 3: This research question is conditional on the previous research question. If we find differences between the two approaches, we will explore if the subgroups that represent different symptom dynamics additionally differ on other factors like age, gender, psychopathology, well-being and social functioning.

This paper presents a static and dynamic voltage stability analysis of a power network with thermal and wind generation considering static and dynamic load models. The thermal plant was modeled as a synchronous machine and the wind farm as a variable speed induction generator based on a doubly-fed induction generator. The load considered the ZIP, exponential recovery, induction motor, and frequency-dependent load models. The bifurcation points were found by continuation power flow and sensitivity analyses. In addition, dynamic voltage stability assessments were performed considering changes in the moment of inertia and the frequency parameters. All simulations were carried out in a 4-bus power system and using the power system analysis toolbox (PSAT) and MATLAB script code. The results show that the thermal generator had difficulties to maintain stability under dynamic load variations and frequency changes, the wind generator had difficulties to maintain voltage for the load with induction motors, and both generators had difficulties when the moment of inertia is increased.

Quantifying the tip-sample interaction at the nanoscale in Amplitude Modulation mode AFM is challenging, especially when measuring in liquids. Here, we derive formulas for the tip-sample conservative and dissipative interactions and investigate the effect that spurious resonances have on the measured interaction. Both direct and acoustic excitation are considered. We also highlight the differences between measuring directly the tip position or the cantilever deflection. We show that, when probing the tip-sample forces, the acoustically excited cantilever behavior is insensitive to spurious resonances as long as the measured signal corresponds to the tip position, or if the excitation force is correctly taken into account. Since the effective excitation force may depend on the presence of such spurious resonances, we consider the cases where the frequency is kept constant during the measurement so that the proportionality between excitation signal and actual excitation force is kept constant. With the present work we show the advantages that result from the use of a calibration method based on the acquisition of approach-retract curves. Optical beam deflection based AFMs benefit from the use of this calibration method, especially in presence of spurious resonances in the cantilever transfer function.

In this paper, we model dependence between operational risks by allowing risk profiles to evolve stochastically in time and to be dependent. This allows for a flexible correlation structure where the dependence between frequencies of different risk categories and between severities of different risk categories as well as within risk categories can be modeled. The model is estimated using Bayesian inference methodology, allowing for combination of internal data, external data and expert opinion in the estimation procedure. We use a specialized Markov chain Monte Carlo simulation methodology known as Slice sampling to obtain samples from the resulting posterior distribution and estimate the model parameters.

We study how an irreducible closed algebraic curve X embedded in CP^3 can be recovered using its projections from points onto embedded projective planes. The different embeddings are unknown. The only input is the defining equation of each projected curve. We show how both the embeddings and the curve in CP^3 can be recovered modulo some actions of the group of projective transformations of CP^3. For two projections, we show how in a generic situation, a characteristic matrix of the two embeddings can be recovered. We also establish the minimal number of irreducible algebraic curves required to compute this characteristic matrix up to a finite-fold ambiguity, as a function of their degree and genus. Then we use this matrix to recover the class of the couple of maps and as a consequence to recover the curve. Then we consider another problem. N projections, with known projections operators and N >> 1, are considered as an input and we want to recover the curve. The recovery can be done by linear computations in the dual space and in the Grassmannian of lines in CP^3. A closely related question is also considered. Each point of a finite closed subset of an irreducible algebraic curve, is projected onto a plane from a different point. The projections operators are known. We show when and how the recovery of the algebraic curve is possible, in function of the degree of the curve of minimal degree generated by the centers of projection. A second part is devoted to applications to computer vision. The results in this paper solve a long standing problem in computer vision that could not have been solved without algebraic-geometric methods.

Language is not static. It flows like a river in response to the riverbank and the rocks that border and run beneath it. In the same way, glossaries are dynamic expressions of current language usage. Developmental education and learning assistance have changed dramatically in recent years, and so must also the language used to describe and define them. This glossary is useful for the wide field of educators involved with promoting student success. It provides precise language and definitions to use when communicating with peers and more effectively influencing administrators, legislators, and the media. Some of these glossary terms are emerging with frequent use while others are declining. This is why this glossary is not static and future editions will continue to reflect the changes in language. Based on advice from some of the reviewers to make this glossary more accessible to readers, I reorganized it into different topical categories rather than a traditional alphabetical order. I hope this format will not only make it easier to locate a particular glossary term, but also discover related terms in the same category. The nine glossary categories are: (1) teaching and learning process; (2) antiracism and racism; (3) assessment; (4) copyright and academic integrity; (5) pedagogies for teaching and learning; (6) program management; (7) student-to-student learning; (8) transitional courses and programs; and (9) less acceptable glossary terms. This third edition of the glossary of developmental education and learning assistance terms has dramatically changed since the last edition 14 years ago. For that reason, the name of this glossary has changed and reflects its use in the wider education community. These terms could be useful for educators working in learning assistance, learning centers, developmental-level courses, first-year experience courses and programs, orientation courses and programs, federally-funded TRIO and other equity programs, and instructors teaching first-year and subsequent courses in the general course curriculum. In recognition of the expanded scope of this glossary and broader utility for other members involved with postsecondary education, the glossary title has become more inclusive, "Essential Glossary for Increasing Postsecondary Student Success: Administrators, Faculty, Staff, and Policymakers." [This paper was prepared for the College Reading and Learning Association.]

In modern science, the issue of studying the decision-making process is challenging. If these decisions are connected with finances: monetary gains or losses - the problem becomes even more acute. Decision-making is almost always connected with risk and uncertainty. In order to investigate the problem of financial decision-making at risk laboratory studies have been conducted to determine the degree of rationality of such decisions as well as the neural and psychodynamic characteristics of the subject. This paper presents the results of the study of this problem at the extreme values of the probability of a gain or a loss - 0.99 and 0.01.

We comment on a recent theory of dynamic wetting, that is based directly upon a model for interface formation, introduced by Shikhmurzaev. We argue that the treatment of surface tension and its relaxation, inherent in the original model, is physically flawed.