bluuebunny/crossref_metadata_2025 huggingface dataset:
Models and simulations of time-averaging in terrestrial vertebrate accumulations
Authors: Behrensmeyer A. K. , Chapman Ralph E.
Published: June 2019

Plants and shelly marine invertebrates often have diverse and densely packed communities that generate dense accumulations of organic remains. In contrast, populations in vertebrate communities are relatively dispersed in life, and normal annual mortality results in a relatively low density of remains scattered over the land surface. This attritional “bone rain” differs from unusual circumstances such as mass mortality and predator bone-collecting, which can generate high density accumulations of vertebrate remains in a short period of time.
Using numerical models to evaluate the consequences of time-averaging in marine fossil assemblages
Authors: Miller Arnold I. , Cummins Hays
Published: June 2019

Taphonomic studies of marine fossil assemblages have achieved new levels of sophistication in the past several years, but field-based investigations of time-averaged skeletal accumulations continue to suffer from an unavoidable problem: to date, a time machine has yet to be invented that would permit the researcher to observe directly the formation of the assemblage under study. Even when working with Recent subfossil accumulations on the sea floor, where it is theoretically possible to view the activity of (possibly myriad) taphonomic processes, practical considerations prevent the extensive, day-to-day monitoring that would be required to “bear witness”, in a kinetic sense, to the formation of skeletal assemblages. At best, we are sometimes provided with opportunities for comparative glimpses of skeletal accumulations before and after events of potential taphonomic significance, such as hurricanes (e.g., Miller et al., 1992).
Models of time-averaging as a maturation process: How soon do sedimentary sections escape reworking?
Authors: Sadler Peter M.
Published: June 2019

Holocene sediments are the traditional classroom for learning to recognize the geologic record of different environments. Box cores and shallow trenches display sedimentary stratification and assemblages of organic remains together with their relationship to active surface processes and living organisms. Sedimentologists see the origin of particular bed-forms; paleoecologists learn to match animals to trace fossils, for example; and stratigraphers are reminded that it is not just the sediment surface that is active. Shells, bones, and sediment grains below the surface are still subject to rearrangement. Until this activity has ceased we have not seen what will ultimately be preserved as the mature stratigraphic record of the environment that we have trenched.
Taphonomic approaches to temporal resolution in stratigraphy: Examples from Paleozoic marine mudrocks
Authors: Brett Carlton E. , Baird Gordon C.
Published: June 2019

One of the most important and challenging aspects of stratigraphy is the interpretation of the temporal scope of sedimentary units (Schindel, 1980, 1982; Sadler, 1981; Brandt Velbel, 1984). The problem arises at the scale of individual beds and of stratigraphic intervals up to many meters thick. Does a particular bed or interval-represent hours, days, years, centuries, or millennia? Resolution of this question is critical for determination of rates of sedimentation and biotic processes, and in assessing the reliability of the sample for paleoecological or evolutionary analysis. In the absence of a reliable framework of absolute radiometric dates the question can only be answered by indirect inference. Biostratigraphic zonation is a critical first step. But zonation is typically too coarse to resolve temporal scales less than 106years and many zones are not firmly anchored to absolute dates. It is also important to keep separate the issue of temporal duration represented byfossils (as bioclasts)within a given stratum and that of the deposition of thesedimentaryunit itself. There are many instances of thin graded beds full of fossils, which would be characterized unambiguously by sedimentologists as deposits of a single event of sedimentation, but in which the fossils may differ in age by thousands or even millions of years. Examples include many condensed, lag deposits of bones and conodonts (Baird and Brett, 1991), and condensed ammonoid beds containing fossils of several ammonite zones (Fürsich, 1971). Sedimentologic criteria provide one avenue of approach to this issue but commonly fall short of unambiguous answers.
Cenozoic Marine Diatom Biostratigraphy and Applications to Paleoclimatology and Paleoceanography
Authors: Barron John A. , Baldauf Jack G.
Published: June 2019

Diatoms, golden brown algae, are present in most aqueous environments. Within the marine environment marine diatoms occupy the photic zone and represent the lowest level of the marine food chain. Diatoms are either planktonic or benthic and possess an external siliceous skeleton or frustule, that is boxlike in structure. The size of diatom frustules ranges from less than 1 μm to more than 1,000 μm, but most frustules range in size from 10 to 100 μm. Diatoms are present in the geological record from at least the Cretaceous (Harwood and Nikolaev, this volume) and have numerous advantages for biostratigraphic correlation and paleoenvironmental reconstruction of marine sedimentary sequences. This chapter summarizes the current state of marine diatom biostratigraphy for the Cenozoic and provides examples of how marine diatoms are used in paleoenvironmental reconstructions. No attempt is made to illustrate the various diatom taxa discussed; the reader is referred to published references such as the syntheses of Fenner (1985) and Barron (1985).
Siliceous Chrysophycean Microfossils: Recent Advances and Applications to Paleoenvironmental Investigations
Authors: Duff Katharine E. , Zeeb Barbara A.
Published: June 2019

Chrysophytes are a diverse group of algae, commonly known as the golden-brown algae (Bold and Wynne, 1978), and consist of two classes, the Chrysophyceae and Synurophyceae (Andersen, 1987). Over 800 species have been described (Kristiansen, 1990; Kristiansen and Takahashi, 1982; Preisig, 1995), and it is estimated that more than 1,000 species exist. Chrysophytes are distinguished from other algae on the basis of chloroplast type and structure, photosynthetic pigments, storage product, flagellar apparatus, and especially the production of a siliceous resting stage, called the stomatocyst, statospore, or cyst (Hibberd, 1976; Kristiansen, 1990; Kristiansen and Takahashi, 1982).
Silicoflagellates
Authors: McCartney Kevin
Published: June 2019

The silicoflagellates are single-celled plankton that have a delicate siliceous skeleton made up of tubular rod-shaped elements. The group is both photosynthetic and autotrophic and has thus been claimed by botanists and zoologists. All silicoflagellates are included in the order Dictyochales, which is now generally considered to be in the division Chrysophyta, golden algae, on the basis of pigmentation and the structure of the chloroplasts and mitochondria.
Paleobiology of the Arthropod Cuticle
Authors: Plotnick Roy E.
Published: June 2019

To a large extent, a chitinous external cuticle is the distinguishing feature of arthropods (Barnes, 1980). Many of the other features considered characteristic of arthropods, such as growth by molting or the jointed appendages, are either directly or indirectly tied to the possession of the cuticle (Cisne, 1974; Neville, 1975; Grasshoff, 1981).
Crustacean Phylogeny
Authors: Schram Frederick R.
Published: June 2019

Crustacean phylogeny, long the focus of intense speculation, has undergone a renaissance in the last decade. This has been largely propelled by the use of cladistic analyses on the part of several workers, though there are still many who prefer more subjective, evolutionary systematic approaches.
Sampling from the Fossil Record
Authors: Koch Carl F.
Published: June 2019

The effects of sampling the fossil record are much greater then one would intuitively expect because most species are rare. That is, most species are represented by extremely few specimens and occur in extremely few collections. In many studies, species which occur only once are considered to be either endemic, stenotopic or of short species duration when in fact these species may not have any of these characteristics but, in fact, are very rare and thus occur in the fossil record very infrequently.
Estimation of Taxonomic Ranges from the Fossil Record
Authors: Marshall Charles R.
Published: June 2019

Many areas of paleontological enquiry, from questions of correlation to the characterization of macroevolutionary patterns, require estimates of taxonomic longevities. However, the fossil record is incomplete and biased and, as such, provides an incomplete sampling of true temporal ranges. “It is incomplete because many individuals, species, and higher taxa are not recorded as fossils. It is biased because the probability that a taxon is represented by a fossil is a function of the taxon's morphology, abundance, ecological habitat and spatial distribution, as well as the taxon's age.” (Pease, 1985, p. 272) To what extent do the inadequacies of the fossil record compromise our ability to estimate taxonomic longevities? What analytic methods exist for estimating true longevities from stratigraphic data, or for detecting situations where significant biases may be present? And perhaps most importantly, do analytic methods provide an effective way of dealing with the inadequacies of the fossil record?
Analysis of Morphological Data
Authors: Foote Mike
Published: June 2019

Taxonomic data analysis has benefited greatly from standardization of systematic and stratigraphic practices. In contrast, the unique features of each group of organisms and the specific nature of many workers' questions have helped make analysis of morphological data relatively less standardized and more idiosyncratic. In addition, paleobiological analysis of morphological data at larger (roughly, suprafamilial) scales seems to have lagged behind analysis, of taxonomic data because of the relative difficulty with which morphological data are collected (both from fossils themselves and from published sources). In this review, I will briefly touch upon some of the areas in which morphological analysis has contributed significantly to our understanding of life's history. Space limitations preclude a thorough treatment of all aspects of morphological analysis, and the decision to omit certain topics, such as functional morphology, is not a reflection of the importance of these fields.
Theoretical Morphology: The Concept and its Applications
Authors: McGhee George R.
Published: June 2019

Two quite different conceptual areas are understood today under the umbrella term of theoretical morphology: (1) the mathematical simulation of form, and (2) the analysis of the possible spectra of form via hypothetical morphospace construction. The second concept follows from the first, but has quite different goals.
Phylogenetic Analysis and its Application in Evolutionary Paleobiology
Authors: Fisher Daniel C.
Published: June 2019

Each of the perspectives on the fossil record represented by contributions to this short course (and many that are not) can claim a legitimate share of the mantle of “Analytical Paleontology,” earned by combining rigor and insight to provide some unique constraint on our understanding of the history of life. Dare I claim more for phylogeny? Certainly not, if “more” suggests that phylogeny is some final synthesis, complete unto itself, sought by all, and needing no further justification. Such a posture would make phylogenetic inference an end in itself, and, although it may sometimes appear that phylogeneticists have this in mind, I will argue here that it is the service role of phylogenetic analysis that makes it important in shaping our knowledge of evolution. Interpretation of the phylogenetic relationships of the organisms we study has profound implications for virtually all of our other ways of handling data from the fossil (or Recent) record.
Random Models in Paleobiology
Authors: Signor Philip W.
Published: June 2019

The fossil record is replete with patterns. Nearly two centuries of intensive paleontological research has produced a vast number of apparent patterns: stratigraphic and temporal distributions of taxa, paleogeographic distributions, paleoecological relationships, patterns of co-occurrence, morphology and morphological variation, and so forth. Many of these patterns reflect the interplay of important intrinsic processes operating within the biosphere and extrinsic influences acting from without. Others, however, follow from the ordinary processes of everyday life and require no special explanation. How, then, are inquiring paleontologists to separate meaningful patterns from the meaningless? For the most part, the selection of patterns appropriate for further study and explication has remained a matter of subjective judgment.
The Pace of Taxonomic Evolution
Authors: Gilinsky Norman L.
Published: June 2019

G. Udny Yule (1924) was perhaps the first to examine the subject of rates of taxonomic evolution mathematically, but George Gaylord Simpson was the first to examine the subject from within the confines of the so-called Modern Synthesis of Biology (Simpson, 1944). In that sense, therefore, Simpson's can be regarded as the first modern study of rates of taxonomic evolution. Although he is almost universally regarded as the catalyst behind the current interest in taxonomic evolutionary rates, it is a remarkable fact that Simpson's aims were almost entirely different from those of current workers. In a very important sense, Simpson's taxonomic rates of evolution were not taxonomic at all, but were morphological, or even more to the point, genetic.
Taxonomic Survivorship Curves
Authors: German R. Z.
Published: June 2019

Taxonomic survivorship curves were derived from ecological and biomedical techniques for examining population structure and demographic trends. In simplest form, survivorship curves are graphical representations of the numbers or proportions of taxa that survive specific lengths of time. These curves provide a basis for calculating longevity, extinction rates, and other “life history” attributes of higher taxa. Survivorship curves have also been fruitful for comparative studies of contemporaneous higher taxa (e.g., cohorts), or among higher taxa that existed at different periods of geologic time. Various modifications of the concepts, both theoretical and methodological, have changed the way these curves are used to analyze paleontologic data.
Bootstrapping and the Fossil Record
Authors: Gilinsky Norman L.
Published: June 2019

A new statistical term has been cropping up in the literature of paleobiological analysis: bootstrapping. This term, which refers to a relatively new general-purpose statistical method, has appeared in papers on subjects as diverse as rates of morphological change (Kitchell et al., 1987), patterns of morphological difference (between dextral and sinistral snail shells, for instance; Gould et al., 1985), survivorship analysis (Gilinsky, 1988), mass extinctions (Hubbard and Gilinsky, in press), the shapes of diversity paths (Gilinsky and Bambach, 1986), and periodicity of extinction (Connor, 1986). Some other papers do not explicitly mention the word bootstrapping, but nonetheless use methods that are quite similar (e.g., Raup and Sepkoski, 1984). Jennifer A. Kitchell convened an entire symposium on the subject at the Fourth North American Paleontological Convention in 1986. What is bootstrapping, and why is it being so widely applied in analytical paleobiology?
Invertebrate Trace Fossils: The Backbone of Continental Ichnology
Authors: Hasiotis Stephen T. , Bown Thomas M.
Published: June 2019

The purpose of this chapter is to evoke new concepts, provide guidelines and new frontiers for future research, and demonstrate that invertebrate traces actually comprise the “backbone” of continental (as well as marine) ichnology. Invertebrate organisms that inhabit the continental, nonmarine realm include some of the most diverse and populous classes in the animal kingdom. For example, both the Insecta and Crustacea exhibit burrowing behaviors unique to subaqueous freshwater and subaerial systems. Because of the sheer biomass of burrowing pupae, larvae, juvenile, and adult stages of these organisms, invertebrates dependent on the position of the water table form the basis for ecological niche-partitioning of depositional systems within all of the continental realm. A distinction must be made here between continental and marine ichnocoenoses because they represent distinctly different styles of living. These in turn dictate different behavioral and genetic responses of the organisms that inhabit them. Burrow architectures that occur in both continental and marine ichnocoenoses can be differentiated by subtle differences in morphology that are due to convergence of the burrowing mechanisms of the respective organisms.
Trace Fossils and Benthic Oxygenation
Authors: Savrda Charles E.
Published: June 2019

The general theme of this chapter is the relationships between trace fossils and benthic oxygen availability in marine environments. Discussion is organized into three sections, which correspond to related yet distinct approaches to the analysis of ichnofossil/oxygen relationships.
Seasonal and Annual Changes in Pitch in Blue Whale Calls
Authors: Cook Terri
Published: June 2019

Six years of acoustic recordings detect seasonal shifts in blue whale vocalizations that correlate with the presence of icebergs, a primary source of ambient ocean noise in the southern Indian Ocean.
Eight Ways to Support Women in Science
Authors: Drake Henri
Published: June 2019

Attracting and retaining women in the sciences require action on all fronts: stopping outright harassment, changing institutional cultures, and ensuring that women are included, recognized, and heard.
Rapidly Evolving Cirrus Clouds Modulated by Convectively Generated Gravity Waves
Authors: Prasad Abhnil A. , Sherwood Steven C. , Reeder Michael J. , Lane Todd P.
Published: June 2019

Cirrus clouds can strongly affect Earth's radiation balance, but questions remain about their growth mechanisms and rates. Here we show that gravity (buoyancy) waves generated by a storm in Northern Australia on 13 November 2015 caused an observable rippling effect on cirrus clouds up to 1,000 km away, as seen by the recently launched Himawari‐8/9 geostationary satellite. Regional model simulations reproduce the propagation speed of the wave, which agrees with theoretical predictions, and show that the wave amplitude and timing near the tropopause can account for the cirrus modulation. The observed cirrus reach peak optical depths of order 0.3–1.0 and appear roughly in phase with the arrival of the relative humidity maximum, providing new evidence that cirrus clouds can respond rapidly (<30 min) to environmental lifting. Moreover, the edge of a thick anvil cloud attached to the storm itself is observed to expand at the same speed as the wave, showing that the lifting mechanism can also apply to optically thicker ice clouds close to convective centers.
Bactericidal activity-tunable conjugated polymers as a human-friendly bactericide for the treatment of wound infections
Authors: Wang Haoping , Guo Lixia , Wang Yunxia , Feng Liheng
Published: June 2019

A series of biologically friendly bactericides were designed using the molecular structure to regulate the production capacity of reactive oxygen species and kill bacteria for wound healing.
Lithium-mediated ammonia synthesis from water and nitrogen: a membrane-free approach enabled by an immiscible aqueous/organic hybrid electrolyte system
Authors: Kim Kwiyong , Chen Yifu , Han Jong-In , Yoon Hyung Chul , Li Wenzhen
Published: June 2019

A membrane-free electrochemical cell provides a green and economic way of lithium deposition and its utilization for lithium-mediated ammonia synthesis.
A polyoxometalate-based polymer electrolyte with an improved electrode interface and ion conductivity for high-safety all-solid-state batteries
Authors: Yuan Xiangfei , Sun Cui , Duan Jia-Ning , Fan Jingmin , Yuan Ruming , Chen Jiajia , Chang Jeng-Kuei , Zheng Mingsen , Dong Quanfeng
Published: June 2019

By combining inorganic LVC with organic PEO matrix, a polyoxometalate-based polymer electrolyte (PPE) was constructed for solid state batteries.
Multivariate Shannon's entropy for adaptive IIR filtering via kernel density estimators
Authors: Fantinato D.G. , Silva D.G. , Attux R. , Neves A.
Published: June 2019

In supervised infinite impulse response adaptive filtering, approximate gradient‐based approaches are the usual option among optimisation methods. When based on the mean squared error (MSE) criterion, however, these approaches may present biased solutions in noisy scenarios. In that sense, instead of the MSE, the authors propose the use of Shannon's error entropy, an information theoretic learning criterion, which is able to extract higher order statistics from the underlying signals. In particular, a multivariate entropy definition is considered, which is applied to derive a Recursive Prediction Error‐based algorithm. The performance analyses are carried out in the context of the supervised channel equalisation problem, with results very favourable to the proposal, in high and low noise level environments.
Higher order statistics for modulation and STBC recognition in MIMO systems
Authors: Khosraviyani Mokhtar , Kalbkhani Hashem , Shayesteh Mahrokh G.
Published: June 2019

Identification of modulation and space‐time block code (STBC) is an important task of receivers in applications such as military, civilian, and commercial communications. Here, we consider multiple‐input multiple‐output (MIMO) systems. We propose two methods for STBC identification when the modulation is known. We also introduce a method for joint identification of code and modulation. Additionally, we present an enhanced zero‐forcing (ZF) equaliser to improve the separation between the features of different classes. Higher order cumulants are used as the statistical features. In the first method of STBC identification, after the proposed equalisation, received data samples are segmented, and then using the mean and Frobenius norm of the covariance matrix of extracted cumulants as threshold values, the STBCs are detected. This method requires the knowledge of the threshold values for each modulation type and noise power. In the second method, the knowledge of noise power and the type of modulation are not needed. After the proposed ZF equalisation, feature vector based on the cumulants is calculated, and then support vector machine (SVM) classifier is used to classify different STBCs. In the third method, joint detection of STBC and modulation type is performed using the proposed ZF equaliser and mapping the received samples. This method deals with the theoretical values calculated from the cumulants of four STBCs and four modulations, where there is no need to know the noise power. The results indicate that the proposed methods perform well even at low signal‐to‐noise ratios (SNRs).
Spatial information theory of sensor array and its application in performance evaluation
Authors: Xu Dazhuan , Yan Xiao , Xu Shengkai , Luo Hao , Liu Jingwei , Zhang Xiaofei
Published: June 2019

The direction of arrival (DOA) and amplitude‐phase (AP) of source signal can be estimated through array signal processing, while the process of information acquisition has not been described by information theory yet. In this study, the authors propose a novel spatial information theory framework to describe the DOA and AP estimation process. Firstly, they give a sensor array system model, where the spatial information is defined mathematically. Furthermore, in a single source scenario, the derivations of theoretical expression and an asymptotic upper bound for DOA information are presented. It also proves that the AP information accords with Shannon channel capacity when the source follows complex‐Gaussian distribution. In addition, when in an uncorrelated multi‐sources scenario, the AP information is the sum of that of each source for Gaussian distributed sources. Finally, they propose a definition of entropy error to evaluate the information acquisition capability of a sensor array. Numerical results verify that the entropy error is consistent with mean square error and approaches Cramér–Rao bound in high signal‐to‐noise ratio. It also verifies the correctness of theoretical derivation and shows that the spatial information can be employed as an evaluation index to quantitatively analyse the system performance which has significant guidance.
Maritime target imaging via simultaneous DVB‐T and DVB‐S passive ISAR
Authors: Pisciottano Iole , Cristallini Diego , Pastina Debora
Published: June 2019

This work presents an analysis of passive inverse synthetic aperture radar images obtained exploiting simultaneously digital video broadcasting‐terrestrial (DVB‐T) and digital video broadcasting‐satellite (DVB‐S) as illuminators of opportunity (IOs) over a cooperative maritime target with known motion. The combined exploitation of these two IOs is extremely appealing for passive imaging purposes, given their complementary characteristics. The analysis is first conducted in a simulated environment, to show the different expected outcomes from the two considered bistatic geometries and operating bandwidths. Subsequently, the same analysis is repeated over real data acquired during a field trial, by exploiting experimental setups developed at Fraunhofer FHR. In particular, DVB‐T and DVB‐S data are focused by means of back projection, which enables an easier comparison of the different ISAR products. Real data results show good match with simulated ones. Target size can be estimated with good accuracy in both DVB‐T and DVB‐S cases, and dominant scatterers can also be identified. DVB‐S also enables target‐shape recognition, given its higher signal bandwidth.
Reliability impact for optimal placement of power factor correction capacitors considering transient switching events
Authors: Al‐Muhanna Abdulaziz A. , Al‐Muhaini Mohammad
Published: June 2019

The power factor can be enhanced in many ways, one of which is a capacitor installation to correct the power factor at a particular location. While power factor correction capacitors are commonly used in power systems to generate Mvar at the bus, this could have an adverse reliability impact. To overcome this issue, a new optimal capacitor placement formulation is proposed, and the reliability, as well as the transient switching event impact, is assessed. The proposed formulation is included in the objective function, which is used to find the lowest cost based on many factors. The genetic algorithm optimisation technique is used to find the optimal minimised cost. The new formulation is applied to two test networks to assess its effectiveness. Moreover, the uncertainty impact and future system growth are considered to guarantee the robustness of the objective function. Finally, reliability calculations are added to the objective function to evaluate the capacitor installation impact on the power system.
Efficiency enhancement of perovskite solar cell by modifying the TiO2 with Ag/TiO2 core–shell nanowires
Authors: Liu Yunyan , Li Shutao , Wang Shuo , Zhao Dong , Wang Rendong , Sun Meiling , Xiu Junshan
Published: June 2019

Different ratio incorporation of Ag/TiO2 core–shell nanowires (ATCSN) into TiO2 as an electron transport layer of perovskite solar cells (PSCs) is studied. This structure can prevent the formation of silver halides between perovskite and silver nanowire. It is found that because of the effective improvement of light absorption and separation of photo‐generated electron–hole pairs, the introduction of ATCSN leads to increase of short current density and photoelectric conversion efficiency (PCE) of PSCs. 20 mg incorporation of ATCSN PSCs exhibits the best performance of PCE and a 17.7% increase is achieved compared to the control sample.
Rough set‐based rule generation and Apriori‐based rule generation from table data sets: a survey and a combination
Authors: Sakai Hiroshi , Nakata Michinori
Published: June 2019

The authors have been coping with new computational methodologies such as rough sets, information incompleteness, data mining, granular computing, etc., and developed some software tools on association rules as well as new mathematical frameworks. They simply term this research Rough sets Non‐deterministic Information Analysis (RNIA). They followed several novel types of research, especially Pawlak's rough sets, Lipski's incomplete information databases, Orłowska's non‐deterministic information systems, Agrawal's Apriori algorithm. These are outstanding researches related to information incompleteness, data mining, and rule generation. They have been trying to combine such novel researches, and they have been trying to realise more intelligent rule generator handling data sets with information incompleteness. This study surveys the authors’ research highlights on rule generators, and considers a combination of them.
Expanded models of the project portfolio selection problem with learning effect
Authors: Wang Li , Li Xingmei , Zhao Lu , Liu Zailing
Published: June 2019

This research develops two new models for project portfolio selection, in which the candidate projects are composed of multiple repetitive units. To reflect some real situations, the learning effect is considered in the project portfolio selection problem for the first time. The mathematical representations of the relationship between learning experience and investment cost are provided. One numerical example under different scenarios is demonstrated and the impact of considering learning effect is then discussed.
Discrete duality finite volume method with tangential redistribution of points for surfaces evolving by mean curvature
Authors: Tomek Lukáš , Mikula Karol
Published: June 2019

We propose a new discrete duality finite volume method for solving mean curvature flow of surfaces in ℝ3. In the cotangent scheme, which is widely used discretization of Laplace–Beltrami operator, a two-dimensional surface is usually approximated by a triangular mesh. In the cotangent scheme the unknowns are the vertices of the triangulation. A finite volume around each vertex is constructed as a surface patch bounded by a piecewise linear curve with nodes in the midpoints of the neighbouring edges and a representative point of each adjacent triangle. The basic idea of our new approach is to include the representative points into the numerical scheme as supplementary unknowns and generalize discrete duality finite volume method from ℝ2 to 2D surfaces embedded in ℝ3. To improve the quality of the mesh we use an area-oriented tangential redistribution of the grid points. We derive the numerical scheme for both closed surfaces and surfaces with boundary, and present numerical experiments. Surface evolution models are applied to construction of minimal surfaces with given set of boundary curves.
Transport dynamics of complex fluids
Authors: Song Sanggeun , Park Seong Jun , Kim Minjung , Kim Jun Soo , Sung Bong June , Lee Sangyoub , Kim Ji-Hyun , Sung Jaeyoung
Published: June 2019

Significance

Many disordered fluid systems exhibit anomalous transport dynamics, which do not obey Einstein's theory of Brownian motion or other currently available theories. Here, we present a new transport equation governing thermal motion of complex fluidic systems, which provides a unified, quantitative explanation of the mean-square displacement, the non-Gaussian parameter, and the displacement distribution of various complex fluids. The applicability of our theory is demonstrated for molecular dynamics simulation results of supercooled water and dense hard disc fluids and for experimental results of colloidal beads diffusing on lipid tubes. This work suggests previously unexplored directions for quantitative investigation into transport and transport-coupled processes in complex disordered media, including living cells.
Processing metal powders via field assisted sintering technology (FAST): A critical review
Authors: Weston N. S. , Thomas B. , Jackson M.
Published: June 2019

The current status of field assisted sintering technology (FAST) of structural metals from powder is critically reviewed. Recently, there have been significant increases in the uptake of FAST for metallic systems, composites and porous materials at the laboratory-scale. It is clear that FAST is tolerant of powder/particulate feedstock, allowing rapid production of materials, some of which would be challenging through conventional sintering techniques. Yet, the underlying mechanisms allowing this are not fully understood. Final specimen sizes tend to be small, which restricts rigorous mechanical assessment. This review demonstrates the clear benefits in transitioning laboratory-scale demonstrators to the industrial scale over the next few years. However, consideration will need to be given to size, throughput, and shape complexities to attract commercial investment.
Prevalence of Mental Disorders and Symptoms Among Incarcerated Youth: A Meta-Analysis of 30 Studies
Authors: Livanou Maria , Furtado Vivek , Winsper Catherine , Silvester Annabelle , Singh Swaran P.
Published: June 2019

Incarcerated youth have high levels of mental disorders. However, there are no up-to-date reviews examining the prevalence rates of a broad range of mental disorders and symptoms across youth justice populations. The current review aims to bridge this gap. We conducted a systematic search of the literature using PsycINFO, Medline, Embase, and Web of Science databases. We used meta-analyses to produce pooled prevalence figures for each mental health disorder and symptoms, and meta-regression to test for the moderating effects of covariates, such as gender. Thirty studies were included involving 8,153 participants. Meta-regression analysis showed that females had higher prevalence rates for depression, separation anxiety disorder and suicide. Males had higher prevalence rates for conduct disorder and emerging antisocial personality disorder. Emerging personality disorders (borderline personality disorder: 21%; 95% CI: 13–28%; antisocial personality disorder: 62%; 95% CI: 39–82%) were relatively common in both genders. The findings of this meta-analysis show the need for robust mental health services in custody settings. Adopting a developmentally focused approach would increase understanding of incarcerated youths’ needs and help to early detection of emerging personality symptoms. To improve young people’s mental health, we need to ensure that services do not misidentify young people’s needs due to diagnostic limitations.
Effect of saturation on mechanical behavior of cement mortar based on 8-type tensile test
Authors: Gu C , Xu J Y , Meng B X
Published: June 2019

Based on the purpose of revealing the effect of saturation on static tensile mechanical behaviour of cement mortar, the single-axis static tensile test was carried out for 8-type cement mortar specimens with the saturation of 0%, 50%, and100% respectively. The WDW-20 microcomputer controlled electronic universal testing machine was used in this paper. The date obtained from test indicates that the stress-strain curves of different saturation cement mortar are similar, stress with strain increases, the stress growth rate increases gradually. With the increase of saturation, the static tensile strength of cement mortar gradually decreases, and the stiffness of cement mortar gradually decreases, and the deformation performance gradually improves, and the maximum tensile strain increases gradually. Compared with dry cement mortar specimens, the tensile strength of saturated cement mortar specimens is decreased by 23.36%; the maximum tensile strain of semi-saturated and saturated cement mortar specimens is increased by 4.79% and 23.43% respectively. The elastic modulus of the dry and the semi-saturated cement mortar specimens are similar, when they are under pulled, and are larger than the elastic modulus of saturation cement mortar specimens.
Sequence Division and Sedimentary characteristics of Shahezi formation in Northwest Xujiaweizi fault depression
Authors: Dijiaxiang
Published: June 2019

In the light of the unclear current conditions of the sequence stratigraphic framework division and sedimentary for Shahezi Formation in Northwest Xujiaweizi fault depression. Based on single well, well logging and seismic data,the stratigraphic sequences of the formatio n are confirmed with the help of Vail sequence stratigraphy theory. Based on the single well facies and source supply, the sedimentary facies types and the distribution characteristics of the Northwest of Xujiaweizi are analyzed. The studies show that Northwest Shahezi Formation can be divided into one second-class sequences and furthermore it can be classified into four third-class sequence; Fan delta sedimentary facies is developed in the west of study area, braided river delta sedimentary facies is developed in the east of study area, lacustrine facies is developed in the central sag; In the Northwest of the Shahezi formation, the area of the lake basin in the early stage of the sedimentary basin is small, and the latter is gradually enlarged, lake facies is the main one and the fan is mainly developed in the East and the West in this area.
Research on carbon dioxide transcritical refrigeration cycle with vortex tube
Authors: Liu Yefeng , Sun Ying , Wang Dongliang
Published: June 2019

A kind of carbon dioxide transcritical refrigeration cycle with vortex tube is proposed to replace traditional expansion valve to reduce the irreversible loss of the refrigeration system and improve its COP. The mathematic model of carbon dioxide transcritical refrigeration system is built to simulate the effect of the vortex tube performance on the COP. The results show that outlet temperature of gas cooler, the discharge pressure, cold mass fraction and isentropic efficiency of the vortex tube have significant effects on the COP improvement of the proposed system. COP increases with the increase of cold mass fraction, isentropic efficiency of the vortex tube and the gas cooler outlet temperature. However, COP decreases with the increase of the discharge pressure. When the cold mass fraction is 0.8, the COP improvement increases by 12%.
Energy Efficient Rare Earth Lifting Permanent Magnet
Authors: Ding N , Liu C , Duan J S , Jiang S N , Hou Y Q
Published: June 2019

Nowadays lifting electromagnet is widely used in the world, but its fatal disadvantages are related to the electrical power input. A novel and energy efficient Rare Earth lifting permanent magnet is presented, which can completely overcome the lifting electromagnet disadvantages. In this paper, first, the developed optimization magnetic circuit design rule for Rare Earth lifting permanent magnet is discussed. Second, the lifting permanent magnet magnetic circuit design procedure is introduced. Finally, the invented mechanical drive system is expatiated. Industry prototype is manufactured, and it verifies that the proposed Rare Earth lifting permanent magnet is feasible.
Black shale of Wufeng-Longmaxi Formation in southeast Chongqing pore type of reservoir
Authors: Weiqi Xiao , Enhao Xing
Published: June 2019

On the basis of previous research results, a series of studies on black shales of the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in southeastern Chongqing have been carried out with thin sections and scanning electron microscopy. The results show that the pore types of black shale reservoirs in Wufeng-Longmaxi Formation in southeastern Chongqing include intergranular pore, intragranular dissolution pore, organic pore and fracture.
The Biological Basis of the Cultivation of Medical Senior Innovative Talents
Authors: Wang Xiaoyan , Li Siqi , Deng Kai , Wang Jianguo
Published: June 2019

Every new discovery in the history of biology, such as the essence of life, the origin of life, the discovery of cells, the establishment of cytology, the cell biology at the molecular level, etc., the biologist has left brilliant track in the journey of scientific innovation. The home climbs the glorious footprint of the Science Foothills. Nowadays, to cultivate cross-century competitive high-quality talents, we must advocate the spirit of not afraid of difficulties, fore ahead, and be brave to explore; we must conscientiously study and master the basic concepts, theories and methods of biology, with history and philosophy. Trace back to these concepts, theories and methods. In this way, we will improve our ability of innovation, continue to have new and more discoveries in science.
On the Innovative Operation of Exhibition of the Taobao E-commerce Run by Internet Celebrity
Authors: Zhang Jiankang , Zhao Yu
Published: June 2019

The exhibition of the electronic commerce run by Internet celebrity is a major driving force for China’s new economy.Innovative operation is an important cornerstone of the vigorous development.The innovative operation of exhibition of the Taobao electronic commerce run by Internet celebrity includes Seller Show— clothes hall,cosmetics hall,hello player—peripherals hall,the most delicious expression—foods hall,Time Warp—the development History from 1.0 times to 4.0 times.The micro-challenges of the innovative operation of exhibition are to attack fake products and establish a brand image for the exhibition,eliminate internet celebrity depraved image and establish a positive and healthy social image and avoid monopoly of large-scale electronic commerce and encourage diversified electronic commerce platform to join the exhibition.The macro-challenges of the innovative operation of exhibition of the Taobao electronic commerce run by Internet celebrity are no precedent providing experience for it,the exhibition industry management system and industrialization process being backward and lack of professional talents.The innovative operation of exhibition of the Taobao electronic commerce run by Internet celebrity needs to encourage the development of diversified Internet celebrity companies,improve third-party logistics warehousing management,and cultivate professional exhibition talents.
Effect of straw carbonization on properties of cement-based straw fiber composites
Authors: Xiao Li-guang , Liu Xi-xu
Published: June 2019

The raw materials of straw fibers were treated by different methods of nitrogen filling and carbonization at different temperatures. The cementitious materials consisted of ordinary Portland cement with strength grade 52.5 and sulphoaluminate cement with a ratio of 3:7. The surface morphology and material analysis of the fibers were carried out by means of SEM and EDS. The SiO2 content in the surface layer of carbonized straw fibers was 86.69% higher than that of common straw fibers, and the interfacial bonding of the composites was more compact because of the hydration reaction. The initial setting time of composites with carbonized straw fibers is shorter than that of ordinary straw fibers, the flexural strength is slightly reduced by 6.3%, and the compressive strength is significantly increased by 21.93%.
Effect of Alkali Treatment of Straw Fiber on Mechanical Properties of Alkali Slag Cement Composites
Authors: Xiao Li-guang , Liu Xi-xu , Jing-yao LI
Published: June 2019

In this paper, NaOH solution was used to treat straw fiber modified alkali slag cement, which enhanced the interfacial bonding between straw fiber and cementitious materials. The results showed that the best modification effect of straw fibers was obtained by soaking 3% NaOH solution for 16 hours. The compressive strength and flexural strength of alkali slag cement specimens cured for 28 days are 81.5 MPa and 10.9 MPa respectively. The toughness of the composites increases with the increase of fiber content. The flexural strength of straw fiber composites treated with NaOH solution and without NaOH solution increased by 5.6% and 11.3% compared with those without NaOH solution, and the compressive strength of straw fiber composites treated with NaOH solution increased by 34.08% compared with those without NaOH solution when the content of straw fiber was 10%.
Comparative Study of the Impact of Biomass and Clean Fuels Burning as Cooking Energy on Rural Indoor Air Quality in Heilongjiang, China
Authors: Zhang Yue , Zhang Yu , Wang Zhicheng
Published: June 2019

In rural areas of the northeast China, the majority of residents use traditional Chinese Kang-stoves for heating and cooking by burning biomass fuels. However, this method is associated with serious indoor air pollution problems. The purpose of this study is to evaluate indoor air quality impacts from biomass combustion and indoor air quality improvements derived from using clean fuel. A comparative study was conducted in three rural households of Heilongjiang to determine indoor air pollution extent during burning biomass (rice straw, cornstalk and corncob) and liquefied petroleum gas (LPG) fuels for cooking. The results indicated that the concentration of CO from the combustion of four kinds of fuels was almost below the guidelines prescribed in Chinese In-door Air Quality Standard. On the contrary, PM2.5 concentrations exceeded the limiting value regardless of which fuel was used, and the lowest PM2.5 concentration values, which were obtained during burning LPG, were about 2.4-7.5 times of 24-h mean PM2.5 concentration limit. The mean values of formaldehyde concentrations during using four types of cooking energy were totally higher than the standard limit, and the lowest formaldehyde concentrations were detected when corncob was used as cooking energy. Compared with LPG fuel, biomass fuels combustion in traditional Kang-stove with chimney increased the concentrations of TVOC and BTEX. To conclude, the pollutants generated from using LPG are relatively less harmful. Among the three biomass fuels, the minimal pollution derives from the combustion of corncob.
Optimization of adsorptive desulfurization process conditions for FCC gasoline
Authors: Nan-ni Xiong , Zheng Li , Peng Wang
Published: June 2019

In order to study the desulfurization of FCC gasoline, Zn/NaY zeolite FCC gasoline adsorbent was synthesized by impregnation method. The effects of space velocity, adsorbent bed temperature, adsorbent roasting temperature and roasting time on the desulfurization rate of FCC gasoline were investigated by adsorbent and fixed bed process. The results showed that the desulfurization rate of FCC gasoline reached about 85% under the conditions of 0.5 h-1 air velocity, 35°C adsorbent bed temperature, 700°C adsorbent roasting temperature and 4 h roasting time. Adsorption desulfurization as a technology with many advantages, such as low investment, low operation cost, complete desulfurization, had good application prospects and popularization value. To develop a fixed bed adsorption desulfurization technology for FCC gasoline which meets the requirements of V gasoline quality standards of producing countries.