bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grain Size and Provenance of Bahia la Choya Sediments
Authors: Sumpter Lawrence T. 
Published: June 2019

A grain size analysis (including the carbonate fraction) was performed on sediment samples from each of the following environments of Bahia la Choya: tidal flat, spit, beach, and estero. The sediments of the tidal flat have an average grain size of 2.88 phi, range from very well sorted to moderately well sorted, and have a carbonate shell fraction ranging from 1 to 30%. The spit sediments have an average grain size of 0.96 phi, are moderately to poorly sorted, and have a carbonate shell fraction of approximately 50%. The beach sediments have an average grain size of 1.22 phi, range from poorly sorted to moderately well sorted, and have a carbonate shell fraction of approximately 48%. The sediments of the estero average 39% sand, 40% silt, and 20% clay. The carbonate fraction in the estero is approximately 25%. The noncarbonate fraction in all the environments is made up of feldspar, quartz, biotite, heavy minerals, and igneous rock fragments.The major source for the sediment is the Pelican Point granite on the south side of the bay. Pleistocene rock in and around the bay provides a second source of sediment and volcanic rocks to the north may also contribute to the sediment.
Keys to the Shells of Bahia la Choya, Sonora, Mexico
Authors: Beckvar Nancy , Norris Richard D. , Suter Sherman 
Published: June 2019

These keys are intended for use on dead shell material found on the sand flat, spit and estero of Bahia la Choya. They describe one hundred seventy molluscan species, three irregular echinoids and an inarticulate brachiopod. The taxonomic list on which the keys are based was compiled from shell material collected mainly during February and March, 1985. An attempt was made to make the keys as complete as possible. However, due to seasonal variations in shell abundances, not all shell material found at Bahia la Choya may be included in the key. Additionally, not all taxa found in the Pleistocene rock exposed around the bay are described here.The keys are based on morphological similarites, not phylogenetic relationships. Descriptive terminology has been kept to a minimum, and a glossary and labeled sketches are included for those technical terms which were employed. The reader is advised to become familiar with the anatomical parts of shells before embarking on an identification.External shell morphology can be altered by physical and biological destruction. In particular, fragile shell structures may be broken off, and shell sculpturing may be worn down. The absence of these sometimes critical features may lead to an incorrect identification. Additionally, bleaching of shells can alter or destroy the original colors. Therefore, shell color is not necessarily diagnostic and is mainly used as an additional character in the description of the species.Species are described only within the keys. When the species name has been reached, phrases within the couplet contain additional descriptive information and often some ecological information.
Variation in Shell Repair in

Cerithium stercusmuscarum

(Mollusca; Gastropoda), Bahia la Choya, Sonora, Mexico
Authors: Schmidt Nancy 
Published: June 2019

Examination of shell repair in the Recent gastropod species Cerithiumstercusmuscarum from several microhabitats within Bahia la Choya, Sonora, Mexico reveals significant intraspecific variation in shell repair frequencies. Samples include approximately 800 individual gastropods from four distinct localities: two rocky and two sandy intertidal habitats. Biometric measurements and the number of scars on the last whorl were used to statistically investigate the relationships between size, habitat and shell repair.Shell repair frequencies vary significantly between the microhabitats examined, and this variation is not related to differences in size-frequency distributions between samples. There is no preference for either larger or smaller snails to be attacked in any sample.Trends in gastropod shell repair frequency provide a method of examining predator-prey relationships through time. However, potential problems, including microhabitat-related intraspecific variation in repair frequency, exist in interpreting repair trends. The results of this study demonstrate that there is significant variation in shell repair frequency through space at any one point in time. Intraspecific variation could, therefore, blur any overall trend in shell repair frequency through time.
Population Structure of Live and Dead Gastropods from Bahia la Choya
Authors: Hartshorne Patricia M. , Gillespie William B. , Flessa Karl W. 
Published: June 2019

Size-frequency distributions and size-survivorship curves were constructed for the following seven species of living gastropods from Bahia la Choya: Cerithideamazatlanica, Cerithideaalbonodosa, Cerithiumstercusmuscarum, Nassariusiodes, Nassariusbrunneostoma, Theodoxusluteofasciatus and Tegularugosa. Size-frequency distributions and size-survivorship curves of empty shells of Cerithideamazatlanica and Cerithiumstercusmuscarum were constructed to evaluate the effects of taphonomic processes on survivorship curves.All size-survivorship curves are convex-up in shape: small size classes show low mortality and mortality increases with increasing size. Despite post-mortem processes, survivorship curves for empty shells mimic the shape of curves based on live individuals.
Biogenic and Physical Modes of Stratification and Shell Bed Formation in the Recent Intertidal Environments of Bahia la Choya, Northern Gulf of California
Authors: Meldahl Keith H. 
Published: June 2019

Fossil concentrations such as shell beds are preferred collection sites for paleontological and paleoecological data. Although ample attention has been paid to the roles and implications of physical processes in shell bed formation, the role of biogenic sediment reworking in generating shell beds has received little study.Subsurface shell beds in the Recent intertidal environment at Bahia la Choya form via three distinct processes: storm deposition, tidal channel migration, and biogenic reworking. Shell beds on the outer tidal flats are produced primarily by storm sedimentation. Lateral migration of the main tidal channel produces shell beds along the channel margins. Shell beds on the inner flats distant from the main tidal channel are generated by vertical “conveyorbelt” recycling of fine sediment by deposit feeders. Biogenic reworking concentrates shells at depth into subsurface shell beds, producing a distinct form of biogenic bedding, termed biogenic stratification.These three modes of shell bed formation leave recognizable taphonomic and sedimentologic signatures. Biogenic stratification in particular has important implications for sedimentation rates, sediment reworking, and faunal condensation in ancient strata.
Taphonomy of Tidal Flat Molluscs in the Northern Gulf of California: Paleoenvironmental Analysis despite the Perils of Preservation
Authors: Fürsich Franz T. , Flessa Karl W. 
Published: June 2019

Taphocoenoses can be powerful indicators of ancient environments, even in depositional settings in which rates of sedimentation are low and tidal currents are strong.The rich subtropical mollusc fauna of the northern Gulf of California exhibits a distinct zonation across an extensive tidal flat at Bahia la Choya (Sonora, Mexico). The distribution of live faunas is largely controlled by substrate, energy level, availability of food, and period of submergence. Despite strong tidal currents and the effects of time-averaging, the distribution of taphocoenoses closely reflects the distribution of the live communities. Indeed, the zonation of individual species is often reflected in the distribution of their shelly remains.The outer flat, middle flat, inner flat, tidal channel, and salt marsh subenvironments within the tidal flat complex can be defined by the taxonomic composition, trophic/life habit groups and taphonomic attributes of their taphocoenoses. Gastropods dominate on hard and firm substrates (rocky flats, channel and marsh) while bivalves prevail on sandy substrates. Herbivores are most common on rocky and shelly substrates; detritus feeders occur on the firm substrates of the inner flat and marsh; suspension-feeders predominate in sandy and rocky bottoms. Shell abrasion, encrustation and boring decrease landward.We tested an integrated approach to paleoenvironmental analysis by examining a Pleistocene shell bed from Bahia la Choya. Taxonomic, ecologic and taphonomic criteria suggest deposition by a storm event in a very shallow subtidal to lowest intertidal environment.
Balancing Resources and Collections Needs: II. Deaccessioning and Disposal of Fossil Invertebrates and Microfossils
Authors: Demouthe Jean , Merritt Elizabeth , Lidgard Scott 
Published: June 2019

AS RECENTLY as thirty years ago, deaccessioning was a dirty word in museums. It was considered an abrogation of an institution's fundamental responsibility to care of its collections in the public trust. Miller (1985) has chronicled some of the public controversy that attended deaccessioning in the early 1970's. However, in the intervening time, museums' approach to deaccessioning has changed as they grapple with burgeoning collections, decreasing funding bases, pressure to narrow and focus their missions, and rising standards of care. Now deaccessioning is regarded by the majority as a necessary and appropriate tool in collections management, albeit one that operates within strict ethical and legal constraints.A museum's collections policy should address criteria for deaccessioning, levels of approval needed, methods of disposition, use of funds resulting from sales, and records keeping. In addition, staff must develop procedures for identifying material for deaccessioning. In the following sections we review the currently accepted standards in the museum field for these areas, as well as discussing how some of these issues apply particularly to paleontological collections. It may be appropriate for paleontology departments to develop guidelines and procedures that further refine the museum's overall collections policy to fit the needs of their collections and the conventions of their field.
A Data Model for Invertebrate Paleontological Collections Information
Authors: Morris Paul J. 
Published: June 2019

PALEONTOLOGICAL data are complex. They involve a wide variety of different classes of information relating physical objects, such as type specimens to all manner of different things including collecting localities, systematic concepts such as a genus, and published statements about stratigraphic or systematic placement. This data model has been designed to describe the structure of information used in invertebrate paleontological museum collections (Appendix IX).The heart of the data model is the concept of Collections Objects. Collections objects are fossils and other such things that make up the material of invertebrate paleontological museum collections. Collections management involves essentially tracking collections objects and maintaining the data that is associated with collections objects. The key data associated with collections objects are their provenance (where and when they came from) and added value data such as what names, if any, have been applied to them, or what publications they have been illustrated in.A data model is a formal description of some set of information. It consists of a picture of the main concepts involved (the Entity-Relationship diagram) and a set of formal written documentation that defines these concepts and their relationships with each other. For an introduction to the concepts and symbols of data models see the references below, or good summaries provided in the ASC and PaleoBank models.
The Scientific Value of Natural History Museum Collections: The Concept of Completeness
Authors: Lieberman Bruce S. , Kaesler Roger L. 
Published: June 2019

NATURAL HISTORY MUSEUMS are one of the greatest resources available to paleontologists and evolutionary biologists. Through their exhibits, they have inspired generations of children to become paleontologists, and they also serve as a tremendous repository of realized and potential data. If invertebrate fossils can be thought of as individual data points, in the United States alone there are perhaps 100 million data points. Yet, in spite of this, museums, like other sources of data, have their shortcomings. What are these short comings, and how severe are they? Are they so severe as to obviate the scientific value of the collections of fossils held by natural history museums? It is this topic that we address herein.There is a useful analogy between the debate about the usefulness of natural history museum collections and the debate about the completeness of the fossil record. Are natural history museums representative of the fossil record, and are they complete enough to be adequate for research? We intend to pursue the analogy between the fossil record and natural history museums as we develop our ideas about paleontological collections. Just as numerous studies have concluded that the fossil record, albeit incomplete, is adequate to answer a wide variety of scientific questions, so too shall we argue that the data preserved in natural history museums are complete enough and adequate to answer a wide variety of important research questions in paleontology.
Effects of Particle Nonsphericity on Dust Optical Properties in a Forecast System: Implications for Model‐Observation Comparison
Authors: Hoshyaripour G. A. , Bachmann V. , Förstner J. , Steiner A. , Vogel H. , Wagner F. , Walter C. , Vogel B. 
Published: June 2019

AbstractMineral dust is a key player in the Earth system that affects the weather and climate through absorbing and scattering the radiation. Such effects strongly depend on the optical properties of the particles that are in turn affected by the particle shape. For simplicity, dust particles are usually assumed to be spherical. But this assumption can lead to large errors in modeling and remote sensing applications. This study investigates the impact of dust particle shape on its direct radiative effect in a next‐generation atmospheric modeling system ICON‐ART (ICOsahedral Nonhydrostatic weather and climate model with Aerosols and Reactive Trace gases) to verify if accounting for nonsphericity enhances the model‐observation agreement. Two sets of numerical experiments are conducted by changing the optical shape of the particles: one assuming spherical particles and the other one assuming a mixture of 35 randomly oriented triaxial ellipsoids. The simulations are compared to MISR (Multiangle Imaging Spectroradiometer), AERONET (Aerosol Robotic Network), and CALIPSO (Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation) observations (with focus on North Africa). The results show that consideration of particle nonsphericity increases the dust AOD (Aerosol Optical Depth) at 550 nm by up to 28% and leads to slight enhancement of the agreement between modeled and measured AOD. However, the model performance varies significantly when focusing on specific regions in North Africa. These differences stem from the uncertainties associated with particle size distribution and emission mechanisms in the model configuration. Regarding the attenuated backscatter, the simulated profile assuming nonsphericity differs by a factor of 2 to 5 from the experiment assuming spherical dust and is in a better agreement with the CALIPSO observations.
Study on the Change of Rainfall Characteristics in Hangzhou’s Urbanization Process
Authors: Zheng Shi , Lin-lin Hu , Huan-Bao Chen , Hong-xia Tang 
Published: June 2019

Abstract
With the development of the economy and expansion of the city size, urbanization has more important effects on rainfall characteristics. This paper takes Hangzhou for example, uses measured data of rainfall stations, and analyses the influence of urbanization on rainfall characteristics. The results show that the urbanization has changed the Hangzhou’s rainfall characteristics, and the heavy rain occurred probability increases, the flood disaster is more and more frequent.
Pilot scale study on medium/low temperature SCR denitration technology for industrial flue gas
Authors: Xiao Xiang , Fang Ping , Huang Jianhang , Wu Haiwen , Tang Zhixiong , Cen Chaoping 
Published: June 2019

Abstract
Based on laboratory research, the titanium-based honeycomb molding catalysts with MnO
x
/CeO2/V2O5 as the main active material were prepared, and a pilot scale study on medium/low temperature SCR denitration technology for ceramic kiln flue gas was carried out on a 5000 m3/h pilot scale equipment. The influences of flue gas flow, ammonia-nitrogen molar ratio and ammonia concentration on denitration efficiency were investigated. The result showed that the medium-low temperature SCR denitration technology had an excellent NO
x
removal efficiency. Under the conditions of the flue gas flow was 3000 m3/h, the ammonia-nitrogen molar ratio was 1.2:1, and the ammonia concentration was 25%, the NO
x
removal efficiency coulld reach 86%, and NO
x
emission concentration and ammonia escape amount were less than 40 mg/m3 and 1 mg/m3 in the flue gas, respectively. The technology can achieve deep reduction of NO
x
in ceramic kiln flue gas, and has a good application prospect.
Comparative Study on the Fractal Dimensions of Soil Particle Size
Authors: Shen Jingfang , Zhang Ying , Ling Chen , Liu Wenwei , Zhang Xu 
Published: June 2019

Abstract
The application of fractal theory provides a new approach for the study of soil science. The calculation of fractal dimension is the basis. The purpose of the study is to find a suitable method for calculating the fractal dimension of the soil particle size and to analyse how the fractal dimension reflects soil properties. We mostly use comparative analysis to study. Comparing the mass fractal dimension method with volume fractal dimension method, we analyze their advantages and disadvantages, and the fractal dimension performance of the soil in different land types.
The application of cracking coefficient method to the study on fractures in volcanic of Anda area
Authors: Yue Zhou , Zhiguo Wang 
Published: June 2019

Abstract
According to the actual situation of volcanic reservoirs in Anda area, this paper uses the comprehensive analysis of drilling and logging data to predict the fracture development of volcanic reservoirs in the study area. Among them, the ratio of longitudinal wave velocity, “crack coefficient” method, is used to analyze and calculate the crack development frequency. The research shows that the fractures of volcanic reservoirs in Anda area are relatively developed, and the characteristics of fracture parameters will inevitably affect the exploration and production of natural gas in this area.
The influence of vehicles load on structural bearing capacity of underground parking garage
Authors: Xijian Liang , Qiuyan Sun , Xingxing Huang 
Published: June 2019

Abstract
For passing vehicles on underground parking garage,the difference between the codes for the bridge design and for the ordinary building structural design in design parameters of materials load combination etc is compared.Specification for Design of Municipal bridge has made the corresponding simplification computation to load function.
Study on the Effects of Carbon Fibers and Carbon nanofibers on Electrical Conductivity of Concrete
Authors: Wang Tengjiao , Xu Jinyu , Bai Erlei , Luo Xin , Chen Haowen , Liu Gaojie , Chang Sen 
Published: June 2019

Abstract
In order to study the effects of carbon fibers and carbon nanofibers on the electrical conductivity of concrete, we adopt the four-electrode method to measure the resistivity of concrete with different test voltages, different ages and different fiber content. The test results show that both carbon fibers and carbon nanofibers can significantly reduce the electrical resistivity of concrete. When carbon fiber content and carbon nanofiber content are same, the resistivity of carbon fiber reinforced concrete (CFRC) is lower than that of carbon nanofiber reinforced concrete (CNFRC). The resistivity of CFRC and CNFRC can decrease with the increase of the test voltage, increase with the development of the concrete, and decrease with the increase of the fiber content. For concrete with an age of 28 days, CFRC has the largest decrease in resistivity when the carbon fiber content is between 0.2% and 0.3%, and the resistivity of CNFRC drops biggest when the carbon nanofiber content is between 0.1% and 0.3%.
Effects of Local Thickening on Surface Precision Control of Membrane Structures
Authors: xiao Xiao , qiao Zhang , qingchun Song 
Published: June 2019

Abstract
It is difficult to maintain the surface flatness like other materials for membrane structure under working conditions, and working performance will be greatly affected due to the extremely low bending stiffness of the membrane. In this paper, the finite element software ABAQUS is used to discuss effects of local thickening on the precision of the membrane structures from three aspects: tilt angles of the wrinkle equilibrium position, out-of-plane deformation of the structures and the wrinkle amplitude of membrane structures were analysed. Also the possible negative effects on the maximum principal stress. By comparing the local reinforcement model with the ordinary model, the accuracy of the local thickening model is far superior to the ordinary model, and little effect on distribution of maximum principal stress. The research results indicated that local thickening membrane structure can achieve better control to surface flatness at a lower cost.
Design and Research on the Information Management System of Qinhuai River Intelligent Pump Station
Authors: Yong Sun , Donglei Wu , Yuquan Zhang , Yuan Zheng 
Published: June 2019

Abstract
The intelligent pump station information management system is located between the computer monitoring system of the pump station and the management information system of the superior management department. Combined with the actual situation of Qinhuai River, this paper presents the design idea, software and hardware structure of the information management system of the intelligent pump station, and introduces the main functions of the information management system so as to provide reference for related construction.
Construction and Application of Sports Towns Characterized by Sports Event Chains
Authors: Zhang Jun , Gan Zhuoting 
Published: June 2019

Abstract
The sports towns’ outlook are strictly restricted by their construction pattern. Different from traditional ones, sports towns characterized by sports event chains is the new and upgraded version. Their competitive advantage include integration effect, synergy effect and brand effect, contributing to better utilize sports resources and social capital input in a comprehensive manner. To make full use of sports event chains during sports towns’ construction, this paper tries to define and analyze sports event chain’s definition, characteristics and function, summarizes its major structural patterns, puts forward some suggestions on implementing sports event chains as well as cites the example of Huangshan Modern Industrial Park to further illustrate the concept.
Construction and Innovation of Guilin Urban Green Rainwater Landscape System from the Perspective of Sustainable Development
Authors: Ren Lili , Wang Jinye , Hao Yafei 
Published: June 2019

Abstract
With the acceleration of China’s urbanization process, there have been many rain and flood problems such as the increase of urban stagnation and serious water pollution. People began to reflect on the relationship between urban green infrastructure construction and ecological nature. As an important part of the urban rainwater system, the green rainwater infrastructure plays an important role in managing urban rainwater, building a benign water cycle in the city, and protecting the ecological environment. The article proposes to build a Guilin urban green rainwater landscape system based on the green rainwater infrastructure and propose innovative suggestions.