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The large-scale Yaogangxian W deposit, located in central of the Nanling metallogenic belt, South China, comprises independent quartz vein-type and skarn-type W mineralization. Wolframite-bearing quartz veins occur invariably in metasandstone and slate to the northwest of the Yaogangxian granitic intrusion, whereas scheelite-skarn are mainly hosted by the limestone to the east. The vertical extension of single wolframite-bearing quartz vein can reach up to 1000 m and we focused on the vein samples collected from the deepest level (26 level) which likely recorded early magmatic fluids. For skarn mineralization, two scheelite precipitation stages were recognized, namely scheelite-1 in retrograde stage and scheelite-2 from sulfide-stage. To reveal the fluid sources and characteristics of two mineralizing systems, detailed petrography and microthermometry analyses were carried out on fluid inclusion assemblages (FIA) in scheelite, wolframite and their coexisting quartz. Fluid compositions were obtained from individual fluid inclusion (FI) in ore and gangue minerals via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis. These data aid elucidation on the source and nature of fluids in the two distinct W mineralization styles. The chemical compositions of FIs hosted in wolframite and scheelite points to a common magmatic source. The fluid in the scheelite ore section exhibits lower As and B than the wolframite ore section, indicating that boiling may have occurred at early skarn stage. Fluid evolution in the two mineralizing systems suggest that formation of diverse W mineralization styles is mainly controlled by different host lithology and fluid processes. In the wolframite ore section, ore-forming fluid recorded in the deepest level of vein show elevated As, B, K and Rb contents than previously reported ore-forming fluid obtained from the tip of the vein. This likely indicate absence of intensive fluid immiscibility in the deep during wolf

Casting is a vital process in steel production where solidification process of molten steel occurs in mold coupled with fluid flow, heat transfer, crystal growth, inclusion motion, solute redistribution, segregation, and so on. All these phenomena are closely related to the steel flow behavior. To optimize the flow field in mold at initial moment, the swirling flow casting technology is developed and has received extensive attention in past years. It is believed to be a promising method to further optimize the steel flow and to improve the solidification process. Herein, the swirling flow steel casting is comprehensively reviewed to introduce different realization technologies, new research progress, and the current situation of their application. This aims to promote the development and usage of swirling flow technology in steel casting., QC 20220516

Mixing plays a key role in mass and heat transfer, as well as chemical reactions in various vessels involving agitation. Several studies have confirmed that the mixing time obtained from several monitor locations cannot reflect the mixing time for the whole bath because stirring situation in different locations is variable due to the change of operation schemes. It is proved that some zones with inefficient stirring cannot be monitored by applying a limited amount of probes in physical and mathematical models. This study provides a novel approach to quantify mixing time evaluation considering the tracer variation for the whole bath using a mathematical model. It was found that the mixing time obtained by considering the whole bath is more representative than that of the probe monitor method. Compared with the traditional probe method, about 50 to 70 pct longer mixing times were obtained for different operations by applying the volume track method. In addition, the volume integral of the concerned variable for the whole bath is more representative to determine the developed flow compared to the points monitoring method for a transient simulation., QC 20230613

In this note involving mathematical induction, an identity involving the combinatorial numbers and the partial sums of the harmonic and related series is verified. (Author)

Describes a project in which students collect native seeds and build a greenhouse to propagate native plants in a desert laboratory. (DDR)

Describes a three-week inservice teacher education program that involves two sessions of preparatory classes ashore in nautical science and oceanography, and concludes with a nine-day sea voyage. (ASK)

The quantification of the uncertainty effect of random system parameters, such as the loading conditions, material and geometric properties, on the system output response has gained significant attention in recent years. One of the well-known methods is the first-order second-moment (FOSM) method, which can be used to determine the mean value and variance of the system output. However, this method needs to derive the formulas for calculating the local sensitivity and it can only be used for systems with low-level uncertainties. Polynomial Chaos (PC) expansion is a new non-sampling-based method to evaluate the uncertainty evolution and quantification of a dynamical system. In this paper, PC expansion is used to represent the stochastic system output responses of civil bridge structures, which could be the natural frequencies, linear and nonlinear dynamic responses. The PC coefficients are obtained from the non-intrusive regression based method, and the statistical characteristic can be evaluated from these coefficients. The results from the proposed approach are compared with those calculated with commonly used methods, such as Monte Carlo Simulation (MCS) and FOSM. The accuracy and efficiency of the presented PC based method for uncertainty quantification and global sensitivity analysis are investigated. Global sensitivity analysis is performed to quantify the effect of uncertainty in each random system parameter on the variance of the stochastic system output response, which can be obtained directly from the PC coefficients. The results demonstrate that PC expansion can be a powerful and efficient tool for uncertainty quantification and sensitivity analysis in linear and nonlinear structure analysis.

The effect of the immersion depth of a new swirling flow tundish SEN (Submerged Entry Nozzle) on the multiphase flow and heat transfer in a mold was studied using numerical simulation. The RSM (Reynolds Stress Model) and the VOF (Volume of Fluid) model were used to solve the steel and slag flow phenomena. The results show that the SEN immersion depth can significantly influence the steel flow near the meniscus. Specifically, an increase of the SEN immersion depth decreases the interfacial velocity, and this reduces the risk for the slag entrainment. The calculated Weber Number decreases from 0.8 to 0.2 when the SEN immersion depth increases from 15 cm to 25 cm. With a large SEN immersion depth, the steel flow velocity near the solidification front, which is below the mold level of SEN outlet, was increased. The temperature distribution has a similar distribution characteristic for different SEN immersion depths. The high temperature region is located near the solidification front. Temperature near the meniscus was slightly decreased when the SEN immersion depth was increased, due to an increased steel moving distance from the SEN outlet to the meniscus., QC 20190625

A kinetic model was developed to predict the dynamic change of the oxygen content in the sub-interface region as well as the dynamic change of the interfacial tension between molten steel and slag. The dynamic steel/slag interfacial phenomena are very complex, where the combined effect of thermodynamics and kinetics on the interfacial tension needs to be accounted for. As a first step, the current model only considers the SiO2 decomposition, oxygen adsorption and desorption at the steel/slag interface to realize the modeling of the dynamic change of the steel/slag interface phenomena. The oxygen desorption rate was derived based on the slope of the interfacial tension change over oxygen content. Specifically, the oxygen change with time in a sub-interface was predicted by the current model. The oxygen desorption rate was found to have an important influence on the dynamic change of the oxygen content in the sub-interface region. Furthermore, a low slag viscosity was found to increase the oxygen content at the interface due to the fast supply of SiO2 from the slag bulk to the interface. In addition, the equilibrium constant for the oxygen adsorption at an interface due to the interfacial tension effect increases the oxygen content in the sub-interface region., QC 20190404

© 2018 Elsevier Ltd Artificial neural networks are computational approaches based on machine learning to learn and make predictions based on data, and have been applied successfully in diverse applications including structural health monitoring in civil engineering. It is difficult to optimize the weights in the neural networks that have multiple hidden layers due to the vanishing gradient issue. This paper proposes an autoencoder based framework for structural damage identification, which can support deep neural networks and be utilized to obtain optimal solutions for pattern recognition problems of highly non-linear nature, such as learning a mapping between the vibration characteristics and structural damage. Two main components are defined in the proposed framework, namely, dimensionality reduction and relationship learning. The first component is to reduce the dimensionality of the original input vector while preserving the required necessary information, and the second component is to perform the relationship learning between the features with the reduced dimensionality and the stiffness reduction parameters of the structure. Vibration characteristics, such as natural frequencies and mode shapes, are used as the input and the structural damage are considered as the output vector. A pre-training scheme is performed to train the hidden layers in the autoencoders layer by layer, and fine tuning is conducted to optimize the whole network. Numerical and experimental investigations on steel frame structures are conducted to demonstrate the accuracy and efficiency of the proposed framework, comparing with the traditional ANN methods.

A new time-varying system identification approach is proposed in this paper by using variational mode decomposition. The newly developed variational mode decomposition technique can decompose the measured responses into a limited number of intrinsic mode functions, and the instantaneous frequencies of time-varying systems are identified by the Hilbert transform of each intrinsic mode function. Numerical and experimental verifications are conducted to demonstrate the effectiveness and accuracy of using the proposed approach for time-varying system identification, that is, to obtain the instantaneous frequency. Numerical studies on a structural system with time-varying stiffness are conducted. Experimental validations on analyzing the measured vibration data in the laboratory from a steel frame structure and a time-varying bridge-vehicle system are also conducted. The results from the presented technique are compared with those from empirical mode decomposition-based methods, which verify that the developed approach can identify the instantaneous frequencies with a better accuracy.

© Copyright 2017 Techno-Press, Ltd. Identification of damping characteristics is of significant importance for dynamic response analysis and condition assessment of structural systems. Damping is associated with the behavior of the energy dissipation mechanism. Identification of damping ratios based on the sensitivity of dynamic responses and the model updating technique is investigated with numerical and experimental investigations. The effectiveness and performance of using the sensitivity-based model updating method and vibration monitoring data for damping ratios identification are investigated. Numerical studies on a three-dimensional truss bridge model are conducted to verify the effectiveness of the proposed approach. Measurement noise effect and the initial finite element modelling errors are considered. The results demonstrate that the damping ratio identification with the proposed approach is not sensitive to the noise effect but could be affected significantly by the modelling errors. Experimental studies on a steel planar frame structure are conducted. The robustness and performance of the proposed damping identification approach are investigated with real measured vibration data. The results demonstrate that the proposed approach has a decent and reliable performance to identify the damping ratios.

© 2017 Elsevier Ltd. This paper proposes an improved decentralized structural identification approach with output-only measurements. The improved approach can be used for system identification of both linear and nonlinear structures. A large-scale structure is divided into a number of smaller zones according to its finite element configuration. Each zone is dynamically tested in sequence with its own set of sensor placement. The external excitation forces in each zone are identified using the Kalman filter technique. Structural parameters of the whole structure are divided into several subsets and then updated by using the Newton-SOR method. Both the external excitations and structural parameters are iteratively updated until a defined convergence criterion is met. The proposed technique is then applied to two numerical examples: a six floor building and a planar truss structure. The nonlinear system parameters of the building are correctly identified. The unknown excitation force, damage location, and damage severity in the plane truss structure are successfully identified. The effect of measurement noise on the identified results is also studied. An eight floor shear type structure is finally tested in the laboratory. The experimental results further verify the effectiveness and efficiency of the proposed technique in damage identification using output-only measurements.

The origin of the largest modern vertebrate group, the Teleostei, saw major refinements in the last decades, thanks to newly discovered and stratigraphically closely spaced Triassic Lagerstätten. Here we report the oldest Pholidophoriformes (stem teleosts) that were collected during a large scale yet detailed excavation of Upper Ladinian (Middle Triassic) marine deposits in Xingyi City, Guizhou Province, China. Taxonomic comparisons support the erection of a new pholidophorid genus, Malingichthys gen. nov., with two species. The new genus shows a partially fused skull roof, a preopercular bone with a hockey-stick shape and, for the first time in Pholidophoridae, supraneural elements. Most Triassic marine vertebrate clades (fishes and reptiles, Malingichthys included) first emerged in the South China Block, with Late Ladinian showing an important faunal transformation that was strengthened by our last findings. The material here described is about 2 million years older than the previous records for pholidophorids.

© 2014 AMDA - The Society for Post-Acute and Long-Term Care Medicine. Objectives: To describe Chinese nursing home residents' knowledge of advance directive (AD) and end-of-life care preferences and to explore the predictors of their preference for AD. Design: Population-based cross-sectional survey. Settings: Nursing homes (n= 31) in Wuhan, Mainland Southern China. Participants: Cognitively intact nursing home residents (n= 467) older than 60 years. Measures: Face-to-face questionnaire interviews were used to collect information on demographics, chronic diseases, life-sustaining treatment, AD, and other end-of-life care preferences. Results: Most (95.3%) had never heard of AD, and fewer than one-third (31.5%) preferred to make an AD. More than half (52.5%) would receive life-sustaining treatment if they sustained a life-threatening condition. Fewer than one-half (43.3%) chose doctors as the surrogate decision maker about life-sustaining treatment, whereas most (78.8%) nominated their eldest son or daughter as their proxy. More than half (58.2%) wanted to live and die in their present nursing homes. The significant independent predictors of AD preference included having heard of AD before (odds ratio [OR] 9.323), having definite answers of receiving (OR 3.433) or rejecting (OR 2.530) life-sustaining treatment, and higher Cumulative Illness Rating Scale score (OR 1.098). Conclusions: Most nursing home residents did not know about AD, and nearly one-third showed positive attitudes toward it. AD should be promoted in mainland China. Education of residents, the proxy decision maker, and nursing home staff on AD is very important. Necessary policy support, legislation, or practice guidelines about AD should be made with flexibility to respect nursing home residents' rights in mainland China.

For 10,000 years pigs and humans have shared a close and complex relationship. From domestication to modern breeding practices, humans have shaped the genomes of domestic pigs. Here we present the assembly and analysis of the genome sequence of a female domestic Duroc pig (Sus scrofa) and a comparison with the genomes of wild and domestic pigs from Europe and Asia. Wild pigs emerged in South East Asia and subsequently spread across Eurasia. Our results reveal a deep phylogenetic split between European and Asian wild boars approximately 1 million years ago, and a selective sweep analysis indicates selection on genes involved in RNA processing and regulation. Genes associated with immune response and olfaction exhibit fast evolution. Pigs have the largest repertoire of functional olfactory receptor genes, reflecting the importance of smell in this scavenging animal. The pig genome sequence provides an important resource for further improvements of this important livestock species, and our identification of many putative disease-causing variants extends the potential of the pig as a biomedical model.

Item does not contain fulltext, PURPOSE: To examine the discriminant validity, test-retest reliability, administration time and acceptability of the pediatric evaluation of disability inventory computer adaptive test (PEDI-CAT). METHODS: A sample of 102 parents of children 3 through 20 years of age with (n = 50) and without (n = 52) disabilities was recruited for this prospective field study. A sub-sample (n = 25) also completed the PEDI-CAT a second time within one month. Parents completed 15 items in each of the four PEDI-CAT domains (daily activities, mobility, social/cognitive, responsibility) using a laptop computer. Following completion, parents answered a four-question user evaluation survey. RESULTS: PEDI-CAT scores based on parent responses differentiated between groups of children with and without disabilities in all four domains. Test-retest reliability estimates were high (ICC = 0.96-0.99) for all four domains. The mean time to complete 60 items for the full sample (n = 102) was 12.66 minutes (SD = 4.47). Parents reported favorable reactions to the PEDI-CAT. CONCLUSIONS: The PEDI-CAT offers a valid and reliable assessment acceptable to parents.

For 10,000 years pigs and humans have shared a close and complex relationship. From domestication to modern breeding practices, humans have shaped the genomes of domestic pigs. Here we present the assembly and analysis of the genome sequence of a female domestic Duroc pig (Sus scrofa) and a comparison with the genomes of wild and domestic pigs from Europe and Asia. Wild pigs emerged in South East Asia and subsequently spread across Eurasia. Our results reveal a deep phylogenetic split between European and Asian wild boars ∼1 million years ago, and a selective sweep analysis indicates selection on genes involved in RNA processing and regulation. Genes associated with immune response and olfaction exhibit fast evolution. Pigs have the largest repertoire of functional olfactory receptor genes, reflecting the importance of smell in this scavenging animal. The pig genome sequence provides an important resource for further improvements of this important livestock species, and our identification of many putative disease-causing variants extends the potential of the pig as a biomedical model.

Objectives To investigate the patterns, predictors, and benefits associated with driving a modified vehicle for people with spinal cord injuries (SCIs). Design Cross-sectional retrospective survey design. Settings Sixteen Model SCI Systems (MSCISs) throughout the United States. Participants People (N=3726) post-SCI from the National MSCIS Database. Interventions Not applicable. Main Outcome Measures Driving, employment, and community reintegration post-SCI. Results The study found that 36.5% of the sample drove a modified vehicle after SCI. Significant predictors of driving a modified vehicle post-SCI included married at injury, younger age at injury, associate's degree or higher before injury, paraplegia, a longer time since the injury, non-Hispanic race, white race, male sex, and using a wheelchair for more than 40 hours a week after the injury (accounting for 37% of the variance). Higher activity of daily living independence (in total motor function) at hospital discharge also increased the odds of driving. Driving increased the odds of being employed at follow-up by almost 2 times compared with not driving postinjury (odds ratio, 1.85). Drivers tended to have higher community reintegration scores, especially for community mobility and total community reintegration. Driving was also associated with small health-related quality-of-life gains, including less depression and pain interference and better life satisfaction, general health status, and transportation availability scores. Conclusions The associated benefits of driving and the relatively low percentage of drivers post-SCI in the sample provide evidence for the need to increase rehabilitation and assistive technology services and resources in the United States devoted to facilitating driving after SCI. © 2011 American Congress of Rehabilitation Medicine.

Transporting, manipulating, and delivering intense ion beams to produce WDM conditions in volumetric material samples requires precise control and diagnostic measurement. The NDCX-II facility will deliver ~;55nC pulses of Li+ at 2-3 MeV in a sub-nanosecond duration within a 1 mm spot radius. We report on proposed methods to determine beam energy, charge and pulse duration, beam centroid offset, transverse distribution, and target plane fluence. We discuss recent work on calorimetric methods to determine peak beam intensity on the NDCX-I facility, and on beam position monitor development at the NDCX-II induction cell test stand.

Recent changes to the NDCX beamline offer the promise of higher current compressed bunches, with correspondingly greater fluence delivered to the target plane for ion-beam driven warm dense matter experiments. We report modeling and commissioning results of the upgraded NDCX beamline that includes a new induction bunching module with approximately twice the volt-seconds and greater tuning flexibility, combined with a longer neutralized drift compression channel.

A teacher of environmental studies at a magnet Montessori school for gifted children, ages 3 to 9, describes the development of Our Green Classroom, an outdoor garden featuring 100 species of plants, a pond, a birdbath, a bird and butterfly feeding station, a composting demonstration site, and a recycling center. Program emphasis is on hands-on experience with nature. (DB)

Pre-harvest sprouting results in significant economic loss for the grain industry around the world. Lack of adequate seed dormancy is the major reason for pre-harvest sprouting in the field under wet weather conditions. Although this trait is governed by multiple genes it is also highly heritable. A major QTL controlling both pre-harvest sprouting and seed dormancy has been identified on the long arm of barley chromosome 5H, and it explains over 70% of the phenotypic variation. Comparative genomics approaches among barley, wheat and rice were used to identify candidate gene(s) controlling seed dormancy and hence one aspect of pre-harvest sprouting. The barley seed dormancy/pre-harvest sprouting QTL was located in a region that showed good synteny with the terminal end of the long arm of rice chromosome 3. The rice DNA sequences were annotated and a gene encoding GA20-oxidase was identified as a candidate gene controlling the seed dormancy/pre-harvest sprouting QTL on 5HL. This chromosomal region also shared synteny with the telomere region of wheat chromosome 4AL, but was located outside of the QTL reported for seed dormancy in wheat. The wheat chromosome 4AL QTL region for seed dormancy was syntenic to both rice chromosome 3 and 11. In both cases, corresponding QTLs for seed dormancy have been mapped in rice.

More than 20 sediment-hosted massive sulphide deposits occur in Late Palaeozoic basins in South China. These deposits are accompanied by a certain amount of volcanic rocks in the host sequence and are economically important for their Cu, Pb, Zn, Au and Ag reserves. The deposits and their host strata were commonly intruded by Mesozoic granitoids. Remobilisation of sedimentary ores and magmatic hydrothermal overprinting processes resulted in the coexistence of massive sulphides with vein-, skarn- and porphyry-type orebodies in the same region or within a single deposit. The ore-containing basins occur in different tectonic settings. The Lower Yangtze basin occurs on a passive continental margin, where the deposits are high in Cu and Au with minor Pb and Zn and recoverable Ag, Co and Mo. The ores have a lower concentration of radiogenic lead, and δ34S values close to zero. Fluid inclusions are highly saline and Na-rich. Fluids and metals of the Lower Yangtze Region are interpreted to have been derived essentially from deep sources including the Precambrian basement. By contrast, basins of the Nanling Region formed in an intracontinental setting developed on a folded Caledonian basement. These deposits are higher in Pb, Zn, Sn and W, as well as Cu, with recoverable Ag, Sb, Hg, U, Bi, Tl and Mo. The ores are characterised by a higher concentration of radiogenic lead and a wide variation of δ34S composition. Fluid inclusions have lower salinities and higher K+/Na+ ratios. Fluids are considered to have been sourced substantially from seawater by convection. Metals for the Nanling deposits were essentially derived from the Caledonian basement by leaching. The contrast in ore composition between these two regions appears to have been controlled by differences in basement composition of the ore-forming basins.

The Hongtoushan Archaean Cu–Zn Volcanic-hosted Massive Sulphide (VHMS) deposit occurs in the Hunbei granite–greenstone terrane, Liaoning Province of NE China. The ores were metamorphosed (3.0–2.8 Ga) to upper amphibolite facies at temperatures between 600 and 650 8C, and underwent three phases of deformation. The deformation has transposed the stratiform orebodies into a Y-shaped configuration. Ore minerals in the deposit were originally composed of pyrite, pyrrhotite, chalcopyrite and sphalerite. Prograde metamorphism obliterated almost all the sedimentary textures in the ores, and the present ore textures were formed substantially during peak and post-peak metamorphism. Intensive remobilisations have occurred in the Hongtoushan deposit at various scales. There are more than 30 oreshoots inside the main massive sulphide orebodies. The oreshoots range from 2 to 30 m in length, 0.1 to 1.5 m in width, and 2 to 30 m in depth extension. Most run parallel or sub-parallel to the strike of the massive sulphide ore layers with only a few being developed in metamorphic rocks in the immediate vicinity of the sulphide orebodies. Almost all the sulphide and gangue minerals in the oreshoots have been affected by intense shearing. Pyrite is characterised by cataclastic flow; pyrrhotite, chalcopyrite and sphalerite exhibit strong plasticity. Hydrothermal alteration minerals in the oreshoots are dominated by deformation-free hornblende, actinolite, epidote, clinozoisite, biotite, muscovite, albite, carbonate and quartz. Cu, Au and Ag in the ore mylonites average 11 wt.%, 1.74 and 235 g/t, respectively. Compared to the massive sulphide ores, these oreshoots show remarkable enrichment of these elements with enrichment coefficients of 5.3, 5.0 and 4.6, respectively.We draw the conclusion that these oreshoots are actually ore mylonites overprinted by late-stage fluids. The presence of annealing textures in pyrrhotite and the absence in pyrite suggest that formation and succeeding annea

The Hongtoushan Archaean Cu–Zn Volcanic-hosted Massive Sulphide (VHMS) deposit occurs in the Hunbei granite–greenstone terrane, Liaoning Province of NE China. The ores were metamorphosed (3.0–2.8 Ga) to upper amphibolite facies at temperatures between 600 and 650 8C, and underwent three phases of deformation. The deformation has transposed the stratiform orebodies into a Y-shaped configuration. Ore minerals in the deposit were originally composed of pyrite, pyrrhotite, chalcopyrite and sphalerite. Prograde metamorphism obliterated almost all the sedimentary textures in the ores, and the present ore textures were formed substantially during peak and post-peak metamorphism. Intensive remobilisations have occurred in the Hongtoushan deposit at various scales. There are more than 30 oreshoots inside the main massive sulphide orebodies. The oreshoots range from 2 to 30 m in length, 0.1 to 1.5 m in width, and 2 to 30 m in depth extension. Most run parallel or sub-parallel to the strike of the massive sulphide ore layers with only a few being developed in metamorphic rocks in the immediate vicinity of the sulphide orebodies. Almost all the sulphide and gangue minerals in the oreshoots have been affected by intense shearing. Pyrite is characterised by cataclastic flow; pyrrhotite, chalcopyrite and sphalerite exhibit strong plasticity. Hydrothermal alteration minerals in the oreshoots are dominated by deformation-free hornblende, actinolite, epidote, clinozoisite, biotite, muscovite, albite, carbonate and quartz. Cu, Au and Ag in the ore mylonites average 11 wt.%, 1.74 and 235 g/t, respectively. Compared to the massive sulphide ores, these oreshoots show remarkable enrichment of these elements with enrichment coefficients of 5.3, 5.0 and 4.6, respectively.We draw the conclusion that these oreshoots are actually ore mylonites overprinted by late-stage fluids. The presence of annealing textures in pyrrhotite and the absence in pyrite suggest that formation and succeeding annea