检索结果-南通市图书馆

Effect of intermittent aeration mode on nitrogen concentration in the water column and sediment pore water of aquaculture ponds

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2020年第4期32卷 331-342页

作者： Dantong Zhu Xiangju Cheng David j.Sample Mohammad Nayeb Yazdi State Key Laboratory of Subtropical Building Science South China University of TechnologyGuangzhou 510640China School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510640China Department of Biological System Engineering Virginia Polytechnic Institute and State UniversityVirginia Beach 23455United States

Nitrogen in pond sediments is a major water quality concern and can impact the productivity of *** oxygen is an important factor for improving water quality and boosting fish growth in aquaculture ponds,and plays an important role in the conversion of ammonium-nitrogen(NH4-N)to nitrite-nitrogen(NO2--N)and eventually nitrate-nitrogen(NO3--N).A central goal of the study was to identify the best aeration method and strategy for improving water quality in aquaculture *** conducted an experiment with six tanks,each with a different aeration mode to simulate the behavior of aquaculture *** results show that a 36 hr aeration interval(Tc=36 hr:36 hr)and no aeration resulted in high concentrations of NH4-N in the water *** a 12 hr interval time(Tc=12 hr:12 hr)resulted in higher NO2--N and NO3--N concentrations than any other aeration *** from an 8 hr interval time(Tc=8 hr:8 hr)and 24 hr interval time(Tc=24 hr:24 hr)were comparable with those of continuous aeration,and had the benefit of being in use for only half of the time,consequently reducing energy consumption.

关键词： Intermittent aeration Nitrogen Water column Sediment resuspension and release Sediment Sediment pore water

Assessing the microbiota of recycled bedding sand on a Wisconsin dairy farm

在线全文

学校读者我要写书评

暂无评论

journal of Animal Science and Biotechnology 2022年第2期13卷 601-612页

作者： Hannah E.Pilch Andrew j.Steinberger Donald C.Sockett Nicole Aulik Garret Suen Charles j.Czuprynski Department of Pathobiological Sciences School of Veterinary MedicineUniversity of Wisconsin-MadisonMadison 53706USA Department of Bacteriology University of Wisconsin-MadisonMadison 53706USA Microbiology Doctoral Training Program University of Wisconsin-MadisonMadison 53706USA Wisconsin Veterinary Diagnostic Laboratory School of Veterinary MedicineUniversity of Wisconsin-MadisonMadison 53706USA

Background:Sand is often considered the preferred bedding material for dairy cows as it is thought to have lower bacterial counts than organic bedding materials and cows bedded on sand experience fewer cases of lameness and *** can also be efficiently recycled and reused,making it ***,some studies have suggested that the residual organic material present in recycled sand can serve as a reservoir for commensal and pathogenic bacteria,although no studies have yet characterized the total bacterial community *** we sought to characterize the bacterial community composition of a Wisconsin dairy farm bedding sand recycling system and its dynamics across several stages of the recycling process during both summer and winter using 16S rRNA gene amplicon ***:Bacterial community compositions of the sand recycling system differed by both seasons and *** samples had higher richness and distinct community compositions,relative to winter *** both summer and winter samples,the diversity of recycled sand decreased with time drying in the recycling ***,summer sand 14 d post-recycling was enriched in operational taxonomic units(OTUs)belonging to the genera Acinetobacter and Pseudomonas,relative to freshly washed sand and sand from cow *** contrast,no OTUs were found to be enriched in winter *** sand recycling system contained an overall core microbiota of 141 OTUs representing 68.45%±10.33%SD of the total bacterial relative abundance at each sampled *** 4 most abundant genera in this core microbiota included Acinetobacter,Psychrobacter,Corynebacterium,and *** was present in greater abundance in summer samples,whereas Psychrobacter and Corynebacterium had higher relative abundances in winter *** had consistent relative abundances across both ***:These findings highlight the potential of recycled bedding sand as a bacterial reservo

关键词： Bovine Dairy farm Microbiota Recycled bedding sand 16S rRNA sequencing

Analysis of PfAAs in American alligators part 2： Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat

在线全文

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2017年第11期29卷 31-38页

作者： jessica j.Tipton Louis j.Guillette jr Susan Lovelace Benjamin B.Parrott Thomas R.Rainwater jessica L.Reiner College of Charleston Charleston SC 29724 USA Medical University of South Carolina Department of Obstetrics and Gynecology Charleston SC 29425 USA University of Georgia Odum School of Ecology Savannah River Ecology Laboratory Jackson SC 29831 USA Torn Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and forest Science Clemson University P.O. Box 59(5 Georgetown SC 29442 USA National Institute of Standards and Technology Chemical Sciences Division Hollings Marine Laboratory Charleston SC 29412 USA

Exposure to perfluorinated alkyl acids（PfAAs） has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PfAAs,occurs through consumption of contaminated food or drinking water. This study uses PfAA data from meat samples collected from recreationally harvested American alligators（Alligator mississippiensis） in South Carolina to assess potential dietary exposure of hunters and their families to PfAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid（PfOS） concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11 ng/kg body weight per day for an adult human. Dietary PfOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PfOS found in Minnesota state guidelines, exposure to a mixture of PfAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PfAAs through consumption of wild alligator meat.

关键词： Public hunt American alligator Dietary exposure PfOS Consumption advisory Contaminant consumption

An Alternative Tool for Determining flavonoid Compounds in Markhamia tomentosa and Bunchosia glandulifera Using Digital Image Analysis

在线全文

学校读者我要写书评

暂无评论

Open journal of Applied Sciences 2022年第5期12卷 714-722页

作者： Luciana M. Santos Antonio j. Demuner Daiane E. Blank Cristiane I. Cerceau Iara f. Demuner Marcela R. Coura Maria j. M. firmino Marcelo H. Santos Neusa f. Moura Chemistry Department Federal University of Vi&ccedil osa Vi&ccedil osa Brazil Pulp and Paper Laboratory Federal University of Vi&ccedil osa Vi&ccedil osa Brazil Research Group in Natural Product Federal University of Rio Grande Rio Grande Brazil

Bunchosia glanduliera stands out because of the high content of flavonoid compounds in the pulp, contributing to the antioxidant potential of fruit extracts. Another plant species rich in flavonoid compounds is Markhamia tomentosa. However, to perform such an assay, a high-cost instrument is needed. To develop a simple and low-cost method for the determination of flavonoid compounds in M. tomentosa and B. glandulifera with PhotoMetrix® program application use pixels of digital imaging as an alternative method and linear correlation techniques for univariate analysis implementing systems of RGB colors (red, green, and blue). To determine the total flavonoids, the reaction with ferric chloride and quercetin was used as a control. for the acquisition of data or smartphones, low-cost materials were used, demonstrating the applicability of this analytical tool while comparing its cost to other analytical instrumentation. The total flavonoid content was also determined using a spectrophotometry technique in the visible ultraviolet spectrum (UV-Vis). The pulp of B. glandulifera showed the highest content of flavonoid compounds. The content of flavonoid compounds found in the fruit of B. glandulifera was 259.54 mg 100 g-1. In relation to the results found in the analysis of total flavonoids of M. tomentosa can be observed in the flower in natura has a higher content of these compounds. The use of PhotoMetrix® for the determination of flavonoid compounds in M. tomentosa and B. glandulifera reduced expense and analysis time. The method is reproducible and efficient. The proposed method can be adopted in different species.

关键词： Markhamia tomentosa Bunchosia glandulifera PhotoMetrix® flavonoid Smartphone

Modeling limit force capacities of high force to volume lead extrusion dampers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

frontiers of Structural and Civil Engineering 2021年第3期15卷 609-622页

作者： V.VISHNUPRIYA Geoffrey.W.RODGERS j.Geoffrey CHASE Department of Mechanical Engineering University of CanterburyChristchurch8140New Zealand QuakeCoRE NZ Centre for Earthquake Resilience Christchurch8041New Zealand

Lead extrusion dampers are supplemental energy-dissipation devices that are used to mitigate seismic structural *** volumetric sizes and high force capacities define high-force-to-volume(Hf2V)devices,which can absorb significant response energy without sacrificial ***,the design of such devices for specific force capacities has proven difficult based on the complexities of their internal reaction mechanisms,leading to the adoption of empirical *** study developed upper-and lower-bound force capacity estimates from analytical mechanics based on direct and indirect metal extrusion for guiding *** derived equations are strictly functions of Hf2V device geometric parameters,lead material properties,and extrusion *** upper-bound estimates from direct and indirect extrusion are denoted as(f_(UB,1),f_(UB,2))and(f_(UB,3),f_(UB,4)),respectively,and the lower-bound estimates are denoted as(f_(LB),f_(LB,1))based on the combination of extrusion and friction *** proposed models were validated by comparing the predicted bounds to experimental force capacity data from 15 experimental Hf2V device *** experimental device forces all lie above the lower-bound estimates(f_(LB),f_(LB,1))and below the upper-bound estimates(f_(UB,1),f_(UB,2),f_(UB,4)).Overall,the(f_(LB),f_(UB,2))pair provides wider bounds and the(f_(LB,1),f_(UB,4)/f_(UB,1))pair provides narrower ***(f_(LB,1),f_(UB,1))pair has a mean lower-bound gap of 36%,meaning the lower bound was 74%of the actual device force on *** mean upper-bound gap was 33%.The bulge area and cylinder diameter of Hf2V devices are key parameters affecting device *** relatively tight bounds provide useful mechanics-based predictive design guides for ensuring that device forces are within the targeted design range after manufacturing.

关键词： extrusion lead dampers upper and lower bound analytical modelling limit force

Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第9期15卷 1639-1649页

作者： Yanjun Xie Kevin j.Schneider Syed A.Ali Norman D.Hogikyan Eva L.feldman Michael j.Brenner Department of Otolaryngology-Head and Neck Surgery University of Michigan Medical SchoolAnn ArborMIUSA Department of Neurology University of Michigan Medical SchoolAnn ArborMIUSA

The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing

关键词： axon degeneration cranial neuropathy facial nerve facial paralysis motoneuron nerve regeneration peripheral nerve recurrent laryngeal nerve synkinesis vocal fold paralysis

Why Literature Matters to Me

在线全文

学校读者我要写书评

暂无评论

中国比较文学 2013年第4期 71-83页

作者： j. Hillis Miller University of California at Irvine USA

我一直很看重对文学作品的细读,对我而言,文学理论是辅助性的。尽管文学曾对西方和全球都有至关重要的作用,新的交流技术的兴起已经剧烈地改变了文学的社会地位。我对文学的兴趣始自大学时代,文学作品的意义至今仍令我痴迷。电影、电视... 详细信息

我一直很看重对文学作品的细读,对我而言,文学理论是辅助性的。尽管文学曾对西方和全球都有至关重要的作用,新的交流技术的兴起已经剧烈地改变了文学的社会地位。我对文学的兴趣始自大学时代,文学作品的意义至今仍令我痴迷。电影、电视、因特网、万维网、电子邮件、iPhone及iPad意味着今日文学对人们所思所信的影响已经式微,这种情况已经以不同的方式、在不同的程度上在全球各地发生。大学里老式的研究文学的方式今天似乎在中国比在美国更加繁荣。文学阅读的训练有助于人们更好地理解大众媒介。而且,文学仍然是人类满足其居留于想象世界之需求的无与伦比的方式。

关键词：细读迷惑新交流技术想象世界中国的文学研究

Development of New Interspecific Monosomic f_1 Substitution Stocks for Investigations in Cotton Genome

在线全文

学校读者我要写书评

暂无评论

棉花学报 2008年第S1期20卷 98-页

作者： SANAMYAN M f PETLYAKOVA j E SHARIPOVA E A RAKHMATULLINA E M Department of Biology Laboratory of Cotton Genetics Vuzgorodok

As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still *** the detection of new types of aneuploids especially in different cytogenetic collections is very *** Uzbe... 详细信息

关键词： In Development of New Interspecific Monosomic f1 Substitution Stocks for Investigations in Cotton Genome

Experimental and Numerical Investigation on Impact Performance of Carbon Reinforced Aluminum Laminates

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2010年第4期26卷 327-332页

作者： S.H. Song Y.S. Byun T.W. Ku W.j. Song j. Kim B.S. Kang National Core Research Center Pusan National University Busan 609-735 Korea Dept. of Aerospace Engineering Pusan National University Busan 609-735 Korea Industrial Liaison Innovation Cluster Pusan National University Busan 609-735 Korea

It is known that fiber metal laminates （fML） as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a relatively low density. Therefore, the mechanical components using fML can contribute the enhanced safety level of the sound construction toward the whole body. In this study, the impact performance of carbon reinforced aluminum laminates （CARAL） is investigated by experiments and numerical simulations. Drop weight tests are carried out with the weight of 4.7 kg at the speed of 1 and 2 m/s, respectively. Dynamic non-linear transient analyses are also accomplished using a finite element analysis software, ABAQUS. The experiment results and numerical results are compared with impact load-time histories. Also, energy-time histories are applied to investigate the impact performance of CARAL.

关键词： fiber metal laminates (fML) Carbon reinforced aluminum laminates (CARAL) Numerical simulation Impact performance