Wyniki wyszukiwania - Biblioteka Nauki

1

Marine search and rescue of UAV in long-distance security modeling simulation

100%

Zheng L. , Hu J. , Xu S.

Polish Maritime Research

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2017

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tom 24

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nr Special Issue S3

EN

Long-distance safety of Marine search and rescue using drones can improve the searching speed. The current method is based on the long distance security classification of UAV.The degree of accuracy is low. A long-distance security modeling approach based on ArduinoMiniPro’s Marine search-and-rescue applying UAV is proposed. The method puts the fault tree analysis and relevant calculation for risk identification into use. The main factors affecting the safety of unmanned aerial vehicle (UAV) are long-distance searching and rescuing. The experimental results show that the proposed method can effectively build modeling for the long-distance safety of the Marine search and rescue UAV

2

Three dimensional finite element analysis of a novel osteointegrated dental implant designed to reduce stress peak of cortical bone

100%

Zheng L. , Yang J. , Hu X. , Luo J.

Acta of Bioengineering and Biomechanics

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2014

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tom Vol. 16, no. 3

21--28

EN

A new type of dental implant was designed as multi-component mainly including inset and abutment between which a gap was introduced to guide the force to transmit from the cancellous bone to cortical bone, with the intention to lower the stress peak at cortical bone. By the way of finite element analysis (FEA) associated with advanced computer tomography (CT) and 3D model reconstruction technology to construct precise mandible model, biomechanical aspects of implant were investigated. Compared with traditional implant that created stress dominantly at cortical bone, stress peak at the implant/bone interface in the cervical cortex decreased sharply (about 51%) for new type of implant. Furthermore, varying implant shape and gap dimensions to optimize the design of this new implant was performed. Optimization results revealed that: 1) screwed cylindrical implant is superior to tapered, stepped and smooth cylindrical implant in effectively decreasing the stress peak of bone; 2) deepening and widening gap would contribute to the decline of stress peak, but at the cost of break and destruction of the inset; 3) suitable gap size with the depth of 7mm and width of 0.3mm would be applicable. This work may provide reference forclinical application of dental implant.

3

Analytical approximants for a boundary layer flow on a stretching moving surface with a power law velocity

100%

Zheng L. , Chen X. , Zhang X.

International Journal of Applied Mechanics and Engineering

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2004

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tom Vol. 9, no 4

795-802

EN

This paper presents an efficient analytical decomposition and numerical procedure technique for solving a self-similarity boundary layer on a moving surface with power law velocity. The types of potential flows necessary for similar solutions to the boundary layer equations and the existence conditions of the Pad e' approximants [2/2] of degree 4 are determined. Furthermore, the analytical approximations and numerical solutions are presented for different velocity parameters. The results demonstrate the reliability and efficiency of the proposed algorithm.

4

Marine search and rescue of UAV in long-distance security modeling simulation

100%

Zheng L. , Hu J. , Xu S.

Polish Maritime Research

|

2017

|

tom S 3

192--199

EN

Long-distance safety of Marine search and rescue using drones can improve the searching speed. The current method is based on the long distance security classification of UAV.The degree of accuracy is low. A long-distance security modeling approach based on ArduinoMiniPro’s Marine search-and-rescue applying UAV is proposed. The method puts the fault tree analysis and relevant calculation for risk identification into use. The main factors affecting the safety of unmanned aerial vehicle (UAV) are long-distance searching and rescuing. The experimental results show that the proposed method can effectively build modeling for the long-distance safety of the Marine search and rescue UAV.

5

The characteristics of radon and thoron concentration from soil gas in Shenzhen City of Southern China

88%

Wang N. , Zheng L. , Chu X. , Li S. , Yan S.

Nukleonika

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2016

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tom Vol. 61, No. 3

315--319

EN

Radon (222Rn) and thoron (220Rn) from soil gas are very significant factors that can affect the indoor radon level in the first floor or in the basement. China is one of the countries with the highest thorium content in the world. Therefore, it is very significant to study 222Rn/220Rn concentration in the soil in Shenzhen City (SC). A 222Rn/220Rn survey was performed using a portable radon monitor (model RAD7) at 69 sites, covered a total area of 1800 km2 in 2013 to get the original data for radon risk estimation in SC. The average values of 222Rn and 220Rn concentration of soil gas of the total 69 locations are 86 ± 72 kBq•m–3 and 118 ± 85 kBq•m–3, respectively. 222Rn/220Rn concentrations are related to geological lithology. 222Rn concentrations vary from 40 to 370 kBq•m–3 and from 15 to 118 kBq•m–3 in weathered granite products and sediments, respectively, while 220Rn concentrations are from 103 to 435 kBq•m–3 and 2.2 to 96 kBq•m–3. The higher 220Rn values were mainly observed at the sites covered by the weathered granite products. Comparing with the areas of high 222Rn concentration, the areas of high 220Rn values are larger. The distribution of 222Rn concentration in the vertical direction displays an exponential distribution mode, but there is no rule of 220Rn concentration. The investigation suggests that people should pay attention to 220Rn contribution in the radon mapping of SC, as well as in the indoor radon survey.

6

Simplified Model for Predicting Fabric Thermal Resistance According to its Microstructural Parameters

88%

Wei J. , Xu S. , Liu H. , Zheng L. , Qian Y.

Fibres & Textiles in Eastern Europe

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2015

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tom Vol. 23, no. 4 (112)

57--60

EN

This paper presents a modified model to calculate the thermal resistance of woven and knitted fabrics according to the microstructural parameters. The model was established by analysing the heat transfer process in the simplified basic unit of the fabrics. The model was modified and checked by experimental values of various fabric samples. Pearson correlation coefficients between the thermal resistance and fabric structural parameters were calculated. Results indicate that fabric thermal resistance can be predicted by the modified equation satisfactorily. The Pearson correlation coefficient from high to low follows such a sequence: fabric thickness, fabric volume density, fabric structural parameter a, fibre volume density, and fibre thermal conductivity.

PL

W artykule przedstawiono zmodyfikowany model pozwalający obliczyć opór termiczny tkanin i dzianin w zależności od parametrów ich mikrostruktury. Model został skonstruowany poprzez analizę procesu przepływu ciepła przez uproszczoną jednostkę płaskiego materiału włókienniczego. Model został sprawdzony w praktyce przez badanie różnych próbek tkanin i dzianin. Przy ocenie zastosowano porównanie współczynników korelacji Pearsona między oporem termicznym i parametrami strukturalnymi. Wyniki wskazują, że termiczną izolację płaskich materiałów włókienniczych można przewidzieć w zadowalającym stopniu przez zaproponowane zmodyfikowane równania. Współczynniki korelacji Pearsona począwszy od dużych do małych można uszeregować dla następujących parametrów: grubość tkaniny, gęstość właściwa tkaniny, parametry strukturalne, gęstość właściwa włókien i przewodność cieplna włókien.

7

Understanding Farmers’ Adoption Decisions for New Cash Crops: Evidence from Xishuangbanna in Tropical China

88%

Zhang L. , Kono Y. , Hua X. , Zheng L. , Zhou R.

Problemy Ekorozwoju

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2017

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tom Vol. 12, nr 2

99--108

EN

On a global basis, cash cropping is usually identified as an important enterprise undertaken by farmers to increase incomes. However, the responses of farmers to these new enterprises vary greatly. Through a case study of a Dai village in Xishuangbanna, China, this paper examines how farmers make decisions about adopting new cash crops by focusing on the farm economy and land conditions. The results show that farmers did not adopt watermelons due to poor irrigation and accessibility conditions, and then they did not adopt bananas due to a transient collapse of banana market, induced by a rumor suggesting that eating bananas causes cancer. Consequently, although these non-adopters benefited from commercial exchanges with external businessmen in terms of ecological experiments and management diversification, and leasing lowlands to external businessmen is a livelihood choice that is based on the outcome of the farmer’s trade-off between profitability and risk, they missed opportunities to substantially increase incomes through cash cropping, as evidenced by the success of the farmers who adopted the cash crops. These findings suggest that the government ought to design tailored extension programs for villages, implement efficient refutation strategies to prevent rumor-induced market collapse and promote extension services as early as possible in the initial stages of transition to cash cropping.

XX

Patrząc z perspektywy globalnej za uprawy komercyjne uznaje się istotne działania podejmowane przez rolników w celu zwiększenia swoich dochodów. Jednakże zainteresowanie rolników nowymi rozwiązaniami jest bardzo zróżnicowane. Niniejszy artykuł na przykładzie doliny Dai w należącym do Chin rejonie Xishuangbanna pokazuje jakie czynniki finansowe i środowiskowe wpływają na podjęcie przez rolników decyzji odnoszących się do nowych upraw komercyjnych. Otrzymane wyniki pokazują, że za odrzuceniem arbuzów stały ograniczone możliwości nawadniania i ograniczony dostęp, a za odrzuceniem bananów chwilowe załamanie rynku zbytu tych owoców, związane z szerzącą się pogłoską, jakoby konsumpcja bananów mogło być przyczyną nowotworów.Konsekwentnie, chociaż rolnicy odrzucający nowe uprawy korzystali z wymiany handlowej z zewnętrznymi przedsiębiorcami pod kątem eksperymentów ekologicznych i dywersyfikacji zarządzania, a ponadto biorąc pod uwagę, że przeznaczanie pól dla zewnętrznych przedsiębiorców jest decyzją opartą na ocenie możliwych zysków i strat, ci rolnicy stracili szansę na znaczące zwiększenie przychodów z upraw komercyjnych. Pokazuje to przykład rolników, którzy jednak zdecydowali się na nowe uprawy. Uzyskane rezultatu wskazują, że rząd powinien przygotować dostosowane do potrzeb rolników programy i strategie odnoszące się do tych zagadnień.

8

Spatial and seasonal variations of large tintinnid ciliates in Shenhu Bay of China

88%

Wang Y. , Zhang W. , Lin Y. , Zheng L. , Yang J.

Oceanological and Hydrobiological Studies

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2014

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tom 43

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nr 3

9

Cloning and functional analysis of two flavanone-3-hydroxylase genes from Reaumuria trigyna

75%

Zhang H. , Zhao L. , Wang J. , Zheng L. , Dang Z. , Wang Y.

Acta Physiologiae Plantarum

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2014

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tom 36

|

nr 05

EN

Reaumuria trigyna is a highly xeric small shrub and is a rare wild plant in Mediterranean areas. The flavonoid biosynthesis pathway in R. trigyna is strongly activated under salt stress, and many genes related to this pathway showed significant differences in transcript abundance under salt stress in a previous transcriptomic profiling analysis. The F3H gene, which encodes flavanone-3-hydroxylase, is an essential gene in the flavonoid biosynthetic pathway. The transcript levels of two F3H genes, RtF3H1 and RtF3H2, were increased in R. trigyna not only under salt stress but also under drought and cold stresses, and by abscisic acid. We measured the transcript levels of the two genes in different organs. There were high transcript levels of RtF3H1 in stems, and high transcript levels of RtF3H2 in roots and stems. The full-length cDNAs for RtF3H1 (Accession No. AB850638) and RtF3H2 (Accession No. AB850639) were cloned and were found to encode 353- and 358-amino-acid proteins, respectively. Escherichia coli overexpressing RtF3H1 or RtF3H2 showed better growth than that of a control E. coli line under various stress treatments. The survival rate of the recombinant E. coli strain expressing RtF3H2 was higher than that of the strain expressing RtF3H1 under salt and drought stresses.

10

Spatial and seasonal variations of large tintinnid ciliates in Shenhu Bay of China

75%

Wang Y. , Zhang W. , Lin Y. , Zheng L. , Cao W. , Yang J.

Oceanological and Hydrobiological Studies

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2014

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tom Vol. 43, No. 3

292--302

EN

In this study, the spatial distribution and seasonal variation of large tintinnids (>76 μm) were investigated in Shenhu Bay during three seasons of 2012. Of the 36 species identified, 9 were dominant (i.e. Tintinnopsis radix, Leprotintinnus simplex, Tintinnopsis japonica, Tintinnopsis tubulosoides, Leprotintinnus nordqvisti, Tintinnopsis beroidea, Stenosemella parvicollis, Tintinnidium primitivum, Tintinnopsis nana). A clear seasonal shift of the taxonomic composition as well as the lorica size of the dominant species was observed. The highest numbers of tintinnid species occurred in spring, while the highest abundance and biomass occurred in summer. Clustering indicated that the seasonal variations of the community structure were more obvious than spatial variations. Spearman correlation analysis revealed that density of phytoplankton prey had a significant impact on the tintinnid abundance. Redundancy analysis (RDA) illustrated that temperature, salinity and the nutrient level were the most important abiotic factors affecting the spatial and seasonal pattern of tintinnid communities in Shenhu Bay.

11

Spatial pattern of the planktonic ciliate community and its relationship with the environment in spring in the northern Beibu Gulf, South China Sea

75%

Wang Y. , Zhang W. , Lin Y. , Zheng L. , Cao W. , Yang J.

Oceanological and Hydrobiological Studies

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2013

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tom Vol. 42, No. 4

470--479

EN

Surface water samples were collected from 19 sites in the northern Beibu Gulf in April 2011. Species composition and abundance of planktonic ciliates were investigated. They were combined with environmental data to obtain the spatial pattern of the ciliate community and its relationship with the environment. A total of 36 species belonging to 13 genera and 3 orders (Oligotrichida, Haptorida and Tintinnida) were identified, including 10 dominant species. All 19 samples were divided into three groups using cluster analysis and multidimensional scaling (MDS) on the basis of the ciliate species composition and abundance. Group 1 was the least abundant. The species of the order Oligotrichida dominated in Group 2. In contrast, Mesodinium species were of increased importance in Group 3. Redundancy analysis (RDA) revealed that ciliate communities were more closely related to the level of nitrogen (total nitrogen, nitrate nitrogen, nitrite nitrogen) and phosphorus (total phosphorus, active phosphorus) rather than other variables. As the levels of nitrogen and phosphorus increased, communities dominated by species from the order Oligotrichida were replaced by those dominated by Mesodinium species.

12

IFN-λ1 in CHO cells: its expression and biological activity

75%

Yuan W. , Zhang W. , Ma F. , Li J. , Zhang Q. , Zheng L.

Cellular and Molecular Biology Letters

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2017

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tom 22

13

Cardioprotection of exogenous erythropoietin in mice with ligature-induced aortic stenosis: effects on maladaptive cardiac hypertrophy

75%

Zheng L. , Xu J. , Qiu W. , Liu X. , Zhao C.-M. , Chen D. , Chen Y.

Journal of Physiology and Pharmacology

|

2010

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tom 61

|

nr 1

13-20

EN

Pre-operative treatment with recombinant human erythropoietin may improve aortic stenosis patients' condition, including anemia and/or cardiac dysfunction, for subjecting to aortic valve replacement. In this study, we tested this hypothesis in a mouse model of aortic stenosis. Adult male mice were subjected to either aortic stenosis created by aortic ligature or sham operation. Aortic stenosis for 4 weeks caused cardiac hypertrophy, pulmonary congestion and left ventricular dysfunction. It was associated with increased levels of tumor necrosis factor-a in serum and myocardium, and reduced levels of interleukin-10 in myocardium but not in serum. Mytocyte apoptosis rate, level of cleaved caspase 3, activity of nuclear factor-B and expression of p38-MAPK pathway were also elevated. Erythropoietin treatment increased hematocrit but did not prevent the development of cardiac hypertrophy. It, however, reduced the apoptosis, prevented the increases in tumor necrosis factor-, nuclear factor-B activation and phosphorylation of p38, and attenuated the increases in lung weight, the decreases in LVEF and LVFS, and the increases in LVDd and LVDs. In conclusion recombinant human erythropoietin has cardioprotective effects in maladaptive cardiac hypertrophy by inhibiting nuclear factor-B activation, phosphorylation of p38-MAPK pathway, and production of tumor necrosis factor-, together leading to a reduced apoptosis.

14

Spatial pattern of the planktonic ciliate community and its relationship with the environment in spring in the Northern Beibu Gulf, South China Sea

75%

Wang Y. , Zhang W. , Lin Y. , Zheng L. , Cao W. , Yang J.

Oceanological and Hydrobiological Studies

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2013

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tom 42

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nr 4

15

Multiple compounds determination and fingerprint analysis of Agrimonia pilosa Ledeb by high-performance liquid chromatography

63%

Wang Y. , Yin L. , Lv G. , Xu Y. , Xu L. , Qi Y. , Zheng L. , Peng J.

Acta Chromatographica

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2014

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tom Vol. 26, no. 1

137--156

EN

In the present paper, a simple and reliable high-performance liquid chromatography-diode array detection (HPLC-DAD) method was developed both for quantitative determination and fingerprint analysis of Agrimonia pilosa Ledeb for quality control. Under the optimized HPLC conditions, seven bioactive compounds including rutin, quercetin-3-rhamnoside, luteoloside, tiliroside, apigenin, kaempferol, and agrimonolide were determined simultaneously. For fingerprint analysis, 11 common peaks were selected as the characteristic peaks to evaluate the similarities of 16 different samples collected from different origins in China. Besides, hierarchical cluster analysis (HCA) was also performed to evaluate the variation of the raw materials. This is the first report of using a simple method for quality control of A. pilosa Ledeb through multi-component determination and chromatographic fingerprint analysis to the best of our knowledge.

16

Concentrations of heavy metals in six municipal sludges from Guangzhou and their potential ecological risk assessment for agricultural land use

63%

Liu J. , Zhou Z. , Sun S. , Ning X. , Zhao S. , Xie W. , Wang Y. , Zheng L. , Huang R. , Li B.

Polish Journal of Environmental Studies

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2015

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tom 24

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nr 1

EN

Six kinds of municipal sludge samples were collected from wastewater treatment plants (WWTPs) from Guangzhou in southern China. Total concentration of Cu, Pb, Zn, Cr, Ni, Cd, and Mn in the sludge was determined, and used obtained values to appraise the degree of agricultural land pollution on the base of four pollution indixes. Results showed that the concentrations of the heavy metals Cu (4.567 mg/kg), Mn (1.844 mg/kg), Ni (148 mg/kg), Cr (121 mg/kg), and Cd (5.99 mg/kg) in S1 sludge were higher than that of the other sludges. In six sludge samples the concentrations of Mn, Zn, and Cu were highest, followed by Ni, Pb, and Cr. Cd had the lowest concentration. All were higher than those recorded in the background data for crop soils. With the exception of Cu and Cd from site S1, and Ni from sites S1, S2, and S5, all other metal concentrations conformed to permissible levels prescribed by the national application standard of acid soil in China (GB18918-2002). The geoaccumulation index (Igeo) assessment results indicate that there are serious risks in agricultural utilization for the existing Cu and Zn in these six kinds of sludges, especially the Igeo, which was 6.53 for Cu, 3.21 for Mn, 2.78 for Cd in the S1 sludge. The results of RI showed that sludge had high potential ecological risks, especially caused by Cd, which should give rise to widespread concerns. The potential ecological risk index (RI) of heavy metals in six sludge samples was ranked in the order of S1>S2>S4>S3>S5>S6.

17

Genetic characterisation and local genotypes of canine parvovirus strains collected from pet dogs in Central and Eastern China during 2018–2019

63%

Hu W. , Zheng L. , Xu X. , Liu Q. , Ji J. , Yao L. , Kan Y. , Bi Y.

Journal of Veterinary Research

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2020

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tom 64

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nr 4

18

Genome-wide identification and expression profiling analysis of brassinolide signal transduction genes regulating apple tree architecture

63%

Zheng L. , Ma J. , Song C. , An N. , Zhang D. , Zhao C. , Qi S. , Han M.

Acta Physiologiae Plantarum

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2017

|

tom 39

|

nr 08

19

Expression analysis of key auxin synthesis, transport, and metabolism genes in different young dwarfing apple trees

63%

Song H. , Zhang D. , Zhang J. , Zheng L. , Zhao C. , Ma J. , An N. , Han M.

Acta Physiologiae Plantarum

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2016

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tom 38

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nr 02