Wyniki wyszukiwania - Biblioteka Nauki

1

Modeling and experimental investigation of a controllable rotary fluid damper

100%

Cao X. , Zhou J. , Yu M. , Wang Y.

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2023

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tom Vol. 75, nr 4

493--516

EN

Controllable rotary fluid damper (CRFD) is an efficient and cheap energy dissipation device, which is used to reduce the impact of vibration in mechanical systems. In this paper, the CRFD controlled by a servo motor is developed to reduce the effects of vibrations in the helicopter flight control system. The dynamic mechanical characteristic of the CRFD is experimentally investigated by the MTS machine. Due to the complex factors such as high shear thinning rate and compressibility of the damping medium, inertia of moving parts and internal friction, the CRFD studied has highly nonlinear hysteresis characteristics. The accuracy of the damper modeling is of great significance for designing effective vibration reduction methods. Therefore, a new generalized viscous–nonlinear elastic model is proposed to track the mechanical characteristics of CRFD. On the basis of parameter sensitivity analysis, the proposed generalized viscous–nonlinear elastic model is modified. According to the identification results of the modified model, the main parameters are fitted as polynomial functions of motor rotation angle. Through error analysis between analytical torques and experimental torques, it is concluded that the modified generalized viscous–nonlinear elastic model has the smallest error compared with Kwok and Maxwell models, which indicates that the proposed modified model can accurately describe the mechanical characteristics of the CRFD under different working conditions.

2

A Iontophoretic delivery of transdermal patches containing ropivacaine: sustaining the anesthetic effect in children

100%

Yu T. , Zhang S. , Cao X. , Liu C.

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nr 2

3

Study on the Initiation Capacities of Conical Ring Booster Pellets

100%

Hu L. , Hu S. , Cao X. , Li J.

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tom Vol. 11, no. 3

335--348

EN

The insensitive main charge explosive is becoming an important part of modern weapon development. Insensitive main charge explosives generally have a high critical initiation pressure. The detonation pressure of a traditional cylindrical booster pellet is constant at a specific density and consequently has insufficient energy output to reliably initiate an insensitive main charge explosive. To ensure that this requirement could be achieved, the conical ring booster pellet was designed and optimized. Eight-point-synchronous explosive circuits were designed as appropriate to the sizes of the four booster pellets. The initiation processes of the four conical booster pellets equipped with the eight-point circuit were simulated using ANSYS/LY-DYNA software. The experimental measurements were performed in order to test the initiation capacities of these conical booster pellets. The results demonstrated that their initiation capacities are much better than the initiation capacity of a cylindrical booster pellet. The optimum size of the conical ring booster pellet is when the ratio of the inner to the upper diameter is 0.52, the ratio of the inner to the lower diameter is 0.44, and the ratio of the height to the lower diameter is 0.50.

4

Challenge of water sources in urbanizing China: an analysis of agricultural water footprint

100%

Cao X. , Wu P. , Wang Y. , Zhao X.

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tom 24

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nr 1

EN

It is widely recognized that China is facing the dual challenge of food scarcity and water shortage. A large amount of water is to be demanded for the country’s huge population and rapid economic growth. The agricultural water footprint (AWF) proposes a new approach to indicate the interaction between food consumption and water utilization. This paper aims to quantify a long-time series of China’s AWF, map its variation trend, and assess its potential influence. The findings show that the total agricultural water footprint (TAWF) has increased from 7,593 km³ in 1990 to 10,929 km³ in 2011 due to increases in population and in per capita agricultural water footprint (CAWF). Over the past few years, China has also held an increasing external AWF volume, which climbed up to nearly 10% of the TAWF respectively in 2009, 2010, and 2011. The animal WF proportion of a single urban resident was much higher than that of a rural one because of their different consumption patterns, but neither of their proportions varied significantly over the same period of time. China’s CAWF increased over time and held a multi-year average value of 741 m³ ·cap⁻¹·y⁻¹. The results suggest that CAWF stayed linear positively related to the urban population proportion (UPP) during the study period and that urbanization proves to be the dominant driving force to the water requirement for food consumption augmentation. Considering the irresistible economic growth and urbanization, China should take active measures to cope with troubles potentially brought by the increase in AWF and water dependency degree (WDD). Suggestions with regard to how to guarantee China’s food and water resource security are raised in this paper.

5

Influence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene

100%

Gao Y. , Zheng W. , Cao X. , Chen S.

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tom Vol. 59, No. 4

123--128

EN

In light of the issue of radiolysis of the solvent system in PUREX process, alpha and gamma radiation stability of tributyl phosphate (TBP)/kerosene (OK) have been studied in this paper, in which 238Pu dissolved in the organic phase and 60Co are selected as alpha and gamma irradiation sources, respectively. The amount of the degradation products not easily removed after the washing process has been measured by the plutonium retention. The effects of the absorbed dose, the TBP volume fraction, the cumulative absorbed dose and the presence of UO2 2+ and Zr4+ on the radiolysis of the solvents have been investigated. The results have indicated that the Pu retention increases with the increase of the absorbed dose after alpha or gamma irradiation, and is larger for the solvent containing less TBP. There is competition between UO2 2+ and Pu4+ to complex with the degradation products, and Zr4+ accelerates the radiolysis of the system.

6

Dynamic Measurement of Foam-Sized Yarn Properties from Yarn Sequence Images

88%

Zhu B. , Li Z. , Cao X. , Liu J. , Gao W.

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2018

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tom Vol. 18, no. 3

314--322

EN

Unlike the normal sizing method, the foam sizing had been proven to be a low-add-on technology. To investigate the effect of foam sizing, film thickness, sized-yarn evenness, and size penetration rate were necessary to evaluate the performances of foam-sized yarns. However, the conventional image analysis of sized-yarn cross sections primarily relied on artificial testing with a low efficiency. This paper proposed a novel dynamic method to measure the sized-yarn properties including film thickness, sized-yarn evenness, and size penetration rate based on yarn sequence images captured from a moving yarn. A method of dynamic threshold module was adopted to obtain threshold for segmenting yarns in the sequence images. K-means clustering algorithm was applied to segment pixels of the images into yarn and background. To further remove burrs and noise in the images, two judgment templates were carried out to extract the information of yarn core. The film thickness, sized-yarn evenness, and size penetration rate were measured based on the yarn core of each frame in sequence images. In order to compare with the experimental results of the dynamic method, the yarn properties of the same samples were tested by static and artificial testing. Results revealed that the proposed method could efficiently and accurately detect the film thickness, sized-yarn evenness, and size penetration rate.

7

Effects of watering regime and nitrogen application rate on the photosynthetic parameters, physiological characteristics, and agronomic traits of rice

75%

Cao X. , Zhong C. , Sajid H. , Zhu L. , Zhang J. , Wu L. , Jin Q.

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nr 06

8

Improvement of LiCoO2 cathodes by using Ag2V4O11 as an additive

75%

Cao X. , Liu J. , Wan J. , Xie L. , Yan X. , Wang H.

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tom Vol. 27, No. 1

287--295

EN

LiCoO2/Ag2V4O11 composites were fabricated as cathode materials for lithium ion batteries by mechanical mixing of commercial LiCoO2 and Ag2V4O11 powders. The underlying principle of this idea was that the metallic silver particles were formed and acted as a conducting matrix when Ag2V4O11 cathode was electrochemically reduced which could significantly increase the electronic conductivity and decrease the polarization of cathode materials. The structure, morphology and electrochemical performance of bare LiCoO2 and LiCoO2/Ag2V4O11 composites were analyzed by XRD, SEM and charge-discharge test of CR2016 coin cells. The results show that a low amount of Ag2V4O11 additive can effectively enhance the discharge capacity and cycleability of LiCoO2. The composite containing 3 wt. % of Ag2V4O11 exhibits a higher discharge capacity and better cycle life than bare LiCoO2.

9

Comparative transcriptome reveals circadian and hormonal control of adventitious rooting in mulberry hardwood cuttings

75%

Cao X. , Du W. , Shang C. , Shen Q. , Liu L. , Cheng J.

Acta Physiologiae Plantarum

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2018

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tom 40

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nr 11

10

Molecular cloning and functional analysis of an organ-specific expressing gene coding for farnesyl diphosphate synthase from Michelia chapensis Dandy

75%

Yin T. , Cao X. , Miao Q. , Li C. , Chen X. , Zhou M. , Jiang J.

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nr 1

EN

Farnesyl diphosphate synthase (FPS; EC 2.5.1.1/EC 2.5.1.10) catalyzes the synthesis of farnesyl diphosphate, a key intermediate in the biosynthesis of sesquiterpenes. This present study described the cloning and characterization of a cDNA encoding FPS from leaves of Michelia chapensis Dandy (designated as McFPS, GenBank accession number: GQ214406) for the first time. McFPS was 1,432 bp and contained an open reading frame (ORF) of 1,056 bp, encoding a protein of 351 amino acids with a calculated molecular mass of 40.52 kDa. Bioinformatic analysis revealed that the deduced McFPS had high homology with FPSs from other plant species. Phylogenetic tree analysis indicated that McFPS belonged to the plant FPS group and had the closest relationship with FPS from Chimonanthus praecox. Southern blot analysis revealed that there were at most two copies of McFPS gene existed in M. chapensis genome. The organ expression pattern analysis showed that McFPS expressed strongly only in leaves, and there were no expression in stems and roots, implying that McFPS was an organ-specific expressing gene. Functional complementation of McFPS in a FPS-deficient yeast strain demonstrated that cloned cDNA encoded a farnesyl diphosphate synthase.

11

Basic research on determining optical properties of tissues in vivo by measuring diffuse reflectance with a charge-coupled device

75%

Sun P. , Cao X. , Yang R. , Xie F. , Ding J. , Zhang F.

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2011

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tom Vol. 41, nr 3

541--555

EN

We measured the absorption coefficient and the reduced scattering coefficient of Intralipid solution and human forearm tissues in vivo by measuring diffuse reflectance with a charge-coupled device, examining the techniques involved. The experimental results indicate that the error is less than or equal to 8% using the diffusion theory, under the condition that the reduced scattering coefficient is one order of magnitude greater than the absorption coefficient. The stability and precision of optical property measurements are significantly improved by using the multistep iterative fitting method and using the ring-zone-constraint method to determine the diffuse reflectance center. The efficiency of reverse algorithm is greatly enhanced by selecting a one-dimensional array on the straight line crossing both the entry point and the diffusion center for fitting.

12

Evaluation of agronomic and physiological traits associated with high temperature stress tolerance in the winter wheat cultivars

63%

Cao X. , Mondal S. , Cheng D. , Wang C. , Liu A. , Song J. , Li H. , Zhao Z. , Liu J.

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tom 37

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nr 04

EN

Post-anthesis high temperature stress is a major concern for the winter wheat producing areas in east China, especially in Shandong province. Fourteen agronomic and physiological traits were studied in 58 Chinese wheat accessions under high-temperature conditions in 2012 and 2013. High temperature stress led to reduction in grain yield and other yield component traits. Significant variations were observed for grain yield per plant (GYPP), grain weight per spike (GWS), thousand kernel weight (TKW), grain number of the main-spike, spikelet number and biological yield per plant. Among the physiological traits measured, chlorophyll content and normalized difference vegetation index showed significant variation under high temperature stress. The results indicate that heat susceptibility index estimated for TKW, GYPP, GWS and flag leaf senescence scale (FLSS) could be used as selection criteria for identifying heat tolerant genotypes for the Shandong province. The results also suggest that FLSS is a good, quick visual indicator of staygreen for field selection for heat tolerance. After harvest, TKW can be measured as final indicator of heat tolerance. The varieties Gaoyou 9415, Hemai 13, Jimai 22, Kexin 9, Shannong 8355, Taishan 23, Yannong 5286 and Zimai 7 were heat tolerant and potential germplasm for heat tolerance breeding in Shandong province and other parts of China. The results could be useful for breeding climate resilient varieties for China or other countries in the world suffering high temperature stresses during grain filling period.

13

Root restriction affected anthocyanin composition and up-regulated the transcription of their biosynthetic genes during berry development in ‘Summer Black’ grape

63%

Wang B. , He J. , Bai Y. , Yu X. , Li J. , Zhang C. , Xu W. , Bai X. , Cao X. , Wang S.

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2013

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tom 35

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nr 07

EN

Root restriction was applied to ‘Summer black’ grape (Vitis vinifera L. 9 Vitis labrusca L.) to investigate its effect on anthocyanin biosynthesis in grape berry during development. Anthocyanin composition and expression patterns of 16 genes in anthocyanin pathway were thus analyzed. The results showed that the anthocyanin levels in berry skin were significantly increased and the anthocyanin profile was enriched. Gene expression pattern revealed that the increased anthocyanins coincide with the up-regulated expression of all 16 genes investigated, including phenylalanine ammonia-lyase, 4-coumarate CoA ligase, chalcone synthase 1, chalcone synthase 2, chalcone synthase 3, chalcone isomerase, flavanone 3-hydroxylase 1, flavanone 3-hydroxylase 2, flavonoid 30-hydroxylase (F30H), flavonoid 30,50-hydroxylase (F3050H), di-hydroflavonol 4-reductase, leucoanthocyanidin dioxygenase, O-methyltransferases (OMT), UDP-glucose:flavonoid 3-O-glucosyltransferase (3GT), UDP-glucose:flavonoid 5-O-glucosyltransferase (5GT) and glutathione S-transferase (GST). The increased total anthocyanins predominantly resulted from the increase of tri-hydroxylated, methoxylated and monoglycosylated rather than di-hydroxylated, non-methoxylated, and di-glycosylated forms, which might be due to the differential regulation of F3050H/F30H, OMT and 3GT, respectively.