Wyniki wyszukiwania - Biblioteka Nauki

1

Potential of miR-25-3p in protection of chondrocytes: emphasis on osteoarthritis

100%

He X. , Deng L.

Folia Histochemica et Cytobiologica

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2021

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tom 59

|

nr 1

2

Designing a monolithic tip-tilt-piston flexure manipulator

100%

Hao G. , He X.

|

2017

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tom Vol. 17, no. 4

871--879

EN

This paper deals with the design of a monolithic tip-tilt-piston flexure manipulator for high-precision applications. The manipulator is first proposed with consideration of actuation isolation, which is a symmetrical and compact design and can be monolithically fabricated without using additive manufacturing. Kinematic and kinetostatic models are then analytically derived for quick parameter assessments. A case study is discussed finally, where a monolithic prototype has been made using CNC milling machining, comparisons among analytical, FEA and testing results are also undertaken.

3

Multigene evidence reveals the systematic position of Pleurocladopsis simulans (C. Massal.) R. M. Schust. within Schistochila Dumort., Schistochilaceae

100%

He X. , Sun Y.

Polish Botanical Journal

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2013

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tom 58

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nr 2

4

The transmission characteristics under the influence of the fifth-order nonlinearity management

100%

He X. , Xie K.

Optica Applicata

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2012

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tom Vol. 42, nr 1

103-110

EN

Starting with the nonlinear Schrödinger (NLS) equation, we have derived the evolution equations for the parameters of soliton pulse with propagation distance in optical fibers, taking into consideration the combined effect of second-order dispersion and the fifth-order nonlinearity by means of variation method. According to nonlinear evolution equations, the evolution of the pulse width with propagation distance is obtained under the influence of the different fifth-order nonlinearity. The results show that the pulse width fluctuates periodically under the influence of the different fifth-order nonlinearity. In the cycle, the negative fifth-order nonlinearity makes the pulse-width greater than the initial value while the positive fifth-order nonlinearity makes the pulse width less than the initial value. However, under the positive and negative fifth-order nonlinearity management, compared to the impact of positive or negative fifth-order nonlinearity only, the fluctuations of the solitons width are greatly reduced, even disappear. In other words, the width maintains almost steady. Therefore, it is possible that the pulse width is to be transmitted without any deformation.

5

Investigation of HFC-134a decomposition by combustion and its kinetic characteristics in a laboratory scale reactor

80%

Mi T. , Han J. , He X. , Qin L.

Environment Protection Engineering

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2015

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tom Vol. 41, nr 4

143--150

EN

Thermal decomposition of HFC-134a at 900–1000 K was investigated using a laboratory scale reactor. The experimental results indicate that the lower initial HFC-134a concentration and higher reaction temperature could enhance HFC-134a decomposition efficiency. Based on the results of measurements, it seems that the reaction order is around 1. Its activation energy (Ea) and the frequency factor (A) in the investigated temperature range are 300.5 kJ·mol–1 and 2.96×1014, respectively. The results demonstrate that 99.9% destruction efficiency could be achieved when HFC-134a/LPG is below 0.5 and the excess air ratio – above 0.6.

6

Effect of slope gradient on phosphorus loss from a sloping land of purple soil under simulated rainfall

80%

He X. , Zheng Z. , Li T. , He S.

Polish Journal of Environmental Studies

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2020

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tom 29

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nr 2

7

A stability based neural networks controller design method

80%

Song J. , Xu X. , He X.

Control and Cybernetics

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1998

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tom Vol. 27, no 1

119-133

EN

The use of neural networks in control systems can be seen as a natural step in the evolution of control methodology to meet new challenges. Many attempts have been made to apply the neural networks to deal with non-linearities and uncertainties of the control systems. Research in neural network applications to control can be classified according to the major methods depending on structures of the control system, such as NN-based NON-linear System Identification, NN-based Supervised Control, NN-based Direct Control, NN-based Indirect Control, NN-based Adaptive Control, NN-based Self-learning Control, NN-based Fuzzy Control, and NN Variable Structure Control. All these control methods cannot, however, effectively guarantee system stability, i.e. none of these neural network controls, except for NN-based Variable Structure Control, is based on system stability. This also limits the application and development of the neural networks in control theory. The paper shows the effort to solve this difficulty and give a way for the design method of the stability based neural networks controller using Lyapunov second stability theorem. This kind of controller can not only guarantee system stability, but also fully compensate for the influence of system uncertainties and non-linearities.Simulation results also show the effectiveness of the controller.

8

Underwater Explosion Performance of RDX/AP-based Aluminized Explosives

80%

Xiang D. , Rong J. , He X. , Feng Z.

Central European Journal of Energetic Materials

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2017

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tom Vol. 14, no. 1

60--76

EN

To understand the underwater explosion (UNDEX) performance of RDX/AP-based aluminized explosives, six formulations of the explosives were prepared, with Al content varying from 30% to 55% and ammonium perchlorate (AP) content from 45% to 20%. A series of UNDEX tests that used a 1 kg cylindrical charge was conducted underwater at a depth of 4.7 m. The pressure histories of the shock wave produced at different positions and the bubble periods were measured. The coefficients of the similarity law equation for the shock wave parameters were fitted with experimental data. The effect of the aluminum/oxygen (Al/O) ratio on the performance of the energy output structure for RDX/AP-based aluminized explosives is discussed. The bubble motion during UNDEX was simulated using MSC.DYTRAN software, and the radius-time curves of the bubbles were determined. The results show that AP influences the detonation reaction mechanism of RDX/AP-based aluminized explosives, which causes different UNDEX performances. The bubble energy of the RDX/AP-based aluminized explosive was higher than that of RDX-based and HMX-based aluminized explosives.

9

Detonation Performance of Four Groups of Aluminized Explosives

80%

Xiang D.-L. , Rong J.-L. , He X.

|

2016

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tom Vol. 13, no. 4

903--915

EN

The detonation performances of TNT-, RDX-, HMX-, and RDX/AP-based aluminized explosives were examined through detonation experiments. The detonation pressure, velocity, and heat of detonation of the four groups of aluminized explosives were measured. Reliability verification was conducted for the experimental results and for those calculated with an empirical formula and the KHT code. The test results on detonation pressures and velocities were in good agreement with the predicted values when aluminum (Al) particles were considered inert. The experimental heat of detonation values exhibited good consistency with the predicted values when a certain proportion of Al particles was active. Ammonium perchlorate (AP) can effectively reduce the detonation pressure and improve the heat of detonation for the RDX/AP-based aluminized explosive. A comparison of the current test results and literature data shows that errors may exist in early test data. The test data presented in this study allow for an improved understanding of the detonation performance of the four groups of aluminized explosives.

10

Rough Truth Degrees of Formulas and Approximate Reasoning in Rough Logic

80%

She Y. , He X. , Wang G.

|

2011

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tom Vol. 111, nr 2

223-239

EN

A propositional logic PRL for rough sets was proposed in [1]. In this paper, we initially introduce the concepts of rough (upper, lower) truth degrees on the set of formulas in PRL. Then, by grading the rough equality relations, we propose the concepts of rough (upper, lower) similarity degree. Finally, three different pseudo-metrics on the set of rough formulas are obtained, and thus an approximate reasoning mechanism is established.

11

Stability and Hopf bifurcation analysis for a Lotka-Volterra predator-prey model with two delays

80%

Xu C. , Liao M. , He X.

International Journal of Applied Mathematics and Computer Science

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2011

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tom Vol. 21, no 1

97-107

EN

In this paper, a two-species Lotka-Volterra predator-prey model with two delays is considered. By analyzing the associated characteristic transcendental equation, the linear stability of the positive equilibrium is investigated and Hopf bifurcation is demonstrated. Some explicit formulae for determining the stability and direction of Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using normal form theory and center manifold theory. Some numerical simulations for supporting the theoretical results are also included.

12

Secondary metabolites, carbohydrate accumulation, and nutrient uptake in Aralia elata (Miq.) Seem seedlings exposed to shoot cutting and different LED spectra

80%

Wei H. , Zhao X. , Chen X. , He X.

Acta Physiologiae Plantarum

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2020

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tom 42

|

nr 11

13

Different sensitivities of unicellular and colonial microcystis strains (Cyanophyceae) to six emergent macrophytes

80%

Zhao J. , He X. , Sun P. , Zhang S.

Polish Journal of Environmental Studies

|

2013

|

tom 22

|

nr 5

EN

The effects of six emergent macrophytes (Typha orientalis, Acorus calamus, Oenanthe javanica, Scirpus validus, Sagittaria sagittifolia, and Pontederia cordata) on the growth of two strain Microcystis aeruginosa were studied under co-culture conditions. And the sensitivities of unicellular and colonial Microcystis strains to six emergent macrophytes were compared using an exudation experiment. Based on laboratory experiments, T. orientalis, A. calamus, O. javanica, S. validus, S. sagittifolia, and P. cordata had strong inhibitory effects on growth of unicellular M. aeruginosa, while only A. calamus and P. cordata show obvious growth inhibition on colonial M. aeruginosa. When the biomass density was 20 g FW·L⁻¹, the growth inhibition rate of unicellular M. aeruginosa can exceed 90% for all of the six emergent macrophytes. When macrophytes coexisted with the colonial M. aeruginosa, only A. calamus, P. cordata, and S. sagittifolia showed the growth inhibition of algae. Maximal inhibition of Chl a growth was 75% (p<0.05) for A. calamus, 69% (p<0.05) for P. cordata, and 40% for S. sagittifolia at 45 g FW·L⁻¹ on day 15. The results of the exudation experiment indicated that there were no significant differences between control and treatment of Chl a concentrations of colonial M. aeruginosa for all of the six macrophyte exudations on days 6 and 12. While after 6 d incubation in 100% and 50% macrophyte exudations (40 g FW·L⁻¹), the cell densities of unicellular M. aeruginosa in control were obviously higher than all those in treatment (p < 0.05). The maximal algal growth inhibition (89.62%) of unicellular M. aeruginosa was achieved in 100% exudation of A. calamus on day 6 (p < 0.05). So according to the results of exudation experiments, the unicellular M. aeruginosa was more sensitive than the colonial strain to six emergent macrophytes. And this different sensitivity between Microcystis species probably correlated positively with colony size.

14

Induction of cold tolerance by priming and stress memory in crops

80%

Li X. , Song F. , Liu F. , He X.

Acta Physiologiae Plantarum

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2018

|

tom 40

|

nr 11-11th International Conference Plant Functioning under Environmental Stress...

15

Antibiotics in WWTP discharge into the Chaobai River, Beijing

80%

Zhang C. , Wang L. , Gao X. , He X.

|

2016

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tom Vol. 42, no. 4

48--57

EN

22 representative antibiotics, including 8 quinolones (QNs), 9 sulfonamides (SAs), and 5 macrolides (MCs) were selected to investigate their occurrence and removal efficiencies in a Wastewater Treatment Plant (WWTP) and their distribution in the receiving water of the Chaobai River in Beijing, China. Water quality monitoring was performed in an integrated way at different selected points in the WWTP to explore the potential mechanism of antibiotics removal during wastewater treatment. Water quality of the Chaobai River wa s also analyzed to examine environmental distribution in a river ecosystem. The results showed that within all the 22 compounds examined, 10 antibiotics were quantifi ed in wastewater influent, 10 in effluent, and 7 in river. Sulfadiazine (SDZ, 396 ng/L) and Sulfamethazine (SMZ, 382 ng/L) were the dominating antibiotics in the influent. Both the conventional treatment and advanced Biological Aerated Filter (BAF) system was important for the removal of antibiotics from the wastewater. And the concentrations of selected antibiotics were ranged from 0–41.8 ng/L in the effluent-receiving river. Despite the fact that the concentrations were reduced more than 50% compared to effluent concentrations, WWTP discharge was still regarded as a dominant point-source input of antibiotics into the Chaobai River.

16

Rough Truth Degrees of Formulas and Approximate Reasoning in Rough Logic

80%

She Y. , He X. , Wang G.

|

2011

|

tom Vol. 107, nr 1

67-83

EN

A propositional logic PRL for rough sets was proposed in [1]. In this paper, we initially introduce the concepts of rough (upper, lower) truth degrees on the set of formulas in PRL. Then, by grading the rough equality relations, we propose the concepts of rough (upper, lower) similarity degree. Finally, three different pseudo-metrics on the set of rough formulas are obtained, and thus an approximate reasoning mechanism is established

17

Glen canyon dam operation effects on rainbow trout habitat and population status

80%

Yao W. , Chen Y. , He X.

Polish Journal of Environmental Studies

|

2018

|

tom 27

|

nr 1

EN

A dynamic habitat and population model has been developed and applied to the tailwater below Glen Canyon Dam to estimate the dam operation’s effects on rainbow trout (Oncorhynchus mykiss) habitat and population dynamics. Water depth, flow temperature, flow velocity, and substrate types were used as the suitability parameters and to evaluate these indicators. Historic hydraulic data from 1991 to 2009 were analyzed to determine the minimum, mean, and maximum flow rates that were used to represent the habitat suitability index (HSI) and overall suitability index (OSI) of the rainbow trout fry, adult, and spawning life stages, respectively. Fish abundance and the simulation results were also compared with observed fish numbers. Results indicated that under the historic dam operation, the habitat suitability level in the Colorado River was not suitable for fry and spawning rainbow trout, but very suitable for adult rainbow trout. It is indicated that high HSI levels do not mean high fish abundance. It can also be seen that overall rainbow trout abundance decreased during the period 1991 to 2009.

18

Nitrogen-fixing bacterial communities exhibit strong spatial structure along a slope gradient in karst shrublands ecosystem

71%

Liang Y. , He X. , Chen X. , Hu Y. , Su Y.

Polish Journal of Environmental Studies

|

2019

|

tom 28

|

nr 5

EN

Environmental heterogeneity is a primary factor in determining soil microbial spatial patterns. However, few studies have demonstrated a link between environmental heterogeneity and the spatial patterns in free-living nitrogen-fixing bacteria, which are important in nitrogen cycling. Here, quantitative polymerase chain reaction and terminal restriction fragment length polymorphism were used to determine the spatial distribution of free-living nitrogen-fixing bacteria along a slope gradient. Plant communities were evaluated through field surveys, and basic soil properties were measured in the laboratory. Soil properties (e.g., soil available phosphorus, soil organic carbon, and total nitrogen) were higher in upper- and middle -slope soils than in lower-slope soils, while bacterial abundance was the opposite. Bacterial and plant communities all varied along the slope gradient. Redundancy analysis revealed that bacterial community composition was closely linked to pH, soil organic carbon, available phosphorus, and total nitrogen. These results indicate that free-living nitrogen-fixing bacterial communities show strong spatial structure along a slope gradient, and emphasize the importance of soil heterogeneity in affecting bacterial spatial patterns in a karst region.

19

Adsorption behaviors of typical aromatic pollutants in biologically treated coking wastewater on powdered coal

71%

Sun H. , Wang Y. , Bian Y. , He X. , Li G.

Physicochemical Problems of Mineral Processing

|

2018

|

tom Vol. 54, iss. 2

496--504

EN

The raw coal was utilized as adsorbent based on its remarkable adsorption ability of coal slime to organic compounds in the flotation process. This paper mainly investigates adsorption behaviors of benzpyrole (BZP), pyrrole (PR) and benzoic acid (BA) on powdered coal (PC). In the monocomponent solution, the removal efficiencies of BZP, PR and BA reached 85.23%, 55.02% and 24.84% at PC dosage of 20 g/dm3. Adsorption behaviors of three pollutants fitted perfectly to the pseudo-second order kinetics model and liquid film diffusion occupied the largest proportion in rate-limiting step according to the diffusion rates. Furthermore, the influences of pH on adsorption behaviors and competitive adsorption mechanism of three pollutants were also reported.

20

Two-stage classification approach for human detection in camera video in bulk ports

71%

Mi C. , Zhang Z. , He X. , Huang Y. , Mi W.

Polish Maritime Research

|

2015

|

tom S 1

163--170

EN

With the development of automation in ports, the video surveillance systems with automated human detection begun to be applied in open-air handling operation areas for safety and security. The accuracy of traditional human detection based on the video camera is not high enough to meet the requirements of operation surveillance. One of the key reasons is that Histograms of Oriented Gradients (HOG) features of the human body will show great different between front & back standing (F&B) and side standing (Side) human body. Therefore, the final training for classifier will only gain a few useful specific features which have contribution to classification and are insufficient to support effective classification, while using the HOG features directly extracted by the samples from different human postures. This paper proposes a two-stage classification method to improve the accuracy of human detection. In the first stage, during preprocessing classification, images is mainly divided into possible F&B human body and not F&B human body, and then they were put into the second-stage classification among side human and non-human recognition. The experimental results in Tianjin port show that the two-stage classifier can improve the classification accuracy of human detection obviously.