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1

The multiple dimension of water in the designing and governance of public spaces. The case of Shanghai West Bund Project compared to other Western Waterfronts renovations

Semprebon G., Ma W., Fabris L. M. F.

Środowisko Mieszkaniowe

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2018

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nr 22

22--27

EN

In 2010, the municipality of Shanghai started the “Huangpu River Comprehensive Development Plan”, a large regeneration initiative including the Expo site, targeted to revitalize the river banks and generally the urban environment, making Xuhui waterfront one of the six key construction areas of the 12th Five-Year Plan in Shanghai. Formerly one of the largest industrial districts, the so-called West Bund area has experienced a process of substantial transformation, currently still ongoing. Particular attention has been paid to the rehabilitation of the riverside, as a source of landscape enhancement, providing a system of open spaces and public facilities able to meet the dweller’s demands and to attract touristic fluxes. For this reason, the West Bund Project represents one of the most relevant regeneration initiative currently taking place in Shanghai. This paper aims to investigate, starting from this specific case-study, the role of water in the definition of cultural and natural elements, revealing new perspectives for the revitalization of the urban environment.

2

Numerical simulations of linearly stratified flow past submerged bodies

Ma W., Li Y., Ding Y., Hu K., Lan L.

Polish Maritime Research

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2018

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S 3

68--77

EN

In this study, a methodology was presented to predict density stratified flows in the near-field of submerged bodies. The energy equation in temperature form was solved coupled with momentum and mass conservation equations. Linear stratification was achieved by the definition of the density as a function of temperature. At first, verifications were performed for the stratified flows passing a submerged horizontal circular cylinder, showing excellent agreement with available experimental data. The ability of the method to cope with variable density was demonstrated. Different turbulence models were used for different Re numbers and flow states. Based on the numerical methods proposed in this paper, the stratified flow was studied for the real scale benchmark DAPRA Suboff submarine. The approach used the VOF method for tracing the free surface. Turbulence was implemented with a k − ω based Detached Eddy Simulation (DES) approach. The effects of submarine speed, depth and density gradient on the free surface wave pattern were quantitatively analyzed. It was shown that, with the increasing of the speed of the submarine, the wavelength and wave height of the free surface wave were gradually increasing. The wave height of the free surface wave was gradually reduced as the submarine’s depth increased. Relative to the speed and submarine depth, the changes of the gradient density gradient have negligible effects on the free surface wave field.

3

Research on interaction of APFs based on relative gain array

Feng X., Sun T., Ma W.

Archives of Electrical Engineering

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2018

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Vol. 67, nr 1

165--177

EN

Different APFs (Active Power Filter) interact with each other when multiple APFs are connected to the grid, and the interactions deteriorate the control performance of APFs and even lead to system instability. This paper presents a method to analyze the dynamic interaction of multiple APFs in a weak grid. This method uses the Norton equivalent principle to establish the mathematical model of a single APF. The mathematical model of the multiple APFs connected to the grid is set up based on the single APF mode. The RGA (Relative Gain Array) principle is used to analyze the interactions among multiple APFs. Besides, this paper analyzes the effect of changing circuit parameters and controller parameters on the change of the interactions. The strategy of weakening and eliminating the interaction is proposed based on rational selection and combination of parameters. Analysis, along with time domain simulation and experimental results, is presented to verify the feasibility and effectiveness of the proposed method and strategy.

4

Simulation on vessel intelligent collision avoidance based on artificial fish swarm algorithm

Li W., Ma W.

Polish Maritime Research

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2016

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S 1

138--143

EN

TAs the rapid development of the ship equipments and navigation technology, vessel intelligent collision avoidance theory was researched world widely. Meantime, more and more ship intelligent collision avoidance products are put into use. It not only makes the ship much safer, but also lighten the officers work intensity and improve the ship’s economy. The paper based on the International Regulation for Preventing Collision at sea and ship domain theories, with the ship proceeding distance when collision avoidance as the objective function, through the artificial fish swarm algorithm to optimize the collision avoidance path, and finally simulates overtaking situation, crossing situation and head-on situation three classic meeting situation of ships on the sea by VC++ computer language. Calculation and simulation results are basically consistent with the actual situation which certifies that its validity.

5

Motion prediction of catamaran with a semisubmersible bow in wave

Sun H., Jing F., Jiang Y., Zou J., Zhuang J., Ma W.

Polish Maritime Research

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2016

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nr 1

37--44

EN

Compared with standard vessels, a slender catamaran with a semi-submerged bow (SSB) demonstrates superior seakeeping performance. To predict the motion of an SSB catamaran, computational fluid dynamics methods are adopted in this study and results are validated through small-scale model tests. The pitch, heave, and vertical acceleration are calculated at various wavelengths and speeds. Based on the overset grid and motion region methods, this study obtains the motion responses of an SSB catamaran in regular head waves. The results of the numerical studies are validated with the experimental data and show that the overset grid method is more accurate in predicting the motion of an SSB catamaran; the errors can be controlled within 20%. The movement data in regular waves shows that at a constant speed, the motion response initially increases and then decreases with increasing wavelength. This motion response peak is due to the encountering frequency being close to the natural frequency. Under identical sea conditions, the motion response increases with the increasing Froude number. The motion prediction results, that derive from a shortterm irregular sea state, show that there is an optimal speed range that can effectively reduce the amplitude of motion.

6

Effects of Abietinella abietina Extracts on the Germination and Seedling Emergence of Picea crassifolia: Results of Greenhouse Experiments

Wang Q., Zhao C., Gao Y., Gao C., Qiao Y., Xie H., Wang W., Yuan L., Liu J., Ma W., Li W.

Polish Journal of Ecology

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2016

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Vol. 64, nr 3

357--368

EN

Moss cushion plays an important role in recruitment of vascular plants. In this study, we examined the effects of water soluble extracts (WSE) of Abietinella abietina on germination of Qinghai spruce (Picea crassifolia) and the effects of moss substrates (A. abietina) on seedling emergence of P. crassifolia in two greenhouse experiments. We found that the WSE of moss affected germination of P. crassifolia in two ways: (1) the WSE reducing the risk of fungal infection to the seeds, improve the germination rate; and (2) the WSE affects germination by its concentration, that is, low concentrations of WSE (i.e., 0.5 mg ml-1 and 5 mg ml-1) stimulate, while high concentrations (i.e., 50 mg ml-1) inhibit it. In seedling emergence experiments, we detected that the moss substrates (both thick and thin mosses) facilitate the emergence of P. crassifolia in dry and intermediate moisture conditions, but inhibit it in moist conditions. In bare soil, the P. crassifolia emergence was also controlled by moisture conditions; the highest (60%) and the lowest (35%) emergence occurred in the moist conditions and dry conditions, respectively. We also found that P. crassifolia seedlings were thinner and taller, but their number higher in moss cushion than in bare soil. Thus we conclude that there is nurse effect of A. abietina cushion on recruitment of P. crassifolia in both dry and intermediate moisture conditions.

7

Test studies of the resistance and seakeeping performance of a trimaran planing hull

Ma W., Sun H., Sun H., Zou J., Zhuang J.

Polish Maritime Research

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2015

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nr 1

22—27

EN

Towing tank tests in calm water were performed on a trimaran planing hull to verify its navigational properties with different displacements and centres of gravity, as well as to assess the effects of air jets and bilge keels on the hull’s planing capabilities, and to increase the longitudinal stability of the hull. Hydrostatic roll tests, zero speed tests, and sea trials in the presence of regular waves were conducted to investigate the hull’s seakeeping ability. The test results indicate that the influence of the location of the centre of gravity on the hull resistance is similar to that of a normal trimaran planing hull; namely, moving the centre of gravity backward will reduce the resistance but lower the stability. Bilge keels improve the longitudinal stability but slightly affect the resistance, and the presence of air jets in the hull’s channels decreases the trim angle and increases heaving but has little effect on the resistance. Frequent small-angle rolling occurs in waves. The heaving and pitching motions peak at the encounter frequency of , and the peaks increase with velocity and move towards greater encounter frequencies. When the encounter frequency exceeds, the hull motion decreases, which leads to changes in the navigation speed and frequency.

8

Właściwości antykorozyjne żywic styrenowo-akrylowych zawierających tripolifosforan glinu

Shangguan L. J., Ma W., Liu G., Song W.

Chemik

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2015

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Vol. 69, nr 9

578--585

PL

Tripolifosforan glinu zdyspergowano w emulsji styrenowo-akrylowej. Rozkład i wielkości cząstek lateksu badano za pomocą laserowego analizatora cząstek. Właściwości antykorozyjne układu żywice styrenowo-akrylowe – tripolifosforan glinu badano za pomocą elektrochemicznej spektroskopii impedacyjnej (EIS), próby w komorze solnej według normy ASTM B-117 oraz testów adhezji. Wyniki wskazują na wzmocnienie działania ochronnego żywic styrenowo-akrylowych po dodaniu tripolifosforanu glinu.

EN

Aluminum tripolyphosphate was introduced into the dispersion solution of styrene-acrylic emulsion The laser particle size analyzer was used to analyse the distribution and particles size of the latex particle. The anticorrosion performance of styrene-acrylic resins/aluminum tripolyphosphate was studied using electrochemical impedance spectroscopy (EIS), salt spray standard test according to ASTM B-117 and adhesion tests. The results indicated the protective performance of styrene-acrylic resins was improved by adding aluminum tripolyphosphate.

9

A novel process of dye wastewater treatment by linking advanced chemical oxidation with biological oxidation

Zou H., Ma W., Wang Y.

Archives of Environmental Protection

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2015

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Vol. 41, no. 4

33--39

EN

Dye wastewater is one of typically non-biodegradable industrial effluents. A new process linking Fenton’s oxidation with biological oxidation proposed in this study was investigated to degrade the organic substances from real dye wastewater. During the combination process, the Fenton’s oxidation process can reduce the organic load and enhance biodegradability of dye wastewater, which is followed by biological aerated filter (BAF) system to further remove organic substances in terms of discharge requirement. The results showed that 97.6% of chemical oxygen demand (COD) removal by the combination process was achieved at the optimum process parameters: pH of 3.5, H22

10

Test research on the resistance performance of high-speed trimaran planing hull

Ma W., Sun H., Zou J., Yang H.

Polish Maritime Research

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2013

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nr 4

45--51

EN

In order to identify high-speed navigation ability of trimaran planing hull, as well as investigate the characteristics of its resistance and hull form, ship model tests were conducted to measure resistance, trim and heaving under different displacements and gravity centre locations. The test results were then used to study the influence of spray strips on resistance and sea-keeping qualities. Moreover, different planning surfaces were compared in the model tests which helped to look into influence of steps on hull resistance and its moving position. Also, the resistance features of monohull and trimaran planing hulls, both with and without steps, were compared to each other. From the tests it can be concluded that: the two auxiliary side hulls increase aerodynamic lift at high-speed motion, which improves the hydrodynamic performance; the trimaran planing hull has also excellent longitudinal stability and low wave-making action; when Fr∇> 8, its motion is still stable and two distinct resistance peaks and two changes of sailing state (the second change is smaller) appear; spray strips are favourable for sea-keeping qualities at high speed. The change trends before the second resistance peak as to the resistance and sailing behaviour of trimaran planing hull without steps are the same as for monohull planing hull without steps. but when steps in both hulls exist the change trends are different; more specifically: trimaran planing hull with steps has only one resistance peak and its resistance increases along with its speed increasing, and the resistance is improved at the increasing speed as the number of steps increases.

11

Analyses of the Additional Stiffness Function of the Traction Bar on the Vertical Dynamics Performance of Subway Vehicle

Ma W., Song R.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 1b

39-43

EN

This paper analyses the influence of the additional stiffness function of the traction bar on the vehicle vertical dynamic performance. Based on the subway vehicle dynamics model, the influences of the additional stiffness function of the traction bar on vehicle’s response to vertical impact, carbody vertical ride index and relevant phenomena of wheelset longitudinal vibration resonance were analyzed. Results indicate that the additional stiffness function of the traction bar will increase the stiffness of the secondary suspension system. It not only increase the response of the vehicle to vertical impact and reduces the ride comfort of vehicle, but also increase the vertical and longitudinal vibration acceleration, and the vertical dynamic load of the first and secondary suspension increased too. Put forward that the vertical dynamic performance of the vehicle can be improved through decrease the connection stiffness of the traction bar to 25% of the present value.

PL

W pracy nalizowano wpływ dodatkowej funkcji sztywności trakcyjnej belki na poziome dynamiczne właściwości pojazdu podziemnego. Rezultaty analizy pokazały że sztywność belki trakcyjnej zwiększa sztywność systemu zawieszenia. Może to zwiększać wibracje poziome pojazdu.

12

A simulation study on optimal oil spraying mode for high-speed rolling bearing

Pang B. T., Li J. S., Liu H. B., Ma W., Xue Y. J.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

553-557

EN

Purpose: In this study, a numerical simulation model of the oil spraying system is established. Design/methodology/approach: Spraying lubrication is a common form of the rolling bearing lubrication. But with the increase of the bearing speed, the roller cage is frequently shattered, which may lead to failure of the bearing. The shatter of roller cage may be related to the spraying mode of oil. For high-speed rolling bearing, the roller cage shatter can be cracked due to the shortage of oil, caused by lubricating oil not sprayed into the roller cage shatter. This condition can be ameliorated by changing the spraying mode of oil supply system. The model considered the spraying speed, spraying angle, oil pressure, oil viscosity, structure of roller cage shatter, rotating speed as the main parameters. By optimization, the best way of oil spraying was obtained which can meet lubrication requirement of high-speed rolling bearing. At the same time, the numerical simulation results also revealed that the optimal spraying mode is different for different rolling bearings. Findings: The simulating results indicate that due to the effect of the air pressure and airflow thickness, the optimal spraying position is at a region closer to the inner ring of the bearings. Practical implications: This paper will provide useful information to applying numerical simulation of the oil spraying system. Originality/value: The computer simulation allows to better understand the interdependence between parameters of process and choosing optimal solution.

13

Simultaneous electrochemical determination of dopamine and epinephrine with a silver-doped poly(L-glutamic acid) modified electrode

Hu W., Sun D., Ma W.

Chemia Analityczna

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2008

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Vol. 53, No. 5

703-716

EN

In this paper, a silver-doped poly(L-glutamic acid) modified electrode (PLG-Ag/GCE) was fabricated by electrochemical modification of a glassy carbon electrode (GCE) surface. The modified electrode was used to detect dopamine (DA) and epinephrine (EP) in the presence of high concentration of ascorbic acid (AA). In cyclic voltammograms obtained at the modified electrode the cathodic peak potentials of DA and EP in the presence of AA were separated by about 389 mV in phosphate buffer solution (PBS) of pil 7.5 and AA did not interfere with the measurement of DA and KP. The peak separation distance was large enough to determine DA and EP individually and simultaneously. Detection limit of DA in the presence of AA was 5.0 x 10- 7 mol L-1 and the cathodic current of DA increased linearly with the increase of its concentration from 5.0 x l 0-6 to 1.0 x 10-4 mol L~' with a correlation coefficient of 0.9902. Furthermore, the cathodic peak current of EP was pro-portional to the concentration in the ranges 3.0 x l0-6- x 10- 5 mol L-1 and 1.0 x 10 5-1.0 x 10 -5 mol L-1 wilh the correlation coefficients of 0.9934 and 0.9921, respectively. Detection limit of EP was 8.0 x 10 7 mol L-1. Practical utility of the PLG-Ag modified electrode was demonstraled by determining DA and EP contents in the injeclion solution and human urine with satisfactory results.

PL

Opisano elektrochemiczną modyfikację elektrody z węgla szklistego kwasem poli(L-gluta-minowym). Zmodyfikowaną elektrodę zastosowano do wykrywania dopaminy (DA) i epinefryny (EP) w obecności kwasu askorbowego (AA) o dużym stężeniu. Na cyklicznych Yoltamperogramach potencjały pików katodowych DA i EP w obecności AA byly rozdzielone do około 389 mV, przy pH 7,5 w roztworze buforu fosforanowego. AA nie przeszkadzał w pomiarach. Duże rozdzielenie pików pozwoliło na indywidualne i jednoczesne oznaczanie DA i EP. Granicę wykrywalności DA w obecności AA oszacowano na 5,0 x l 0 -7 mol L -1 . a prąd katodowy DA wzrastał liniowo ze stężeniem DA w granicach od 5,0 x l0-6 do l .0 x 10-4 mol L-4, r = 0,9902. Natomiast plik katodowy EP był proporcjonalny do stężenia EP w zakresie od 3,0 x 10-6 do 1,0 x l0-4 mol L-1 i dalej do 1,0 x l 0-1 mol L-1 ze współczynnikami krelacji 0.9934 i 0,9921. Granicę wykrywalności EP określono na 8,0 x 10-7 mol L-1. Użyteczność nowej elektrody wykazano przy oznaczaniu DA i AP w roztworach do zastrzyków i w ludzkim moczu.

14

Separation of two isomers of benzocarbazoles by ß-cyclodextrin modified micellar electrokinetic capillary chromatography

Shi X., Ma W., Chen D.

Chemia Analityczna

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2001

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Vol. 46, No. 3

433-438

EN

To optimize the separation conditions of the two isomers of benzocarbazoles, micellar electrokinetic capillary electrophoresis (MECC) was employed in this study. In this procedure, a fused silica capillary of 57 cm x 50 um (50 cm to detector) was used. Running buffer was 5.0 mmol 1(-1) aqueous sodium tetraborate solution containing 70 mmol1 (-1) sodium dodecyl sulfate (pH9.16) and 20 mmol 1(-1) p-cyclodextrin. The separation voltage and the pH value of the buffer were optimized. At the optimized separation conditions, the two isomers were separated well within 10 min. It is thus proved that MECC is an effective method for oil chemical exploration.

PL

W celu optymalizacji rozdzielania dwóch izomerów benzokarbazoli zastosowano mice-larną elektrokinetyczną kapilarną chromatografię. Stosowano kapilary z topionego kwarcu o wymiarach 57 cm x 50 urn, przy odległości 50 cm do detektora. Jako bufor zastosowano 5 mmol 1(-1) roztwór wodny tetraboranu sodowego, zawierający 70 mmol 1(-1)dodecylosiarczan sodowy (pH 9,16) i 20 mmol 1(-1) p-cykodekstrynę. Optymalizowano napięcie i wartość pH buforu. W wybranych warunkach rozdzielania oba izomery ulegają dobremu rozdzieleniu w ciągu 10 min co może być wykorzystane przy identyfikacji złóż ropy.