What is Cheerful Planet?

Zhangning(장닝) 한국디자인학회 2021 한국디자인학회 국제초대전도록 Vol.2021 No.5

Responsiveness to reduced dosage of rituximab in Chinese patients with neuromyelitis optica

Yang, C.-S.,Yang, L.,Li, T.,Zhang, D.-Q.,Jin, W.-N.,Li, M.-S.,Su, N.,Zhangning, N.,Liu, Q.,Shao, Z.-H.,Yu, C.,Shi, F.-D. Ovid Technologies (Wolters Kluwer) - American Acad 2013 Neurology Vol.81 No.8

Wind tunnel observation on the effect of a porous wind fence on shelter of saltating sand particles

Zhang, Ning,Kang, Jong-Hoon,Lee, Sang-Joon Elsevier 2010 Geomorphology Vol.120 No.3

<P><B>Abstract</B></P><P>A porous wind fence is an artificial barrier widely employed to abate wind erosion. This study investigated the shelter effect of a porous wind fence on saltating sand in a simulated atmospheric boundary layer (ABL). A wind fence with a porosity <I>ε</I>=38.5% was installed on a flat bed of sand collected from a beach (diameter, <I>d</I>=200–300μm). A high-speed digital camera was used to capture consecutive images of saltating sand particles around the fence at a frame rate of 4000 frames per second (fps). In addition, the particle tracking velocimetry (PTV) method was employed to extract the instantaneous velocity fields of saltating sand particles. From these data, the mean velocity and volume concentration of saltating sand, mass flux, and kinetic energy were evaluated. As a result, the mean velocities decrease dramatically on the leeward side of the fence, and a high-velocity region exists in the shear layer above the fence. The sand mass flux distributions with height around the fence are represented by an exponential function. Both the particle concentration and mass flux decay largely in the leeward region. The present experimental results can provide useful information to understand sand transport through a porous fence and allow the creation of a new control measure of wind erosion of sand particles.</P>

Effects of boron source composition ratio on the microstructure and adsorption performance of hexagonal boron nitride prepared by template method

Zhang Ning,Liu Huan,Zhang Tianwen,Kan Hongmin,Wang Xiaoyang,Cui Xingyu 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.3

The paper was prepared spherical hexagonal boron nitride with different microstructures under flowing ammoniaatmosphere. The effect of boron source component ratios (molar ratio of borax and boric acid) on the phase composition ofthe sample were studied: the work also explored the effect of boron source component ratio on the microstructure andadsorption performance of h-BN. Spherical hexagonal boron nitride had corresponding to shell structure, mesoporousstructure, and solid structure when the ratio of boron source components respectively was 1 : 0.5, 1 : 1, and 1 : 2. Between 1 : 1and 1:0.5, the former had an lower adsorptions at low relative pressures. On the contrary, the adsorption of former wouldincreased at higher relative pressures and reached up 276.02 cm3 g−1, and the maximum adsorption of the latter reached only228.20 cm3 g−1. Under any relative pressure, the adsorption capacity was the lowest when the boron source composition ratiowas 1 : 2.

S-I model of horizontal jet grouting reinforcement for soft soil

Zhang, Ning,Li, Zhongyin,Ma, Qingsong,Ma, Tianchi,Niu, Xiaodong,Liu, Xixi,Feng, Tao Techno-Press 2018 Geomechanics & engineering Vol.15 No.5

A superposition-iteration (S-I) model is proposed to simulate the jet grouting pre-reinforcing impact for a shallow-buried tunnel. The common model is deduced by theoretical (force equilibrium) analysis and then transformed into the numerical formulation. After applying it to an actual engineering problem, the most obvious deficiency was found to be continuous error accumulation, even when the parameters change slightly. In order to address this problem, a superposition-iteration model is developed based on the basic assumption and superposition theory. First, the additional deflection between two successive excavation steps is determined. This is caused by the disappearance of the supporting force in the excavated zone and the soil pressure in the disturbed zone. Consequently, the final deflection can be obtained by repeatedly superposing the additional deflection to the initial deflection in the previous steps. The analytical solution is then determined with the boundary conditions. The superposition-iteration model is thus established. This model was then applied and found to be suitable for real-life engineering applications. During the calculation, the error induced by the ill-conditioned problem of the matrix is easily addressed. The precision of this model is greater compared to previous models. The sensitivity factors and their impact are determined through this superposition-iteration model.

Enhanced drought and salinity tolerance in transgenic potato plants with a BADH gene from spinach

Zhang, Ning,Si, Huai-Jun,Wen, Gang,Du, Hong-Hui,Liu, Bai-Lin,Wang, Di The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.1

Drought and salinity are the most important abiotic stresses that affect the normal growth and development of plants. Glycine betaine is one of the most important osmolytes present in higher plants that enable them to cope with environmental stresses through osmotic adjustment. In this study, a betaine aldehyde dehydrogenase (BADH) gene from spinach under the control of the stress-induced promoter rd29A from Arabidopsis thaliana was introduced into potato cultivar Gannongshu 2 by the Agrobacterium tumefaciens system. Putative transgenic plants were confirmed by Southern blot analysis. Northern hybridization analysis demonstrated that expression of BADH gene was induced by drought and NaCl stress in the transgenic potato plants. The BADH activity in the transgenic potato plants was between 10.8 and 11.7 U. There was a negative relationship (y = -2.2083x + 43.329, r = 0.9495) between BADH activity and the relative electrical conductivity of the transgenic potato plant leaves. Plant height increased by 0.4-0.9 cm and fresh weight per plant increased by 17-29% for the transgenic potato plants under NaCl and polyethylene glycol stresses compared with the control potato plants. These results indicated that the ability of transgenic plants to tolerate drought and salt was increased when their BADH activity was increased.

Determination of Urban Surface Aerodynamic Characteristics Using Marquardt Method

Zhang, Ning,Jiang, Weimei,Gao, Zhiqiu,Hu, Fei,Peng, Zhen Techno-Press 2009 Wind and Structures, An International Journal (WAS Vol.12 No.3

Marquardt method is used to estimate the aerodynamic parameters in urban area of Beijing City, China, including displacement length (d), roughness length ($z_0$) and friction velocity (u*) and drag coefficient. The surface drag coefficient defined as the ratio between friction velocity and mean wind speed is 0.125 in our research, which is close to typical urban area value. The averaged d and $z_0$ are 1.2 m and 7.6 m. d and $z_0$ change with direction because of the surface heterogeneity over urban surface and reach their maximum values at S-SW sector, this tendency agrees with the surface rough element distribution around the observation tower.

The Walking Brain

Zhang Ning 한국디자인학회 2020 한국디자인학회 국제초대전도록 Vol.2020 No.7

A large eddy simulation on the effect of buildings on urban flows

Zhang, Ning,Jiang, Weimei,Miao, Shiguang Techno-Press 2006 Wind and Structures, An International Journal (WAS Vol.9 No.1

The effect of buildings on flow in urban canopy is one of the most important problems in local/micro-scale meteorology. A large eddy simulation model is used to simulate the flow structure in an urban neighborhood and the bulk effect of the buildings on surrounding flows is analyzed. The results demonstrate that: (a) The inflow conditions affect the detailed flow characteristics much in the building group, including: the distortion or disappearance of the wake vortexes, the change of funneling effect area and the change of location, size of the static-wind area. (b) The bulk effect of the buildings leads to a loss of wind speed in the low layer where height is less than four times of the average building height, and this loss effect changes little when the inflow direction changes. (c) In the bulk effect to environmental fields, the change of inflow direction affects the vertical distribution of turbulence greatly. The peak value of the turbulence energy appears at the height of the average building height. The attribution of fluctuations of different components to turbulence changes greatly at different height levels, in the low levels the horizontal speed fluctuation attribute mostly, while the vertical speed fluctuation does in high levels.

Transient performance of a solar humidification–dehumidification desalination system based on hollow fiber membrane

Zhang Ning,Yin Shao-You,Vafai Kambiz 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.3

Solar humidification–dehumidification desalination system based on hollow fiber membrane is a promising method to produce drinkable water from brine due to its abilities for low primary energy consumption and pollution prevention for the liquid seawater droplets. As operating conditions change with temporal weather conditions, a dynamic model of this desalination system is developed and experimentally validated in this study. Transient performance is investigated and a regulation strategy is proposed. It is found that the startup time can be reduced substantially by decreasing the mean pore diameter, porosity of the membrane, solar collector area, and volume of the seawater in the storage tank, and increasing the packing fractions of the humidifier. The specific freshwater production (SWP) rate at the equilibrium state grows with longer mean pore diameter, higher porosity of the membrane, more solar collector areas, and less packing fractions of the humidifier. SWP is basically constant with different volumes of the seawater in the storage tank. Variations of solar radiation cause the low freshwater production and high energy consumption especially in the morning and afternoon. Utilizing our model, the hour-by-hour adjustment is also established. The accumulated water production in 1 day can be increased by 13.5% and the energy consumption can decrease by over 23% based on decreasing flow rates of the seawater in the morning and increasing flow rates of the cooling water in the afternoon. The proposed dynamic model will be helpful for the daily regulation of the seawater desalination system and a better performance can be realized.