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| 1 | Empirical Research on Carrying Capacity of Human Settlement System in Dalian City, Liaoning Province, China显示文摘Using the theories of population carrying capacity and ecological elasticity in other fields for reference, the connotation of regional human settlement system was defined from the viewpoint of the complex relationship among the factors such as regional population, resources, environment and economic and social development in the context of China′s rapid urbanization. Then the concept and characterization methods of the regional human settlement carrying capacity were proposed by means of population scale. Furthermore, a model of carrying capacity-pressure-state-response(CPSR) on regional human settlement system was established by referencing pressure-state-response(PSR) model, and the Catastrophe Theory was introduced to determine the corresponding standards of multi-criteria programming and evaluation. Taking Dalian City, Liaoning Province, China as an example, an empirical analysis on evaluation of human settlement system from 2000 to 2012 was carried out. The results showed that the carrying capacity of human settlement system in Dalian was fluctuating between 9.6 × 106 to 10 × 106 persons with a quantitative stage of the dynamic regulation. During the research period the load index of human settlement system in Dalian dropped from 0.96 to 0.84 with a lower pressure of human settlement system than the national average level. And the emergency response grades of human settlement system in Dalian were kept in grade Ⅱ(orange warning) or grade Ⅲ(yellow warning). Human settlement system of Dalian was in slight security state as a whole, but the load had a tendency of increase in recent years. The related departments should pay close attention to regional human settlement system and take active measures to improve human settlement by both intensity control and total quantity control. By comparison, analysis and discussion, it was considered that the results were basically accordded with the current situations of human settlement in Dalian, and the evaluation results were more reliable, visualized and easily applied in practice. Therefore, the above-mentioned concepts, characterization and evaluation methods of the regional human settlement system and carrying capacity could provide a new thought and method for quantitative evaluation of human settlement. | ZHENG Defeng ZHANG Yu ZANG Zheng SUN Caizhi | 2015 | Chinese Geographical Science2015，25，2： | 13 |
| 2 | Quorum sensing systems regulate heterotrophic nitrification-aerobic denitrification by changing the activity of nitrogen-cycling enzymes显示文摘Heterotrophic nitrification-aerobic denitrification(HNAD)is essential in diverse nitrogen-transforming processes.How HNAD is modulated by quorum sensing(QS)systems is still ambiguous.The QS system in Pseudomonas aeruginosa manipulates colony behavior.Here,we described the influence of the Pseudomonas quinolone signal(PQS)and N-acyl-L-homoserine lactone(AHL)on HNAD.The HNAD of P.aeruginosa was inhibited by the oversecretion of PQS.AHL-or PQS-deficient P.aeruginosa mutants had a higher ability for nitrogen removal.QS inhibited heterotrophic nitrification mainly via controlling the activity of nitrite oxidoreductase(NXR)and the depressed aerobic denitrification by regulating the catalytic abilities of nitric oxide reductase(NOR),nitrite reductase(NIR),and nitrate reductase(NAR).The addition of citrate as the sole carbon source increased the nitrogen removal efficiency compared with other carbon sources.Nitrite,as the sole nitrogen source,could be used entirely with only the moderate concentration of PQS contained.AHL and PQS controlled both nitrification and denitrification,suggesting that QS plays an important role in nitrogen cycle under aerobic conditions. | Ziqian Zhu Yang Yang Anran Fang Yu Lou Guojun Xie Nanqi Ren Defeng Xing | 2020 | Environmental Science and Ecotechnology2020，，2： | 2 |
| 3 | Effects of inorganic and organic salts on aggregation behavior of cationic gemini surfactants 显示文摘 | YU DEFENG HUANG XU DENG MANLI | 2010 | J Phys Chem B2010，114，14： | 1 |
| 4 | Electricity generation from food wastes and microbial community structure in microbial fuel cells显示文摘 | Jianna Jia Yu Tang Bingfeng Liu Di Wu Nanqi Ren Defeng Xing | 2013 | Bioresource Technology2013，，： | 1 |
| 5 | Effects of calcium ions on solubility and aggregation behavior of an anionic sulfonate Gemini surfactant in aqueous solu- tions显示文摘 | YU Defeng WANG Yingxiong ZHANG Jian | 2012 | Journal of Colloid and Interface Science2012，381，1： | 1 |
| 6 | Effects of Inorganic and Organic Salts on Aggregation Behavior of Cationic Gemini Surfactants显示文摘 | Defeng Yu Xu Huang | 2010 | J Phys Chem2010，114，14： | 1 |
| 7 | Using X-ray computed tomography and micro-Raman spectrometry to measure individual particle surface area, volume, and morphology towards investigating atmospheric heterogeneous reactions显示文摘Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle. | Mingjin Wang Nan Zheng Tong Zhu Jing Shang Ting Yu Xiaojuan Song Defeng Zhao Yong Guan Yangchao Tian | 2018 | Journal of Environmental Sciences2018，30，7： | 1 |
| 8 | Effects of inorganic and organic salts on aggregation behavior of cationic gemini surfactants 显示文摘 | Yu Defeng Huang Xu Wang Yilin | 2010 | The Journal of Physical Chemistry B2010，114，14： | 1 |
| 9 | Crystallization and thermal behavior Of multiwalled carbon nanotube/poly( bu- tylenes terephthalate) composites显示文摘 | Wu Defeng Wu Liang Yu Guangcai | 2008 | Polym Eng Sci2008，48，6： | 1 |
| 10 | Effect of Blending Sequence on the Morphologies of Poly(butylene terephthalate)/Epoxy/Clay Nanocomposites by a Rheo logical Approach显示文摘 | Wu Defeng Zhou Chixing Yu Wei | 2006 | Journal of Applied Polymer Science2006，99，： | 1 |
| 11 | Crystallization and thermal behavior of multiwalled carbon nanotube/poly (butylenes terephthalate) composites显示文摘 | WU Defeng WU Liang YU Guangcai | 2008 | Polym Eng Sci2008，48，6： | 1 |
| 12 | Modeling and Experimental Study for Automotive Dry Clutch Sliding Noise显示文摘Automotive dry clutches have been found to produce a low frequency sliding noise in many applications,which challenges the ride comfort of vehicles.In order to study this clutch sliding noise,a detailed finite element model including both a pressure plate assembly and a driven plate assembly was developed.Based on this model,a complex eigenvalue analysis is performed in this research.The effect of several major factors on the clutch sliding noise,such as the coefficient of friction,the clamping force,the geometric imperfection of the friction plate,and the thermal deformation of the pressure plate,were investigated numerically.A vehicle road test with clutch sliding noise was conducted for several different conditions.The leading frequencies of the clutch sliding noise in the testing were obtained and compared with the frequencies predicted by the numerical model.The simulation results show the same tendency as the road test.It is found that the clutch sliding noise can be reduced by decreasing the coefficient of friction.With the presence of the surface bumping of the friction plate,the propensity of the clutch sliding noise greatly increases and the corresponding squeal frequencies fall into the range lower than 1 kHz.With the consideration of the thermally introduced deformation of the clutch pressure plate,the possibility of clutch sliding noise is significantly reduced.It is concluded that the model with the incorporation of the thermal deformation of the pressure plate is more effective for the frequency prediction of clutch sliding noise. | Jiali Yu Zhili Xiang Defeng Zhang Yubing Gong | 2022 | Computer Modeling in Engineering & Sciences2022，，6： | 0 |
| 13 | New di-spirocyclic labdane diterpenoids from the aerial parts of Leonurus japonicus显示文摘Phytochemical investigation on the ethanol extract of a well-known medicinal herb Leonurus japonicus,led to the separation of 18 labdane type diterpenoids(1-18).Through comprehensive spectroscopic analyses and quantum chemical calculations,these compounds were structurally characterized as six new interesting 5,5,5-di-spirocyclic ones(1-6),two new(7 and 8)and six known(13-18)interesting 6,5,5-di-spirocyclic ones,a new rare 14,15-dinor derivative(9),and three new ones incorporating a y-lactone unit(10-12).An in vitro neuroprotective assay in RSC96 cells revealed that compounds 7 and 12 exhibited neuroprotective activity in a concentration-dependent way,comparable to the reference drug N-acetylcysteine. | CAO Xinxin WANG Xinxin ZHANG Yu XU Defeng SONG Xiuqing YU Jinhai BAO Jie ZHANG Junsheng ZHANG Hua | 2023 | Chinese Journal of Natural Medicines2023，21，7： | 0 |
| 14 | Flexible predictive power-split control for battery-supercapacitor systems of electric vehicles using IVHS显示文摘The utilization of traffic information received from intelligent vehicle highway systems(IVHS) to plan velocity and split output power for multi-source vehicles is currently a research hotspot. However, it is an open issue to plan vehicle velocity and distribute output power between different supply units simultaneously due to the strongly coupling characteristic of the velocity planning and the power distribution. To address this issue, a flexible predictive power-split control strategy based on IVHS is proposed for electric vehicles(EVs) equipped with battery-supercapacitor system(BSS). Unlike hierarchical strategies to plan vehicle velocity and distribute output power separately, a monolayer model predictive control(MPC) method is employed to optimize them online at the same time. Firstly, a flexible velocity planning strategy is designed based on the signal phase and time(SPAT) information received from IVHS and then the Pontryagin’s minimum principle(PMP) is adopted to formulate the optimal control problem of the BSS. Then, the flexible velocity planning strategy and the optimal control problem of BSS are embedded into an MPC framework, which is online solved using the shooting method in a fashion of receding horizon. Simulation results verify that the proposed strategy achieves a superior performance compared with the hierarchical strategy in terms of transportation efficiency, battery capacity loss, energy consumption and computation time. | HE Defeng LUO Jie LIN Di YU Shiming | 2023 | Journal of Systems Engineering and Electronics2023，34，1： | 0 |
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