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Modification of free-energy density functional theory approach for prediction of high-pressure mixture adsorption

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Chinese Science Bulletin 2008年第9期53卷 1358-1364页

作者： liu shuyan YANG XiaoNing YANG Zhen School of Mechanical and Power Engineering Nanjing University of Technology Nanjing 210009 China College of Chemistry and Chemical Engineering Nanjing University of Technology Nanjing 210009 China

A modified non-local free energy density functional theory (NDFT) model, with the consideration of the nonadditivity term of solid-fluid and fluid-fluid interactions and finite pore wall thickness (≈2 layers), was developed to model the confined fluid mixtures in slit pore. This improved NDFT approach, com- bining with the pore size distribution (PSD) analysis of adsorbent material can be applied to predicting the adsorption equilibria of high-pressure gas mixtures on activated carbon. Compared with the con- ventional NDFT method, this new approach partly improves the correlation performance of adsorption equilibrium for pure species and increases the reliability of the PSD analysis. For the mixtures, CH4/N2 and CO2/N2, a relatively improved performance has been observed for the adsorption equilibrium pre- diction of the mixtures under high-pressure conditions, especially for the weakly adsorbed species.

关键词：高压吸附作用碳裂缝气孔自由能密度

Molecular dynamics simulation of wetting behavior at CO_2/water/solid interfaces

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Chinese Science Bulletin 2010年第21期55卷 2252-2257页

作者： liu shuyan YANG XiaoNing QIN Yan State Key Laboratory of Material-Orientated Chemical Engineering Nanjing University of Technology Nanjing 210009 China School of Mechanical and Power Engineering Nanjing University of Technology Nanjing 210009 China

We used molecular dynamics simulation to demonstrate the microscopic wetting behavior of two solid model surfaces for the first *** and hydrophobic features were modeled in a dense CO2 fluid environment under various *** water droplet loses contact with the surface under the influence of higher density CO2 fluids on the hydrophobic *** the hydrophilic surface,no separation between the water droplet and the surface was ***,the contact angle of the water droplet on the hydrophilic surface was found to increase with the fluid *** effect of dense CO2 fluid on the surface wettability can be interpreted in terms of enhanced interactions from the surrounding CO2 molecules.

关键词：分子动力学模拟界面润湿行为模式二氧化碳流体固体表面二氧化碳分子疏水表面表面润湿性

Model of Airflow Field on the Deck for Shipborne Helicopter Flight Dynamics Analysis

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第5期34卷 567-577页

作者： Hu Guocai Xu Guang Wang Yunliang liu shuyan Department of Airborne Vehicle Engineering Naval Aeronautical and Astronautical University Yantai 264001 P.R. China Troops 92074 PLA Ningbo 315000 P. R. China

For the research of helicopter/ship dynamic interface,the method of combining steady flow and stochastic flow is adopted to establish a flow field model applied to the flight dynamics analysis of shipborne *** steady flow is calculated by computational fluid dynamics(CFD)method,while the stochastic flow is composed of the compensation velocity derived from ship motion and turbulence above the *** accuracy of the proposed flow field model is verified by comparing the helicopter response in the proposed flow field with the results calculated by US Army′s Military Specifications(MIL)model which is commonly used in ***,it also shows the proposed flow field model is more appliable to flight dynamics analysis of shipborne *** that the basis,ship deck flow field is simulated at different sea conditions by adjusting the wind speed on the deck,mother ship movement and shipboard turbulence,*** helicopter angular rate response is *** results show that the difference of dynamic stability between helicopter′s roll and pitch leads to the facts that the influence of above factors on the helicopter′s roll angular rate response is greater than that of pitch angular rate,that the frequency and amplitude of mother ship roll motion are much greater than those of pitch motion,and that the disturbance caused by roll motion on the air has greater influence on the helicopter *** shipboard turbulence is the main disturbance factor that influences helicopter flight stability and its intensity determines the amplitudes of angular rate response.

关键词： shipborne helicopter flight dynamics airflow field on the deck time-space characteristics sea condition

N-Glycosylated type Ⅱ collagen peptides as therapeutic saccharide vaccines for rheumatoid arthritis

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Chinese Chemical Letters 2024年第5期35卷 197-200页

作者： Dake liu shuyan liu Fanlei Hu Zhongtang Li Zhongjun Li State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China Department of Rheumatology and Immunology Peking University People’s HospitalBeijing 100044China

The interaction among type Ⅱ collagen(CⅡ),human DR4 major histocompatibility complex type Ⅱ molecule(MHC Ⅱ)and T-cell receptor(TCR)is associated with the development of rheumatoid arthritis(RA).The activation of T cells can be reduced through exposure to modified CⅡ(263-272)glycopeptide fragment via competitive inhibition with *** this work,30 peptides based on the sequence of CⅡ(263-272)were prepared and evaluated for their binding to DR4 protein by surface plasmon resonance(SPR)*** effect on the secretion of pro-inflammatory factors by the spleen cells in collagen induced rheumatoid arthritis(CIA)mouse was also *** N-glycosylated CⅡ peptides were identified to have strong binding to the human recombinant DR4 protein and weak proinflammatory *** glycopeptides could be developed as therapeutic saccharide vaccines for the treatment of rheumatoid arthritis(RA).

关键词： Rheumatoid arthritis TypeⅡcollegan Glycosylation N-Glycosylated altered peptides Saccharide vaccines

A novel thermophilic endoglucanase from a mesophilic fungus Fusarium oxysporum

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Chinese Science Bulletin 2006年第2期51卷 191-197页

作者： liu shuyan DUAN Xinyuan LU Xuemei GAO Peiji State Key Laboratory of Microbial Technology Shandong University Ji'nan 250100 China

A novel thermophilic endoglucanase (EGt) was extracted from a mesophilic fungus (Fusarium oxysporum L19). We invoked conventional kinetic enzyme reactions using the sodium salt of carboxymethyl cellulose (CMC-Na) as substrate. EGt displayed optimal activity at 75℃ when kept running 30 min in the temperature range of 30―85℃. Thermal stability curve measured at 70℃ suggested that its half-life time is 15.1 min. The activity was enhanced in the presence of Co2+ or Mg2+ but inhibited by Pb2+ and Fe3+. Moreover, N-bromosuccinimide (NBS) modification resulted in a complete loss of EGt activity, suggesting that tryptophan residues may be involved in the enzyme active site. Amino acid composition analysis demonstrated that EGt contains more proline residues. EGt lacks activity towards p-nitro- phenyl cellobiose (pNPC). The N-terminal amino acid se- quence of EGt is SYRVPAANGFPNPDASQEKQ, and the gene of EGt was sequenced and analyzed. Extensive se- quence alignments failed to show any homology between EGt and any known endoglucanases. This is the first report addressing the thermal adaptation of a cellulolytic enzyme from the mesophilic fungus F. oxysporum. Maybe the ex- pression of multiple isoenzyme in an organism helps it adapt to complex living environments.

关键词：嗜温菌尖镰孢香蕉枯萎病嗜热葡聚糖内切酶热稳定性热活性

Anti-colon cancer activity of water-soluble polysaccharides extracted from Gloeostereum incarnatum via Wnt/β-catenin signaling pathway

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Food Science and Human Wellness 2021年第4期10卷 460-470页

作者： Jiawei He Anhui Yang Xuyu Zhao Yang liu shuyan liu Di Wang Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi Jilin Agricultural UniversityChangchun 130118China School of Life Sciences Jilin UniversityChangchun 130012China

The incidence rate of colon cancer ranks the third among malignant tumors *** incarnatum(GI),a fungus with homology of medicine and food,has multiple pharmacological *** was investigated in this study that the anti-colon cancer effect of polysaccharides purifi ed from GI(GIPS)in ApcMinC/Gpt mice(an in situ colon cancer mouse model).Eight-week administration with GIPS at doses of 30 or 90 mg/kg strongly inhibited tumor growth including the reduction on numbers and the suppression of the size without infl uencing the animals’body weight and organ *** to the proteomics performing by antibody array,among 308 detected cytokines,GIPS significantly regulated 89 of *** with vehicle-treated mice,GIPS effectively reduced the levels of interleukin(IL)-1β,IL-4,IL-6,IL-17,IL-22,tumor necrosis factor(TNF)-α,matrix metalloproteinase(MMP)-2,and enhanced the levels of IL-15 and IL-18 in serum and/or colon tissues,which suggested its anti-inflammation of *** suppressed nuclear aggregation of β-catenin,affected the expression of WNT1 and related proteins,thereby regulated the activation of the Wnt ***,GIPS can inhibit the growth of colon cancer,at least partially,via inhibiting the Wnt/β-catenin signaling pathway.

关键词： Gloeostereum incarnatum Water-soluble polysaccharides Colon cancer Wnt/β-catenin

Regional climate model downscaling may improve the prediction of alien plant species distributions

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Frontiers of Earth Science 2014年第4期8卷 457-471页

作者： shuyan liu Xin-Zhong LIANG Wei GAO Thomas J. STOHLGREN Earth System Science Interdisciplinary Center University of Maryland College Park MD 20740 USA Department of Atmospheric and Oceanic Sciences University of Maryland College Park MD 20740 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523 USA Fort Collins Science Center U.S. Geological Survey Fort Collins CO 80526 USA

Distributions of invasive species are commonly predicted with species distribution models that build upon the statistical relationships between observed species presence data and climate data. We used field observations, climate station data, and Maximum Entropy species distribution models for 13 invasive plant species in the United States, and then compared the models with inputs from a General Circulation Model （hereafter GCM-based models） and a downscaled Regional Climate Model （hereafter, RCM-based models）. We also compared species distributions based on either GCM-based or RCM-based models for the present （1990-1999） to the future （2046- 2055）. RCM-based species distribution models replicated observed distributions remarkably better than GCM- based models for all invasive species under the current climate. This was shown for the presence locations of the species, and by using four common statistical metrics to compare modeled distributions. For two widespread invasive taxa （Bromus tectorum or cheatgrass, and Tamarix spp. or tamarisk）, GCM-based models failed miserably to reproduce observed species distributions. In contrast, RCM-based species distribution models closely matched observations. Future species distributions may be significantly affected by using GCM-based inputs. Because invasive plants species often show high resilience and low rates of local extinction, RCM-based species distribution models may perform better than GCM-based species distribution models for planning containment programs for invasive species.

关键词： climate change species distribution model,Maxent downscaling

Negotiation System of Ecological Compensation of Water Source Areas

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Chinese Journal of Population,Resources and Environment 2010年第4期8卷 49-54页

作者： Ge Yanxiang liu shuyan Wu Feifei Liang Lijuan School of Economics and Management Shandong Agricultural UniversityTai＇an Shandong 271018China Shandong Communication Media College Jinan Shandong 250200China

In view of no generally accepted ecological compensation standards and methods at present,this paper discusses the introduction of the negotiation system to the process of ecological compensation for water source *** is,the government in water source areas and the downstream regions of river basins should confirm their respective rights and obligations and then establish their compensation standards through negotiations according to the different purposes of water *** amount of compensation should be determined in the comprehensive consideration of the quality,quantity and compensation price of *** open and fair negotiations,an institutional arrangement will be set up,which can make the water source areas and the downstream regions of river basins fully express their true preferences and their independent choices on the ecological environment.

关键词： water resource ecological compensation negotiation system externality

Design and experiment of high-speed straw cleaning unit with double air springs

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 89-97页

作者： Xiaomeng Xia Honggang Li shuyan liu Ruiqiang Ran Yongjian Cong Yuhan Jin Dongyan Huang School of Biological and Agricultural Engineering Jilin UniversityChangchun 130022China Key Laboratory of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130022China Jilin Agricultural Machinery Research Institute Changchun 130022China

No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the *** two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high *** analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was *** experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high *** results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.

关键词： conservation tillage row cleaners straw cleaning unit double air spring system