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EffectS of sequence of nylon bags rumen incubation on kinetics of degradation in some commonly used feedstuffs in dairy rations

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Journal of Integrative Agriculture 2017年第1期16卷 162-168页

作者： DONG Shuang-zhao Arash Azarfar ZOU Yang li sheng-li WANG Ya-jing cao Zhi-jun State Key Laboratory of Animal Nutrition Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control/College of Animal Science and Technology China Agricultural University Beijing 100193 P.R.China Department of Animal Science Faculty of Agriculture Lorestan University Khorramabad PO Box 465 Iran

Nowadays, most available information on the degradative behaviour of feeds in ruminants is based on in situ incubation in the rumen, and it is adopted by many feed evaluation systems currently in use for ruminants. However, the outcome *** technique might be affected by many factors such as sequence of nylon bags incubation in the rumen. The objective of current study was to investigate effects of sequence of nylon bag incubation on degradative behavior of dry matter （DM）, crude protein （CP）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） in some feed ingredients commonly used in dairy rations, including alfalfa haylage, corn silage, corn grain and soybean meal. Four multiparous Holstein lactating cows fitted with permanent ruminal cannulas were used. The nylon bags containing feed samples either were placed in the rumen at once and removed at designated time intervals （all in-gradually out method; AG） or were placed in the rumen at designated time points and retrieved at once （gradually in-all out method; GA）. Fractional rate of degradation of potentially degradable fraction, lag time and effective rumen degradability （ED） of DM and CP were significantly higher in the AG compared to the GA method （P〈0.05）. Fractional rates of DM and CP degradation was higher in alfalfa haylage samples incubated in the rumen using the AG method compared to that using the GA method （0.138 h-1 vs. 0.073 h-1 and 0.002 h-1 vs. 0.1125 h-1, for DM and CP, respectively; P〈0.05）. Due to a higher fractional rate of degradation （Kd） of DM and CP, the ED of DM and CP at different fractional passage rates were higher in the AG than those in the GA method （P〈0.05）. Potentially degradable fraction and lag time of NDF were higher in the AG method compared to the GA method （P〈0.05）. Placing all bags in the rumen at once and removing them at designated time intervals compared with introduction of bags in reverse sequence and removing them all at once led to a lower undegradable fra

关键词： in situ technique sequence of bag incubation feedstuffs degradative behavior

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The effects of step-wise improvement of forage combination in total mixed rations on fatty acid profile in the rumen and milk of Holstein cows

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Journal of Integrative Agriculture 2018年第8期17卷 1833-1842页

作者： BAI Sarvvl cao Zhi-jun JIN Xin WANG Ya-jing YANG Hong-jian li sheng-li State Key Laboratory of Animal Nutrition College of Animal Science and Technology China Agricultural University Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control College of Animal Science and Technology China Agricultural University

Five lactating Holstein cows in a 5×5 Latin square experiment were fed five high-concentrate total mixed rations(TMRs) to investigate the effects of step-wise improvement of forage combination on ruminal and milk fatty acid profiles. The ratio of concentrate to forage was fixed as 61:39, and the step-wise improvement of forage combination was applied as: TMR1, a ration containing corn stover; TMR2, a ration containing corn stover and ensiled corn stover; TMR3, a ration containing ensiled corn stover and Chinese wild ryegrass hay(Leymus chinensis); TMR4, a ration containing the ryegrass hay and whole corn silage; TMR5, a ration containing the ryegrass hay, whole corn silage and alfalfa hay. The TMRs were offered to the cows twice daily at 0700 and 1900 h. The entire experiment was completed in five periods, and each period lasted for 18 days. Diurnal samples of rumen fluids were collected at 0100, 0700, 1300 and 1900 h(day 16); 0300, 0900, 1500 and 2100 h(day 17); and 0500, 1100, 1700 and 2300 h(day 18). The step-wise improvement of forage combination increased energy and crude protein contents and decreased fibre content. As a result, the step-wise improvement of forage combination increased dry matter intake and milk yield(Plinolenic acid(C18:3 n-3), but did not alter dietary proportions of palmitic acid(C16:0), stearic acid(C18:0), oleic acid(C18:1 cis-9), linoleic acid(C18:2 n-6) and arachidic acid(C20:0). In response to the forage combination, ruminal concentration of C16:0, C18:2 n-6 and C18:3 n-3 linearly increased against their dietary intakes(Plinearly increased by the increase of these fatty acids in the rumen(R2≥0.79, P<0.05), and milk yields of C18:2

关键词： forage combination lactating cow ruminal fatty acid milk fatty acid

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Group inverses for some 2 × 2 block matrices over rings

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Frontiers of Mathematics in China 2016年第3期11卷 521-538页

作者： Chongguang cao Yingchun WANG Yuqiu sheng School of Mathematical Science Heilongjiang University Harbin 150080 China

Abstract We first consider the group inverses of the block matrices（AB0C）over a weakly finite ring. Then we study the sufficient and necessary conditions for the existence and the representations of the group inverses of the block matrices（ABCD）over a ring with unity 1 under the following conditions respectively：（i） B = C, D = 0,B#and（BπA0#both exist; （ii） B is invertible and m = n;（iii）A#and （D - CA#B）# both exist, C = CAA#, where A and D are m × m and n × n matrices, respectively.

关键词： Group inverse block matrix right Ore domain associative ring

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The Physical Chemistry for the Self-assembly of Peptide Hydrogels

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Chinese Journal of Polymer Science 2018年第3期36卷 366-378页

作者： Ying li Yi cao Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and EngineeringJiangsu Engineering Technology Research Centre of Environmental Cleaning MaterialsJiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlJiangsu Joint Laboratory of Atmaspheric Pollution ControlNanjing University of Information Science&TechnologyNanjing 210044China Collaborative Innovation Center of Advanced Microstrucures National Laboratony of Solid State MicrostrucureDepartment of PhysicsNanjing UniversityNanjing 210093China

Peptide hydrogels have been widely used for diverse biomedical applications. However, our current understanding of the physical principles underlying the self-assembly process is still limited. In this review, we summarize our current understanding on the physical chemistry principles from the basic interactions that drive the self-assembly process to the energy landscapes that dictate the thermodynamics and kinetics of the process. We discuss the effect of different factors that affect the kinetics of the self-assembly of peptide fibrils and how this is related to the macroscopic gelation process. We provide our understanding on the molecular origin of the complex and rugged energy landscape for the self-assembly of peptide hydrogels. The hierarchical self-assembled structures and the diverse self-assembling mechanism make it difficult and challenging to rationally design the physical and chemical properties of peptide hydrogels at the molecular revel. We also give our personal perspective to the potential future directions in this field.

关键词： Hydrogel Peptide Self-assembly Kinetics Thermodynamics

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Biomimetic transformation of gentiopicroside to erythrocentaurin

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Chinese Chemical Letters 2009年第2期20卷 150-152页

作者： Cui ling Wang Jian li liu Zhu Lan liu Xin sheng li Xiao Yong cao School of life Science Northwest University Xi'an 710069 China Department of Biology Shaanxi University of Technology Hanzhong 723001 China

Biomimetic transformation of gentiopicroside was carded out by β-glucosidase at pH 7.0 for 3 days at 37 ℃. Two products, erythrocentaurin and 5,6-dihydro-5-formyl-6-methyl-1H,3H-pyrano[3,4-c]pyran-1-one were isolate... 详细信息

关键词： Gentiopicroside Biomimetic transformation β-Glucosidase Erythrocentaurin 5,6-Dihydro-5-formyl-6-methyl-1H,3H-pyrano[3,4-c]pyran-1-one

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Effect of Rotor-stator Axial Gap on the Tip Seal Leakage Flow of a Steam Turbine

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Journal of Thermal Science 2021年第3期30卷 973-982页

作者： li Pan cao lihua School of Energy and Power Engineering Northeast Electric Power UniversityJilin 132012China

The tip leakage flow in different axial gaps is numerically investigated based on the Reynolds-Averaged Navier-Stokes equations and k-ω SST turbulent model using commercial CFD software ANSYS *** characteristics of vortexes in the flow field of tip seal and the distribution law of rotor tip leakage loss are analyzed under the change of axial *** results show that the flow field in the blade tip seal undergoes complex changes with the increase of axial *** are two opposite vortices in the seal cavity with small axial gap,namely,the large vortex in the cavity and the small vortex near the wall of the *** small vortex gradually disappears with the increase of the axial *** the axial gap is increased to a certain value,the reverse large vortex is formed in the cavity behind the low teeth of seal,and the leakage rate increases significantly;the steam flow angle and the mixing loss also show different *** on the traditional calculation formula of tip leakage rate,a more accurate calculation formula of tip leakage rate is constructed by introducing equivalent labyrinth seal teeth to consider the variation of axial gap.

关键词： steam turbine axial gap tip leakage labyrinth seal prediction formulation

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Vibration-induced nanoscale friction modulation on piezoelectric materials

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Friction 2022年第10期10卷 1650-1659页

作者： Jiawei cao Qunyang li Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua UniversityBeijing 100084China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

Mechanical vibration,as an alternative of application of solid/liquid lubricants,has been an effective means to modulate friction at the ***,atomic force microscopy(AFM)experiments and model simulations also suggest a similar vibration-induced friction reduction effect for nanoscale contact interfaces,although an additional external vibration source is typically needed to excite the ***,by introducing a piezoelectric thin film along the contact interface,we demonstrate that friction measured by a conductive AFM probe can be significantly reduced(more than 70%)when an alternating current(AC)voltage is *** real-time friction modulation is achieved owing to the localized nanoscale vibration originating from the intrinsic inverse piezoelectric effect,and is applicable for various material *** by analysis with the Prandtl–Tomlinson(P–T)friction model,our experimental results suggest that there exists an approximately linear correlation between the vibrational amplitude and the relative factor for perturbation of sliding energy *** work offers a viable strategy for realizing active friction modulation for small-scale interfaces without the need of additional vibration source or global excitation that may adversely impact device functionalities.

关键词： vibration friction modulation piezoelectric materials contact resonance Prandtl-Tomlinson(P-T)model

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Modulating ion current rectification generating high energy output in a single glass conical nanopore channel by concentration gradient

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Chinese Chemical Letters 2015年第1期26卷 43-46页

作者： li-Xiang Zhang Yu-Bin Zheng sheng-lin Cai Xiao-Hong cao Yao-Qun li Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation College of Chemistry and Chemical Engineering.Xiamen University Shenzhen Haibin Pharmaceutical Co. Ltd.

Inspired by biological systems that have the inherent skill to generate considerable bioelectricity from the salt content in fluids with highly selective ion channels and pumps on cell membranes, herein, a fully abiotic, single glass conical nanopores energy-harvesting is demonstrated. Ion current rectification （ICR） in negatively charged glass conical nanopores is shown to be controlled by the electrolyte concentration gradient depending on the direction of ion diffusion. The degree of ICR is enhanced with the increasing forward concentration difference. An unusual rectification inversion is observed when the concentration gradient is reversely applied. The maximum power output with the individual nanopore approaches 10^4pW. This facile and cost-efficient energy-harvesting system has the potential to power tiny biomedical devices or construct future clean-energy recovery plants.

关键词： Glass conical nanopore channe Ion current rectification Concentration gradient Energy generation

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Review of Antiswing Control of Shipboard Cranes

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IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 346-354页

作者： Yuchi cao Tieshan li Navigation College Dalian Maritime University

Shipboard cranes are extensively utilized in numerous fields such as cargo transferring and offshore *** control of shipboard cranes,especially the antiswing control of payloads,has attracted much research attention due to their typical underactuation characteristics and complicated *** comparisons of the traditional land-fixed cranes,a brief review on modeling and dynamics analysis is presented to illustrate the tremendous challenges and difficulties in controller design for shipboard cranes.A comprehensive review and brief analysis of shipboard crane control strategies are further *** future research directions are also put forward for *** is expected that the paper will be useful for improving existing control schemes and generating novel control approaches for shipboard crane systems.

关键词： Control review shipboard crane underactuated system

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A flight experimental platform for synchrophasing control based on a small propeller UAV

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Science China(Technological Sciences) 2018年第12期61卷 1915-1924页

作者： cao YunFei HUANG XiangHua sheng Long WANG ZhiPeng College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China JiangSu Province Key Laboratory of Aerospace Power System Nanjing 210016 China

Turboprop engine has the advantages of high efficiency and high thrust, but it has not been widely used in the civil field because of the noise excited by the low speed propellers. Propeller synchrophasing control is an active noise control method without increasing the weight of the airframe, which can attenuate the noise level in the cabin by controlling the relative phase among multiple propellers. It is generally accepted that altitude and airspeed have a great influence on the noise reduction effect of propeller synchrophasing, but there is no theoretical research about how these two factors affect the noise level. Therefore, flight experiment is considered to be a credible way. However, flight experiments of propeller synchrophasing control in turboprop aircraft have been accomplished in few countries due to enormous cost and inconvenience. An experimental platform of synchrophasing control based on a two-propeller small unmanned air vehicle(UAV) is proposed which can carry out the flight experiment research in a low-cost way. The phase angle sensor, the FOC-based scheme of motor driving, the all-slave synchrophasing control and the coordination between speed and phase difference control are presented in the UAV platform to meet its synchrophasing control precision requirement, experimental results prove that all of them can significantly enhance the performance of synchrophasing control. Noise characteristics of propellers are studied in the flight experiments, the noise predicted by the noise model is highly consistent with the actual measured noise, which verifies that the noise characteristics of small UAV accord with propeller signature theory. Based on the noise model, propeller synchrophasing has a steady effect to minimizing noise in the UAV platform. These show that the UAV platform is a feasible solution for propeller synchrophasing research.

关键词： propeller synchrophasing noise reduction small UAV flight experimental platform low cost

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