Characteristics of isolated lactic acid bacteria and their effects on the silage quality

Siran Wang,Xianjun Yuan,Zhihao Dong,Junfeng Li,Gang Guo,Yunfeng Bai,Junyu Zhang,Tao Shao 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: Four lactic acid bacteria (LAB) strains isolated from common vetch, tall fescue and perennial ryegrass on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) silage were studied. Methods: The four isolated strains and one commercial inoculant (G, Lactobacillus plantarum MTD-1) were evaluated using the acid production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. The five LAB strains were added to Italian ryegrass for ensiling at three different temperatures (10°C, 15°C, and 25°C). Results: All isolated strains (LCG3, LTG7, I5, and LI3) could grow at 5°C to 20°C, pH 3.0 to 8.0 and NaCl (3.0%, 6.5%). Strains LCG3, LTG7, I5, and LI3 were identified as Lactobacillus plantarum, Pediococcus acidilactici, Lactobacillus paraplantarum, and Lactobacillus casei by sequencing 16S rDNA, respectively. All LAB inoculants significantly (p<0.05) increased lactic acid (LA) contents and ratios of lactic acid to acetic acid, and reduced pH and ammonia nitrogen/ total nitrogen (AN/TN) compared with uninoculated silages at various temperatures (10°C, 15°C, and 25°C). Compared to the commercial inoculant G, I5, and LI3 showed similar effects on improving the silage quality of Italian ryegrass at 10°C and 15°C, indicated by similar pH, LA content and AN/TN. Conclusion: All inoculants could improve the silage fermentation quality at various temperatures (10°C, 15°C, and 25°C). At the temperature of 10°C and 15°C, strain I5 and LI3 had similar effects with the commercial inoculant G on improving the silage quality of Italian ryegrass.

Fuzzy Time Delay Algorithms for Position Control of Soft Robot Actuated by Shape Memory Alloy

Junfeng Li,Yunyao Pi 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.6

Due to the nonlinear saturated hysteretic behavior of SMA during the phase transformation, it is not easy to achieve accurate position tracking control by establishing an effective controller for the SMA actuator system. In this paper, an accurate position control method based on fuzzy time delay algorithms for a soft robot is proposed. The error of TDE is unavoidable because the smallest value for the time delay is the sampling time of the microcontroller, a rule-based fuzzy logic controller for online gain tuning combined with TDC is proposed to eliminate the position control errors. Three different sets of experiments are conducted, using step, sine and ramp signals as reference inputs. The experimental results demonstrate that the proposed method has the smallest steady state error and the least overshoot than TDE and PI controller. In conclusion, the proposed method should be a viable alternative for position control of SMA actuator.

Phase Resistance with Displacement Feedback Control for Thick SMA Actuators

Junfeng Li,Hiroyuki Harada 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

The purpose of this study is to design and control a thick shape memory alloy (SMA) actuator to achieve rapid position control withtwo connected SMA wires. In the past, research has focused on position and force control of thin SMA wires, because they cool rapidlyin air and as it is easy to get rapid response for SMA actuators in this manner. However, the cooling time is longer with thick SMAwires, making it difficult to obtain rapid position responses with traditional displacement feedback control methods. Phase resistanceand displacement feedback control (PRDFC), combing phase resistance and displacement as feedback, minimizes cooling time byshortening the latency duration of thick SMA wires, and experimental results here show that more rapid responses are achieved usingthe method proposed here than when only displacement is used as feedback.

Capacity Bounds on the Ergodic Capacity of Distributed MIMO Systems over K Fading Channels

( Xingwang Li ),( Junfeng Wang ),( Lihua Li ),( Charles C. Cavalcante ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.7

The performance of D-MIMO systems is not only affected by multipath fading but also from shadowing fading, as well as path loss. In this paper, we investigate the ergodic capacity of D-MIMO systems operating in non-correlated fading (Rayleigh/Gamma) channels. With the aid of majorization and Minkowski theory, we derive analytical closed-form expressions of the upper and lower bounds on the ergodic capacity for D-MIMO systems over non-correlated K fading channels, which are quite general and applicable for arbitrary signal-to-noise ratio (SNR) and the number of transceiver antennas. To intuitively reveal the impacts of system and fading parameters on the ergodic capacity, we deduce asymptotic approximations in the high and low SNR regimes. Finally, we pursue the massive MIMO systems analysis for the lower bound and derive closed-form expressions when the number of antennas at BS grows large, and when the number of antennas at transceivers becomes large with a fixed and finite ratio. It is demonstrated that the proposed expressions on the ergodic capacity accurately match with the theoretical analysis.

Synthesis and Crystal Structure of Bis-3,3'-(nitro-NNO-azoxy)-4,4'-azofurazan

Hui Li,Bozhou Wang,Xiang Zhi Li,Junfeng Tong,Wei Peng Lai,Xue Zhong Fan 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

Setosphapyrone C and D accelerate macrophages cholesterol effl ux by promoting LXRa/ABCA1 pathway

Ting Li,Jiayu Yin,Yubin Ji,Ping Lin,Yanjie Li,Zixun Yang,Shumei Hu,Jin Wang,Baihui Zhang,Saloni Koshti,Junfeng Wang,Chenfeng Ji,Shoudong Guo 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.8

LXRα agonists have attracted signifi cant attentiondue to their potential biological activities on promotingcholesterol effl ux. This study was designed to investigatewhether setosphapyrone C and D have potential lipid-loweringcapacity and the underlying mechanisms in vitro. Ourdata showed that setosphapyrone C and D had weak cytotoxicitycompared to the liver X receptor α (LXRα) agonistT0901317. In RAW 264.7 macrophages, setosphapyroneC and D signifi cantly enhanced [ 3 H]-cholesterol effl ux by~ 21.3% and 32.4%, respectively; furthermore, setosphapyroneC and D enhanced the protein levels of ATP-bindingcassette transporter (ABC) A1 and LXRα by 58% and 69%,and 60% and 70% (8 μM), respectively; however, they had noeff ect on the protein levels of ABCG1 and scavenger receptorB type 1; additionally, they had minor eff ect on the mRNAexpression of lipogenic genes. Of note, setosphapyrone C and D signifi cantly enhanced LXRα/ABCA1pathway inmice primary macrophages. In BRL cells, setosphapyroneC and D signifi cantly improved the protein levels of ABCA1and ABCG1; setosphapyrone D signifi cantly enhanced theprotein expression of low-density lipoprotein. Collectively,setosphapyrone C and D with weak cytotoxicity exhibitedeff ective lipid-lowering eff ect via enhancing LXRα/ABCpathways. Setosphapyrones possess potential applicationfor the treatment of hyperlipidemic diseases.

Coral‑Like NiFe2O4/C Composite as the High‑Performance Anode Material for Lithium‑Ion Batteries

Shanshan Bao,Yifei Xiao,Junfeng Li,Bo Yue,Yanjun Li,Wenxian Sun,Lei Liu,Yi Huang,Li Wang,Peicong Zhang,Xuefei Lai 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.3

In this work, we fabricated NiFe2O4/C composite with a coral-like structure through co-precipitation approach followed bythermal decomposition. The composite with a large surface area of 162.1 m2 g−1 and an average pore size of 11.8 nm wasobtained. The porous structure in the composite derived from oxalate can Effectively accommodate the volume changesof NiFe2O4 during the cycling processes. When used as anode materials, the initial charge and discharge capacities of thecomposite were 926.7 and 1277.7 mAh g−1 at 100 mA g−1. After 50 cycles, the reversible capacity of NiFe2O4/C could stillremain at 892.4 mAh g−1. Even at a current density of 2000 mA g−1, the reversible capacity still reached 523.3 mAh g−1. The results showed that the synergy between NiFe2O4 and carbon improved the electrochemical performance, and the porouscomposite could stabilize the structure of the electrode.

Robust Model Predictive Control for Uncertain Positive Time-delay Systems

Junfeng Zhang,Haoyue Yang,Miao Li,Qian Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.2

This paper proposes the robust model predictive control of positive time-delay systems with interval andpolytopic uncertainties, respectively. The model predictive control framework consists of linear constraint, linearperformance index, linear Lyapunov function, linear programming algorithm, and cone invariant set. By virtue ofmatrix decomposition technique, robust model predictive controllers of interval and polytopic positive systems withmultiple state delays are designed, respectively. A multi step control strategy is utilized and a cone invariant set isconstructed. Linear programming is used for the corresponding MPC conditions. Finally, a numerical example isgiven to verify the effectiveness of the proposed design.

Parameter optimization of five-axis polishing using abrasive belt flap wheel for blisk blade

Junfeng Zhang,Yaoyao Shi,Xiaojun Lin,Zhishan Li 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.10

Considering the weak rigidity of blisk blades and the limited accessibility of blisk tunnels, polishing blisk blades is difficult when using tools with poor flexibility and large dimension. Hence, to reduce the surface roughness (SR) of a blisk blade, five-axis polishing method with abrasive belt flap wheel (ABFW) is employed to polish the blisk blade based on the analysis of the blisk structure and advantages of ABFW polishing. Polishing experiments based on central composite design are performed using ABFW. Response surface method (RSM) is employed to establish a predictive model between SR and various parameters, including ABFW size, contact force, spindle speed, and feed rate. Analysis of variance is then performed to evaluate the proposed model. The degree of influence of each factor on SR after polishing using ABFW is determined by plotting main effects. The interactions of polishing factors on SR are analyzed by RSM. Optimal parameters are obtained by response surface optimization. Finally, an experiment on blisk blade polishing using ABFW on a five-axis polishing machine is carried out for confirmation. Results indicate that the surface quality of the blisk blade after polishing is significantly improved, with SR being less than 0.4 μm.

Synthesis and Photovoltaic Properties of Alternating Conjugated Polymers Derived from Thiophene-Benzothiadiazole Block and Fluorene/Indenofluorene Units

Li, Jianfeng,Tong, Junfeng,Zhang, Peng,Yang, Chunyan,Chen, Dejia,Zhu, Yuancheng,Xia, Yangjun,Fan, Duowang Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

A new donor-accepter-donor-accepter-donor (D-A-D-A-D) type 2,1,3-benzothiadiazole-thiophene-based acceptor unit 2,5-di(4-(5-bromo-4-octylthiophen-2-yl)-2,1,3-benzothiadiazol-7-yl)thiophene ($DTBTTBr_2$) was synthesized. Copolymerized with fluorene and indeno[1,2-b]fluorene electron-rich moieties, two alternating narrow band gap (NBG) copolymers PF-DTBTT and PIF-DTBTT were prepared. And two copolymers exhibit broad and strong absorption in the range of 300-700 nm with optical band gap of about 1.75 eV. The highest occupied molecular orbital (HOMO) energy levels vary between -5.43 and -5.52 eV and the lowest unoccupied molecular orbital (LUMO) energy levels range from -3.64 to -3.77 eV. Potential applications of the copolymers as electron donor material and $PC_{71}BM$ ([6,6]-phenyl-$C_{71}$ butyric acid methyl ester) as electron acceptors were investigated for photovoltaic solar cells (PSCs). Photovoltaic performances based on the blend of PF-DTBTT/$PC_{71}BM$ (w:w; 1:2) and PIF-DTBTT/$PC_{71}BM$ (w:w; 1:2) with devices configuration as ITO/PEDOT: PSS/blend/Ca/Al, show an incident photon-to-current conversion efficiency (IPCE) of 2.34% and 2.56% with the open circuit voltage ($V_{oc}$) of 0.87 V and 0.90 V, short circuit current density ($J_{sc}$) of $6.02mA/cm^2$ and $6.12mA/cm^2$ under an AM1.5 simulator ($100mA/cm^2$). The photocurrent responses exhibit the onset wavelength extending up to 720 nm. These results indicate that the resulted narrow band gap copolymers are viable electron donor materials for polymer solar cells.