Novel torsional spring with corrugated flexible units for series elastic actuators for cooperative robots

Yanlin Chen,Yanjiang Huang,Kaibin Chen,Yeping Wang,Yanbin Wu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

Reasonable robot joint stiffness is necessary to guarantee the safety and control accuracy of cooperative robots. In this study, a novel flat torsional spring with corrugated flexible units for a series elastic actuator (SEA) was developed to meet the requirements of cooperative robots. The torsional spring can absorb impact energy. The spring was optimized through the design of experiment method, and its theoretical stiffness was verified through numerical calculation and finite element analysis. Compared with other existing flat torsional springs in the simulation, the proposed torsional spring showed reasonable torsional stiffness and high radial and axial stiffness, which could guarantee safety and control accuracy. The proposed torsional spring was also evaluated through real experiments. Simulation and experimental results revealed that the proposed torsional spring has a linear torque versus angle characteristic.

Intercalation of Europium Inclusion Complex of β-Cyclodextrin into Layered Double Hydroxides Through Layer-By-Layer Assembly and Its Luminescent Properties

Wenjun Zhang,Yi Chen,Yanlin Li,Sumin Guan,Yan Chen,Qian-Qian Yang,Lu Liu,Qing-Chen Xue,Yu-Cui Guang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10

"In this work, organic–inorganic hybrid ultrathin transparent films (UTFs), produced by layer-by-layer (LBL) assembly of the europium inclusion complex of β-cyclodextrin ( β-CD) and Mg–Al layered double hydroxide (MgAl–NO3–LDHs) nanosheets, are reported. UV-visible (UV-Vis) absorption and fluorescence spectroscopy show orderly growth of the europium inclusion complex of β-CD/layered double hydroxide (EICC/LDH) films with an increasing number of deposition cycles. X-ray diffraction and scanning electron microscopy measurements indicate that the films feature periodic layered structures with uniform surface morphology. Moreover, when EICC is assembled with inorganic rigid LDH nanosheets, the lifetimes are prolonged due to the isolation effect, and the UTFs are transparent with high brightness, which indicate that these films could serve as new optical materials."

Luminescence properties of sodalite-type Zn₄B₆O₁₃:Mn²⁺

Chen, Cuili,Cai, Peiqing,Qin, Lin,Wang, Jing,Bi, Shala,Huang, Yanlin,Seo, Hyo Jin Elsevier 2018 Journal of luminescence Vol.199 No.-

<P><B>Abstract</B></P> <P>Luminescence properties of sodalite Zn<SUB>4</SUB>B<SUB>6</SUB>O<SUB>13</SUB>:Mn<SUP>2+</SUP> are investigated by optical and laser excitation spectroscopy in the temperature range 10 – 300 K. The samples of Zn<SUB>4</SUB>B<SUB>6</SUB>O<SUB>13</SUB>:Mn<SUP>2+</SUP> are prepared in the carbon reducing atmosphere. The green emission at 540 nm are observed in Zn<SUB>4</SUB>B<SUB>6</SUB>O<SUB>13</SUB>:Mn<SUP>2+</SUP> for various Mn<SUP>2+</SUP> concentration. Optimum Mn<SUP>2+</SUP> concentration and critical distances between Mn<SUP>2+</SUP> ions in Zn<SUB>4</SUB>B<SUB>6</SUB>O<SUB>13</SUB> are obtained by the luminescence intensity as functions of Mn<SUP>2+</SUP> concentration. The decays of Mn<SUP>2+</SUP> emission depend strongly on Mn<SUP>2+</SUP> concentration due to the energy transfer and energy diffusion in Zn<SUB>4</SUB>B<SUB>6</SUB>O<SUB>13</SUB>:Mn<SUP>2+</SUP>. The fine structures consisting of the intense zero phonon line (ZPL) and weak vibrational sidebands are observed at low temperature. The relevant mechanism of excitation bands, ZPL, vibrational sidebands and the bandwidth as functions of temperature are interpreted in detail by energy level diagram of the 3d<SUP>5</SUP> transition metal ions and configuration coordinated diagram. The high thermal stability of the Zn<SUB>4</SUB>B<SUB>6</SUB>O<SUB>13</SUB>:Mn<SUP>2+</SUP> phosphor are observed in the temperature range 10–300 K.</P>

Hydrothermal synthesis and upconversion luminescence of Y₂WO₆:Yb³⁺/Er³⁺ crystals

Chen, Cuili,Cai, Peiqing,Qin, Lin,Wang, Jing,Huang, Yanlin,Seo, Hyo Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.747 No.-

<P><B>Abstract</B></P> <P>The Y<SUB>2</SUB>WO<SUB>6</SUB>:Yb<SUP>3+</SUP>/Er<SUP>3+</SUP> crystals were synthesized by the hydrothermal method. The needle-shaped morphology is controllably formed and a number of crystals aggregate as spheres by adding the surfactant of sodium dodecylbenzenesulfonate (SDBS) into the reaction system. The crystal structure, morphology and upconversion luminescence properties of the Y<SUB>2</SUB>WO<SUB>6</SUB>:Yb<SUP>3+</SUP>/Er<SUP>3+</SUP> crystals are conducted on the basis of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), FTIR and emission spectra. The different emission intensity ratio of the red and green bands is observed for the Y<SUB>2</SUB>WO<SUB>6</SUB>:Yb<SUP>3+</SUP>/Er<SUP>3+</SUP> precursors under different heat treatments. The different intensity ratio are illustrated according to the upconversion mechanism.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The needle-shaped Y<SUB>2</SUB>WO<SUB>6</SUB>:Yb<SUP>3+</SUP>/Er<SUP>3+</SUP> crystals were synthesized by the hydrothermal method. </LI> <LI> The morphology was controlled by surfactant SDBS and the relevant mechanism. </LI> <LI> The different emission intensity ratios of the red and green bands were observed due to heat treatments. </LI> <LI> The distinct luminescence performance was illustrated according to the upconversion mechanism. </LI> </UL> </P>

Modified Double-Reduction Method considering Strain Softening and Equivalent Influence Angle

Yifan Chen,Hang Lin,Yixian Wang,Rihong Cao,Chunyang Zhang,Yanlin Zhao 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.11

Slope stability has been the research focus in the field of geotechnical engineering. Both the asynchronous decay speeds and distinct stability contributions of cohesion c and friction ϕduring slope instability have been evidenced. In this study, based on linear softening model and weighted average hypothesis, a modified double-reduction method is established. The research includes: 1) the asynchronism between decay speeds of c and ϕ are described by adopting different slopes in linear softening model for c and tanϕ, in which case the respective reduction factors in strength reduction method Fc and Fϕ are solved. 2) The distinct slope stability contributions of c and ϕ is readily linked with the different influences to safety factor, and therefore, introducing the equivalent influence angle θe (defined as the slope angle at which c and ϕ share identical contributions to stability), as well as its determination method. 3) According to weighted average hypothesis that the overall safety factor FS is the weighted average of Fc and Fϕ, the contribution scaling factor μ (defined as the weighted ratio of Fc and Fϕ is proposed, which promotes the solution of respective weighted coefficients wc and wϕ of two reduction factors by combining θe, achieving a new double-reduction method. 4) The validity of this method is verified via comprehensive comparison with existing double-reduction methods of practical slope examples.

INTERNATIONAL AIR LAW MOOT COURT COMPETITION 2018

( Jiangnan Chen ),( Yanlin Guo ),( Meng Sha ),( Rui Zhao ) 한국항공우주정책·법학회(구 한국항공우주법학회) 2018 한국항공우주정책·법학회지 Vol.33 No.1

International Digital Design Invitation Exhibition

Boyang Feng,Chen Song,HanwenXU,He Gao,Kai Huo,Kuifang Li,Niu Wei,Shaopeng Han,Tingting Qu,Ting Li,Wang, di,Xu Yeni,Yanlin Xie,Bertrand Planes,Chi-Wook Nho,Jean-benoit Lallemant,Yeon Gyu-Seok,Bettina W 한국콘텐츠학회 2010 ICCC International Digital Design Invitation Exhib Vol.2010 No.12

An efficient yellow-emitting vanadate Cs₅V₃O₁₀ under UV light and X-ray excitation

Pu, Yinfu,Huang, Yanlin,Tsuboi, Taiju,Huang, Wei,Chen, Cuili,Seo, Hyo Jin Elsevier 2015 Materials letters Vol.149 No.-

<P><B>Abstract</B></P> <P>A self-activated yellow-emitting phosphor of nano-sized Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> was synthesized by the Pechini method. The crystal phase and structure were investigated by X-ray diffraction (XRD) and structural refinement. The nanoparticles were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopic (XPS) measurements. Luminescence properties such as excitation and emission spectra as well as the absolute external quantum efficiency (<I>η</I>) are presented. Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> is efficiently excited by UV light and X-ray and presents a bright yellow luminescence with the maximum <I>η</I> of 85.2%. It is suggested that Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> is expected to be an efficient phosphor for lighting and display.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Efficient yellow-emitting Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> nanoparticles were developed. </LI> <LI> Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> has high quantum efficiency of 85.2% under UV light. </LI> <LI> Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> shows scintillating luminescence with 40% intensity of that of Bi<SUB>4</SUB>Ge<SUB>3</SUB>O<SUB>12</SUB>. </LI> <LI> Efficient luminescence of Cs<SUB>5</SUB>V<SUB>3</SUB>O<SUB>10</SUB> is related to structural characteristics. </LI> </UL> </P>

Optical Thermometry Based on Vibration Sidebands in Y₂MgTiO₆:Mn⁴⁺ Double Perovskite

Cai, Peiqing,Qin, Lin,Chen, Cuili,Wang, Jing,Bi, Shala,Kim, Sun Il,Huang, Yanlin,Seo, Hyo Jin American Chemical Society 2018 Inorganic Chemistry Vol.57 No.6

<P>Mn<SUP>4+</SUP>-doped Y<SUB>2</SUB>MgTiO<SUB>6</SUB> phosphors are synthesized by the traditional solid-state method. Powder X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectrometer are employed to characterize the samples. The Mn<SUP>4+</SUP>-doped Y<SUB>2</SUB>MgTiO<SUB>6</SUB> phosphors show the far-red emission at ∼715 nm, which is assigned to the <SUP>2</SUP>E<SUB>g</SUB> → <SUP>4</SUP>A<SUB>2</SUB> spin-forbidden transition of Mn<SUP>4+</SUP>. The temperature-dependent luminescent dynamics of Mn<SUP>4+</SUP> is described by a complete model associated with electron-lattice interaction and spin-orbit coupling. The noncontact optical thermometry of Y<SUB>2</SUB>MgTiO<SUB>6</SUB>:Mn<SUP>4+</SUP> is discussed based on the fluorescence intensity ratio of thermally coupled anti-Stokes and Stokes sidebands of the efficient ∼715 nm far-red emission in the temperature range of 10-513 K. The maximum sensor sensitivity of Y<SUB>2</SUB>MgTiO<SUB>6</SUB>:Mn<SUP>4+</SUP> is determined to be as high as 0.001 42 K<SUP>-1</SUP> at 153 K, which demonstrates potential applications for the optical thermometry at low-temperature environments.</P><P>The vibration sidebands-based Mn<SUP>4+</SUP> doped Y<SUB>2</SUB>MgTiO<SUB>6</SUB> double perovskite was designed for ratiometric optical temperature sensing in the range from 10 to 513 K; the Mn<SUP>4+</SUP> ions can be located at the Ti<SUP>4+</SUP> sites and form MnO<SUB>6</SUB> octahedron with deep red emission under UV excitation. The highest relative temperature sensitivity was obtained as 0.001 42 K<SUP>−1</SUP> at 153 K.</P> [FIG OMISSION]</BR>

Optical performance of the Ba₅Al₃F₁₉:Eu²⁺ blue phosphors with high thermal stability

Qin, Lin,Cai, Peiqing,Chen, Cuili,Wang, Jing,Kim, Sun Il,Huang, Yanlin,Seo, Hyo Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.738 No.-

<P><B>Abstract</B></P> <P>Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> blue-emitting phosphors were synthesized by the solid state reaction in a reductive atmosphere. The crystal structure of Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphors were characterized by using the X-ray powder diffraction (XRD) measurement. The luminescence properties are investigated systematically based on the crystal structure. Emission and excitation spectra of the Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphor along with the decay curves were characterized. Under the excitation of UV light, the phosphor exhibits a broad band emission around 410 nm ascribed to the allowed 4<I>f</I> <SUP>6</SUP>5<I>d</I>→4<I>f</I> <SUP>7</SUP>(<SUP>8</SUP>S<SUB>7/2</SUB>) transition, together with a sharp line at 360 nm corresponding to the forbidden 4<I>f</I> <SUP>7</SUP>(<SUP>6</SUP>P<SUB>7/2</SUB>)→4<I>f</I> <SUP>7</SUP>(<SUP>8</SUP>S<SUB>7/2</SUB>) transition of the Eu<SUP>2+</SUP> ions. The temperature dependent emission spectra and decay curves were measured to investigate the origins of the emission and the thermal stabilities of the as-prepared phosphors. The as-prepared Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphors display interesting and stable luminescence properties, which can act as promising blue-emitting phosphor candidates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We developed Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB> fluoride by a simple solid state method. </LI> <LI> The phosphor exhibits a bright broad band emission. </LI> <LI> 4<I>f</I> <SUP>7</SUP>(<SUP>6</SUP>P<SUB>7/2</SUB>)→4<I>f</I> <SUP>7</SUP>(<SUP>8</SUP>S<SUB>7/2</SUB>) transition of the Eu<SUP>2+</SUP> ions can be observed in this system; </LI> <LI> The Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphor shows excellent thermal stability at high temperature. </LI> </UL> </P>