Microstructure Evolution and Mechanical Properties of AA2099 Al–Li Alloy with Tailored Li‐Containing Precipitates in Uniaxial Compression at Medium Temperature

Li Hu,Mengdi Li,Weijiu Huang,Xusheng Yang,Fei Guo,Haipeng Dong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

Microstructure characteristics and mechanical behavior of AA2099 Al–Li alloy with no pre-existing Li-containing precipitates(AA2099-1 sample), pre-existing δ′ precipitates (AA2099-2 sample), pre-existing T1phase (AA2099-3 sample) andpre-existing T2phase (AA2099-4 sample) are systematically investigated via isothermal uniaxial compression at 250 °C inthe present study. Experimental results demonstrate that at the onset of plastic deformation, dynamic precipitation of smallsizedT1phase occurs rapidly within AA2099-1 sample, while it will be hindered within AA2099-2 sample. The increasingplastic strain benefits to dynamic precipitation of small-sized T1phase in AA2099-2 sample. Consequently, AA2099-1 andAA2099-2 samples possess similar and intermediate mechanical behaviors. In terms of AA2099-3 sample, the existence oflarge-sized T1phase results in the maximum yielding stress. However, some regions within these large-sized T1precipitatesare suspected to be sheared by cross-slip, leading to the destruction of crystallographic structure and the formation of Almatrix intervals. This aspect is responsible for the gradual degradation in true stress-strain curve after peak stress. As forAA2099-4 sample, dynamic precipitation rarely happens during plastic deformation and the interaction between dislocationand the pre-existing T2phase belongs to Orowan looping, resulting in the minimal mechanical response. Besides,AA2099-1 sample possesses the average minimum deviation angle (MDA) of ~ 16.5° between the loading direction and the<110> crystal direction, whereas AA2099-4 sample owns the average MDA of ~ 7.5°. The difference in MDA is mainlyattributed to δ′ phase and T1phase, which will separately accelerate and postpone the rotation of orientation towards the<110> crystal direction.

Effect of carbon black on properties of 0–3 piezoelectric ceramic/cement composites

Huang Shifeng,Li Xue,Liu Futian,Chang Jun,Xu Dongyu,Cheng Xin 한국물리학회 2009 Current Applied Physics Vol.9 No.6

0–3 cement-based piezoelectric composites were fabricated using sulphoaluminate cement and piezoelectric ceramic [0.08Pb(Li1/4Nb3/4)O3 . 0.47PbTiO3 . 0.45PbZrO3] [P(LN)ZT] as raw materials by compressing technique. The influences of carbon black content on the piezoelectric and dielectric properties, electric conductivity and impedance were investigated. The results indicate that the piezoelectric strain constant d33 and piezoelectric voltage constant g33 of the composites increase gradually with a suitable carbon black addition. When the carbon black content is 0.3 wt%, both of the piezoelectric strain constant d33 and piezoelectric voltage constant g33 of the composite exist the maximum value, which are 17.45 pC N-1 and 36.3 mV m N-1, respectively. As the carbon black content increases, the dielectric constant εr, dielectric loss tanδ and electric conductivity σ of the composites all increase, while the impedance decreases. In the frequency range tested, the more the carbon black content, the higher the εr value. The planar electromechanical coupling coefficient Kp, the thickness electromechanical coupling coefficient Kt and the mechanical quality factor Qm are almost unaffected by the carbon black content.

Optimized Assembly of Micro-/Meso-/Macroporous Carbon for Li–S Batteries

Qiong Tang,Heqin Li,Min Zuo,Jing Zhang,Yiqin Huang,Peiwen Bai,Jiaqi Xu,Kuan Zhou 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.2

In order to explore the effect of hierarchical porous carbon on the performances of Li–S batteries, we synthesized three kinds of micro-/meso-/macroporous carbon materials with different pore properties by facile hard-template method. Different from the majority of reports on porous carbon ensuing large specific surface area (SSA) and total pore volume, it was found that in the case of identically high sulfur content, the pore size distribution substantially influences the performances of Li–S batteries rather than the SSA and total pore volume. Furthermore, in the assembly of micro-/meso-/macropores, the micropore volume ratio to the total pore volume is dominant to the capabilities of batteries. Among the samples, the porous carbon carbonized with the precursor of sucrose at 950℃ presents the highest initial discharge specific capacity of 1327 mAh/g and retention of 630 mAh/g over 100 cycles at 0.2C rate along with the best rate capability. This sample possesses the largest micropore volume ratio of 47.54% but a medium SSA of 1217 m2 /g and inferior total pore volume of 0.54 cm3 /g. The abundant micropores effectively improve the conductivity of dispersed sulfur particles, inhibit the loss of sulfur series and enable the cathode to exhibit superior electrochemical performances.

Effect of Initial Microstructure on the Hot Deformation Behavior and Microstructure Evolution of Aluminum Alloy AA2060

Chaoyang Li,Guangjie Huang,Lingfei Cao,Ruoxi Zhang,Yu Cao,Bin Liao,Lin Lin 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The microstructure evolution and hot deformation behavior of a Li-containing aluminum alloy AA2060 with different initialmicrostructure (homogenized vs. pre-rolled) were studied by isothermal hot deformation. The tests were performed within awide range of deformation temperatures of 370–490 ℃ and strain rates of 0.01–10 s−1. Results show that the stress drop ratioof the pre-rolled specimen is higher than that of the homogenized one under the same deformation condition. Microstructurewere analyzed on the thermal processing maps in unstable and optimum processing domain, and a higher dynamic recrystallizationfraction can be observed in the pre-rolled specimen that has more substructures and smaller grains. Four typesof the dynamic recrystallization were observed and the mechanism for deformation softening was discussed in this work.

Research on Li0.3Na0.18K0.52NO3 promoted Mg20Al-CO3 LDH/GO composites for CO2 capture

Ying Yang,Kai Chen,Liang Huang,Min Li,Taiping Zhang,Mi Zhong,Ping Ning,Junya Wang,Shikun Wen 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.102 No.-

It has been reported that the addition of graphene oxide (GO) can increase the dispersion and heterogeneousnucleation of layered double hydroxide (LDH), thus providing more active sites, which is more conduciveto CO2 adsorption. Herein, we reported alkali metal nitrates ((Li0.3Na0.18K0.52)NO3) promoted LDHand GO composites (LDH/GO) as adsorbents for CO2 capture. The influence of mass ratio of LDH to GO, theimpregnation ratio of alkali metal nitrates, the calcination and adsorption temperature, as well as thecycling stability were investigated systematically. The results indicated that the CO2 capture capacityof LDH/GO composite with 30 mol% (Li0.3Na0.18K0.52)NO3 could reach 4.51 mmol g 1, which was 5.86times higher than LDH/GO1 without loading alkali metal nitrates. Moreover, it had outstanding CO2adsorption capacity in the range from 200 C to 320 C. In addition, the cyclic adsorption and desorptiontest manifested that the CO2 uptake of the material can reach 3.07 mmol g 1 after 22 cycles. We believethat this study will give a significant contribution to fabrication of LDH based composites as CO2 adsorbentsin future study.

Realizing highly efficient multicolor tunable emissions from Tb³⁺ and Eu³⁺ co-doped CaGd₂(WO₄)₄ phosphors via energy transfer by single ultraviolet excitation for lighting and display applications

Huang, Xiaoyong,Li, Bin,Du, Peng,Guo, Heng,Cao, Renping,Yu, Jae Su,Wang, Kai,Sun, Xiao Wei Elsevier 2018 Dyes and pigments Vol.151 No.-

<P><B>Abstract</B></P> <P>In this paper, we reported on multicolor emission tuning in Tb<SUP>3+</SUP> and Eu<SUP>3+</SUP> co-doped CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB> phosphors prepared by a traditional high-temperature solid-state reaction. Upon 380 nm ultraviolet excitation, the emission color of CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> phosphors can be readily tuned from green to yellow, orange and finally to pure red through varying the concentration ratio of Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> ions. The energy transfer mechanism from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP> was systematically investigated by photoluminescence spectra, luminescence decay times, and time-resolved spectra. The internal quantum efficiencies of these phosphors were measured, and their thermal stability was also studied. A prototype white light-emitting diode (LED) device was fabricated by using an ultraviolet chip combined with a blend of blue-emitting BaMgAl<SUB>10</SUB>O<SUB>l7</SUB>:Eu<SUP>2+</SUP> phosphors, green-emitting BaSrSiO<SUB>4</SUB>:Eu<SUP>2+</SUP> phosphors, and red-emitting CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:50%Tb<SUP>3+</SUP>,50%Eu<SUP>3+</SUP> phosphors. All the results indicate that the CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> has great potential application in lighting and displays.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> showed efficient energy-transfer from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP>. </LI> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> exhibited tunable color emission under 380 nm excitation. </LI> <LI> The energy-transfer mechanism was studied in detail. </LI> <LI> Quantum efficiency and thermal stability were investigated. </LI> <LI> The proof-of-concept LED lamps were fabricated by employing phosphors and UV LEDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Phthalocyanines as medicinal photosensitizers: Developments in the last five years

Li, Xingshu,Zheng, Bing-De,Peng, Xiao-Hui,Li, Song-Zi,Ying, Jia-Wen,Zhao, Yuanyuan,Huang, Jian-Dong,Yoon, Juyoung Elsevier 2019 Coordination Chemistry Reviews Vol.379 No.-

<P><B>Abstract</B></P> <P>Owing to their high extinction coefficients, long absorption wavelengths, and modification tunable photophysical and photochemical properties, phthalocyanines (Pcs) have been widely used as photosensitizers for photodynamic therapy (PDT). Advances made in the past five years on the development of Pcs as medicinal photosensitizers are reviewed and the main design considerations for medicinal applications of these substances are discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recent progresses made in the development of phthalocyanines for photodynamic therapy are outlined. </LI> <LI> Representative water-soluble phthalocyanines are presented. </LI> <LI> Main targeting strategies are discussed. </LI> <LI> Future challenges are also presented. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Red, green, and blue fluorescent folate-receptor-targeting carbon dots for cervical cancer cellular and tissue imaging

Li, Shihao,Jiang, Jie,Yan, Yinan,Wang, Ping,Huang, Gang,Kim, Nam hoon,Lee, Joong Hee,He, Dannong Elsevier 2018 Materials science & engineering. C, Materials for Vol.93 No.-

<P><B>Abstract</B></P> <P>Folate receptor targeted photo-luminescent quantum carbon dots (Fr-CDs) were successfully prepared from folic acid and phenylenediamine isomers through hydrothermal approaches. Fr-CDs were spherical particles smaller than 10 nm, and emit stable green, blue and red luminescence under ultraviolet region excitation (λex = 365 nm) with maximum emissive lengths at 530, 429, and 612 nm. And the corresponding photoluminescence quantum yield as 15.4%, 12.6% and 16.2% respectively. Up-converted photoluminescent properties in near infrared 800 nm spectral region located in green, blue and yellow region. In-vitro studies showed Fr-CDs had almost none cytotoxicity (cell viability over 80%) and high affinitive to the Hela celline highly-expressed-folate-receptor membranes, and lighted on cytoplasm as the fluorescent marker. It displayed long luminescent-stability with PL intensity above 90% in ultraviolet illuminant exposure over 24 h. In in-vivo studies, Fr-CDs were internalized and accumulated in targeted cancer tissues of cervical carcinoma and the emitting fluorescence maintains over 30 min.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Multicolor carbon dots was prepared from folic acid and phenylenediamin isomers. </LI> <LI> These carbon dots exhibit targeting abilities with high affinity to ovarian cancer cells and tissues. </LI> <LI> Ultra-violet and near-infrared light excited photo-luminescent spectrums were investigated, and related quantum yield was calculated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>FA-doped CDs can effectively target ovarian cancer cells and aggregate in ovarian tumor tissue in a short 15 min.</P> <P>[DISPLAY OMISSION]</P>

ECG PVC Classification Algorithm based on Fusion SVM and Wavelet Transform

Huang Dong,Liao Zhengquan,Li Changbin,Li Dan,Huang Wendong 보안공학연구지원센터(IJSIP) 2015 International Journal of Signal Processing, Image Vol.8 No.1

In the process of ventricular premature beat (PVC) and normal sinus rhythm (NSR) identification base on electrocardiogram (ECG), there exists problems like negative effect from ECG rhythm and low recognition rate. This paper proposes the electrocardiogram PVC classification algorithm based on support vector machine (SVM) and wavelet algorithm. The algorithm uses the wavelet transform to analyze ECG beating model, which is not influenced by the change of ECG waveform. The two feature sets respectively compose of statistical parameters of the wavelet coefficients and the selected wavelet coefficients. PVC and NSR are analyzed by using SVM. The experimental results show that this method improves the recognition rate of ECG.

Perspective on Oncogenic Processes at the End of the Beginning of Cancer Genomics

Ding, Li,Bailey, Matthew H.,Porta-Pardo, Eduard,Thorsson, Vesteinn,Colaprico, Antonio,Bertrand, Denis,Gibbs, David L.,Weerasinghe, Amila,Huang, Kuan-lin,Tokheim, Collin,Corté,s-Ciriano, Isidro,J Elsevier 2018 Cell Vol.173 No.2

<P><B>Summary</B></P> <P>The Cancer Genome Atlas (TCGA) has catalyzed systematic characterization of diverse genomic alterations underlying human cancers. At this historic junction marking the completion of genomic characterization of over 11,000 tumors from 33 cancer types, we present our current understanding of the molecular processes governing oncogenesis. We illustrate our insights into cancer through synthesis of the findings of the TCGA PanCancer Atlas project on three facets of oncogenesis: (1) somatic driver mutations, germline pathogenic variants, and their interactions in the tumor; (2) the influence of the tumor genome and epigenome on transcriptome and proteome; and (3) the relationship between tumor and the microenvironment, including implications for drugs targeting driver events and immunotherapies. These results will anchor future characterization of rare and common tumor types, primary and relapsed tumors, and cancers across ancestry groups and will guide the deployment of clinical genomic sequencing.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An overview of PanCancer Atlas analyses on oncogenic molecular processes </LI> <LI> Germline genome affects somatic genomic landscape in a pathway-dependent fashion </LI> <LI> Genome mutations impact expression, signaling, and multi-omic profiles </LI> <LI> Mutation burdens and drivers influence immune-cell composition in microenvironment </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>