A successive ‘‘conversion-deposition” mechanism achieved by micro-crystalline Cu2O modified current collector for composite lithium anode

Yifei Cai,Bin Qin,Chun Li,Xiaoqing Si,Jian Cao,Xiaohang Zheng,LIANG QIAO,Junlei Qi 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Lithium (Li) metal is a promising material for high-energy–density batteries, but it is still plagued byobvious capacity degradation and low average Coulombic efficiency resulting from dendrite Li propagation. One main reason is the electro-mechanic coupled failure of plated Li on the current collector, whichcontributes to non-dense Li deposition on the anode. Transition metal oxides (TMOs) with a conversiontypemechanism have been used directly as the anode materials for lithium ion batteries, which demonstratedbetter electro-mechanical stability than metal Li. Herein, a successive ’’conversion-deposition’’mechanism is ingeniously developed to restrain the generation of dendritic Li. Specifically, a microcrystallineCu2O modified current collector was prepared, in which Li+ are sequentially inserted intoCu2O and deposited in the form of Li metal at successive low potential. A Li-Cu half-cell based on thehybrid mechanism sustains a high Coulombic efficiency of over 99.3 % in up to 800 cycles. This work ingeniouslyinhibits the generation of dendrite Li by incorporating conversion-type materials withdeposition-dissolution type metal Li, which contributes to a novel concept for the design of functionalcurrent collectors for composite Li anodes.

전자기 듀오캐스팅으로 제조한 Al-Mn/Al-Si 하이브리드 알루미늄합금의 미세조직과 인장 특성

박성진,김종호,박준표,장시영,Park, Sung-Jin,Li, Tingju,Kim, Chong-Ho,Park, Jun-Pyo,Chang, Si-Young 한국재료학회 2012 한국재료학회지 Vol.22 No.2

The microstructure and tensile properties of Al-Mn/Al-Si hybrid aluminum alloys prepared by electromagnetic duocasting were investigated. Only the Al-Mn alloy showed the typical cast microstructure of columnar and equiaxed crystals. The primary dendrites and eutectic structure were clearly observed in the Al-Si alloy. There existed a macro-interface of Al-Mn/Al-Si alloys in the hybrid aluminum alloys. The macro-interface was well bonded, and the growth of primary dendrites in Al-Si alloy occurred from the macro-interface. The Al-Mn/Al-Si hybrid aluminum alloys with a well-bonded macro-interface showed excellent tensile strength and 0.2% proof stress, both of which are comparable to those values for binary Al-Mn alloy, indicating that the strength is preferentially dominated by the deformation of the Al-Mn alloy side. However, the degree of elongation was between that of binary Al-Mn and Al-Si alloys. The Al-Mn/Al-Si hybrid aluminum alloys were fractured on the Al-Mn alloy side. This was considered to have resulted from the limited deformation in the Al-Mn alloy side, which led to relatively low elongation compared to the binary Al-Mn alloy.

Effects of Ga-doping on the microstructure and magnetic properties of MnBi alloys

Yang, Yang,Kim, Jong-Woo,Si, Ping-Zhan,Qian, Hui-Dong,Shin, Yongho,Wang, Xinyou,Park, Jihoon,Li, Oi Lun,Wu, Qiong,Ge, Hongliang,Choi, Chul-Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>The low temperature phase Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> (<I>x</I> = 0, 1, 3, 5, and 10) alloys were prepared by induction melting process with subsequent low temperature annealing. The effects of Ga-doping on the crystal structure and magnetic properties of the alloys were systematically studied. The room temperature coercivities of Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> after ball milling increased from 1.43 T for <I>x</I> = 0 to 1.66 T for <I>x</I> = 5, while the saturation magnetization decreased from 60.7 Am<SUP>2</SUP>/kg (<I>x</I> = 0) to 45.1 Am<SUP>2</SUP>/kg (<I>x</I> = 5). The maximum energy product (<I>BH</I>)<SUB>max</SUB> of Mn<SUB>55</SUB>Bi<SUB>44</SUB>Ga powders reached 7.87 MGOe. The Curie temperature of the Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> alloys increased from 633 K to 658 K with increasing Ga concentration in the range of 0 ≤ <I>x</I> ≤ 5.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of doping Ga on the microstructural and magnetic properties of MnBi alloy. </LI> <LI> The MnBi-Ga powders are achieved by surfactant assisted high energy ball milling. </LI> <LI> The maximum energy produce (<I>BH</I>)<SUB>max</SUB> shows 7.87 MGOe for Mn<SUB>55</SUB>Bi<SUB>44</SUB>Ga sample. </LI> <LI> The coercivity of Mn<SUB>55</SUB>Bi<SUB>40</SUB>Ga<SUB>5</SUB> after ball milling reached 1.66 T at room temperature. </LI> <LI> The elevated curie temperature (<I>T</I> <SUB>c</SUB>) by doping Ga makes it a possible candidate for high temperature applications. </LI> </UL> </P>

Microstructural evolution and oxidation resistance of T92 boiler tube steel upon long-term supercritical steam test

Li, Kejian,Ma, Houyu,He, Yinsheng,Chang, Jungchel,Bae, Si-yeon,Shin, Keesam Elsevier 2017 Fusion engineering and design Vol.125 No.-

<P><B>Abstract</B></P> <P>High-chromium heat-resistant steels are widely used as key materials to improve the condition of steam pressure and temperature in the boiler tube system of the supercritical power plants. Material-related failures in boiler system have occurred mainly due to internal oxidation and corrosion. For the stable maintenance of boilers, determination of the corrosion mechanism, microstructural evolution and data collection pertaining to the oxidation is essential. In this study, the supercritical steam test was carried out on T92 steel at the temperatures of 600/650/700°C for 10,000/15,000/20,000h. The matrix of steels and the oxide scale layers were investigated after steam treatment using scanning electron microscopy, back-scattered electron microscopy and electron backscattered diffraction. The oxide scale layers from the outer surface to the matrix consisted of: i) an outer layer of nanoscale iron oxide (Fe<SUB>2</SUB>O<SUB>3</SUB>); ii) inner layer of microscale crystals of Fe<SUB>3</SUB>O<SUB>4</SUB>, and iii) a mixture of chromium oxide and chromite (Cr<SUB>2</SUB>O<SUB>3</SUB> and FeCr<SUB>2</SUB>O<SUB>4</SUB>) adjacent to the matrix.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The matrix and scale layers were subsequently investigated using various electronic microscope analysis. </LI> <LI> The order of scale layers from the surface to the matrix are: i) nanoscaled Fe<SUB>2</SUB>O<SUB>3</SUB>; ii) microscaled Fe<SUB>3</SUB>O<SUB>4</SUB>; and iii) a mixture of Cr<SUB>2</SUB>O<SUB>3</SUB> and FeCr<SUB>2</SUB>O<SUB>4</SUB>. </LI> <LI> The Cr-rich layer was considered as protective for the matrix, which was stable at 600°C and 650°C, but the thickness decreased at 700°C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>(a) EBSD phase mapping of the scale layer, (b) SEM, (c) BSE, and (d∼g) EDS elemental mapping of the steam tested at 650°C for 10,000h.</P> <P>[DISPLAY OMISSION]</P>

A large-area free-standing graphene oxide multilayer membrane with high stability for nanofiltration applications

Chen, Long,Li, Yanhui,Chen, Lina,Li, Na,Dong, Chenglong,Chen, Qiong,Liu, Beibei,Ai, Qing,Si, Pengchao,Feng, Jinkui,Zhang, Lin,Suhr, Jonghwan,Lou, Jun,Ci, Lijie Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.345 No.-

<P><B>Abstract</B></P> <P>A flexible and free-standing graphene oxide and nylon 6 (GO@nylon 6) multilayer nanofiltration membrane was prepared by a layer-by-layer assembly process. The combination of electrospinning and electrospraying technique was employed, which can facilely prepare large-area membrane with size of 20 × 30 cm. The mechanical stability of multilayer membrane has enhanced significantly due to the tightly locked structure achieved by nylon 6 nanofibers network. The novel GO@nylon 6–13 multilayer nanofiltration membrane demonstrated a pure water flux up to 11.15 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP>, while keeping high organic dye rejection rate (>95% for methylene blue, and >99% for methyl orange). The rejections rate of the Na<SUB>2</SUB>SO<SUB>4</SUB>, NaCl, CuSO<SUB>4</SUB>, and Pb(NO<SUB>3</SUB>)<SUB>2</SUB> were 56.5%, 27.6%, 36.7%, and 18.9%, respectively. Furthermore, GO@nylon 6–13 multilayer nanofiltration membrane also demonstrated a high flux of some common organic solvents (8.4, 5.3, and 0.8 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP> for methanol, ethanol, and NMP, respectively), showing excellent chemical stability for separation process in those solvents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Large-area GO@nylon 6 multilayer nanofiltration membrane was prepared. </LI> <LI> The multilayer structure enhances the mechanical stability. </LI> <LI> The multilayer membrane demonstrates a high water flux. </LI> <LI> The multilayer membrane shows high rejection rate for organic dyes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Photograph and cross-section SEM image of GO@nylon 6 multilayer nanofiltration membrane, the inset shows the water contact angle.</P> <P>[DISPLAY OMISSION]</P>

Asymptotic normality of estimator in non-parametric model under censored samples

Si-Li Niu,Qian-Ru Li 대한수학회 2007 대한수학회지 Vol.44 No.3

Consider the regression modelY_i=g(x_i)+e_i for i=1,2,ldots, n,where: (1) x_i are fixed design points, (2) e_i are independentrandom errors with mean zero, (3) g(cdot) is unknown regressionfunction defined on [0,1]. Under Y_i are censored randomly, wediscuss the asymptotic normality of the weighted kernel estimatorsof g when the censored distribution function is known or unknown.

Clinical Characteristics of Patients with Persistent Apogeotropic and Persistent Geotropic Direction-Changing Positional Nystagmus

Si Lihong,Shen Bo,Li Yuanzhe,Ling Xia,Li Kangzhi,Yang Xu 대한신경과학회 2021 Journal of Clinical Neurology Vol.17 No.3

Background and Purpose This study aimed to determine the clinical features, diagnosis, and treatment of patients with persistent geotropic (pG) and persistent apogeotropic (pAG) direction-changing positional nystagmus (DCPN). Methods This retrospective study included 30 patients with pG-DCPN and 44 patients with pAG-DCPN. All patients underwent neurological and neurotological examinations, including an evaluation of gaze-evoked nystagmus, eye-movement tests, and assessments of limb ataxia and balance, as well as magnetic resonance imaging to exclude central causes. The characteristics of positional nystagmus were detected using the supine roll test (SRT) and bow-andlean test (BLT). The null point (NP) at which the nystagmus disappeared was determined. All patients were treated with the barbecue maneuver, and treatment efficacy was evaluated immediately, 1 week, and 1 month after treatment. Results The history of diseases associated with atherosclerosis, peripheral vestibular disorders, otological disease, and migraine differed significantly between patients with pG-DCPN and pAG-DCPN. The affected sides of persistent horizontal DCPN can be determined using the SRT and the BLT, while determining the second NP and vestibular function as well as performing an audiological evaluation can be used to assist in identifying the affected side. The efficacy rates immediately and 1 week after treatment with the barbecue maneuver were higher in patients with pAG-DCPN than in patients with pG-DCPN. Conclusions pAG-DCPN was more compatible with the characteristics of cupulolithiasis, and pG-DCPN was more likely to be associated with a light cupula rather than canalolithiasis. pAG-DCPN was more likely to be accompanied by a disease associated with atherosclerosis, while pG-DCPN was often accompanied by autoimmune-related diseases and a history of migraine. The associations between pAG-DCPN, pG-DCPN, and the above-mentioned diseases need to be clarified further. The canalith-repositioning maneuver was effective in patients with pAG-DCPN and ineffective in patients with pG-DCPN, but most cases of pGDCPN are self-limiting.

Mirror symmetry for exceptional unimodular singularities

Li, Changzheng,Li, Si,Saito, Kyoji,Shen, Yefeng European Mathematical Society Publishing House 2017 Journal of the European Mathematical Society Vol.19 No.4

GSTP1, ERCC1 and ERCC2 Polymorphisms, Expression and Clinical Outcome of Oxaliplatin-based Adjuvant Chemotherapy in Colorectal Cancer in Chinese Population

Li, Hui-Yan,Ge, Xin,Huang, Guang-Ming,Li, Kai-Yu,Zhao, Jing-Quan,Yu, Xi-Miao,Bi, Wen-Si,Wang, Yu-Lin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Aim: Platinum agents have shown to be effective in the treatment of colorectal cancer. We assessed whether single nucleotide polymorphisms (SNPs) in GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln might predict the overall survival in patients receiving oxaliplatin-based chemotherapy in a Chinese population. Methods: SNPs of GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln in 335 colorectal cancer patients were assessed using TaqMan nuclease assays. Results: At the time of final analysis on Nov. 2011, the median follow-up period was 37.7 months (range from 1 to 60 months). A total of 229 patients died during follow-up. Our study showed GSTP1 Val/Val (HR=0.44, 95% CI=0.18-0.98), ERCC1 C/C (HR=0.20, 95% CI=0.10-0.79) and ERCC2 G/G (HR=0.48, 95% CI=0.19-0.97) to be significantly associated with better survival of colorectal cancer. GSTP1 Val/Val, ERCC1 C/C and ERCC2 G/G were also related to longer survival among patients with colon cancer, with HRs (95% CIs) of 0.41 (0.16-0.91), 0.16 (0.09-0.74) and 0.34 (0.16-0.91), respectively. Conclusion: GSTP1, GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln genotyping might facilitate tailored oxaliplatin-based chemotherapy for colorectal cancer patients.

Effects of IFN-γ on IL-18 Expression in Pregnant Rats and Pregnancy Outcomes

Si, Li-Fang,Zhang, Shou-Yan,Gao, Chun-Sheng,Chen, Shu-Lin,Zhao, Jin,Cheng, Xiang-Chao Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.10

The present study focused on establishing the effects of interferon-gamma (IFN-${\gamma}$) on interleukin-18 (IL-18) expression patterns and pregnancy outcomes in pregnant rats. Pregnant rats at the post-implantation stage were randomized into control, low IFN-${\gamma}$ (L-IFN-${\gamma}$) and high IFN-${\gamma}$ groups (H-IFN-${\gamma}$) that received normal saline, 100 IU/g of IFN-${\gamma}$ and 500 IU/g of IFN-${\gamma}$ vaginal muscular injection, respectively. The effects of IFN-${\gamma}$ on IL-18 expression and pregnancy outcomes were assessed systematically using several methods, including immunohistochemistry streptavidin-perosidase (SP), image pattern analysis, enzyme-linked immune-sorbent assay (ELISA), whole blood count (WBC) count, microscopy and visual observation. IL-18 was detected in the uteri of all pregnant rats, and mainly distributed in the endometrium, decidual cells, vascular endothelium and myometrium. Immunohistochemistry and image pattern analyses revealed significantly lower IL-18 expression in the H-IFN-${\gamma}$ group compared to the L-IFN-${\gamma}$ and control groups (p<0.01), indicating that high doses of IFN-${\gamma}$ induce downregulation of IL-18 in the uterus of pregnant rats. ELISA results disclosed that IL-18 expression in peripheral blood of the H-IFN-${\gamma}$ group was lower than that of the L-IFN-${\gamma}$ group (p<0.05), and significantly reduced compared to the control group (p<0.01). Moreover, the number of peripheral leukocytes in the H-IFN-${\gamma}$ group was significantly higher than those in the control and L-IFN-${\gamma}$ groups (p<0.01). Morphology analysis showed no evident differences between the L-IFN-${\gamma}$ and control groups. However, for the H-IFN-${\gamma}$ group, uterine mucosa bleeding, necrosis and excoriation were observed using microscopy. Visual observation revealed marroon, swelling, crassitude and no embryo in the uterus, which are obvious indicators of abortion. These results indicate that IFN-${\gamma}$ plays a regulatory role in IL-18 expression in the uterus and peripheral blood of pregnant rats at the post-implantation stage. Moreover, high levels (500 IU/g) of IFN-${\gamma}$ influence normal pregnancy at the early stages in rats by downregulating IL-18 expression in the uterus and peripheral blood and increasing the number of peripheral leukocytes, consequently triggering termination of pregnancy.