Temperature-dependent rheological behavior of cathode slurry for lithium-ion battery under steady and dynamic tests

Zhao Bin,Yin Deshun,Gao Yunfei,Ren Jiangtao 한국유변학회 2023 Korea-Australia rheology journal Vol.35 No.3

The rheological property of cathode slurry is commonly influenced by coating speed and mixing temperature, thereby leading to its storage stability and coating uniformity. In this study, the effect of the temperature of slurry on the rheological behaviors is investigated under various shear rates and temperatures based on steady and dynamic tests as well as theoretical models. In the flow experiments, the thixotropic behavior of the slurry is observed at all temperatures tested, and it is reduced with the increase in temperature. The experimental data is captured well by rheological models, and the model parameters are evaluated under the combined effects of shearing and temperature, resulting in two generalized state equations for the description of the flow properties of the slurry. In addition, microstructural rearrangement and polymeric entanglement at high temperatures cause viscosity and modulus to change, giving rise to complex rheological behavior in creep and oscillatory shear. Compared with slurry at 25 and 40 °C, both storage and loss moduli are dependent on oscillatory strain in the range of 0.1–1000% at 65 °C. The difference in characteristic strain corresponding to yielding and strain stiffening behavior is only observed at high temperatures, whereas relaxation times were independent of temperature in the oscillatory shear test. Understanding the effect of the temperature of slurry on rheological behaviors will be useful for improving the manufacturing efficiency of electrodes.

Crystalline Bilayer Graphene with Preferential Stacking from Ni-Cu Gradient Alloy

Gao, Zhaoli,Zhang, Qicheng,Naylor, Carl H.,Kim, Youngkuk,Abidi, Irfan Haider,Ping, Jinglei,Ducos, Pedro,Zauberman, Jonathan,Zhao, Meng-Qiang,Rappe, Andrew M.,Luo, Zhengtang,Ren, Li,Johnson, Alan T. Ch American Chemical Society 2018 ACS NANO Vol.12 No.3

<P>We developed a high-yield synthesis of highly crystalline bilayer graphene (BLG) with two preferential stacking modes using a Ni-Cu gradient alloy growth substrate. Previously reported approaches for BLG growth include flat growth substrates of Cu or Ni-Cu <I>uniform</I> alloys and “copper pocket” structures. Use of flat substrates has the advantage of being scalable, but the growth mechanism is either “surface limited” (for Cu) or carbon precipitation (for uniform Ni-Cu), which results in multicrystalline BLG grains. For copper pockets, growth proceeds through a carbon back-diffusion mechanism, which leads to the formation of highly crystalline BLG, but scaling of the copper pocket structure is expected to be difficult. Here we demonstrate a Ni-Cu gradient alloy that combines the advantages of these earlier methods: the substrate is flat, so easy to scale, while growth proceeds by a carbon back-diffusion mechanism leading to high-yield growth of BLG with high crystallinity. The BLG layer stacking was almost exclusively Bernal or twisted with an angle of 30°, consistent with first-principles calculations we conducted. Furthermore, we demonstrated scalable production of transistor arrays based crystalline Bernal-stacked BLG with a band gap that was tunable at room temperature.</P> [FIG OMISSION]</BR>

Histone demethylase KDM4A plays an oncogenic role in nasopharyngeal carcinoma by promoting cell migration and invasion

Zhao Jingyi,Li Bingyan,Ren Yongxia,Liang Tiansong,Wang Juan,Zhai Suna,Zhang Xiqian,Zhou Pengcheng,Zhang Xiangxian,Pan Yuanyuan,Gao Fangfang,Zhang Sulan,Li Liming,Yang Yongqiang,Deng Xiaoyu,Li Xiaole,C 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Compelling evidence has indicated the vital role of lysine-specific demethylase 4 A (KDM4A), hypoxia-inducible factor-1α (HIF1α) and the mechanistic target of rapamycin (mTOR) signaling pathway in nasopharyngeal carcinoma (NPC). Therefore, we aimed to investigate whether KDM4A affects NPC progression by regulating the HIF1α/DDIT4/mTOR signaling pathway. First, NPC and adjacent tissue samples were collected, and KDM4A protein expression was examined by immunohistochemistry. Then, the interactions among KDM4A, HIF1α and DDIT4 were assessed. Gain- and loss-of-function approaches were used to alter KDM4A, HIF1α and DDIT4 expression in NPC cells. The mechanism of KDM4A in NPC was evaluated both in vivo and in vitro via RT-qPCR, Western blot analysis, MTT assay, Transwell assay, flow cytometry and tumor formation experiments. KDM4A, HIF1α, and DDIT4 were highly expressed in NPC tissues and cells. Mechanistically, KDM4A inhibited the enrichment of histone H3 lysine 9 trimethylation (H3K9me3) in the HIF1α promoter region and thus inhibited the methylation of HIF1α to promote HIF1α expression, thus upregulating DDIT4 and activating the mTOR signaling pathway. Overexpression of KDM4A, HIF1α, or DDIT4 or activation of the mTOR signaling pathway promoted SUNE1 cell proliferation, migration, and invasion but inhibited apoptosis. KDM4A silencing blocked the mTOR signaling pathway by inhibiting the HIF1α/DDIT4 axis to inhibit the growth of SUNE1 cells in vivo. Collectively, KDM4A silencing could inhibit NPC progression by blocking the activation of the HIF1α/DDIT4/mTOR signaling pathway by increasing H3K9me3, highlighting a promising therapeutic target for NPC.

Leader-following Consensus of Second-order Multi-agent Systems With Input Delays

Wei Gao,Yan Ren,LiYun Zhao,Kai Weng,HuiMin Wang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.9

This paper studies the leader-following consensus of second-order multi-agent systems with input delays. Firstly, a feedback-tracking control protocol with the leader’s delayed state derivative is proposed to guarantee the leader-following consensus. Secondly, considering the same input delay of the second-order multi-agent system, the explicit formula of the upper bound of delay for the asymptotic stability of the second-order multi-agent system is obtained by using the frequency domain analysis method. Compared with the latest existing controllers, the controller designed in this paper improves the convergence speed and tracking accuracy. Thirdly, a variety of diverse input delays are further considered, the feedback tracking controller is designed to improve the convergence speed and tracking accuracy, and sufficient conditions of leader-following consensus are given by using the generalized Nyquist stability criterion. Finally, simulation examples are given to show the effectiveness of our control protocol.

Clinical Evidence of Chemotherapy or Endocrine Therapy Maintenance in Patients with Metastatic Breast Cancer: Meta-analysis from Randomized Clinical Trials and Propensity Score Matching of Multicentre Cohort Study

Wei Ren,Yunfang Yu,Huangming Hong,Ying Wang,Quanlong Gao,Yongjian Chen,Peixian Chen,Jianli Zhao,Qiyun Ou,Dagui Lin,Tuping Fu,Yujie Tan,Chenchen Li,Xinxin Xie,Guolin Ye,Jun Tang,Herui Yao 대한암학회 2022 Cancer Research and Treatment Vol.54 No.4

Purpose This study aims to comprehensively evaluate the clinical efficacy of chemotherapy or endocrine therapy maintenance in metastatic breast cancer (MBC) patients. Materials and Methods The meta-analysis of randomized clinical trials (RCTs) and propensity score matching of multicenter cohort study evaluated MBC patients who underwent first-line chemotherapy or endocrine therapy maintenance. This study is registered with PROSPERO: CRD42017071858 and ClinicalTrials.gov: NCT04258163. Results A total of 2,867 patients from 15 RCTs and 760 patients from multicenter cohort were included. The results from meta-analysis showed that chemotherapy maintenance improved progression-free survival (PFS) (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.54 to 0.73; p < 0.001; moderate-quality evidence) and overall survival (OS) (HR, 0.87; 95% CI, 0.78 to 0.97; p=0.016; high-quality evidence) than observation. In the cohort study, for hormone receptor–positive MBC patients, chemotherapy maintenance improved PFS (HR, 0.67; 95% CI, 0.52 to 0.85; p < 0.001) and OS (HR, 0.55; 95% CI, 0.42 to 0.73; p < 0.001) compared with observation, and endocrine therapy maintenance also improved PFS (HR, 0.65; 95% CI, 0.53 to 0.80; p < 0.001) and OS (HR, 0.55; 95% CI, 0.44 to 0.69; p < 0.001). There were no differences between chemotherapy and endocrine therapy maintenance in PFS and OS (all p > 0.05). Regardless of the continuum or switch maintenance therapy, showed prolonged survival in MBC patients who were response to first-line treatment. Conclusion This study provided evidences for survival benefits of chemotherapy and endocrine therapy maintenance in MBC patients, and there was no difference efficacy between chemotherapy and endocrine therapy maintenance for hormone receptor–positive patients.

Ultrathin Biocompatible Electrospun Fiber Films for Self-Powered Human Motion Sensor

Gengrui Zhao,Shaobo Gong,Honggang Wang,Junfang Ren,Na Wang,Yawen Yang,Gui Gao,Shengsheng Chen,Linlin Li 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.3

In recent years, triboelectric nanogenerator (TENG) has been proven to be an effective and simple solution for self-powered wearable sensing, and a wide variety of materials and methods have been applied to TENG based sensors. In this study, an ultrathin fiber film with nanoporous brain-like structure (BUF) was obtained by cold-pressing the electrospun biocompatible fiber mats, and a wearable TENG sensor based on the BUF films that could sensitively detect human motion was demonstrated. This simply designed self-powered sensor was composed of Kapton as the shell and ultrathin, biocompatible poly L-lactic acid and ethyl cellulose (EC) fiber films as the triboelectric layers, prepared by convenient electrospinning method and cold-pressing. Compared to as-spun fiber mats, cold-pressed fiber membranes not only acquire overall compact structure but also remained porous surface morphology, which improved the triboelectric outputs and operational stability of TENG. Three TENGs were fabricated to evaluate the effects of different triboelectric layers on triboelectric outputs, and the BUF-TENG had the maximum triboelectric outputs (19 V, 630 nA at 3.5 Hz) and longer life than as-spun fiber mats based TENG. The BUF-TENG had linear relationship between triboelectric outputs and frequency, and sensitivities of 32.4, 0.94 and 0.22 V Hz−1 in the range of 0.1–0.35, 0.35–2 and 2–3.5 Hz, respectively. Moreover, a self-powered sensor based on the BUF-TENG was proposed to sensitively detect human walking state and limbs motion. With convenient preparation process and biocompatible materials, the BUF-TENG sensor could be a potential self-powered wearable and portable sensor in future health care and monitoring field.

GA_3_ 및 ABA 사용이 매장처리 중 미국삼 종자의 후숙에 미치는 영향 ( Effects of GA_3_ and ABA Application on After-ripening of Panax quinquefolium Seeds during Stratification )

Guixing Ren,Feng Chen,Haozhe Lian,Jinghui Zhao,Xianzong Gao,Chongming Guo 고려인삼학회 1996 Journal of Ginseng Research Vol.20 No.1

Comparative Study on Volatile Flavor Compounds of Traditional Chinese-type Soy Sauces Prepared with Soybean and Defatted Soy Meal

Xian-Li Gao,Hai-Feng Zhao,Mou-Ming Zhao,Chun Cui,Jiao-Yan Ren 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.6

Volatile extracts obtained from traditional Chinese-type soy sauces prepared with soybean (SSSB) and defatted soy meal (SSDSM) by solid phase microextraction (SPME) and direct solvent extraction (DSE) were analyzed by gas chromatography-mass spectrometry (GC-MS). The volatile flavor compounds and relative contents of different chemical classes detected in SSSB and SSDSM were compared for their differences. Results showed that significant differences in both constituents of volatile flavor compounds and relative contents of different chemical classes were observed for both kinds of soy sauces. A total of 152 and 131 compounds were identified in SSSB and SSDSM, respectively, and 102 volatile flavor compounds were common in both kinds of soy sauces. Moreover, relative contents of acids, aldehydes, esters, furan(one)s, miscellaneous compounds, phenols, pyrazines, pyrrol(idinon)es, and sulfur-containing compounds in both kinds of soy sauces were all significantly different.

Non-isothermal Decomposition Kinetics of a New High-energy Organic Potassium Salt: K(DNDZ)

Xu, Kangzhen,Zhao, Fengqi,Song, Jirong,Ren, Xiaolei,Gao, Hongxu,Xu, Siyu,Hu, Rongzu Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.10

A new high-energy organic potassium salt, 2-(dinitromethylene)-1,3-diazepentane potassium salt K(DNDZ), was synthesized by reacting of 2-(dinitromethylene)-1,3-diazepentane (DNDZ) and potassium hydroxide. The thermal behavior and non-isothermal decomposition kinetics of K(DNDZ) were studied with DSC, TG/DTG methods. The kinetic equation is $\frac{d{\alpha}}{dT}$ = $\frac{10^{13.92}}{\beta}$3(1 - $\alpha$[-ln(1 - $\alpha$)]$^{\frac{2}{3}}$ exp(-1.52 ${\times}\;10^5$ / RT). The critical temperature of thermal explosion of K(DNDZ) is $208.63\;{^{\circ}C}$. The specific heat capacity of K(DNDZ) was determined with a micro-DSC method, and the molar heat capacity is 224.63 J $mol^{-1}\;K^{-1}$ at 298.15 K. Adiabatic time-to-explosion of K(DNDZ) obtained is 157.96 s.

Changes in Volatile Aroma Compounds of Traditional Chinese-type Soy Sauce During Moromi Fermentation and Heat Treatment

Xian-Li Gao,Chun Cui,Hai-Feng Zhao,Mou-Ming Zhao,Lan Yang,Jiao-Yan Ren 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.4

Considering the important influence of longtime (150 day) moromi fermentation and heat treatment on the aroma formation of traditional Chinese-type soy sauce (TCSS), volatile compounds in samples taken from different stages of moromi fermentation and heat treatment were analyzed by solid phase microextraction coupled with gas chromatography-mass spectrometry. Results showed that a total of 76 volatile compounds were identified in all the samples, and most of the volatile compounds were common. During 150 day of moromi fermentation, relative contents of acids, alcohols, aldehydes and ketones, esters,and furan(one)s along with all the sensory attributes of acidic, alcoholic, fruity, caramel-like, smoky, and malty changed greatly. Notably, relative contents of alcohols,aldehydes and ketones along with the sensory intensities of alcoholic, caramel-like, and smoky of heated sample (80℃/60 min) decreased markedly, whereas there were slight increases in relative contents of furan(one)s, phenols,and sulfur-containing compounds of it. Long-time moromi fermentation and heat treatment have significant influence on the formation and relative contents of volatile compounds in TCSS, whereas changes in volatile compounds and their relative contents of the samples were responsible for the differences in sensory attributes.