A New Species of the Spider Genus Oxyopes from Guangxi, China (Araneae: Oxyopidae)

Junxia Zhang, Yongqiang Zhang, 김주필(Joo-Pil Kim) 한국거미연구소 2005 한국거미 Vol.21 No.1

중국의 Guangxi 지역에서 채집된 Oxyopes 속의 1 신종인 Oxyopes gaofengensis sp. nov을 보고한다. A new species of the genus Oxyopes collected from Guangxi Province, China, is illustrated and described here under the name of Oxyopes gaofengensis sp. nov.

Nonradiative energy transfer between colloidal quantum dot-phosphors and nanopillar nitride LEDs.

Zhang, Fan,Liu, Jie,You, Guanjun,Zhang, Chunfeng,Mohney, Suzanne E,Park, Min Joo,Kwak, Joon Seop,Wang, Yongqiang,Koleske, Daniel D,Xu, Jian Optical Society of America 2012 Optics express Vol.20 No.2

<P>We present in this communication our study of the nonradiative energy transfer between colloidal quantum dot (QD) phosphors and nitride nanopillar light emitting diodes (LEDs). An epitaxial p-i-n InGaN/GaN multiple quantum-well (QW) heterostructure was patterned and dry-etched to form dense arrays of nanopillars using a novel etch mask consisting of self-assembled In3Sn clusters. Colloidal QD phosphors have been deposited into the gaps between the nanopillars, leading to sidewall coupling between the QDs and InGaN QW emitters. In this approach, close QW-QD contact and a low-resistance design of the LED contact layer were achieved simultaneously. Strong non-radiative energy transfer was observed from the InGaN QW to the colloidal QD phosphors, which led to a 263% enhancement in effective internal quantum efficiency for the QDs incorporated in the nanopillar LEDs, as compared to those deposited over planar LED structures. Time-resolved photoluminescence was used to characterize the energy transfer process between the QW and QDs. The measured rate of non-radiative QD-QW energy-transfer agrees well with the value calculated from the quantum efficiency data for the QDs in the nanopillar LED.</P>

A Compensated Software Reliability Model Based on Unascertained Rational Number

Yongqiang Zhang,Wen Chen,Huizhen Yan 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

The software reliability model based on unascertained ration number has unique superiority. It does not have any assumption about software fault process. Moreover, its algorithm is simple, and it avoids derivation of nonlinear equations set. But the characteristic of the algorithm itself determines that the estimation of this model is the pessimistic estimation. In this view, this paper makes some improvement to this model, and puts forward the compensated software reliability model based on unascertained rational number, which make the model have wider applicability and suit the reliability growth feature better.

The Hardware Cost and Computing Accuracy Trade-off in Multipliers using Imprecise 4-2 Compressors for Image Processing Applications

Yongqiang Zhang,Cong He,Xiaoyue Chen,Guangjun Xie 대한전자공학회 2022 IEIE Transactions on Smart Processing & Computing Vol.11 No.3

Approximate computing has been widely used in image processing applications to significantly reduce the hardware cost of circuits; however, this induces a sacrifice in computing accuracy. The compromise between accuracy and hardware cost in approximate multipliers has not been investigated yet. To address this issue, this paper proposes a set of approximate 8×8 Dadda multipliers built by using an efficient imprecise 4-2 compressor. The compressor introduces symmetrical errors into the truth table of the exact design to reach a simpler structure. Furthermore, as an important image processing application, image multiplication is implemented with the proposed multipliers. Synthesis and simulation results show that the overall performance of the multipliers varies depending on the various assessment criteria. Utilization of the modified compressor in the multipliers results in area, delay, and power reductions of 38%-72%, 14%-33%, and 39%-77%, respectively, compared to the exact design, while maintaining acceptable computing accuracy in image multiplication. According to the results, the proposed multipliers achieve a better trade-off between energy efficacy and computing accuracy than the existing designs, which could be certified as options for exact multipliers in image processing.

Construction of Constitutive Model and Strain-Rate Sensitivity Coefficient Distribution Map of Ti2AlNb

Yongqiang Zhang,Xiangyi Xue,Jingli Zhang,Shewei Xin,Hao Pan,Huamei Sun,Huiming Li 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

The hot deformation behavior of Ti–22Al–25Nb was studied by the high temperature compression over a range of temperatures (950–1050 °C) and strain rates (0.001–10 s−1) in this paper. The work-hardening (WH) and softening deformationbehaviors of Ti–22Al–25Nb were analyzed. Obvious linear decreasing regimes of WH rate curves can be found before thedynamic recrystallization (DRX) onset, which indicates WH+ DRV (dynamic recovery) stage. And WH rate decreasedsignifcantly with strain rate reduced and temperature elevated. A physically-based constitutive model was established,which can well predict the fow behavior of Ti–22Al–25Nb. Additional, strain-rate sensitivity coefcient distribution mapwas established. The higher values of m appeared at the low strain rate. When the strain rate exceeded 0.1 s−1, the values ofm were lower than 0.25.

Research on Operating Performance and E-business Marketing Strategy in Retail Enterprises based on Online Shopping

Yongqiang Zhang,Yanlei Gao,Xiang Li,Duchun Wang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.11

In recent years, with the rapid development of internet technology, enterprise business model has entered a new century. The emergence of network economy has forced retail enterprises to change the original marketing mode, global information resources can be shared instantly, which greatly improve the operational efficiency and reduce the cost. In this paper, we analyze the influence factors that impact on retail enterprises based on consumers online shopping behavior, survey data from small and medium enterprises. The result shows that macro environment factors, market competition, enterprise self factors will affect the enterprise's e-commerce performance, and significantly promote the enterprise's market strategy innovation. Therefore, it is an important way to improve the competitiveness of enterprises by carrying out the E-business market strategy.

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.

Epigallocatechin-3-Gallate (EGCG) Attenuates Traumatic Brain Injury by Inhibition of Edema Formation and Oxidative Stress

Zhang, Bo,Wang, Bing,Cao, Shuhua,Wang, Yongqiang The Korean Society of Pharmacology 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.6

Traumatic brain injury (TBI) is a major cause of mortality and long-term disability, which can decrease quality of life. In spite of numerous studies suggesting that Epigallocatechin-3- gallate (EGCG) has been used as a therapeutic agent for a broad range of disorders, the effect of EGCG on TBI remains unknown. In this study, a weight drop model was established to evaluate the therapeutic potential of EGCG on TBI. Rats were administered with 100 mg/kg EGCG or PBS intraperitoneally. At different times following trauma, rats were sacrificed for analysis. It was found that EGCG (100 mg/kg, i.p.) treatment significantly reduced brain water content and vascular permeability at 12, 24, 48, 72 hour after TBI. Real-time PCR results revealed that EGCG inhibited TBI-induced IL-$1{\beta}$ and TNF-${\alpha}$ mRNA expression. Importantly, CD68 mRNA expression decreasing in the brain suggested that EGCG inhibited microglia activation. Western blotting and immunohistochemistry results showed that administering of EGCG significantly inhibited the levels of aquaporin-4 (AQP4) and glial fibrillary acidic protein (GFAP) expression. TBI-induced oxidative stress was remarkably impaired by EGCG treatment, which elevated the activities of SOD and GSH-PX. Conversely, EGCG significantly reduced the contents of MDA after TBI. In addition, EGCG decreased TBI-induced NADPH oxidase activation through inhibition of $p47^{phox}$ translocation from cytoplasm to plasma membrane. These data demonstrate that EGCG treatment may be an effective therapeutic strategy for TBI and the underlying mechanism involves inhibition of oxidative stress.

An effective method for directly extracting lithium from a-spodumene by activated roasting and sulfuric acid leaching

Yuqing Zhang,Baozhong Ma,Yingwei Lv,Chengyan Wang,Yongqiang Chen 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

The global trend toward electrification has encouraged lithium’s market position to grow prominently. Spodumene is the focus of lithium extraction owing to its abundant lithium resources. In this study, anovel lithium extraction method was proposed for a-spodumene by combining activated roasting andsulfuric acid leaching. First, the thermodynamics of the roasting process demonstrated that aspodumenewas converted into b-spodumene, which reacted with CaO to produce acid-solubleLiAlSiO4 and CaSiO3 concurrently. The addition of CaO reduced the melting temperature, which promotedthe structural transformation of b-spodumene and further acid leaching. Then, the influences of variousfactors on lithium extraction were investigated by a single-factor test. A lithium leaching yield of 96.18%was obtained under optimum conditions: 20% CaO, roasting temperature of 1200 C, holding time of1.5 h, H2SO4 concentration of 120 g/L, liquid–solid ratio of 7:1 mL/g, leaching temperature of 80 Cand leaching time of 1.5 h. Finally, Li entered into leach liquor by the action of sulfuric acid, and the maincomponents of the leach residue were silicate and calcium sulfate. Compared to the conventional acidapproach, this method has a higher lithium recovery and lower energy and acid consumption (decreaseby approximately 0.42 kg/ kg).

Structural evolution and kinetic study of high isotacticity poly(acrylonitrile) during isothermal pre-oxidation

Li Zhang,Yongqiang Dai,Yi Kai,Ri-Guang Jin 한국탄소학회 2011 Carbon Letters Vol.12 No.4

Isotactic polyacrylonitrile (PAN) with triad isotacticity of 0.53, which was determined by 13C NMR, using dialkylmagnesium as an initiator, was successfully synthesized. Isothermal treatment of iso-PAN was conducted in air at 200, 220, 250 and 280℃. Structural evolutions and chemical changes were studied with Fourier transformation infrared and wide-angle X-ray diffraction during stabilization. A new parameter CNF=I2240cm-1/ (I1595cm-1+f*I1595cm-1) was defined to evaluate residual nitrile groups. Crystallinity and crystal size were calculated with X-ray diffraction dates. The results indicated that the nitrile groups had partly converted into a ladder structure as stabilization proceeded. The rate of reaction increased with treatment temperature; crystallinity and crystal size decreased proportionally to pyrolysis temperature. The iso-conversional method coupled with the Kissinger and Flynn-Wall-Ozawa methods were used to determine kinetic parameters via differential scanning calorimetry analysis with different heating rates. The active energy of the reaction was 171.1 and 169.1 kJ/mol, calculated with the two methods respectively and implied the sensitivity of the reaction with temperature.