An Analyzing Method of Coupled Modes in Multi-Stage Planetary Gear System

Wei Sun,Jing Wei,Xin Ding,Xinglong Hu,Qingguo Wang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

This paper analyzed the natural frequency and coupled mode characteristics in multi-stage planetary gear system. A dynamic modelof multi-stage planetary gears with general description is established based on the lumped mass method. Solving the associatedeigenvalue problem, the vibration modes of the system with identical, equally spaced planets are classified into rotational,translational and planet modes with unique properties. A criterion to distinguish the dominant vibration stage for the two coupledmode types, rotational mode and translational mode, are provided by comparing the eigensensitivity to the component parametersof different planetary stages. Taken the dominant vibration stage as an independent single-stage planetary gear system, the naturalfrequencies and vibration modes are observed to be similar to the multi-stage. It is shown that the coupling in the multi-stageplanetary gear system grows as the frequency reduces. In rotational modes and translational modes, the highest eigensensitivity tomesh stiffness and planet bearing stiffness of each stage are associated with different frequencies in the higher-frequency range, whilethe highest eigensensitivity to bearing stiffness of carriers, rings, and suns occurred in the lower-frequency range.

A study on load-sharing structure of multi-stage planetary transmission system

Wei Sun,Xiang Liu,Jing Wei,Aiqiang Zhang,Xin Ding,Xinglong Hu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

Unequal load distribution is a crucial factor in decreasing bearing capacity and stability of the planetary transmission system. In thispaper, a dynamical model of two-stage helical planetary gear transmission system is established based on lumped-parameter method andLagrange general function. Nonlinearity of gear tooth backlash and error is taken into account. Four load-sharing structures are proposedto study the load-sharing performance. A method to calculate dynamic sensitivity of load-sharing coefficient to errors is presented thatcan provide a reference to component precision determination in order to make planetary system have a better load distribution. Finally, anumerical method of load-sharing performance is validated by a test. These results provide fundamental basis for multi-stage planetarygear transmission system design.

Correlation between in vitro fertilization and artificial insemination in Holstein bulls

Sun Wei,Li Yunxia,Su Jie,Bao Xiangnan,Ding Rui,Zhao Gaoping,Cao Guifang,Hu Shuxiang,Wang Jianguo,Sun Qingyuan,Yu Haiquan,Li Xihe 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.12

Objective: Owing to the lack of a breeding index for efficient and quick fertility evaluations of Holstein bulls when using traditional or genome-wide detection methods, this study aimed to determine whether in vitro fertilization (IVF) could be used as an indicator of conception rate of artificial insemination (AI).Methods: Conventional and sexed frozen semen from nine bulls were used for IVF and AI.Results: The IVF and AI conception rates of each bull were confirmed to be positively correlated between the conventional frozen and sexed frozen semen. The correlation coefficient R values of nine bulls between IVF and AI methods were 0.73 and 0.97 for the conventional frozen and sexed frozen semen, respectively. The average conception rate of three bulls undergoing AI was 69.5% and 64.2%, 61.8% and 58.8%, and 48.2% and 46.2% in first-, second-, and third-born cows when conventional frozen and sexed frozen semen were used, respectively, which showed a positive correlation with the fertilization rate in the same parity. We propose an evaluation standard to assess the fertilization ability of bulls based on their IVF test results, which is categorized into three grades: grade one, normal fertility bull with an AI conception rate of 40%±5% and IVF rate of 45% to 60%; grade two, higher fertility bull with an AI conception rate of 50%±5% and IVF rate of 61% to 80%; and grade three, highest fertility bull with an AI conception rate of 60%±5% and IVF rate of >80%.Conclusion: These findings reveal that IVF results can be used as a breeding index for bulls to evaluate their AI conception ability, which may shorten the time required to select bulls for breeding. Objective: Owing to the lack of a breeding index for efficient and quick fertility evaluations of Holstein bulls when using traditional or genome-wide detection methods, this study aimed to determine whether in vitro fertilization (IVF) could be used as an indicator of conception rate of artificial insemination (AI). Methods: Conventional and sexed frozen semen from nine bulls were used for IVF and AI. Results: The IVF and AI conception rates of each bull were confirmed to be positively correlated between the conventional frozen and sexed frozen semen. The correlation coefficient R values of nine bulls between IVF and AI methods were 0.73 and 0.97 for the conventional frozen and sexed frozen semen, respectively. The average conception rate of three bulls undergoing AI was 69.5% and 64.2%, 61.8% and 58.8%, and 48.2% and 46.2% in first-, second-, and third-born cows when conventional frozen and sexed frozen semen were used, respectively, which showed a positive correlation with the fertilization rate in the same parity. We propose an evaluation standard to assess the fertilization ability of bulls based on their IVF test results, which is categorized into three grades: grade one, normal fertility bull with an AI conception rate of 40%±5% and IVF rate of 45% to 60%; grade two, higher fertility bull with an AI conception rate of 50%±5% and IVF rate of 61% to 80%; and grade three, highest fertility bull with an AI conception rate of 60%±5% and IVF rate of >80%. Conclusion: These findings reveal that IVF results can be used as a breeding index for bulls to evaluate their AI conception ability, which may shorten the time required to select bulls for breeding.

Study on preparation of inorganic binder stabilized material with large dosage of phosphogypsum

Sun Qiqi,Tao Liangjing,Li Xin,Xu Wei,Yao Shuo,Li Jinpeng,Ren Qi-Fang,Chen Yue’e,Xu Chunshan,Wu Zilong,Zhu Yuelei,Ding Yi,오원춘 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.6

With the rapid development of the phosphorus chemical industry, a large amount of phosphogypsum (PG) is discharged. The impurities in PG pollute the surrounding soil, the groundwater and the air in the long-term storage. In this paper, PG as the main raw material is used to study the stable material of inorganic binder in the condition of large dosage of PG. With PG and graded gravel as stabilized materials, and cement and fly ash as binder, materials are mixed to determine the influence of PG ratio and the amount of activator on the mixture. The results show that the mechanical strength of the mixture increased first and then decreased with the increase in the proportion of PG replacing graded gravel in the mixture. The activator significantly improves the properties of the material system and makes a significant contribution to the curing of PG. The best ratio of pretreated PG: cement: fly ash: aggregate is 50:6:5:39. The amount of activator added by the external mixing method is 0.3%, which can make the unconfined compressive strength reach 4.1 MPa after 7d. Finally, water-soluble phosphorus leaching experiment is conducted for all the samples. The results show that phosphorus leaching is so little that no secondary pollution of the environment is caused.

Crystalline ZnO thin film by hydrothermal growth

Sun, Ke,Wei, Wei,Ding, Yong,Jing, Yi,Wang, Zhong Lin,Wang, Deli Royal Society of Chemistry 2011 Chemical communications Vol.47 No.27

<P>In this work, we have successfully synthesised ZnO crystal thin film with a high quality from hydrothermal reaction on sapphire substrate. The growth mechanism is clarified based on an extensive XTEM study. In addition, electrical and optical properties of the crystal thin film, which can be controlled by impurities, are characterized. The synthesis technique provides fairly high quality and cost-effective substrates for optoelectronic and renewable energy applications.</P> <P>Graphic Abstract</P><P>The capability to control the structural/optical/electrical properties is enabled using a high quality ZnO thin film from solution for electronics and optoelectronics applications. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc11397f'> </P>

Recent advances of Na3V2(PO4)3 as cathode for rechargeable zinc-based batteries

Ding Kunpeng,Jiang Tian,Peng Jian,Wang Peng,Gou Wenshan,Xu Qingyu,Fan Qi,Wang Wei,Sun Yueming 한국탄소학회 2023 Carbon Letters Vol.33 No.4

Rechargeable zinc-based batteries (RZBs) with the advantages of high safety, low cost, abundant resources and environmental friendliness, are considered as advanced secondary battery systems that can be applied to large-scale energy storage. As an important cathode material for RZBs, NASICON-type Na3V2(PO4)3 (NVP) possesses three-dimensional and large-scale ion channels that facilitate the rapid diffusion of Zn2+, and has a higher average operating voltage compared with other vanadium-based compounds, thus exhibiting the possibility of realizing RZBs with high energy density. However, NVP still has some problems, such as poor electronic conductivity and spontaneous dissolution in aqueous solution. The sluggish kinetics of Zn2+ (de)intercalation in NVP and dendritic growth on the Zn anode also contribute to the poor rate performance and short cycle life of the batteries. In this review, optimization strategies for the electrochemical performance of RZBs with NVP as cathode are systematically elaborated, including modification of NVP cathode and optimization of electrolyte. Several mainstream energy storage mechanisms and analysis methods in this battery system are sorted out and summarized. On this basis, the development direction of NVP–RZB system is further prospected.

Transmembrane Protein 166 Expression in Esophageal Squamous Cell Carcinoma in Xinjiang, China

Sun, Wei,Ma, Xiu-Min,Bai, Jing-Ping,Zhang, Guo-Qing,Zhu, Yue-Jie,Ma, Hai-Mei,Guo, Hui,Chen, Ying-Yu,Ding, Jian-Bing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Objective: Transmembrane protein 166 (TMEM166) expression in esophageal squamous cell carcinoma (ESCC) and remote normal esophageal tissues was examined to assess any role in tumour biology. Methods: TMEM166 mRNA expression in 36 cases with ESCC (36 tumour samples, 36 remote normal esophageal tissue samples) was detected by RT-PCR. TMEM166 protein expression was analysed in paraffin-embedded tissue samples from the same cases by immunohistochemistry. Results: Semi-quantitative analysis showed TMEM166 mRNA expression in ESCCs to be significantly lower than in remote normal esophageal tissues ($0.759{\pm}0.713$ vs. $2.622{\pm}1.690$, P=0.014). TMEM166 protein expression was also significantly reduced (69.4% vs. 94.4%, P<0.01). Conclusion: TMEM166 mRNA and protein expression demonstrated significant reduction in ESCCs compared with remote esophageal tissues, albeit with no correlation with tumour size, differentiation, stage, and lymph node metastasis, suggesting a role in regulating autophagic and apoptotic processes in the ESCC.

Dibenzoheptazethrene Isomers with Different Biradical Characters: An Exercise of Clar’s Aromatic Sextet Rule in Singlet Biradicaloids

Sun, Zhe,Lee, Sangsu,Park, Kyu Hyung,Zhu, Xiaojian,Zhang, Wenhua,Zheng, Bin,Hu, Pan,Zeng, Zebing,Das, Soumyajit,Li, Yuan,Chi, Chunyan,Li, Run-Wei,Huang, Kuo-Wei,Ding, Jun,Kim, Dongho,Wu, Jishan American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.48

<P><I>Clar’s aromatic sextet rule</I> has been widely used for the prediction of the reactivity and stability of polycyclic aromatic hydrocarbons with a <I>closed-shell</I> electronic configuration. Recent advances in <I>open-shell</I> biradicaloids have shown that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers <B>DBHZ1</B> and <B>DBHZ2</B> were prepared by different synthetic approaches and isolated in crystalline form. These two molecules have different numbers of aromatic sextet rings in their respective biradical resonance forms and thus are expected to exhibit varied singlet biradical character. This assumption was verified by different experimental methods, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), superconducting quantum interference device (SQUID), steady-state and transient absorption spectroscopy (TA), and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. <B>DBHZ2</B>, with more aromatic sextet rings in the biradical form, was demonstrated to possess greater biradical character than <B>DBHZ1</B>; as a result, <B>DBHZ2</B> exhibited an intense one-photon absorption (OPA) in the near-infrared region (λ<SUB>abs</SUB><SUP>max</SUP> <I>=</I> 804 nm) and a large two-photon absorption (TPA) cross-section (σ<SUP>(2)</SUP><SUB>max</SUB> = 2800 GM at 1600 nm). This investigation together with previous studies indicates that Clar’s aromatic sextet rule can be further extended to the singlet biradicaloids to predict their ground states and singlet biradical characters.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-48/ja410279j/production/images/medium/ja-2013-10279j_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja410279j'>ACS Electronic Supporting Info</A></P>

NF-κB Inhibition and PPAR Activation by Phenolic Compounds from Hypericum perforatum L. Adventitious Root

Li, Wei,Ding, Yan,Quang, Tran Hong,Nguyen, Thi Thanh Ngan,Sun, Ya Nan,Yan, Xi Tao,Yang, Seo Young,Choi, Chun Whan,Lee, Eun Jung,Paek, Kee Yoeup,Kim, Young Ho Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

A new compound, perforaphenonoside A (1), along with 11 known compounds (2-12) were isolated from a methanol extract of adventitious roots of Hypericum perforatum. Their chemical structures were elucidated using chemical and physical methods as well as comparison of NMR and mass spectral data with previously reported data. Their inhibition of NF-${\kappa}B$ and activation of PPAR was measured in HepG2 cells using a luciferase reporter system. Among the compounds 3, 6, 7 and 12 inhibited NF-${\kappa}B$ activation stimulated by TNF${\alpha}$ in a dose-dependent manner, with $IC_{50}$ values ranging from 0.85 to $8.10{\mu}M$. Moreover, compounds 1-3, 7, 11 and 12 activated the transcriptional activity of PPARs in a dose-dependent manner, with $EC_{50}$ values ranging from 7.3 to $58.7{\mu}M$. The transactivational effects of compounds 1-3, 7, 11 and 12 were evaluated on three individual PPAR subtypes. Among them, compound 2 activated $PPAR{\alpha}$ transcriptional activity, with 153.97% stimulation at $10{\mu}M$, while compounds 1, 2 and 11 exhibited transcriptional activity of $PPAR{\gamma}$, with stimulation from 124.76% to 126.91% at $10{\mu}M$.

Evaluation of Renal Oxygenation Level Changes after Water Loading Using Susceptibility-Weighted Imaging and T2* Mapping

Jiule Ding,Wei Xing,Dongmei Wu,Jie Chen,Liang Pan,Jun Sun,Shijun Xing,Yongming Dai 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.4

To assess the feasibility of susceptibility-weighted imaging (SWI) while monitoring changes in renal oxygenation level after water loading. Thirty-two volunteers (age, 28.0 ± 2.2 years) were enrolled in this study. SWI and multi-echo gradient echo sequence-based T2* mapping were used to cover the kidney before and after water loading. Cortical and medullary parameters were measured using small regions of interest, and their relative changes due to water loading were calculated based on baseline and post-water loading data. An intraclass correlation coefficient analysis was used to assess inter-observer reliability of each parameter. A receiver operating characteristic curve analysis was conducted to compare the performance of the two methods for detecting renal oxygenation changes due to water loading. Both medullary phase and medullary T2* values increased after water loading (p < 0.001), although poor correlations were found between the phase changes and the T2* changes (p > 0.05). Interobserver reliability was excellent for the T2* values, good for SWI cortical phase values, and moderate for the SWI medullary phase values. The area under receiver operating characteristic curve of the SWI medullary phase values was 0.85 and was not different from the medullary T2* value (0.84). Susceptibility-weighted imaging enabled monitoring changes in the oxygenation level in the medulla after water loading, and may allow comparable feasibility to detect renal oxygenation level changes due to water loading compared with that of T2* mapping.