Meshing characteristics of spur gear pairs with tooth modification under different assembly errors and sensitivity analysis for impact factors

Zhifang Zhao,Yang Yang,Hui Ma,Haixu Wang,Hongxu Tian,Chenyi Han 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.1

Assembly errors may change contact state of gear pairs, then induce failure and vibration. To reveal the effects of assembly errors and tooth modification on the meshing characteristics, the loaded tooth contact analysis (LTCA) is conducted through an improved algorithm. The time-varying meshing stiffness (TVMS), static transmission error (STE) and contact stress (CS) are calculated considering assembly errors and tooth modification. Then, sensitivity of meshing characteristics to coupling assembly errors are investigated based on the design of orthogonal experiment (DOE). The meshing characteristic analysis results show that assembly errors have a significant effect on mesh characteristics of the gear pair. The results of sensitivity analysis indicate that the meshing characteristic is the most sensitive to axial deviation for the model used in this paper.

On the orthogonal similarity transformation (OST)-based sensitivity analysis method for robust topology optimization under loading uncertainty: a mathematical proof and its extension

Zhao, Junpeng,Youn, Byeng Dong,Yoon, Heonjun,Fu, Zhifang,Wang, Chunjie Springer-Verlag 2018 Structural and multidisciplinary optimization Vol.58 No.1

Cosmogenic nuclides (10Be and 26Al) erosion rate constraints in the Badain Jaran Desert, northwest China: implications for surface erosion mechanisms and landform evolution

Tong Zhao,Wenjing Liu,Zhifang Xu,Taoze Liu,Sheng Xu,Lifeng Cui,Chao Shi 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.1

Both tectonics and climate affect surface erosion and change the landform. Long-term surface erosion rates determined by in situ produced cosmogenic nuclides are useful quantitative constraints for landform evolution in geological time scale. Measurements of cosmogenic 10Be and 26Al in the granitic rocks exposed in the Badain Jaran Desert, give a mean erosion rate of 7.3 ± 2.6 m/Ma, which is an order of magnitude higher than those reported in other extremely arid regions. Tectonic activity is supposed to be the first order control on regional erosion rate by comparing the 10Be erosion rates of arid regions with different precipitation ranges and tectonic activities worldwide. However the higher erosion rates in the Badain Jaran Desert compared with other arid regions within the stable tectonic background were attributed to the wind erosion and periodically warmer and wetter climate since late Pleistocene. Besides, the estimated eroded mass flux of 7.8 × 104 t/y suggests that erosion products of bedrocks in the Badian Jaran Desert only contribute minor desert deposits, which indicates massive exogenous materials input to the desert.

One-pot Synthesis of Hierarchical Mesoporous ZSM-5 from the Assembly of Nanocrystals Using Urea as Additive

Yuanyuan Ma,Zhifang Li,Nan Zhao,Fuzhong Han,Qiubin Kan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

A hierarchical mesoporous ZSM-5 catalyst with aggregated nanocrystals structure was one-pot hydrothermally synthesized by using urea as the additive. The crystalline phase, morphology and hierarchical architectures were characterized by the XRD, SEM, TEM and N2 adsorption/desorption analyses. The nano-aggregates showed MFI crystalline phase and were composed of connected nanoparticles. The samples had the high surface area and the pore volume from intercrystalline among the nanoparticles due to spontaneously stacking of nanocrystals. The pyridine-adsorbed FTIR and the catalytic performances in the alkylation of phenol and tert-butyl alcohol were applied to evaluate the accessibility of acid sites and the catalytic activities for the hierarchical mesoporous ZSM-5 samples. The samples possessed high accessibility of acid sites which resulted from their large amount of mesopores, and its catalytic activity was improved dramatically. The phenol conversion could reach up to 95.6%, and the corresponding selectivity of 4-TBP and 2,4-DTBP was 44% and 51.5%, respectively.

Simotang Alleviates the Gastrointestinal Side Effects of Chemotherapy by Altering Gut Microbiota

( Lijing Deng ),( Xingyi Zhou ),( Zhifang Lan ),( Kairui Tang ),( Xiaoxu Zhu ),( Xiaowei Mo ),( Zongyao Zhao ),( Zhiqiang Zhao ),( Mansi Wu ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

Simotang oral liquid (SMT) is a traditional Chinese medicine (TCM) consisting of four natural plants and is used to alleviate gastrointestinal side effects after chemotherapy and functional dyspepsia (FD). However, the mechanism by which SMT helps cure these gastrointestinal diseases is still unknown. Here, we discovered that SMT could alleviate gastrointestinal side effects after chemotherapy by altering gut microbiota. C57BL/6J mice were treated with cisplatin (DDP) and SMT, and biological samples were collected. Pathological changes in the small intestine were observed, and the intestinal injury score was assessed. The expression levels of the inflammatory factors IL-1β and IL-6 and the adhesive factors Occludin and ZO-1 in mouse blood or small intestine tissue were also detected. Moreover, the gut microbiota was analyzed by high-throughput sequencing of 16S rRNA amplicons. SMT was found to effectively reduce gastrointestinal mucositis after DDP injection, which lowered inflammation and tightened the intestinal epithelial cells. Gut microbiota analysis showed that the abundance of the anti-inflammatory microbiota was downregulated and that the inflammatory microbiota was upregulated in DDP-treated mice. SMT upregulated antiinflammatory and anticancer microbiota abundance, while the inflammatory microbiota was downregulated. An antibiotic cocktail (ABX) was also used to delete mice gut microbiota to test the importance of gut microbiota, and we found that SMT could not alleviate gastrointestinal mucositis after DDP injection, showing that gut microbiota might be an important mediator of SMT treatment. Our study provides evidence that SMT might moderate gastrointestinal mucositis after chemotherapy by altering gut microbiota.

Autogenous Shrinkage and Crack Resistance of Carbon Nanotubes Reinforced Cement‑Based Materials

Yanming Liu,Tao Shi,Yujing Zhao,Yuan Gu,Zhifang Zhao,Jiabin Chen,Bingmiao Zheng,Shichong Shi 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.5

Cracking caused by shrinkage deformation of cement-based materials at early age is a major problem leading to material failure in restrained conditions. Carbon nanotubes (CNTs) are incorporated into cement-based materials, and the autogenous shrinkage and crack resistance of the new composite materials obtained by linear shrinkage and ring tests are studied to solve the destruction of the materials caused by the shrinkage of cement-based materials. The results showed that addition of CNTs significantly inhibited the autogenous shrinkage of cement-based materials with maximum reduction rate above 40%. CNTs also significantly improved the cracking resistance of cement-based materials. The optimal effect was noticed at CNTs content of 0.1 wt%. The incorporation of CNTs not only inhibits the autogenous shrinkage of cement-based materials, but also inhibits the drying shrinkage of cement-based materials to some extent. Therefore, carbon nanotubes have the potential to solve the destruction of materials caused by shrinkage of cement-based materials.

Anterior Gradient 3 Promotes Breast Cancer Development and Chemotherapy Response

Qiao Xu,Ying Shao,Jinman Zhang,Huikun Zhang,Yawen Zhao,Xiaoli Liu,Zhifang Guo,Wei Chong,Feng Gu,Yongjie Ma 대한암학회 2020 Cancer Research and Treatment Vol.52 No.1

Purpose Anterior gradient 3 (AGR3) belongs to human anterior gradient (AGR) family. The function of AGR3 on cancer remains unknown. This research aimed to investigate if AGR3 had prognostic values in invasive ductal carcinoma (IDC) of breast cancer and could promote tumor progression. Materials and Methods AGR3 expression was detected in breast benign lesions, ductal carcinoma in situ and IDC by immunohistochemistry analysis. AGR3’s correlations with clinicopathological features and prognosis of IDC patients were analyzed. By cell function experiments, collagen gel droplet-embedded culture drug sensitivity test and cytotoxic analysis, AGR3’s impacts on proliferation, invasion ability, and chemotherapeutic drug sensitivity of breast cancer cells were also detected. Results AGR3 was up-regulated in luminal subtype of histological grade I-II of IDC patients and positively correlated with high risks of recurrence and distant metastasis. AGR3 high expression could lead to bone or liver metastasis and predict poor prognosis of luminal B. In cell lines, AGR3 could promote proliferation and invasion ability of breast cancer cells which were consistent with clinical analysis. Besides, AGR3 could indicate poor prognosis of breast cancer patients treated with taxane but a favorable prognosis with 5-fluoropyrimidines. And breast cancer cells with AGR3 high expression were resistant to taxane but sensitive to 5-fluoropyrimidines. Conclusion AGR3 might be a potential prognostic indicator in luminal B subtype of IDC patients of histological grade I-II. And patients with AGR3 high expression should be treated with chemotherapy regimens consisting of 5-fluoropyrimidines but no taxane.

Identifying natural genotypes of grain number per panicle in rice (Oryza sativa L.) by association mapping

Jianyin Xie,Fengmei Li,Najeeb Ullah Khan,Xiaoyang Zhu,Xueqiang Wang,Zhifang Zhang,Xiaoqian Ma,Yan Zhao,Quan Zhang,Shuyang Zhang,Zhanying Zhang,Jinjie Li,Zichao Li,Hongliang Zhang 한국유전학회 2019 Genes & Genomics Vol.41 No.3

Introduction As one of the main yield components, grain number per panicle (GNP) played critical role in the rice yield improvement. The identification of natural advantageous variations under different situations will promote the sustainable genetic improvement in rice yield. Objectives This study was designed to identify natural genotypes in a rice mini-core collection, to examine the genotypic effects across the indica and japonica genetic background in different environments, and excavating the superior genotypes that had drove the modern genetic improvement. Methods The association mapping of GNP was carried out using a mini-core collection including 154 indica and 119 japonica accessions in seven different environments. Genotypic effects of each genotype for each QTL were calculated and genotype frequency distortion between the commercial rice cultivars and landraces was screened by χ2-test. Results In total, 74 QTLs containing stable and sensitive QTLs in various environments were detected. Within them, 20 positive and 24 negative genotypes in indica, and 24 positive and 16 negative genotypes in japonica were identified. When checking the accumulation of positive genotypes identified in indica across cultivars in each of the two subspecies, it indicated that increased number of positive genotypes identified in indica results in the substantially increased GNP in both indica and japonica across all of the environments, while this trend was not obvious for the positive genotypes identified in japonica especially in short day environments. Moreover, the positive and negative genotype frequency distortion between the landraces and commercial rice cultivars indicated that both positive selection of positive genotypes and negative selection of negative genotypes had driven the genetic improvement on GNP. Conclusion Our findings suggested that the accumulation of positive genotypes and purifying negative genotypes played equivalently important roles in the improvement of rice yield, but the efficient use for some QTLs or genotypes depends on the comprehensive evaluation of their effect under diverse genetic backgrounds and environments.