Investigation on Texture, Magnetic Properties and Inhomogeneities of Hot Deformed Nd–Fe–B Magnet

Hongjian Li,Qiong Wu,Ming Yue,Xiaochang Xu,Yuqing Li,Jingming Liang,Wang Xi,Jiuxing Zhang 한국자기학회 2018 Journal of Magnetics Vol.23 No.3

The anisotropic hot deformed nanocyrstalline Nd.Fe.B magnet was prepared by spark plasma sintering technique using MQU-F powders. The location dependence along radial direction on the magnetic properties, microstructure and crystal alignment of the hot deformed magnet have been investigated. The inhomogeneity of the magnetic performance along radial direction was revealed with a vibrating sample magnetometer (VSM). The crystal structure and microstructure were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM), respectively. In addition, quantitative texture analysis was carried out based on the electron backscattered diffraction technique (EBSD). The experimental results reveal that the coordination of grain size and orientation of Nd.Fe.B grains leads to the inhomogeneities of magnetic performance.

Comparative transcriptome analysis of root hairs proliferation induced by water deficiency in maize

Tingchun Li,Huaying Yang,Wei Zhang,Dafeng Xu,Qing Dong,Fang Wang,Yanli Lei,Guihu Liu,Yingbing Zhou,Hongjian Chen,Cheng Li 한국식물학회 2017 Journal of Plant Biology Vol.60 No.1

Root hairs functions as water channels and nutritional components transporters in plants. It has been shown to enhance nutrient uptake including phosphate, nitrogen, potassium and calcium. In the experiment, the droughtinduced root hairs were collected. By transcriptome sequence and analysis, the molecular mechanisms and differentially expressed genes related to root hairs growth and development were studied. As a result, by using the HiSeq 2500 platform, 61,872,790 clean reads with 96.23% Q20 bases and 9.28 Gb clean bases with 58.88% GC ratio were obtained for normal root. In contrast with Control group, 67,650,572 clean reads with 96.43% Q20 bases and 10.15 Gb clean bases with 58.3% GC content were obtained for drought-induced root hairs. Totally, 323 differentially expressed genes (DEGs) were identified. Among these DEGs, 109 genes were upregulated and 214 genes were downregulated in drought-induced root hairs. Moreover, metabolic pathway enrichment analysises on the 323 DEGs revealed that totally 10 metabolic pathways were distinctly regulated. In details, alanine, aspartate and alutamate metabolism, galactose metabolism and nitrogen metabolism were significantly upregulated. 7 metabolic pathways such as phenylpropanoid biosynthesis, phenylalanine metabolism, biosynthesis of secondary metabolites and flavonoid biosynthesis were significantly downregulated. Furthermore, functional genes and transcription factors were both found to be involved in drought-induced root hair proliferation. These results will help us understand better the molecular mechanism of maize root hair growth and development.

STUDY ON SOFTENING CONSTITUTIVE MODEL OF SOFT ROCK USING STRAIN SPACE BASED UNIFIED STRENGTH THEORY

LI SONG,CHONG DU CHO,SHENG,HONGJIAN 한국소성가공학회 2008 한국소성가공학회 컨퍼런스 Vol.2008 No.10

Identification of putative olfactory genes in newly hatched larvae of a Coleopteran ectoparasitoid Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) by transcriptome analysis

Li Xiaojuan,Dong Guangping,Fang Jianmin,Liu Hongjian,Guo Wanlin,Yin Huayang 한국곤충학회 2020 Entomological Research Vol.50 No.7

Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an effective ectoparasitoid of pine sawyer beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae) which is the major median insect for transmission of pine wood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Aphelenchida: Parasitaphelenchidae). A sensitive and acute olfactory system is extremely essential for newly hatched larva of D. helophoroides to forage for a host. Therefore, we established the transcriptome of newly hatched D. helophoroides larvae and characterized the expression profiles of olfactory genes. We identified 20 transcripts encoding putative odorant binding proteins (OBPs), 11 putative chemosensory proteins (CSPs), 9 putative odorant receptors (ORs), 11 putative ionotropic receptors (IRs), 7 putative gustatory receptors (GRs) and 4 putative sensory neuron membrane proteins (SNMPs) olfactory genes from the transcriptome of newly hatched D. helophoroides larvae. According to the phylogenetic analysis, 3 OBPs (DhelOBP6, DhelOBP14 and DhelOBP19), 1 CSP (DhelCSP11), 1 OR (DhelOrco1), 3 IRs (DhelIR3, DhelIR6 and DhelIR8), 3 GRs (DhelGR2, DhelGR4 and DhelGR5) and 2 SNMPs (DhelSNMP1 and DhelSNMP3) had high similarities with reported Coleopteran species. The highest expressed olfactory gene was DhelCSP3, followed by DhelOBP8 and DhelCSP2. The expression levels of the majority of OR, IR, GR and SNMP genes were low. These results indicate that CSPs and OBPs may play important roles in the olfactory recognition process in newly hatched D. helophoroides larvae. The findings from the present study are helpful in unraveling the profound mystery between D. helophoroides and M. alternatus, as well as improving the parasitism efficiency of D. helophoroides larvae.

High-Temperature Oxidation Behavior of NiCoCrAlY Coatings Deposited by Laser Cladding on 304 Stainless Steel

Yuxin Li,Jinhao Nie,Yixin Yang,Peikang Bai,Hongjian Zhang,Zhanyong Zhao,Shouzheng Wei,Jie Cai,Qingfeng Guan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

To improve the high-temperature resistance of the key hot-end parts of the steam turbine, NiCoCrAlY coatings were depositedon a 304 stainless steel substrate by laser cladding. The microstructure and high-temperature oxidation behavior of theNiCoCrAlY coatings were analyzed. The results showed that the NiCoCrAlY coatings contained γ/γ′ and β phases, and themicrostructure was mainly composed of elongated columnar crystals. In addition, after 100 h of oxidation at three differentoxidation temperatures (750, 850 and 950 °C), the coatings showed a relatively low oxidation rate, which was approximatelya quarter of the oxidation rate of the substrate. At the same time, the protective Cr2O3scales were formed on the coatingsurface. When the oxidation temperature was 850 °C, the FeCr2O4spinel formed and internal oxidation zone appeared,when the oxidation temperature reached 950 °C, the FeCr2O4spinel gathered in the local area on the surface of the Cr2O3scale and the internal oxidation was aggravated. In other words, as the oxidation temperature increased, the Fe element inthe matrix formed the FeCr2O4spinel, which accelerated the consumption of Cr element in the coatings and reduced theoverall oxidation resistance of the NiCoCrAlY coatings.

A three-dimensional statistical damage constitutive model for geomaterials

Hangzhou Li,Hongjian Liao,Guangdong Xiong,Bo Han,Guiping Zhao 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.1

We present a constitutive model for geomaterials. The unified strength theory, which is modified to be more suitable for the geotechnicalengineering, is introduced to reflect the effect of the intermediate principal stress. The polyaxial test data of several rock types verifiesthat the unified strength theory is versatile. The failure of the micro-elements of material is supposed to be distributed randomly and followsWeibull distribution, and the strengths of elements obey the unified strength theory. A statistical damage variable is proposed. Based on the continuum damage mechanics, a statistical damage constitutive model under the complex stress state is proposed. The proposedmodel is verified by the tests of soft rock. The result shows that the model can well predict the stress-strain relationship of soft rock,especially the strain softening behavior. The influences of the parameters of the model are investigated.

Numerical simulation of infill CACB wall cracking subjected to wind loads

Ruige Li,Yu Gao,Hongjian Lin,Mingfeng Huang,Chenghui Wang,Zhongzhi Hu,Lingyi Jin 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.5

The cracking mechanism in ceramsite aerated concrete block (CACB) infill walls were studied in low seismic fortification intensity coastal areas with frequent occurrence of typhoons. The inter-story drifts of an eight-story residential building under wind loads and a seismic fortification intensity of six degrees were analyzed by using the PKPM software. The maximum inter-story drift ratio of the structure in wind load was found to be comparable to that under the seismic fortification intensity of six degrees. However, when accounting for the large gust wind speed of typhoon, the maximum inter-story drift ratio was much larger than that obtained under reference wind load. In addition, the finite element models of RC frames were employed by displacement loading to simulate two scenarios with and without window hole in the CACB infill walls, respectively. The simulation results show no signs of cracking in both the infill walls with window hole and those without window for the inter-story drift caused by seismic loads and the reference wind load. However, both types of infill walls experienced structural creaking when assessing the gust wind pressure recorded from previous typhoon monitoring. It is concluded that an underestimate of wind loads may contribute substantially to the cracking of frame CACB infill walls in low seismic fortification intensity coastal areas. Consequently, it is imperative to adopt wind pressure values derived from gust wind speeds in the design of CACB infill walls within frame structures. Finally, the future research directions of avoiding cracks in CACB filled walls were proposed. They were the material performance improving and building structure optimizing.

The Associations of Family Functioning, General Well-Being, and Exercise with Mental Health among End-Stage Renal Disease Patients

Qi Wang,Hongjian Liu,Zheng Ren,Wenjing Xiong,Minfu He,Nan Li,Xinwen Fan,Xia Guo,Xiangrong Li,Hong Shi,Shuang Zha,Xiumin Zhang 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.4

Objective This study aims to explore the relationships of family functioning, general well-being, and exercise with psychological distress. Furthermore, we investigated the special roles of general well-being and exercise on the association between family functioning and psychological distress. Methods Of 769 end-stage renal disease (ESRD) patients participated in the cross-sectional study which consisted of the 12-item General Health Questionnaire (GHQ-12), the Family APGAR Scales, and the General Well-Being Schedule. The collected data were analyzed using multiple linear regression analysis and path analysis. Results The prevalence of psychological distress was 72.3%. Family functioning, general well-being and exercise were associated factors of psychological distress (p<0.05). The indirect effect of family functioning on psychological distress was partially mediated by general well-being (Effect=-0.08, 95% CI=-0.11, -0.04). In addition, the effect of family functioning on general well-being was moderated by exercise (Index=-0.092, SE=0.033, 95% CI=-0.159, -0.029). Conclusion The prevalence of psychological distress among ESRD patients was high. Family functioning, general well-being and exercise were associated with psychological distress. Family functioning could affect psychological distress partially by affecting general wellbeing. Furthermore, exercise had a significant moderating effect on the relationship between family functioning and general well-being.

Evaluation of 관-Amyloid Peptides Fibrillation Induced by Nanomaterials Based on Molecular Dynamics and Surface Plasmon Resonance.

Hou, Yafei,Li, Pengfei,Zhou, Hongjian,Zhu, Xiaoli,Chen, Haifeng,Lee, Jaebeom,Koh, Kwangnak,Shen, Zhongming,Chen, Hongxia American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.2

<P>This report investigated the effect of carbon nanomaterials, single-wall carbon nanotube (SWCNT) and graphene oxide, on fibrillation of 관-amyloid 40 (A관40) based on surface plasmon resonance (SPR) and molecular dynamics (MD). MD simulations are carried out in order to reveal the molecular mechanisms of the interaction between nanomaterials and A관40. The strong interaction between A관40 and nanomaterials is related to Van der Waals forces and the Coulomb force, inducing delicate manipulation of the main bonding energy for fibrillation of A관40. The interaction energy between the A관 peptide and graphene is higher than that of SWCNT. Experimental results show both carbon nanomaterials enhance the appearance of a critical nucleus for nucleation of peptide fibrils. Graphene is more beneficial to assist the nucleation process than SWCNT. Combination of SPR and molecular dynamics could be a high-throughput method to screen protein fibrillation.</P>

Application of Computer-Aided Approaches to the PUMC Classification of Scoliosis

Junhua Zhang,Hongjian Li,Yufeng Zhang 대한의용생체공학회 2017 Biomedical Engineering Letters (BMEL) Vol.7 No.3

Surgical planning for scoliosis relies on theclassification of the spinal curve pattern. To improve thereliability of the Peking Union Medical College (PUMC)classification system for scoliotic spinal curves, a computer-aided system is proposed and its reliability is evaluated. First, the reliability of curve measurements wasimproved by the computer-aided Cobb measurementapproach. Second, judgmental errors were reduced by thecomputer program through the automation of the PUMCclassification procedure. Four observers divided into anexpert group and a resident group participated in theexperiments. The kappa statistic was used to evaluate thevariability. Classifications of 65 scoliotic cases by the fourobservers showed that with the computer’s aid, the averageintraobserver and interobserver kappa values wereimproved from 0.86 to 0.93 and from 0.75 to 0.86,respectively. The results indicate that the proposed computerizedsystem can assist a surgeon in the PUMC classificationof scoliosis and is especially useful forinexperienced surgeons.