Bioactivity of essential oil of Litsea cubeba from China and its main compounds against two stored product insects

Kai Yang,Cheng FangWang,Chun Xue You,Zhu Feng Geng,Rui Qi Sun,Shan Shan Guo,Shu Shan Du,Zhi Long Liu,Zhi Wei Deng 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oilof Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasiodermaserricorne adults and the booklouse Liposcelis bostrychophila, with LD50 values of 27.33 μg/adult and71.56 μg/cm2, respectively, and also showed strong fumigant toxicity against the two stored product insectswith LC50 values of 22.97 and 0.73 mg/L, respectively. The essential oil obtained by hydrodistillation wasinvestigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial)(27.49%), Z-citral (neral) (23.57%) and D-limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), D-limonene, β-pinene,α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thinlayer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral andlinalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD50 = 11.76, 12.74 μg/adultand 20.15, 99.97 μg/cm2, respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54,18.04 mg/L air and 0.14, 0.71 mg/L air, respectively). Otherwise, citral, D-limonene and linalool were strongly repellentagainst the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weakerrepellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene andlinalool, the other three compounds as well as the essential oil exhibited comparable repellency against thebooklouse relative to DEET.

Influence of Heat Treatment on Microstructure and Mechanical Properties of TC4 Fabricated by Laser Melting Deposition

Qi Chaoqi,Du Yang,Yang Ping,Liu Zhengwu,Lyu Hongya,Zhao Kai,Guo Lijie 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12

The phase composition, microstructure, tensile properties of TC4 samples produced by laser melting deposition (LMD)and LMD followed by solution-aging treatment were investigated to explore a simpler approach to improve the mechanicalperformances and eliminate negative influences by post treatment. The as-deposited TC4 microstructure showed a combinationof α΄martensite and α-colony with various shapes, such as acicular, rod-like and lamellar. As a synergistic result ofsolution and aging treatment, the dispersion strengthening of secondary-α as well as optimization on length-width ratio ofprimary-α and volume fraction of β-phase cause an increase in the ductility and strength. Meanwhile, there is a differencebetween microstructure of water-quenched specimens and air-cooled specimens, subsequently playing a key role in properties. The solution with air-cooling and aging is comparatively found to significantly reduce the anisotropy and improvecomprehensive performance.

VALUE SHARING RESULTS OF A MEROMORPHIC FUNCTION f(z) AND f(qz)

Qi, Xiaoguang,Liu, Kai,Yang, Lianzhong Korean Mathematical Society 2011 대한수학회보 Vol.48 No.6

In this paper, we investigate sharing value problems related to a meromorphic function f(z) and f(qz), where q is a non-zero constant. It is shown, for instance, that if f(z) is zero-order and shares two valves CM and one value IM with f(qz), then f(z) = f(qz).

Preliminary Application of High-Definition CT Gemstone Spectral Imaging in Hand and Foot Tendons

Kai Deng,Cheng-Qi Zhang,Wei Li,Jun-Jun Wang,Xin-Yi Wang,Tao Pang,Guang-Li Wang,Cheng Liu 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ2 = 0, p > 0.05), compression (χ2 = 0.5, p > 0.05), absence (χ2 = 0, p > 0.05) and rupture (χ2 = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ2 = 4.17, p < 0.05), degeneration (χ2 = 4.17, p < 0.05), and tendinous sheath disease (χ2 = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition. Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ2 = 0, p > 0.05), compression (χ2 = 0.5, p > 0.05), absence (χ2 = 0, p > 0.05) and rupture (χ2 = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ2 = 4.17, p < 0.05), degeneration (χ2 = 4.17, p < 0.05), and tendinous sheath disease (χ2 = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition.

Effect of Vanadium on the Microstructure and Mechanical Properties of 2100 MPa Ultra-High Strength High Plasticity Spring Steel Processed by a Novel Online Rapid-Induction Heat Treatment

Qi‑Lei Dai,Kun Li,Kai‑Ren Meng,Zhou Fang,Wen Chen,Tian‑Bao Yang,Chi Feng,Jin‑Ming Wu,R. D. K. Misra 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.4

Advanced automotive industries generate large demand for the next generation of high strength and high toughness springsteels. Vanadium-containing 55SiCrV spring steels subjected to rapid-induction heating treatment can fulfil such requirements. However, the effect of vanadium microalloying under online rapid-induction heat treatments is rarely reported. Acomparative study of the microstructure and tensile properties of 55SiCr and 55SiCrV spring steel wires subjected to a novelonline rapid induction heat treatment has been demonstrated herein. It is found that the tensile strength of the 55SiCr springwire decreases with the decrease in the wire speed in online rapid-induction heating, and the plasticity increases. Whereas,the tensile strength of the 55SiCrV steel wire increases with the decrease in the wire speed with the retained high plasticity,which is attributed to the strengthening effect of the dislocations. Through the optimized rapid-induction heating/coolingthermal cycles and intermediate-temperature tempering treatment, the tensile strength of the 55SiCrV steel wire approaches2106 MPa with total elongation of 9.7%. Compared with the 55SiCr spring steel, the addition of V in 55SiCrV spring steelchanges the strengthening and toughening mechanisms via the grain refinement and enhancement in the hardenability andtempering resistance. The finely dispersed V-containing secondary phases are rarely found in the matrix, which indicates thatthe precipitation effect stemming from the addition of V is not the dominant strengthening factor in the online rapid-inductionheat process. The proposed novel online rapid-induction heat treatment provides a promising pathway for the mechanicalproperty improvement of the spring steel.

Anisotropy of magnetic susceptibility of the Late Cretaceous-Eocene sediments in the southeastern Fenwei Graben and its tectono-sedimentary significance

Kai Jiang,Guanzuo Wu,Guohao Si,Jiangang Li,Boyang Zheng,Qi Shen,Shida Song 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.4

The Fenwei Graben located in the conjoint region between the Neo-Tethys tectonic domain and the western Pacific tectonic domain is key to understanding the tectonic evolution of the East Asian interior. Extensive Late Cretaceous–Paleogene fluvial and lacustrine deposits within the southeastern Fenwei Graben, provide ideal archives of early tectono-sedimentary evolution in Fenwei Graben. Recently, we find two complete Late Cretaceous–Cenozoic sections in the Lingbao Basin. These unique sections provide an excellent opportunity to investigate regional tectono-sedimentary evolution and its potential dynamic mechanisms in Fenwei Graben. The anisotropy of magnetic susceptibility (AMS) is an effective and economic method to obtain information about tectonic and/or sedimentary evolution recorded in deposits. To this end, we present an integrated rock magnetism and AMS study of 36 sampling sites from these two sections that span the interval from the Late Cretaceous to the Early Eocene. Our rock magnetism results suggest that hematite and magnetite are the main magnetic carriers of remanence, and paramagnetic minerals and hematite are major contributors to AMS in the Lingbao Basin. In addition, the reverse, intermediate and anomalous magnetic fabrics are found in these two sections, which may result from the contribution of iron-bearing carbonates in deposits. The AMS of the Lingbao Basin is a primary sedimentary fabric with the K1 direction antiparallel to the preferential paleocurrent direction. During the Paleocene, the clockwise rotation of the paleocurrent directions in both sections is more likely to be caused by the rotation of the Lingbao basin or the relatively rapid uplift of western provenance under the influence of the India–Eurasia convergence. Moreover, the inferred early evolution of the Fenwei Graben is likely controlled by both the western Pacific plate subduction and India–Eurasia convergence.

Experimental Study on Mechanical Behavior of Prefabricated PEC Composite Beams Under Cyclic Loading

Kai Wu,Shi qi Lin,Xiaoyi Liu,Fanshen Mao,Jiangpeng Zhai 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.3

In this paper, a new type prefabricated partially encased composite beam (PEC beam) using screw arbors instead of stirrups or welded transverse links in ordinary PEC structures to connect the upper and lower steel fl ange has been proposed. It not only retains the performance advantages of PEC structures, but also greatly enhances the prefabricated degree of structure and simplifi es construction process. Twelve beams with and without screw arbors were tested under cyclic loading to study the mechanical behavior of this new type of PEC beams. The major factors considered were shear span ratio ( λ = 1.0, 2.0, 3.0 and 4.0), with or without screw arbors and concrete thickness. Test results including failure mode, load–defl ection curves ( P − Δ curves), characteristic points, ductility and stiff ness were introduced and discussed in detail. The test results showed that the failure mode of PEC beams changed from shear failure to bending failure with the increase of shear span ratio, and the asymmetric damage of specimens can be improved by screw arbors. In addition, PEC beams with screw arbors have better ductility and slower stiff ness degeneration than those without screw arbors. Potential application value can be seen from this new type of prefabricated PEC beams.

Rosa roxburghii Tratt juice inhibits NF-κB and increases IL-2 to alleviates the Foxp3-mediated Tregs imbalance in the peripheral blood of arseniasis patients

Qi Wang,Xiaolin Fang,Baofei Sun,Kai Zhu,Maolin Yao,Shaofeng Wei,Aihua Zhang 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.4

Arsenic can cause immune inflammation, which is the basis of arsenic-induced damage to multiple organs and systems. Forkhead box P3 (Foxp3)-labelled CD4+CD25+ regulatory T cells (Tregs) play an essential role in maintaining immune homeostasis. Nuclear factor-κb (NF-κB) and Interleukin-2 (IL-2) are critical regulators of Foxp3. Rosa roxburghii Tratt (RRT) is an edible medicinal plant with anti-inflammation effects. In this study, a control group (n = 41) and an arseniasis group (n = 209) were recruited, and screened subjects from the arseniasis patients for RRTJ (n = 46) or placebo (n = 43) to explore the possible mechanism by which RRT alleviates immune inflammation. The results indicated that RRTJ can inhibits NF-κB and increases IL-2, and alleviates the Foxp3-mediated Tregs imbalance in the peripheral blood of arseniasis patients. In summary, these findings suggest a novel intervention or therapeutic target for immune inflammation in arseniasis patients and provide new evidence that RRTJ inhibits immune inflammation.

[Poster Presentation] THE EFFECT OF FORMATION OF PAPER FROM EUCALYPTUS CHEMIMECHANICAL PULP ON PRINTABILITY

Kai-Tang HU,Guo-Min TAN,Qi-Rong Fu,Nam-Soek Cho 한국펄프·종이공학회 1999 한국펄프종이학회 기타 간행물 Vol.- No.-

The relation between the paper formation analyzed by image process system and smoothness, compressibility, uniform of ink absorption is studied. The results indicate that the paper with bad formation has higher apparent bulk than the paper with good formation. The bad formation of paper results in the nonuniform calendering and decrease of the compressibility. The bad formation of paper also results in deformation and omission of printing dots, which affects the reproduction of the printing images.

Effects of Polymerization and Spinning Conditions on Mechanical Properties of PAN Precursor Fibers

Qi-Feng Qin,Yong-Qiang Dai,Kai Yi,Li Zhang,Seung-Kon Ryu,Ri-Guang Jin 한국탄소학회 2010 Carbon Letters Vol.11 No.3

PAN precursor fibers were produced via wet-spinning process, and effects of polymerization and spinning processes, especially the stretching process, were investigated on mechanical properties and micro-morphologies of precursor fibers. An increase in molecular weight, dope solid and densification and a decrease in surface defects were possible by controlling polymerization temperature, the number of heating rollers for densification and the jet stretch ratio, which improved the mechanical properties of precursor fibers. The curves for strength, modulus, tensile power and diameter as a function of stretch ratio can be divided into three stages: steady change area, little change area and sudden change area. With the increase of stretch ratio, the fiber diameter became smaller, the degree of crystallization increased and the structure of precursor fibers became compact and homogeneous, which resulted in the increase of strength, modulus and tensile power of precursor fibers. Empirical relationship between fiber strength and stretch ratio was studied by using the sub-cluster statistical theory. It was successfully predicted when the strengths were 0.8 GPa and 1.0 GPa under a certain technical condition, the corresponding stretch ratio of the fiber were 11.16 and 12.83 respectively.