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Analysis of floral scent emitted from Syringa plants

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Journal of Forestry Research 2016年第2期27卷 273-281页

作者： Xiaoxia Yang Jing Zhao jian Zheng Pingsheng Leng Xiaolong Li Zenghui Hu jianbin liu Xin Meng College of Landscape Beijing University of AgricultureBeijing 102206People's Republic of China Beijing Rural Landscape Planning and Design Engineering Technology Center Beijing 102206People's Republic of China Beijing Laboratory of Urban and Rural Ecological Environment Beijing 100083People's Republic of China Beijing Botanical Garden Beijing 100093People's Republic of China

Syringa is an important aromatic woody angiosperm that is widely planted in gardens. Its dry flowers are traditionally used to manufacture infusions and spices in China. In this study, the floral volatiles emitted from nine different Syringa species and varieties, viz. S. chinensis, S. protolaciniata, S. oblata, S. oblata var. giraldii, S. oblata var. plena, S. vulgaris ＇Mrs Harry Bickle＇, S. vulgaris ＇Bright Centennial＇, S. vulgaris ＇White Spires＇, and S. vulgaris ＇President Lincoln＇ were collected by the dynamic headspace technique, and then identified by automated thermal desorption-gas chromatography/mass spectrometry. There were significant differences in components and corresponding contents of floral scent emitted from the nine Syringa species and varieties. Among the detected components, β-ocimene exhibited the highest content, accounting for more than 70 % of the floral scent of S. protolaciniata, S. oblata var. giraldii, and S. vulgaris ＇Bright Centennial＇. A significant daytime variation of floral scent emitted from S. pekinensis was recorded, especially for benzaldehyde, whose content first increased and then decreased. We studied the scent emitted from the in vitro flowers of S. vulgaris ＇Pres Lincoln＇ during the process of natural drying. Alcohol compounds were released in the greatest content, and the content of 2-ethyl-l-hexanol accounted for about 40 % of the total release amount. The results described the emission pattern and mechanisms of floral scent in Syringa.

关键词： Component Daytime variation Floralscent Relative amount Syringa

Natural Gas Types,Distribution Controlling Factors,and Future Exploration in the Western Qaidam Basin

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Acta Geologica Sinica(English Edition) 2014年第4期88卷 1214-1226页

作者： GUO Zeqing SUN Ping LI jian ZHANG Lin liu Weihong TIAN Jixian ZHANG Shaosheng ZENG Xu Langfang Branch Research Institute of Petroleum Exploration and DevelopmentCNPC

The Paleogene and Neogene oil and gas in the western Qaidam basin have a regular distribution in three concentric zones from the edge to the center of the basin. Natural gas mainly occurs in the inner zone, and the gas-oil ratio of the northern area of the basin is significantly higher than that of the southern area. Large amounts of carbon isotope data of natural gas, plotted in X- shaped and comprehensive identification diagrams for the southern area and northern area, respectively, were used to identify the types of natural gas. The large-scale distribution of natural gas is highly consistent with the Ro values of major source rocks, but is poorly correlated with the type of organic matter. This indicates that the main controlling factor of natural gas distribution is organic matter maturity, and the kerogen types act as the basis for the formation of different types of natural gas. Paleouplifts and squeezed anticlines near hydrocarbon generation depression centers, which are major natural gas-rich regions, control the migration directions of natural gas, while hydrocarbon migration pathways and fault systems connecting gas sources are the most important factors for natural gas reservoir formation in the inner basin. Therefore, favorable zones for natural gas distribution can be predicted on the basis of the distribution of thermal evolution and the gas generation intensity of major source rocks as well as the structural map. The Shizigou-Youshashan- Yingdong-Dawusi, Youquanzi -Kaitemilike - Youdunzi, and Xiaoliangshan - Nanyishan - Dafengshan structural belts are favorable zones for natural gas accumulation. This study has important theoretical and practical significance for future natural gas exploration.

关键词： western Qaidam basin natural gas types distributional characteristics main controlling factors maturity favorable zones

Risk factors for hepatocellular carcinoma in cirrhosis:A comprehensive analysis from a decade-long study

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World Journal of Gastrointestinal Oncology 2024年第12期16卷 4625-4635页

作者： Da-Qiong Zhou jiang-Yu liu Feng Zhao Jing Zhang Li-Li liu jian-Ru Jia Zhen-Huan Cao Department of Hepatology Beijing Youan HospitalCapital Medical UniversityBeijing 100069China Hepatology Center Baoding People’s HospitalBaoding 071000Hebei ProvinceChina

BACKGROUND Cirrhosis is a significant risk factor for the development of hepatocellular carcinoma(HCC).Variability in HCC risk among patients with cirrhosis is notable,particularly when considering the diverse etiologies of *** To identify specific risk factors contributing to HCC development in patients with *** This retrospective study analyzed data from cirrhotic patients at Beijing Youan Hospital from January 1,2012 to September 30,2022 with at least 6 mo of *** demographics,medical histories,etiologies,and clinical characteristics were *** regression analysis was used to analyze correlations of the above parameters with hepatocarcinogenesis,while competing risk regression was used to estimate their adjusted hazard ratios accounting for *** cumulative incidence was plotted over *** Overall,5417 patients with cirrhosis(median age:54 years;65.8%males)were *** B virus(HBV)was the most common etiology(23.3%),with 25%(n=1352)developing HCC over a 2.9-year follow-up *** with multiple etiologies had the HCC highest incidence(30.3%),followed by those with HBV-related cirrhosis(29.5%).Significant risk factors included male sex,advanced age,hepatitis C virus(HCV)infection,elevated blood ammonia,and low platelet *** had a higher 5-year HCC risk than women(37.0%vs 31.5%).HBV,HCV,and HBV/HCV co-infected patients had 5-year risks of HCC of 45.8%,42.9%,and 48.1%,respectively,compared to 29.5%in nonviral hepatitis cases,highlighting the significant HCC risk from viral hepatitis,especially HBV,and underscores the importance of monitoring these high-risk *** In conclusion,HBV-related cirrhosis strongly correlates with HCC,with male sex,older age,viral hepatitis,elevated blood ammonia,and lower albumin and platelet levels increasing the risk of HCC.

关键词： Cirrhosis Hepatocellular carcinoma Risk factors Hepatitis B virus Competing risk analysis

Effect of Occupational Extremely Low-Frequency Electromagnetic Field Exposure on the Thyroid Gland of Workers:A Prospective Study

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Current Medical Science 2022年第4期42卷 817-823页

作者： Yuan-yuan FANG Qian TU Yu-ting ZHANG jian liu Hui-guo liu Zhi-hua ZHAO Hua WU Tie-jun YIN Department of Respiratory and Critical Care Medicine The Central Hospital of WuhanTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430014China Department of Geriatric Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Respiratory and Critical Care Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Naval University of Engineering Wuhan 430030China Department of Orthopedics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Objective:The aim of this study was to investigate the biological effects of occupational extremely low-frequency electromagnetic field(ELF-EMF)exposure on the thyroid ***:We conducted a prospective analysis of 85 workers(exposure group)exposed to an ELF-EMF(100μT,10-100 Hz)produced by the electromagnetic aircraft launch system and followed up on thyroid function indices,immunological indices,and color Doppler images for 3 ***,116 healthy volunteers were randomly selected as controls(control group),the thyroid function of whom was compared to the exposure ***:No significant difference was observed in thyroid function between the exposure and control *** the follow-up of the exposure group,the serum free triiodothyronine(FT3)level was found to slowly decrease and free thyroxine(FT4)level slowly increase with increasing exposure ***,no significant difference was found in thyroid-stimulating hormone(TSH)over the three years,and no significant difference was observed in the FT3,FT4 and TSH levels between different exposure ***,no significant changes were observed in thyroid autoantibody levels and ultrasound images between subgroups or over ***:Long-term exposure to ELF-EMF may promote thyroid secretion of T4 and inhibit deiodination of T4 to ***-EMF has no significant effect on thyroid immune function and morphology.

关键词： extremely low-frequency electromagnetic field thyroid function thyroid autoantibody thyroid ultrasound thyroid nodule

Ph_3P^+CF_2CO_2^- as an F^- and:CF_2 source for trifluoromethylthiolation of alkyl halides

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Chinese Chemical Letters 2019年第3期30卷 714-716页

作者： Zhuo liu Jin Long Xuan Xiao Jin-Hong Lin Xing Zheng Ji-Chang Xiao Yu-cai Cao Institute of Pharmacy and Pharmacology Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study University of South China Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences Shanghai Research Institute of Chemical Industry Co. LTD.

As trifluoromethylthiolation has received increasing attention recently, many CF_3S-reagents and trifluoromethylthiolation methods have been developed. Herein we describe trifluoromethylthiolation of alkyl halides by using Ph_3 P^+CF_2CO_2 as a fluoride and difluorocarbene source. Difluorocarbene is a versatile intermediate, but its side reactions are usually ignored and the by-products would therefore be discarded. In this work, a side reaction of difluorocarbene, the generation of a fluoride anion from difluorocarbene, was developed into a synthetic tool. Although the trifluoromethylthiolation reaction involved multi-sequential steps, the cleavage of C-F bond, the formation of CF_2=S bond, F-C(S)F_2 bond,and C-SCF_3 bond, the conversion proceeded fast and was completed within 10 min.

关键词： Difluorocarbene Trifluoromethylthiolation Alkyl halides Thiocarbonyl fluoride Fluorine

Crystal Structure of Sar1[H79G]-GDP Which Provides Insight into the Coat-controlled GTP Hydrolysis in the Disassembly of COP Ⅱ

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Chinese Journal of Structural Chemistry 2006年第7期25卷 854-860页

作者： RAO Yi-jian YUAN cai BIAN Chuan-Bing HOU Xiao-Min LI Yong-Dong ZHAO Geng-Xiang YE Xiao-Ming HUANG Zi-Xiang HUANG Ming-Dong State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

Sarl is a small GTPase involved in COPⅡ vesicle transport. Previous studies showed that H79G mutation of Sarl can lock Sarl in its GTP-bound active conformation, stabilize coat assembly, and prevent the disassembly of COP Ⅱ vesicle coats by reducing Sec23/24 GAP- stimulated hydrolysis. We show here that the replacement of His79 by glycine induces a large conformation change in switch Ⅱ and results in the lost of hydrogen bond between His79 and its associated nucleophilic water molecule that was hypothesized to reduce the GAP-stimulated hydrolysis during the COP Ⅱ assembly and disassembly. These results confirm that the switch Ⅱ conformation is important for COP Ⅱ disassembly through coat-controlled GTP hydrolysis.

关键词： Sarl switch Ⅱ COP Ⅱ disassembly crystal structure

Engineering three-layer core–shell S-1/TS-1@dendritic-SiO_(2) supported Au catalysts towards improved performance for propene epoxidation with H_(2) and O_(2)

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Green Energy & Environment 2020年第4期5卷 473-483页

作者： Zhaoning Song Juncong Yuan Zhenping cai Dong Lin Xiang Feng Nan Sheng Yibin liu Xiaobo Chen Xin Jin De Chen Chaohe Yang State Key Laboratory of Heavy Oil Processing China University of PetroleumQingdao266580China Department of Chemical Engineering Norwegian University of Science and TechnologyTrondheim7491Norway State Key Laboratory of Safety and Control for Chemicals SINOPEC Qingdao Research Institute of Safety Engineering218 Yanansan RoadQingdao266580China

The advocacy of green chemical industry has led to the development of highly efficient catalysts for direct gas-phase propene epoxidation with green,sustainable and simple *** S-1/TS-1@dendritic-SiO_(2) material with three-layer core–shell structure was developed and used as the support for Au catalysts,which showed simultaneously fantastic PO formation rate,PO selectivity and stability(over 100 h)for propene epoxidation with H_(2) and O_(2).It is found that silicalite-1(S-1)core and the middle thin layer of TS-1 offer great mass transfer ability,which could be responsible for the excellent *** designed dendritic SiO_(2) shell covers part of the acid sites on the external surface of TS-1,inhibiting the side reactions and improving the PO ***,three kinds of SiO_(2) shell morphologies(i.e.,dendritic,net,mesoporous shell)were designed,and relationship between shell morphology and catalytic performance was *** results in this paper harbour tremendous guiding significance for the design of highly efficient epoxidation catalysts.

关键词： Propene epoxidation Selectivity Core-shell Dendritic SiO_(2)shell TS-1

Single Buffer Using Perovskite-like RE_2Zr_2O_7 Oxides for High Temperature Superconducting Coated Conductors

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稀有金属材料与工程 2011年第S3期40卷 354-357页

作者： Ying Liliang, Lu Yuming, liu Zhiyong, Fan Feng, Gao Bo, cai Chuanbing Shanghai University, Shanghai 200444, China Shanghai Univ Res Ctr Superconductors & Appl Technol Shanghai 200444 Peoples R China

Single buffer layers of either Gd2Zr2O7 (GZO) or La2Zr2O7 (LZO) with different thickness on highly textured Ni-W tapes were compared with respective to the application of YBa2Cu3O7-δ coated conductors. The superconducting performances are improved as the buffer thickness of GZO or LZO increases up to a critical value, such as 310 and 240 nm, respectively. This suggests that a thin buffer layer is insufficient to prevent the Ni diffusion. If the buffer thickness increases further, the superconducting properties degrade, probably due to changes in the microstructure and degradation of the buffer texture. Comparing with LZO, the texture of GZO is hardly dependent on its thickness, due to smaller mismatch for its lattice with that of Ni-W. For both single buffered coated conductors, the superconducting transition temperatures are around 92 K with a transition width less than 1 K. Inductive measurement reveals that the critical current density (Jc) at 77 K in self-field, reaches 1.2 MA/cm2 and 0.77 MA/cm2 for GZO, and LZO, respectively. This implies that the single buffers of GZO and LZO are comparable to standard buffer architectures such as CeO2/YSZ/Y2O3 or CeO2/LZO, being promising for the process simplification and cost reduction.

关键词： coated conductors single buffer biaxial texture

Seismic response of cracking features in Jubao Mountain during the aftershocks of Jiuzhaigou Ms7.0 earthquake

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Journal of Mountain Science 2019年第11期16卷 2532-2547页

作者： SHEN Tong WANG Yun-sheng LUO Yong-hong XIN Cong-cong liu Yong HE jian-xian The State Key Laboratory of Geohazards Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China The Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Jiuzhaigou is a world-heritage site located in the plateau area of Northwest Sichuan Province,*** slope failures in the epicentral area were triggered by the Ms7.0 Jiuzhaigou earthquake occurred on August 8,*** source areas of the hazards are usually concentrated near ridge crests,revealingthe possible occurrence of ground motion amplification *** explore the role of the amplification of ground motions in the formation of earthquake-triggered slope failures,two seismometers were installed,on the next day after the main shock,at the bottom of the slopeof Jubao Mountain near the seismogenic *** two monitoring sites are located at elevations of 1414 m(J1)and 1551 m(J2,the top of the mountain).Five aftershocks were recorded by the monitoring *** compared the mean levels of the peak ground acceleration(PGA)observed at different locations,and investigated the directional variations inthe shaking energy by analyzing the polar diagrams of the Arias intensity(Ia).Then,in order to identify the directional resonance phenomenonandtheir frequencies and amplification coefficients,we examined the horizontal-to-vertical spectral ratio(HVSR)and the standard spectral ratio(SSR).Polar diagrams of theArias intensity(Ia)indicated that the site response of Jubao Mountain showed a pronounced directivity(in theEW direction)with shaking maxima near the hill top oriented orthogonally to the elongation of the *** observed anobvious resonance phenomenonat site J2 at relatively low frequencies(2.5-9 Hz)and very weak spectral amplifications at site J1 at high frequencies(5-15 Hz),which suggested that the predominant frequency of monitoring site J2 was obviously attenuated and that the difference in the spectra was related to the influences of the local-scale site conditions of the whole *** results of spectral ratio analyses(HVSR and SSR)showed that the direction of resonance was concentrated around an EW orientation,and the amplification f

关键词： Jiuzhaigou Ms7.0 earthquake Aftershocks Directivity effects Slope dynamic response HVSR SSR