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1Discovery of ultrahigh-pressure magnesite-bearing garnet lherzolite (>3.8 GPa) in the Altyn Tagh, Northwest China显示文摘Magnesite-bearing garnet Iherzolite from the Altyn Tagh, associated with garnet pyroxenite, and garnet-bearing felsic gneiss, crops out as lenses in Proterozoic gneiss about 100 km east of the Jianggelasayi River. The garnet Iherzolite, together with the eclogite in western Jianggelasayi, composes a high-pressure to ultrahigh-pressure metamorphic belt in the southern margin of the Altyn Tagh. Parageneses of minerals from magnesite-bearing garnet Iherzolite indicate that the rock evolved a multi-stage metamorphism. The peak-stage metamorphism produces an assemblage of Grt+Ol+Opx+Cpx±Mgs, in which A12O3 content of Opxis very low (0.30-0.66wt%). The calculated P-T condition of the peak stage is 3.8-5.lGPa and 880-970°C, some exsolution rods of clinopyroxene and rutile occur in the Grt and magnesite is rimed by dolomite and orthopyroxene, all implying that the peak stage was a UHP metamorphic process. Together with regional geological studies, isotopic dating and the discovery of coesite inclusions inLIU Liang, SUN Yong, XIAO Peixi, CHE Zicheng, LUO Jinhai, CHEN Danling, WANG Yan, ZHANG Anda, CHEN Liang & WANG YongheKey Laboratory of Continental Dynamics of the Ministry of Education, Northwest University, Xi’an 710069, China The Northwest Institute of 2002Chinese Science Bulletin2002,47,11:69
2Relative Contributions of Boundary-Layer Meteorological Factors to the Explosive Growth of PM2.5 during the Red-Alert Heavy Pollution Episodes in Beijing in December 2016显示文摘Based on observations of urban mass concentration of fine particulate matter smaller than 2.5 μm in diameter(PM_(2.5)), ground meteorological data, vertical measurements of winds, temperature, and relative humidity(RH), and ECMWF reanalysis data, the major changes in the vertical structures of meteorological factors in the boundary layer(BL) during the heavy aerosol pollution episodes(HPEs) that occurred in winter 2016 in the urban Beijing area were analyzed. The HPEs are divided into two stages: the transport of pollutants under prevailing southerly winds, known as the transport stage(TS), and the PM_(2.5) explosive growth and pollution accumulation period characterized by a temperature inversion with low winds and high RH in the lower BL, known as the cumulative stage(CS). During the TS, a surface high lies south of Beijing, and pollutants are transported northwards. During the CS, a stable BL forms and is characterized by weak winds, temperature inversion, and moisture accumulation. Stable atmospheric stratification featured with light/calm winds and accumulated moisture(RH > 80%) below 250 m at the beginning of the CS is closely associated with the inversion, which is strengthened by the considerable decrease in near-surface air temperature due to the interaction between aerosols and radiation after the aerosol pollution occurs. A significant increase in the PLAM(Parameter Linking Aerosol Pollution and Meteorological Elements) index is found, which is linearly related to PM mass change. During the first 10 h of the CS, the more stable BL contributes approximately 84% of the explosive growth of PM_(2.5) mass. Additional accumulated near-surface moisture caused by the ground temperature decrease, weak turbulent diffusion, low BL height, and inhibited vertical mixing of water vapor is conducive to the secondary aerosol formation through chemical reactions, including liquid phase and heterogeneous reactions, which further increases the PM_(2.5) concentration levels. The contribution of these reaction mechanisms to the explosive growth of PM_(2.5) mass during the early CS and subsequent pollution accumulation requires further investigation.junting zhong xiaoye zhang yaqiang wang junying sun yangmei zhang jizhi wang kaiyan tan xiaojing shen haochi che lu zhang zhouxiang zhang xuefei qi huarong zhao sanxue ren yang li 2017Journal of Meteorological Research2017,31,5:25
3Effects of AZT and RNA-protein complex (FA-2-b-β) extracted from Liang Jin mushroom on apoptosis of gastric cancer cells显示文摘AIM: To investigate the synergistic effects of 3'-azido-3'-deoxythymidine (AZT) and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS: MTT analysis was made to examine the inhibition rate of MKN45 cells treated with AZT (2.5, 5, 10 and 20 mg/L) and FA-2-b-β (5, 10, 20 and 40 mg/L) singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP-ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR. RESULTS: AZT and FA-2-b-β could signifi cantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose-and time-dependent manner. The inhibition effect of AZT combined with FA-2-b-β was obviously better than that used singly (0.469 ± 0.022 vs 1.075 ± 0.055, P < 0.05, 0.325 ± 0.029 vs 0.469 ± 0.022 P < 0.01). AZT used singly and combination of FA-2-b-β could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA-2-b-β. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA (r = 0.9969, P < 0.01), which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate (r = 0.926, P < 0.01). Furthermore, the effect of AZT combined with FA-2-b-β was signifi cantly higher than that used singly.CONCLUSION: Combination of AZT and FA-2-b-β has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.Yan-Qing Sun Zi-Ren Wang Tian-Kang Guo Ya-Ming Xi Che Chen, Jin-Wang 2007World Journal of Gastroenterology2007,13,31:11
4MdATG18a overexpression improves basal thermotolerance in transgenic apple by decreasing damage to chloroplasts显示文摘High temperature is an abiotic stress factor that threatens plant growth and development.Autophagy in response to heat stress involves the selective removal of heat-induced protein complexes.Previously,we showed that a crucial autophagy protein from apple,MdATG18a,has a positive effect on drought tolerance.In the present study,we treated transgenic apple(Malus domestica)plants overexpressing MdATG18a with high temperature and found that autophagy protected them from heat stress.Overexpression of MdATG18a in apple enhanced antioxidase activity and contributed to the production of increased beneficial antioxidants under heat stress.Transgenic apple plants exhibited higher photosynthetic capacity,as shown by the rate of CO_(2) assimilation,the maximum photochemical efficiency of photosystem II(PSII),the effective quantum yield,and the electron transport rates in photosystems I and II(PSI and PSII,respectively).We also detected elevated autophagic activity and reduced damage to chloroplasts in transgenic plants compared to WT plants.In addition,the transcriptional activities of several HSP genes were increased in transgenic apple plants.In summary,we propose that autophagy plays a critical role in basal thermotolerance in apple,primarily through a combination of enhanced antioxidant activity and reduced chloroplast damage.Liuqing Huo Xun Sun Zijian Guo Xin Jia Runmin Che Yiming Sun Yanfei Zhu Ping Wang Xiaoqing Gong Fengwang Ma 2020Horticulture Research2020,7,1:9
5Overexpression of MdATG18a in apple improves resistance to Diplocarpon mali infection by enhancing antioxidant activity and salicylic acid levels显示文摘Marssonina apple blotch,caused by Diplocarpon mali,is one of the most serious diseases of apple.Autophagy plays a key role in pathogen resistance.We previously showed that MdATG18a has a positive influence on drought tolerance.Herein,we describe how overexpression(OE)of MdATG18a enhances resistance to D.mali infection,probably because less H2O2 but more salicylic acid(SA)is accumulated in the leaves of OE apple plants.Expression of chitinase,β-1,3-glucanase,and SA-related marker genes was induced more strongly by D.mali in OE lines.Transcript levels of other important MdATG genes were also drastically increased by D.mali in OE plants,which indicated increased autophagy activities.Taken together,these results demonstrate that OE of MdATG18a enhances resistance to infection by D.mali and plays positive roles in H2O2-scavenging and SA accumulations.Our findings provide important information for designing strategies which could induce autophagy to minimize the impact of this disease on apple production.Xun Sun Liuqing Huo Xin Jia Runmin Che Xiaoqing Gong Ping Wang Fengwang Ma 2018Horticulture Research2018,5,1:8
6Body mass index does not affect the survival of pancreatic cancer patients显示文摘AIM to evaluate the association of body mass index(b MI) with the overall survival of pancreatic ductal adenocarcinoma(PDAC) patients.METHODS A retrospective analysis of PDAC patients diagnosed in the National Cancer Center of China between January 1999 and December 2014 was performed. these patients were categorized into four b MI groups(< 18.5, 18.5-22.9, 23-27.4 and ≥ 27.5 kg/m2). χ2 tests for comparison of the proportions of categorical variables, and Student's t-test or Mann-Whitney test for continuous variables were employed. Survival analysis was performed with the Kaplan-Meyer method. their HRs of mortality and 95%CIs were estimated using the Cox proportional hazards model.RESULTS With a median age of 59.6 years(range: 22.5-84.6 years), in total 1783 PDAC patients were enrolled in this study. their mean usual b MI was 24.19 ± 3.53 for the whole cohort. More than half of the patients(59.3%) experienced weight loss during the disease onset and progression. Compared with healthy-weight individuals, newly diagnosed patients who were overweight or obese had more severe weight loss during their disease onset and progression(P < 0.001). Individuals who were overweight or obese were associated with positive smoking history(P < 0.001). A significant difference in comorbidity of diabetes(P = 0.044) and coronary artery disease(P < 0.001) was identified between high b MI and normal-weight patients. After a median follow-up of 8 mo, the survival analysis showed no association between b MI and the overall survival(P = 0.90, n = 1783). When we stratified the whole cohort by pancreatic cancer stage, no statistically significant association between b MI and overall survival was found for resectable(P = 0.99, n = 217), unresectable locally advanced(P = 0.90, n = 316) and metastatic patients(P = 0.88, n = 1250), respectively. the results did not change when we used the b MI at diagnosis.CONCLUSION Our results showed no significance of b MI for the overall survival of PDAC patients.Qing-long Jiang Cheng-feng Wang Yan-tao tian Huang Huang Shui-Sheng Zhang Dong-bing Zhao Jie Ma Wei Yuan Yue-Min Sun Xu Che Jian-Wei Zhang Yun-Mian Chu Ya-Wei Zhang Ying-tai Chen 2017World Journal of Gastroenterology2017,23,34:7
7Gasdermin E-derived caspase-3 inhibitors effectively protect mice from acute hepatic failure显示文摘Programmed cell death(PCD),including apoptosis,apoptotic necrosis,and pyroptosis,is involved in various organ dysfunction syndromes.Recent studies have revealed that a substrate of caspase-3,gasdermin E(GSDME),functions as an effector for pyroptosis;however,few inhibitors have been reported to prevent pyroptosis mediated by GSDME.Here,we developed a class of GSDME-derived inhibitors containing the core structure of DMPD or DMLD.Ac-DMPD-CMK and Ac-DMLD-CMK could directly bind to the catalytic domains of caspase-3 and specifically inhibit caspase-3 activity,exhibiting a lower IC50 than that of Z-DEVD-FMK.Functionally,Ac-DMPD/DMLD-CMK substantially inhibited both GSDME and PARP cleavage by caspase-3,preventing apoptotic and pyroptotic events in hepatocytes and macrophages.Furthermore,in a mouse model of bile duct ligation that mimics intrahepatic cholestasis-related acute hepatic failure,Ac-DMPD/DMLD-CMK significantly alleviated liver injury.Together,this study not only identified two specific inhibitors of caspase-3 for investigating PCD but also,more importantly,shed light on novel lead compounds for treating liver failure and organ dysfunctions caused by PCD.Wan-feng Xu Quan Zhang Chu-jie Ding Hui-yong Sun Yuan Che Hai Huang Yun Wang Jia-wei Wu Hai-ping Hao Li-juan Cao 2021Acta Pharmacologica Sinica2021,42,1:7
8An individualized immune signature of pretreatment biopsies predicts pathological complete response to neoadjuvant chemoradiotherapy and outcomes in patients with esophageal squamous cell carcinoma显示文摘No clinically available biomarkers can predict pathological complete response(pCR)for esophageal squamous cell carcinomas(ESCCs)with neoadjuvant chemoradiotherapy(nCRT).Considering that antitumor immunity status is an important determinant for nCRT,we performed an integrative analysis of immune-related gene profiles from pretreatment biopsies and constructed the first individualized immune signature for pCR and outcome prediction of ESCCs through a multicenter analysis.During the discovery phase,14 differentially expressed immune-related genes(DEIGs)with greater than a twofold change between pCRs and less than pCRs(Chaoqi Zhang Guochao Zhang Nan Sun Zhen Zhang Liyan Xue Zhihui Zhang Haijun Yang Yuejun Luo Xiaoli Zheng Yonglei Zhang Yufen Yuan Ruixue Lei Zhaoyang Yang Bo Zheng Le Wang Yun Che Feng Wang Sihui Wang Shugeng Gao Qi Xue Yi Zhang Jie He 2020Signal Transduction and Targeted Therapy2020,5,1:7
9Aerosol Hygroscopicity during the Haze Red-Alert Period in December 2016 at a Rural Site of the North China Plain显示文摘A humidification system was deployed to measure aerosol hygroscopicity at a rural site of the North China Plain during the haze red-alert period 17–22 December 2016. The aerosol scattering coefficients under dry [relative humidity(RH) < 30%] and wet(RH in the range of 40%–85%) conditions were simultaneously measured at wavelengths of450, 550, and 700 nm. It is found that the aerosol scattering coefficient and backscattering coefficient increased by only 29% and 10%, respectively when RH went up from 40% to 80%, while the hemispheric backscatter fraction went down by 14%, implying that the aerosol hygroscopicity represented by the aerosol scattering enhancement factor f(RH) is relatively low and RH exerted little effects on the aerosol light scattering in this case. The scattering enhancement factors do not show significant differences at the three wavelengths, only with an approximate 2% variation, suggesting that the aerosol hygroscopicity is independent of the wavelength. Aerosol hygroscopicity is highly dependent on the aerosol chemical composition. When there is a large mass fraction of inorganics and a small mass fraction of organic matter, f(RH) reaches a high value. The fraction of NO_3^- was strongly correlated with the aerosol scattering coefficient at RH = 80%, which suggests that NO_3^- played an important role in aerosol hygroscopic growth during the heavy pollution period.Xuefei QI Junying SUN Lu ZHANG Xiaojing SHEN Xiaoye ZHANG Yangmei ZHANG Yaqiang WANG Haochi CHE Zhouxiang ZHANG Junting ZHONG Kaiyan TAN Huarong ZHAO Sanxue REN 2018Journal of Meteorological Research2018,32,1:7
10Synergistic therapy of magnetism-responsive hydrogel for soft tissue injuries显示文摘Soft tissue injury is very common and associated with pain,tissue swelling and even malformation if not treated on time.Treating methods include cryotherapy,electrical therapy,ultrasound therapy and anti-inflammatory drug,but none of them is completely satisfying.In this work,for a better therapeutic effect,drug therapy and pulsed electromagnetic field(PEMF)therapy were combined.We constructed a drug delivery system using the tetra-PEG/agar hydrogel(PA).By incorporating Fe3O4 NPs into the hydrogel network,a magnetism-responsive property was achieved in the system.The cytotoxicity and in vivo study showed a good biocompatibility of the PA/Fe3O4 hydrogel.A magnetism-controlled release was attained by the incorporation of Fe3O4.Finally,in vivo study showed a better performance of the DS-loaded PA/Fe3O4 compared with the commercially available DS ointment regarding the recovery of the injured soft tissue.Therefore,this magnetism-responsive hydrogel may represent a promising alternative to treat soft tissue injury.Lining Zhang Xiuqin Zuo Shengjie Li Mi Sun Huimin Xie Kai Zhang Jikun Zhou Liyun Che Junxuan Ma Zishan Jia Fei Yang 2019Bioactive Materials2019,4,1:7
11A geostrophic empirical mode based on altimetric sea surface height显示文摘Recent discovery of low-dimensional coherent structure in oceanic currents along with a new merged altimeter product called Absolute Dynamic Topography (ADT) makes it possible to derive subsurface ocean information from satellite remote sensing data.An altimetric geostrophic empirical mode (η-GEM) is developed in this study by projecting hydrographic transects onto the ADT sea surface height coordinate,based on which the four-dimensional thermohaline and velocity structures of oceanic currents are reconstructed from satellite surface observations.In the WOCE/SR3 area,the η-GEM fields capture more than 95% of the total thermal variance.The GEM-derived flow has equivalent-barotropic structure and represents the velocity profile better than traditional dynamic modes.Comparison with mooring observations also demonstrates that the η-GEM provides good estimates of the deep thermohaline fields.ZHANG Lin SUN Che 2012Science China Earth Sciences2012,55,7:6
12Down-regulation of eIF5A-2 prevents epithelial-mesenchymal transition in non-small-cell lung cancer cells显示文摘Background:Epithelial-mesenchymal transition(EMT) is believed to be the critical process in malignant tumor invasion and metastases,and has a great influence on improving the survival rate in non-small-cell lung cancer(NSCLC) patients.Recent studies suggested that eukaryotic initiation factor 5A-2(eIF5A-2) might serve as an adverse prognostic marker of survival.We detected eIF5A-2 in NSCLC A549 cells,and found that the invasive capability correlates with the eIF5A-2 expression.Methods:Transforming growth factor(TGF)-β1 was used to induce EMT in A549 cells.Western blotting,immunofluorescence,wound healing assay,and transwell-matrigel invasion chambers were used to identify phenotype changes.Western blotting was also used to observe changes of the expression of eIF5A-2.We down-regulated the eIF5A-2 expression using an eIF5A-2 siRNA and identified the phenotype changes by western blotting and immunofluorescence.We tested the change of migration and invasion capabilities of A549 cells by the wound healing assay and transwell-matrigel invasion chambers.Results:After stimulating with TGF-β1,almost all A549 cells changed to the mesenchymal phenotype and acquired more migration and invasion capabilities.These cells also had higher eIF5A-2 protein expression.Down-regulation of eIF5A-2 expression with eIF5A-2 siRNA transfection could change the cells from mesenchymal to epithelial phenotype and decrease tumor cell migration and invasive capabilities significantly.Conclusions:The expression of eIF5A-2 was up-regulated following EMT phenotype changes in A549 cells,which correlated with enhanced tumor invasion and metastatic capabilities.Furthermore,in the A549 cell line,the process of EMT phenotype change could be reversed by eIF5A-2 siRNA,with a consequent weakening of both invasive and metastatic capabilities.Guo-dong XU Xin-bao SHI Le-bo SUN Qing-yun ZHOU Da-wei ZHENG Huo-shun SHI Yong-liang CHE Zi-shan WANG Guo-feng SHAO 2013Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2013,14,6:6
13Clinicopathological analysis of metaplastic meningioma: report of 15 cases in Huashan Hospital显示文摘Objective: Metaplastic meningioma is a rare subtype of benign meningiomas, classified as WHO grade I with well prognosis. Here we presented our experiences on 15 cases of metaplastic meningioma, to investigate the clinicopathological features, therapies and prognosis of these cases. Methods: 15 patients underwent surgical treatment for intracranial metaplastic meningioma between 2001 and 2010 at Neurosurgery Department of Huashan Hospital, Shanghai, China. The clinical data, radiological manifestation, treatment strategy, pathological findings and prognosis of all patients were analyzed retrospectively. Results: Among the 15 cases (10 males and 5 females), the age ranged from 22 to 74 years old (the mean age was 50.67-year old). The clinical manifestations include headache, dizziness, seizure attack, vision decrease, and weakness of bilateral lower limbs. All the patients received surgical treatment, combined with radiotherapy in some cases. In the follow-up period, recurrence occurred in 2 cases, of which 1 patient died of other system complications. Conclusions: Metaplastic meningiomas are characterized by focal or widespread mesenchymal differentiation with formation of bone, cartilage, fat, and xanthomatous tissue elements. Surgical removal is the optimal therapy, and the overall prognosis is well. But recurrence may occur in some cases, thus radiotherapy is necessary for such kind of patients.Hailiang Tang Huaping Sun Hong Chen Ye Gong Ying Mao Qing Xie Liqian Xie Mingzhe Zheng Daijun Wang Hongda Zhu Xiaoming Che Ping Zhong Kang Zheng Shiqi Li Weimin Bao Jianhong Zhu Xuanchun Wang Xiaoyuan Feng Xiancheng Chen Liangfu Zhou 2013Chinese Journal of Cancer Research2013,25,1:6
14Interannual variability of the Antarctic Circumpolar Current strength based on merged altimeter data显示文摘Interannual variability of the Antarctic Circumpolar Current (ACC) strength is studied in stream-coordinate with twenty-year Absolute Dynamic Topography data from satellite altimetry. The stream-coordinate projection method separates the ACC from adjacent subtropical and subpolar gyres, enabling consideration of the zonal asymmetry of the ACC rather than assuming that the ACC is a purely zonal flow. It is shown that the ACC strength has large interannual variations with two recent peaks around 2000 and 2009. The interannual variability appears mainly in the Indo-Pacific sector of the Southern Ocean and the strongest signal is located south of Australia. The intensification of the westerly wind in 1998 and 2008 appears to cause the strengthening of the ACC via baroclinic processes.ZHANG LinLin SUN Che HU DunXin 2012Chinese Science Bulletin2012,57,16:6
15Comparison of Two Air Pollution Episodes over Northeast China in Winter 2016/17 Using Ground-Based Lidar显示文摘This study analyzes and compares aerosol properties and meteorological conditions during two air pollution episodes in 19–22(E1) and 25–26(E2) December 2016 in Northeast China. The visibility, particulate matter(PM) mass concentration, and surface meteorological observations were examined, together with the planetary boundary layer(PBL) properties and vertical profiles of aerosol extinction coefficient and volume depolarization ratio that were measured by a ground-based lidar in Shenyang of Liaoning Province, China during December 2016–January 2017.Results suggest that the low PBL height led to poor pollution dilution in E1, while the high PBL accompanied by low visibility in E2 might have been due to cross-regional and vertical air transmission. The PM mass concentration decreased as the PBL height increased in E1 while these two variables were positively correlated in E2. The enhanced winds in E2 diffused the pollutants and contributed largely to the aerosol transport. Strong temperature inversion in E1 resulted in increased PM2.5 and PM10 concentrations, and the winds in E2 favoured the southwesterly transport of aerosols from the North China Plain into the region surrounding Shenyang. The large extinction coefficient was partially attributed to the local pollution under the low PBL with high ground-surface PM mass concentrations in E1,whereas the cross-regional transport of aerosols within a high PBL and the low PM mass concentration near the ground in E2 were associated with severe aerosol extinction at high altitudes. These results may facilitate better understanding of the vertical distribution of aerosol properties during winter pollution events in Northeast China.Yanjun MA Hujia ZHAO Yunsheng DONG Huizheng CHE Xiaoxiao LI Ye HONG Xiaolan LI Hongbin YANG Yuche LIU Yangfeng WANG Ningwei LIU Cuiyan SUN 2018Journal of Meteorological Research2018,32,2:5
16Analysis on Genetic Diversity and Genetic Basis of the Main Sesame Cultivars Released in China显示文摘SRAP (sequence-related amplified polymorphism) was used for the analysis of 67 sesame (Sesamum indicum L.) cultivars widely used in Chinese sesame major production areas from 1950 to 2007. A total of 561 bands were amplified using 21 SRAP random primer pairs, with 265 of them were polymorphic, resulting in a polymorphism ratio of 47.2%. The total bands and polymorphism amplified by each primer pair averaged 26.7 and 12.6, respectively. The average genetic similar coefficient and genetic distance of the 67 cultivars were 0.9104 and 0.0706, respectively, indicating limited genetic diversity and narrow genetic basis. Comparative analysis on genetic similarity and genetic distance of different classified cultivars showed that the difference of average genetic similarity coefficient and genetic distance between the landraces and cultivars bred through crosses reached significant levels (P=0.01), with the genetic basis of landraces wider than that bred cultivars. The genetic basis of cultivars used in 1990-2007 was more narrow than that of cultivars from 1950 to 1969 and from 1970 to 1989, with the differences of average genetic similarity coefficient and genetic distance reached 0.01 significant level. The genetic basis of Chinese sesame main cultivars is relatively narrow, and the genetic basis of cultivars developed through crosses in recent years is narrower than history cultivars.ZHANG Yan-xin SUN Jian ZHANG Xiu-rong WANG Lin-hai CHE Zhuo 2011Agricultural Sciences in China2011,10,4:5
17Chemical Components, Variation, and Source Identification of PM1 during the Heavy Air Pollution Episodes in Beijing in December 2016显示文摘Air pollution is a current global concern. The heavy air pollution episodes(HPEs) in Beijing in December 2016 severely influenced visibility and public health. This study aims to survey the chemical compositions, sources, and formation processes of the HPEs. An aerodyne quadruple aerosol mass spectrometer(Q-AMS) was utilized to measure the non-refractory PM1(NR-PM1) mass concentration and size distributions of the main chemical components including organics, sulfate, nitrate, ammonium, and chloride in situ during 15–23 December 2016. The NR-PM1 mass concentration was found to increase from 6 to 188 μg m–3 within 5 days. During the most serious polluted episode, the PM1 mass concentration was about 2.6 times that during the first pollution stage and even 40 times that of the clean days. The formation rates of PM2.5 in the five pollution stages were 26, 22, 22, 32, and 67 μg m^(–3) h–1, respectively. Organics and nitrate occupied the largest proportion in the polluted episodes, whereas organics and sulfate dominated the submicron aerosol during the clean days. The size distribution of organics is always broader than those of other species, especially in the clean episodes. The peak sizes of the interested species grew gradually during different HPEs. Aqueous reaction might be important in forming sulfate and chloride, and nitrate was formed via oxidization and condensation processes. PMF(positive matrix factorization) analysis on AMS mass spectra was employed to separate the organics into different subtypes. Two types of secondary organic aerosol with different degrees of oxidation consisted of 43% of total organics. By contrast, primary organics from cooking, coal combustion, and traffic emissions comprised 57% of the organic aerosols during the HPEs.Yangmei ZHANG Yaqiang WANG Xiaoye ZHANG Xiaojing SHEN Junying SUN Lingyan WU Zhouxiang ZHANG Haochi CHE 2018Journal of Meteorological Research2018,32,1:4
18Stand basal area modelling for Chinese fir plantations using an artificial neural network model显示文摘Artificial neural network models are a popular estimation tool for fitting nonlinear relationships because they require no assumptions about the form of the fitting function,non-Gaussian distributions,multicollinearity,outliers and noise in the data.The problems of backpropagation models using artificial neural networks include determination of the structure of the network and overlearning courses.According to data from 1981 to 2008 from 15 permanent sample plots on Dagangshan Mountain in Jiangxi Province,a back-propagation artificial neural network model(BPANN)and a support vector machine model(SVM)for basal area of Chinese fir(Cunninghamia lanceolata)plantations were constructed using four kinds of prediction factors,including stand age,site index,surviving stem numbers and quadratic mean diameters.Artificial intelligence methods,especially SVM,could be effective in describing stand basal area growth of Chinese fir under different growth conditions with higher simulation precision than traditional regression models.SVM and the Chapman–Richards nonlinear mixed-effects model had less systematic bias than the BPANN.Shaohui Che Xiaohong Tan Congwei Xiang Jianjun Sun Xiaoyan Hu Xiongqing Zhang Aiguo Duan Jianguo Zhang 2019Journal of Forestry Research2019,30,5:4
19An altimetric transport index for Kuroshio inflow northeast of Taiwan Island显示文摘The Kuroshio inflow northeast of Taiwan Island plays an important role in the heat and nutrient balances over the East China Sea(ECS). Based on merged satellite altimeter data and the PCM-1 mooring observation at the East Taiwan Channel(ETC), the study employs a correlation iteration scheme to find the optimal transport index for the Kuroshio inflow. The sea level difference with the highest correlation to the ETC transport is across the ECS shelf break rather than along the PCM-1 line. The counter-intuitive result is caused by large signal noise and poor track coverage of altimeters near the Taiwan coast. The optimal altimetric index is highly correlated with the two-year in-situ measurements as well as the ten-year output of the global assimilation model. It serves as a better estimator of Kuroshio inflow than those using tidal gauge data, and helps pinpoint a 5 cm mismatch of mean sea level in the Keelung tidal record. The mean transport of Kuroshio inflow based on the twenty-year altimetric index is 20.55 Sv with a standard deviation of 3.05 Sv. Wavelet spectrum of the index reveals that semi-annual period dominates the Kuroshio variation northeast of Taiwan Island.YAN XiaoMei SUN Che 2015Science China Earth Sciences2015,58,5:4
20Design of near-α Ti alloys via a cluster formula approach and their high-temperature oxidation resistance显示文摘The multi-component composition characteristics of high-temperature near-α Ti alloys were investigated in the present work by means of a cluster formula approach. The uniform cluster formula [CN12 cluster](glue atom)3 for the hexagonal close-packed α solid solution was first obtained based on the Friedel oscillation theory, with a total atom number in the formula of Z = 16. Then it was analyzed that the Z values in the cluster composition formulas of typical near-α Ti alloys are within the range of Z = 16.0016.30, being perfectly consistent with the ideal Z = 16. Based on it, a series of new alloys with Z = 16 and with Nb/Ta substitution for Mo in Ti1100 alloy were designed, suction-cast into φ 6 mm rods, and then heat-treated with solid solution and aging. It was found that the alloy with co-addition of Mo, Ta and Nb has a high strength and good ductility at both room and high temperatures. More importantly, the additions of Nb and Ta can contribute to the formation of continuous and compact Al2O3 scales, resulting in an obvious improvement of oxidation resistances at both 923 K and 1073 K. The effects of Mo, Ta and Nb on the oxidation behaviors of the designed alloys at 1073 K were further discussed.Beibei Jiang Donghui Wen Qing Wang Jinda Che Chuang Dong Peter K. Liaw Fen Xu Lixian Sun 2019Journal of Materials Science & Technology2019,35,6:4
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