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| 1 | Improvement of wheat drought and salt tolerance by expression of a stress- inducible transcription factorGmDREB of soybean (Glycinemax)显示文摘Under stress conditions such as droughthigh-salinity and low-temperature, the transcription factorof DREB (dehydration responsive element binding proteins)improved efficiently stress resistance by regulating the ex-pression of its downstream genes with various environmentastress resistance in plants. GmDREB gene (GenBank Acces-sion No. AF514908) encoding a stress-inducible transcriptionfactor was cloned by screening a cDNA library of Glycinemax cv. Jinong 27 with yeast one-hybrid method. GmDREBgene was 910 bp in length and encoded 174 amino acids con-taining a conserved AP2/EREBP DNA-binding domain of 58amino acids. Two conserved functional amino acids, valineand glutamic acid, were located on the 14th and the 19thamino acid residues in the conserved structural domain. Analkaline amino acid region (KKR) related to a nuclear local-ization signal was at the N-terminal, while an acidic aminoacid region (DDD) related to trans-activation was at theC-terminal. Plant expression vectors were constructed andtransformed into wheat by bombardment. In total, 13 trans-genic plants with Ubi::GmDREB and 11 transgenic plantswith rd29A::GmDREB were identified from 103 regenerationplants by molecular analysis. The drought and salt tolerancesof T1 transgenic lines with Ubi::GmDREB orrd29A::GmDREB were demonstrated to be improved ascompared to wild type. The result also suggested that bothUbiquitin and rd29A promoters could effectively drive theexpression of the GmDREB gene and enhance drought andsalt tolerance of T1 plants. | GAO Shiqing XU Huijun CHENG Xianguo CHEN Ming XU Zhaoshi LI Liancheng YE Xingguo DU Lipu HAO Xiaoyan MA Youzhi | 2005 | Chinese Science Bulletin2005,50,23: | 30 |
| 2 | The determination of 52 elements in marine geological samples by an inductively coupled plasma optical emission spectrometry and an inductively coupled plasma mass spectrometry with a high-pressure closed digestion method显示文摘An improved analytical method to determine the content of 52 major, minor and trace elements in marine geological samples, using a HF-HCl-HNO_3 acid system with a high-pressure closed digestion method(HPCD), is studied by an inductively coupled plasma optical emission spectrometry(ICP-OES) and an inductively coupled plasma mass spectrometry(ICP-MS). The operating parameters of the instruments are optimized, and the optimal analytical parameters are determined. The influences of optical spectrum and mass spectrum interferences, digestion methods and acid systems on the analytical results are investigated. The optimal spectral lines and isotopes are chosen, and internal standard element of rhodium is selected to compensate for matrix effects and analytical signals drifting. Compared with the methods of an electric heating plate digestion and a microwave digestion, a high-pressure closed digestion method is optimized with less acid, complete digestion,less damage for digestion process. The marine geological samples are dissolved completely by a HF-HCl-HNO_3 system, the relative error(RE) for the analytical results are all less than 6.0%. The method detection limits are 2–40μg/g by the ICP-OES, and 6–80 ng/g by ICP-MS. The methods are used to determine the marine sediment reference materials(GBW07309, GBW07311, GBW07313), rock reference materials(GBW07103, GBW07104,GBW07105), and cobalt-rich crust reference materials(GBW07337, GBW07338, GBW07339), the obtained analytical results are in agreement with the certified values, and both of the relative standard deviation(RSD) and the relative error(RE) are less than 6.0%. The analytical method meets the requirements for determining 52 elements contents of bulk marine geological samples. | GAO Jingjing LIU Jihua LI Xianguo YAN Quanshu WANG Xiaojing WANG Hongmin | 2017 | Acta Oceanologica Sinica2017,36,1: | 13 |
| 3 | Determination of Lignin in Marine Sediment Using Alkaline Cupric Oxide Oxidation-Solid Phase Extraction-on-Column Derivatization-Gas Chromatography显示文摘Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide (CuO) oxidation method, the modification consisting in a solid phase extraction (SPE) and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations (RSDs) ranging from 0.57% to 8.04% (n=3), while those with traditional liquid-liquid extraction (LLE) are from 44.52% to 86.16% with RSDs being from 0.53% to 13.14% (n=3). Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8% ± 0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents. Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxyben-zaldehyde. The lignin content Σ8 (produced from 10 g dry sediment) in the research area is between 0.231 and 0.587 mg. S/V and C/V ratios (1.028 ± 0.433 and 0.192 ± 0.066, respectively) indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values of (Ad/Al) v suggest that the TOMs has been highly degraded. | ZHANG Ting LI Xianguo SUN Shuwen LAN Haiqing DU Peirui WANG Min | 2013 | Journal of Ocean University of China2013,12,1: | 10 |
| 4 | New radiocarbon and archaeobotanical evidence reveal the timing and route of southward dispersal of rice farming in south China显示文摘The origins and spreads of rice agriculture have been enduring topics, yet the timing and southward dispersal from the Yangtze River Basin have been difficult to trace, due to the scarcity of archaeobotanical data, especially systematic macro-plant remains examination, combined with the poor preservation in the humid climate and acidic soils of China's southern provinces.Here, we report new radiocarbon dating and preserved rice phytolith evidence, derived from three Late Neolithic archaeological sites in south China, dated about 5,000–4,100 cal a BP.Our results demonstrate that rice farming had spread southward through the mountainous regions of Wuyi and Nanling, then entered the areas of Western Fujian and North Guangdong by 5,000 cal a BP, followed by continued expansion into coastal areas of East China Sea and South China Sea, also crossing the Taiwan Strait, around 4,500–4,000 cal a BP.The North River,East River, Min River, and possibly other river systems likely were influential as pathways or conduits. | Xiaoyan Yang Qiuhe Chen Yongchao Ma Zhao Li Hsiao-chun Hung Qianglu Zhang Zhiwei Jin Suoqiang Liu Zhenyu Zhou Xianguo Fu | 2018 | Science Bulletin2018,63,22: | 9 |
| 5 | Spatial Variation of Dissolved Organic Carbon in Soils of Riparian Wetlands and Responses to Hydro-geomorphologic Changes in Sanjiang Plain, China显示文摘Spatial variation of dissolved organic carbon(DOC) in soils of riparian wetlands and responses to hydro-geomorphologic changes in the Sanjiang Plain were analyzed through in situ collecting soil samples in the Naoli River and the Bielahong River. The results showed that the average contents of DOC for soil layer of 0–100 cm were 730.6 mg/kg, 250.9 mg/kg, 423.0 mg/kg and 333.1 mg/kg respectively from riverbed to river terrace along the transverse directions of the Naoli watershed. The content of the soil DOC was the highest in the riverbed, lower in the high floodplain and much lower in the river terrace, and it was the lowest in the low floodplain. The difference in the content and vertical distribution of DOC between the riverbed and the three riparian wetlands was significant, while it was not significant among the low floodplain, the high floodplain and the river terrace. The variability of soil DOC was related to the hydrological connectivity between different landscape position of the riparian wetlands and the adjacent stream. Extremely significant correlations were observed between DOC and total organic carbon(TOC), total iron(TFe), ferrous iron(Fe(II)) whose correlation coefficients were 0.819, –0.544 and –0.709 in riparian wetlands of the Naoli River. With the increase of wetland destruction, soil p H increased and soil DOC content changed. The correlation coefficients between soil DOC and TOC, TFe, Fe(II) also changed into 0.759, –0.686 and –0.575 respectively in the Bielahong River. Under the impact of drainage ditches, the correlations between soil DOC and TFe, Fe(II) were not obvious, while the soil p H was weakly alkaline and was negatively correlated with soil DOC in the previous high floodplain. It indicates that riparian hydro-geomorphology is the main factor that could well explain this spatial variability of soil DOC, and the agricultural environmental hydraulic works like ditching also must be considered. | XI Min KONG Fanlong LYU Xianguo JIANG Ming LI Yue | 2015 | Chinese Geographical Science2015,25,2: | 7 |
| 6 | The geometric factor of high energy protons detector on FY-3 satellite显示文摘Geometric factor is the key parameter for inversion of particle spectrum in space particle detection. Traditional geometric factor is obtained through the method of numerical calculation with the actual structure of the detector as the input condition. The degree of accuracy for data inversion is reduced since traditional geometric factor fails to take into account the physical process of interaction between the particle and substance as well as the influence of factors such as the particle interference between different energy channels on the measurement result. Here we propose an improved geometrical factor calculation method, the concept of which is to conduct actual structural modelling of the detector in the GEANT4 program, consider the process of interaction between the particle and substance, obtain the response function of the detector to particles of different energy channels through the method of Monte Carlo simulation, calculate the influence of contaminated particle on the geometrical factor, and finally get the geometrical factors for different energy channels of the detector. The imrpoved geometrical factor obtained through the method has carried out inversion for the data of high energy protons detector on China's FY-3 satellite, the energy spectrum after which is more in line with the power law distribution recognized by space physics. The comparison with the measured result of POES satellite indicates that the FY-3 satellite data are in good accordance with the satellite data, which shows the method may effectively improve the quality of data inversion. | ZHANG ShenYi ZHANG XianGuo WANG ChuiQin SHEN GuoHong JIN Tao ZHANG BinQuan SUN YueQiang ZHU GuangWu LIANG JinBao ZHANG XiaoXin LI JiaWei HUANG Cong HAN Ying | 2014 | Science China Earth Sciences2014,57,10: | 6 |
| 7 | Ultralow frequency wave characteristics extracted from particle data:Application of IGSO observations显示文摘3 Summary and discussion In the generalized drift resonance theory[17],a characteristic signature of the ULF wave-particle interactions is the increasingly-tilted stripes in the particle energy spectrum.The phase difference across different energy channels is relatively | LI Li ZHOU XuZhi ZONG QiuGang CHEN XingRan ZOU Hong REN Jie HAO YiXin ZHANG XianGuo | 2017 | Science China(Technological Sciences)2017,60,3: | 6 |
| 8 | Marine Carbon-Sulfur Biogeochemical Cycles during the Steptoean Positive Carbon Isotope Excursion(SPICE) in the Jiangnan Basin, South China显示文摘Global occurrences of Steptoean Positive Carbon Isotope Excursion(SPICE) during Late Cambrian recorded a significant perturbation in marine carbon cycle, and might have had profound impacts on the biological evolution. In previous studies, SPICE has been reported from the Jiangnan slope belt in South China. To evaluate the bathymetric extent of SPICE, we investigate the limestone samples from the upper Qingxi Formation in the Shaijiang Section in the Jiangnan Basin. Our results show the positive excursions for both carbonate carbon(δ^(13)C) and organic carbon(δ^(13)C_(org)) isotopes, as well as the concurrent positive shifts in sulfur isotopes of carbonate associated sulfate(CAS, δ^(34)S_(CAS)) and pyrite(δ^(34)S_(pyrite)), unequivocally indicating the presence of SPICE in the Jiangnan Basin. A 4‰ increase in δ^(13)C_(carb) of the Qingxi limestone implies the increase of the relative flux of organic carbon burial by a factor of two. Concurrent positive excursions in δ^(34)S_(CAS) and δ^(34)S_(pyrite) have been attributed to the enhanced pyrite burial in oceans with extremely low concentration and spatially heterogeneous isotopic composition of seawater sulfate. Here, we propose that the seawater sulfur isotopic heterogeneity can be generated by volatile organic sulfur compound(VOSC, such as methanethiol and dimethyl sulfide) formation in sulfidic continental margins that were widespread during SPICE. Emission of 32S-enriched VOSC in atmosphere, followed by lateral transportation and aerobic oxidation in atmosphere, and precipitation in open oceans result in a net flux of ^(32)S from continental margins to open oceans, elevating δ^(34)S of seawater sulfate in continental margins. A simple box model indicates that about 35% to 75% of seawater sulfate in continental margins needs to be transported to open oceans via VOSC formation. | Yang Peng Yongbo Peng Xianguo Lang Haoran Ma Kangjun Huang Fangbing Li Bing Shen | 2016 | Journal of Earth Science2016,27,2: | 5 |
| 9 | Plant Diversity Performance After Natural Restoration in Reclaimed Deyeuxia angustifolia Wetland显示文摘Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional ecological security greatly. Since the 21 th century, returning farmlands to wetlands was widely adopted for natural restoration in the Sangjiang Plain. As the first reflection of wetland restoration, vegetation succession of restored D. angustifolia wetlands should be fully assessed. In this study, vegetation investigation was carried out in three restored D. angustifolia wetlands with 5, 8 and 12 yr restoration, respectively. Meanwhile, a natural D. angustifolia wetland was selected as reference wetland. Results showed that community composition changed greatly and there was visible community succession. Community dominant species changed from composite to gramineae as restoration time increasing.At first, weeds community appeared in the restored wetlands, especially the xerophytes developed to the pioneer species rapidly. And then, mesophytes and wetland species became the dominant species in the restored wetlands. Finally, wetland species, especially D. angustifolia, occupied the dominant position of restored community. Shannon-wiener index(H) and Simpson index(D) both decreased to close to natural D. angustifolia wetlands. Compared with natural D. angustifolia wetland, species composition and diversity in restored wetlands were more complex and higher. As restoration time increasing, there were not significant differences between community characteristics of restored wetlands and natural wetland. All these suggested that vegetation in reclaimed D. angustifolia wetland could be restored naturally, but its restored period is 10 yr at least. From another angle, it is important to protect current natural wetlands. | WANG Xuehong TONG Shouzheng LI Yunzhao Qi Qing ZHANG Dongjie LYU Xianguo GUO Yue LIU Yan | 2019 | Chinese Geographical Science2019,29,3: | 5 |
| 10 | Molecular Fingerprints of Soil Organic Matter in a Typical Freshwater Wetland in Northeast China显示文摘Natural wetlands are known to store huge amounts of organic carbon in their soils. Despite the importance of this storage,uncertainties remain about the molecular characteristics of soil organic matter(SOM), a key factor governing the stability of soil organic carbon(SOC). In this study, the molecular fingerprints of SOM in a typical freshwater wetland in Northeast China were investigated using pyrolysis gas-chromatography/mass-spectrometry technology(Py-GC/MS). Results indicated that the SOC, total nitrogen(TN),and total sulfur contents of the cores varied between 16.88% and 45.83%, 0.93% and 2.82%, and 1.09% and 3.79%, respectively. The bulk δ^13C and δ^15N varied over a range of 9.85‰, between –26.85‰ and –17.00‰, and between –0.126‰ and 1.002‰, respectively. A total of 134 different pyrolytic products were identified, and they were grouped into alkyl(including n-alkanes(C:0) and n-alkenes(C:1),aliphatics(Al), aromatics(Ar), lignin(Lg), nitrogen-containing compounds(Nc), polycyclic aromatic hydrocarbons(PAHs), phenols(Phs), polysaccharides(Ps), and sulfur-containing compounds(Sc). On average, Phs moieties accounted for roughly 24.11% peak areas of the total pyrolysis products, followed by Lg(19.27%), alkyl(18.96%), other aliphatics(12.39%), Nc compounds(8.08%), Ps(6.49%), aromatics(6.32%), Sc(3.26%), and PAHs(1.12%). Soil organic matter from wetlands had more Phs and Lg and less Nc moieties in pyrolytic products than soil organic matters from forests, lake sediments, pastures, and farmland.δ^13 C distribution patterns implied more C3 plant-derived soil organic matter, but the vegetation was in succession to C4 plant from C3 plant. Significant negative correlations between Lg or Ps proportions and C3 plant proportions were observed. Multiple linear analyses implied that the Ar and Al components had negative effects on SOC. Alkyl and Ar could facilitate ratios between SOC and total nitrogen(C/N), while Al plays the opposite role. Al was positively related to the ratio of dissolved organic carbon(DOC) to SOC. In summary, SOM of wetlands might characterize by more Phs and lignin and less Nc moieties in pyrolytic products. The use of Pyrolysis gas-chromatography/mass-spectrometry(Py-GC/MS) technology provided detailed information on the molecular characteristics of SOM from a typical freshwater wetland. | LI Zhe ZHANG Zhongsheng XUE Zhenshan SONG Xiaolin ZHANG Hongri WU Haitao JIANG Ming LYU Xianguo | 2019 | Chinese Geographical Science2019,29,4: | 4 |
| 11 | Application of Principal Component Analysis(PCA)to the Evaluation and Screening of Multiactivity Fungi显示文摘Continued innovation in screening methodologies remains important for the discovery of high-quality multiactive fungi,which have been of great significance to the development of new drugs.Mangrove-derived fungi,which are well recognized as prolific sources of natural products,are worth sustained attention and further study.In this study,118 fungi,which mainly included Aspergillus spp.(34.62%)and Penicillium spp.(15.38%),were isolated from the mangrove ecosystem of the Maowei Sea,and 83.1%of the cultured fungi showed at least one bioactivity in four antibacterial and three antioxidant assays.To accurately evaluate the fungal bioactivities,the fungi with multiple bioactivities were successfully evaluated and screened by principal component analysis(PCA),and this analysis provided a dataset for comparing and selecting multibioactive fungi.Among the 118 mangrove-derived fungi tested in this study,Aspergillus spp.showed the best comprehensive activity.Fungi such as A.clavatonanicus,A.flavipes and A.citrinoterreus,which exhibited high comprehensive bioactivity as determined by the PCA,have great potential in the exploitation of natural products and the development of new drugs.This study demonstrated the first use of PCA as a time-saving,scientific method with a strong ability to evaluate and screen multiactive fungi,which indicated that this method can affect the discovery and development of new drugs. | YANG Zonglin SHI Yaqi LI Pinglin PAN Kanghong LI Guoqiang LI Xianguo YAO Shuo ZHANG Dahai | 2022 | Journal of Ocean University of China2022,21,3: | 4 |
| 12 | Migration of Some Elements and Radionuclides across aGranite-Granite Contact Zone: A Natural Analoguefor Safe Disposal of High-Level Radwastes显示文摘Elements and natural radionuclides in the contact zone of two granites with different ages would migrate from one to the other because of the difference in their chemical contents and later water-rock interactions. This migration could serve as an analogue for the near-field process of radwastes in a high-level radwaste deep geological disposal repository.In the contact between the Indosinian granite (whole-rock Rb-Sr isochron age at 214@3 Ma) and Hercynian granite (zircon U-Pb isochron age at 296@31 Ma) located in Ziyuan County, Guangxi, the O and Pb isotope characteristics and the activity ratios of 234U/238U, 230Th/238U, 230Th/234U and 226Ra/230Th show that, based on the whole-rock chemical contents, both of the two granites have maintained a relatively open chemical system in their evolution processes. However, as there is no obvious open fault, the migration of major elements, trace elements and natural U-series nu-clides takes place within only 1-2 m in the contact zone, and water-rock | LUO Xingzhang MIN Maozhong ZHANG Guanghui LI Xianguo YANG Zhe ZHAI Liying Zhu Deling | 1999 | Acta Geologica Sinica(English Edition)1999,73,4: | 4 |
| 13 | Cross-calibration of high energetic particles data——A case study between FY-3B and NOAA-17显示文摘Cross-calibration of high energetic particle data is a primary requirement for the availability of multi-instrument,multi-spacecraft data.It also can provide a method to verify relative reliability of data from single satellite measurement.This paper presents a case study of energetic particles data cross-calibration between FY-3B and NOAA-17.A generally good agreement is acquired in the flux values and distribution trend of 2.5–6.9 MeV protons and 0.3–1.1 MeV electrons between FY-3B and NOAA-17 satellites.It suggests that the data observed by FY-3B is properly cross-calibrated.We can also confirm that energetic particles data observed by FY-3B satellite is available. | WANG ChunQin ZHANG XianGuo LI JiaWei HUANG Cong ZHANG XiaoXin JING Tao SHEN GuoHong ZHANG ShenYi CAO GuangWei SUN YueQiang LIANG JinBao ZHU GuangWu HAN Ying | 2013 | Science China(Technological Sciences)2013,56,11: | 4 |
| 14 | Neural network-based matrix effect correction in EDXRF analysis显示文摘In this paper we discuss neural network-based matrix effect correction in energy dispersive X-ray fluorescence (EDXRF) analysis,with detailed algorithm to classify the samples.The method can correct the matrix effect effectively through classifying the samples automatically,and influence of X-ray absorption and enhancement by major elements of the samples is reduced.Experiments for the complex matrix effect correction in EDXRF analysis of samples in Pangang showed improved accuracy of the elemental analysis result. | TUO Xianguo CHENG Bo MU Keliang LI Zhe | 2008 | Nuclear Science and Techniques2008,19,5: | 4 |
| 15 | MC simulation of a PGNAA system for on-line cement analysis显示文摘A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm thickness,a polyethylene moderator of 50-mm thickness,a source-to-sample distance of 70 mm,and cement samples of 1200 mm×600 mm×170 mm.To absorb thermal neutrons and suppress low-energy γ-rays,the optimum-sized sheets are 150 mm×7 mm Cd,and 150 mm×15 mm Pb. | YANG Jianbo TUO Xianguo LI Zhe MU Keliang CHENG Yi MOU Yunfeng | 2010 | Nuclear Science and Techniques2010,21,4: | 4 |
| 16 | A statistical approach to fit Gaussian part of full-energy peaks from Si(PIN) and SDD X-ray spectrometers显示文摘A new statistical fitting approach,named Statistical Distribution-Based Analytic(SDA)method,is proposed to fit single Gaussian-shaped Kαand KβX-ray peaks recorded by Si(PIN)and silicon drift detector(SDD).In this method,we use the discrete distribution theory to calculate standard deviation of energy resolutionσ.The calibration ofσand energy(E)for two detectors between the energy ranges of 4.5–26 keV are also completed by measuring characteristic X-ray spectra of nineteen types of pure elements.With the spectrum fraction(SF)parameter proposed in this paper,the SDA method can be used to resolve overlapping peaks.In measured spectra,the Gaussian part of X-ray peaks can be fitted by a Gaussian function with two parameters,σand SF.This new fitting approach is simpler than traditional methods and it achieves relatively good results when fitting the complex X-ray spectra of national standard alloy samples detected by Si(PIN)and SDD detectors.The2r values are obtained for each spectrum to assess fitting results,and the SDA fitting method gives a preferable fit for the SDD detector. | LI Zhe TUO XianGuo SHI Rui YANG JianBo | 2014 | Science China(Technological Sciences)2014,57,1: | 4 |
| 17 | Novel Approach for Improved Tribological Behavior of Biodiesel Soot in Liquid Paraffin显示文摘To improve the tribological behavior of biodiesel soot(BDS) in liquid paraffin(LP), the order of biodiesel soot was increased through thermally oxidized treatment at 500 ℃, and the oil solubility was then improved through a modification using oleylamine(OLA). The BDS and thermally oxidized oleylamine-modified BDS(T-BDS-OLA)were characterized through various methods including the use of TG, FETEM, Raman spectroscopy, FTIR, and a zeta potentiometer. The tribological properties and mechanisms of the BDS before and after the thermally oxidized treatment modification were investigated using a ball-on-disc reciprocating tribometer, FESEM, 3 D laser-scanning microscopy, and Raman spectroscopy. The results showed that T-BDS-OLA has a higher degree of order than the BDS, with an onion-like microstructure. BDS and T-BDS-OLA can both improve the antifriction and antiwear properties of LP at a soot content of 0.1%-0.4%, while T-BDS-OLA in LP shows better antifriction and antiwear properties than BDS. The tribological mechanisms can be attributed to both types of soot acting as spacing and roll bearing between the friction surfaces. In addition, the exfoliated graphitic sheets from T-BDS-OLA can form a carbon lubrication layer providing easy sliding. | Li Chuan Song Hui Zhang Jun Wu Bo Zhang Qiangqiang Zhuang Yuan Hu Xianguo | 2019 | China Petroleum Processing & Petrochemical Technology2019,21,1: | 3 |
| 18 | Monte-Carlo simulation of cement neutron field distribution characteristics in PGNAA显示文摘The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed that the neutron relative flux proportion reduced with increasing cement thickness.When the cement thickness remains unchanged,the reduced proportion of thermal neutrons increases to a small extent,but the epithermal, intermediate,and fast neutrons will decrease according to the geometric progression.H element in the cement mainly affects the reduction of fast neutrons and other single-substance elements,e.g.,O,Ca,56Fe,Si,and Al.It also slows down the reduction of the fast neutrons via inelastic scattering.O contributes more than other elements in the reduction of fast neutrons.Changing the H content affects the thermal,epithermal,intermediate,and fast neutrons, while changing the Ca,Fe,and Si contents only influences the thermal,epithermal,and intermediate neutrons;hence, there is little effect on the reduction of fast neutrons. | YANG Jianbo YANG Yigang LI Yuanjing TUO Xianguo LI Zhe LIU Mingzhe CHENG Yi MU Keliang WANG Lei | 2012 | Nuclear Science and Techniques2012,23,6: | 3 |
| 19 | Effect of Biodiesel Soot on Tribological Behavior of Liquid Paraffin显示文摘Biodiesel soot(BDS) was collected from the combustion of biodiesel using a self-made soot trap. The effect of BDS on the tribological behavior of liquid paraffin(LP) was investigated using a four-ball tribometer. A rotating viscometer was used to investigate the effect of BDS on the viscosity of LP. The morphology, composition, and tribological mechanism of BDS were studied by means of FETEM, XRD, XPS, SEM/EDS, and the 3D laser scanning microscopy. Test results showed that the BDS aggregates were chain-like, and the average diameter of BDS was 35 nm. The BDS existed in the form of graphitic layers and amorphous carbon. The oxygen-containing functional groups in BDS consisted of the(C-O-C) and(C-O-H). With an increasing BDS content, the dynamic viscosity of LP increased and the maximum non-seizure load increased initially and became stable later. In addition, the average wear scar diameter(AWSD) of LP increased and the average friction coefficient of LP decreased at first and then increased later. The tribological mechanisms could be ascribed to the variation in content of BDS: BDS could act as a friction modifier for a lower friction coefficient in case of low BDS content. However, the BDS aggregates could lead to increase of abrasive wear to influence the lubricating oil film at higher content of BDS, which would reduce the friction reduction ability and wear resistance of LP. | Li Chuan Wei Daozhu Zhuang Yuan Song Ruhong Hu Xianguo | 2018 | China Petroleum Processing & Petrochemical Technology2018,20,3: | 3 |
| 20 | A Genetic-Algorithm-based Neural Network Approach for Radioactive Activity Prediction显示文摘In this paper,a genetic-algorithm-based artificial neural network(GAANN)model radioactivity prediction is proposed,which is verified by measuring results from Long Range Alpha Detector(LRAD).GAANN can integrate capabilities of approximation of Artificial Neural Networks(ANN)and of global optimization of Genetic Algorithms(GA)so that the hybrid model can enhance capability of generalization and prediction accuracy,theoretically.With this model,both the number of hidden nodes and connection weights matrix in ANN are optimized using genetic operation.The real data sets are applied to the introduced method and the results are discussed and compared with the traditional Back Propagation(BP)neural network,showing the feasibility and validity of the proposed approach. | WANG Lei TUO Xianguo YAN Yucheng LIU Mingzhe CHENG Yi LI Pingchuan | 2013 | Nuclear Science and Techniques2013,24,6: | 2 |