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| 1 | A practical guide to amplicon and metagenomic analysis of microbiome data显示文摘Advances in high-throughput sequencing(HTS)have fostered rapid developments in the field of microbiome research,and massive microbiome datasets are now being generated.However,the diversity of software tools and the complexity of analysis pipelines make it difficult to access this field.Here,we systematically summarize the advantages and limitations of microbiome methods.Then,we recommend specific pipelines for amplicon and metagenomic analyses,and describe commonly-used software and databases,to help researchers select the appropriate tools.Furthermore,we introduce statistical and visualization methods suitable for microbiome analysis,including alpha-and betadiversity,taxonomic composition,difference comparisons,correlation,networks,machine learning,evolution,source tracing,and common visualization styles to help researchers make informed choices.Finally,a stepby-step reproducible analysis guide is introduced.We hope this review will allow researchers to carry out data analysis more effectively and to quickly select the appropriate tools in order to efficiently mine the biological significance behind the data. | Yong-Xin Liu Yuan Qin Tong Chen Meiping Lu Xubo Qian Xiaoxuan Guo Yang Bai | 2021 | Protein & Cell2021，12，5： | 20 |
| 2 | Changes in temperature extremes in the Yangtze River Basin, 1962-2011显示文摘Based on daily maximum and minimum temperature observed by the China Meteorological Administration at 115 meteorological stations in the Yangtze River Basin from 1962 to 2011,the methods of linear regression,principal component analysis and correlation analysis are employed to investigate the temporal variability and spatial distribution of temperature extremes.Sixteen indices of extreme temperature are selected.The results are as follows:(1) The occurrence of cold days,cold nights,ice days,frost days and cold spell duration indicator has significantly decreased by –0.84,–2.78,–0.48,–3.29 and –0.67 days per decade,respectively.While the occurrence of warm days,warm nights,summer days,tropical nights,warm spell duration indicator and growing season length shows statistically significant increasing trends at rates of 2.24,2.86,2.93,1.80,0.83 and 2.30 days per decade,respectively.The tendency rate of the coldest day,coldest night,warmest day,warmest night and diurnal temperature range is 0.33,0.47,0.16,0.19 and –0.07℃ per decade,respectively.(2) The magnitudes of changes in cold indices(cold nights,coldest day and coldest night) are obviously greater than those of warm indices(warm nights,warmest day and warmest night).The change ranges of night indices(warm nights and cold nights) are larger than those of day indices(warm days and cold days),which indicates that the change of day and night temperature is asymmetrical.(3) Spatially,the regionally averaged values of cold indices in the upper reaches of the Yangtze River Basin are larger than those in the middle and lower reaches.However,the regionally averaged values of most warm indices(except warm spell duration indicator) and growing season length in the middle and lower reaches are larger than those in the upper reaches.(4) The extreme temperature indices are well correlated with each other except diurnal temperature range. | WANG Qiong ZHANG Mingjun WANG Shengjie MA Qian SUN Meiping | 2014 | Journal of Geographical Sciences2014，24，1： | 14 |
| 3 | Spatial-temporal characteristics of lake area variations in Hoh Xil region from 1970 to 2011显示文摘As one of the areas with numerous lakes on the Tibetan Plateau, the Hoh Xil region plays an extremely important role in the fragile plateau eco-environment. Based on topographic maps in the 1970 s and Landsat TM/ETM+ remote sensing images in the 1990 s and the period from 2000 to 2011, the data of 83 lakes with an area above 10 km2 each were obtained by digitization method and artificial visual interpretation technology, and the causes for lake variations were also analyzed. Some conclusions can be drawn as follows.(1) From the 1970 s to 2011, the lakes in the Hoh Xil region firstly shrank and then expanded. In particular, the area of lakes generally decreased during the 1970s–1990s. Then the lakes expanded from the 1990 s to 2000 and the area was slightly higher than that in the 1970 s. The area of lakes dramatically increased after 2000.(2) From 2000 to 2011, the lakes with different area ranks in the Hoh Xil region showed an overall expansion trend. Meanwhile, some regional differences were also discovered. Most of the lakes expanded and were widely distributed in the northern, central and western parts of the region. Some lakes were merged together or overflowed due to their rapid expansion. A small number of lakes with the trend of area decrease or strong fluctuation were scattered in the central and southern parts of the study area. And their variations were related to their own supply conditions or hydraulic connection with the downstream lakes or rivers.(3) The increase in precipitation was the dominant factor resulting in the expansion of lakes in the Hoh Xil region. The secondary factor was the increase in meltwater from glaciers and frozen soil due to climate warming. | YAO Xiaojun LIU Shiyin LI Long SUN Meiping LUO Jing | 2014 | Journal of Geographical Sciences2014，24，4： | 14 |
| 4 | γ-secretase inhibitor DAPT prevents neuronal death and memory impairment in sepsis associated encephalopathy in septic rats显示文摘 | Huang Man Liu chunhui Hu Yueyu Wang Pengfei Ding Meiping | 2014 | Chinese Medical Journal2014，，5： | 12 |
| 5 | The first airborne scalar gravimetry system based on SINS/DGPS in China显示文摘China has developed an airborne gravimetry system based on SINS/DGPS named SGA-WZ,the first system in which a strapdown inertial navigation system(SINS)has been used for airborne gravimetry in China.This gravity measurement system consists of a strap-down inertial navigation system and a differential global positioning system(DGPS).In April 2010,a flight test was carried out in Shandong Province of China to test the accuracy of this system.The test was designed to assess the repeatability and accuracy of the system.Two repeated flights and six grid flights were made.The flying altitude was about 400 m.The average flying speed was about 60 m/s,which corresponds to a spatial resolution of 4.8 km when using 160-s cutoff low-pass filter.This paper describes the data processing of the system.The evaluation of the internal precision is based on repeated flights and differences in crossover points.Gravity results in this test from the repeated flight lines show that the repeatability of the repeat lines is 1.6 mGal with a spatial resolution of 4.8 km,and the internal precision of grid flight data is3.2 mGal with a spatial resolution of 4.8 km.There are some systematic errors in the gravity results,which can be modeled using trigonometric function.After the systematic errors are compensated,the precision of grid flight data can be better than1 mGal. | CAI ShaoKun WU MeiPing ZHANG KaiDong CAO JuLiang | 2013 | Science China Earth Sciences2013，56，12： | 12 |
| 6 | Effects of lysedEnterococcus faecalis FK-23 on experimental allergic rhinitis in a murine model显示文摘In the current study,we sought to investigate whether lysed Enterococcus faecalis FK-23(LFK),a heat-killed probiotic preparation,attenuated eosinophil influx into the upper airway and had immunomodulatory activity in a murine allergic rhinitis model.Eighteen BALB/c mice were divided into three groups;the ovalbumin(OVA)-sensitized/challenged group,which received saline orally for 6 weeks(OVA group),the OVA-sensitized/challenged group,which received LFK orally for 6 weeks(LFK-fed group),and the non-sensitized group,which received saline for 6 weeks(saline control group).Nasal rubbing and sneezing were monitored during the study.After the final challenge,interleukin(IL)-4,interferon(IFN)-γ,and OVA-specific IgE levels in the sera and splenocyte culture supernatants were determined,eosinophilic infiltrate into the upper airway was quantified,and splenic CD4+CD25+ regulatory T cells(Tregs) were examined by flow cytometry.We found that nasal rubbing was significantly reduced in LFK-fed mice compared to the OVA group on d 27 and 35,and sneezing was significantly inhibited by LFK administration for 35 d.LFK-fed mice had significantly less eosinophil influx into the nasal mucosa than the OVA group.There were no significant differences between the LFK-fed group and OVA group in the serum and splenocyte culture supernatant levels of IL-4,IFN-γ,and OVA-specific IgE.Interestingly,the LFK-fed mice had a significantly greater percentage of splenic CD4+CD25+ Tregs than OVA group.Our results indicate that oral administration of LFK may alleviate nasal symptoms,reduce nasal eosinophilia,and increase the percentage of CD4+CD25+ Tregs in experimental allergic rhinitis. | Luping Zhu Takashi Shimada Ruoxi Chen Meiping Lu Qingzhao Zhang Wenmin Lu Min Yin Tadao Enomoto Lei Cheng | 2012 | The Journal of Biomedical Research2012，26，3： | 11 |
| 7 | BRAF^(V600E) vs. TIRADS in predicting papillary thyroid cancers in Bethesda system Ⅰ, Ⅲ, and Ⅴ nodules显示文摘Objective: Bethesda System for Reporting Thyroid Cytopathology(BSRTC) categories Ⅰ, Ⅲ, and Ⅴaccount for a significant proportion of fine needle aspiration cytology(FNAC) diagnoses. This study aimed to compare the diagnostic efficacy of BRAF^(V600E) mutation and the Thyroid Imaging Reporting and Data System(TIRADS) classification in differentiating papillary thyroid cancers(PTCs) from benign lesions among BSRTC I, III, and V nodules.Methods: A total of 472 patients with 479 nodules were enrolled in this prospective study. Ultrasound, BRAF^(V600E) mutation testing, and FNAC were performed in each nodule, followed by surgery or regular ultrasound examination.Results: In the BSRTC I category, BRAF^(V600E) showed similar sensitivity, higher specificity, and lower accuracy when compared with TIRADS. In the BSRTC III/V category, the sensitivity, specificity, and accuracy of BRAF^(V600E) were similar to those of TIRADS. In comparison to BRAF^(V600E) alone, the combination of the two methods significantly improved sensitivity(BSRTC Ⅰ:93.6% vs. 67.7%, P < 0.01; BSRTC Ⅲ: 93.8% vs. 75.0%, P < 0.01; BSRTC V: 96.0% vs. 85.3%, P < 0.001). When compared with TIRADS alone, the combination improved sensitivity in BSRTC Ⅰ nodules(93.6% vs. 74.2%, P < 0.05), increased sensitivity and decreased accuracy in BSRTC III nodules(93.8% vs. 75.0%, P < 0.01, 91.0% vs. 93.6%, P < 0.01), and improved both sensitivity and accuracy in BSRTC V nodules(96.0% vs. 82.0%, P < 0.001; 94.2% vs. 81.3%, P < 0.001).Conclusions: BRAF^(V600E) exhibited higher specificity and lower accuracy compared with TIRADS in BSRTC Ⅰ nodules, while the two methods showed similar diagnostic value in BSRTC Ⅲ/Ⅴ nodules. The combination of the two methods distinctly improved sensitivity in the diagnosis of PTCs in BSRTC Ⅰ, Ⅲ, and Ⅴ nodules. | Ya Wu Ting Xu Xingyue Cao Xin Zhao Hongyan Deng Jianxiang Wang Xiao Li Qing Yao Xinhua Ye Meiping Shen Xiaohong Wu | 2019 | Cancer Biology & Medicine2019，16，1： | 9 |
| 8 | RS analysis of glaciers change in the Heihe River Basin, Northwest China, during the recent decades显示文摘Heihe 河盆是在西北中国的第二最大的内陆河盆,它也是在干旱水文学,水资源和在冷区域的研究的另外的方面的一个热点。另外, Heihe 河盆有完全的风景,中等分水岭尺寸,和典型社会生态的环境问题。到目前为止,没有对整个河盆的冰河变化信息的详细评价。地志的地图数据, Landsat TM/ETM+ 遥感图象和数字举起建模的 1:50,000 数据在这研究被使用。通过综合计算机自动解释和视觉解释方法,面向对象的图象特征抽取方法被使用提取冰河轮廓信息。冰河变化数据从分析被导出,并且到气候的冰河变化和它的反应在时期 1956/19632007/2011 变化也被分析。结果显示出那:(1 ) 在时期 1956/19632007/2011, Heihe 河盆冰河有一个明显的撤退趋势,冰河的全部的区域从 361.69 km 减少了 < 啜 class= “ a-plus-plus ” > 2 到 231.17 km < 啜 class= “ a-plus-plus ” > 2 ;以 36.08% 的率缩小,与平均单个冰河区域减少 0.14 km < 啜 class= “ a-plus-plus ” > 2 ;冰河的全部的数字从 967 ~ 800 减少了。(2 ) 在这盆的冰河主要在 43004400 m, 44004500 m 和 45004600 m 的举起被散布;并且在冰河分发和冰河变化有重要地区性的差别。(3 ) 与另外的西方的山冰河相比,在 Heihe 河盆的冰河撤退有更高的率。(4 ) 六个气象学的车站的分析从 1960 ~ 2010 的年度平均温度和降水数据建议吝啬的年度温度显著地增加了,年度降水也显示出一个增加的趋势。冰河收缩是密切相关的,而且,温度升起,这被结束冰河融化由增加的降水由比冰河团供应大的升起的温度引起了到某程度。 | HUAI Baojuan LI Zhongqin WANG Shengjie SUN Meiping ZHOU Ping XlAO Yan | 2014 | Journal of Geographical Sciences2014，24，6： | 9 |
| 9 | Application of a novel backwashing process in upflow biological aerated filter显示文摘To improve the efficiency of backwashing in upflow biological aerated filter (BAF), a novel backwashing process named air-water siphon backwashing (AWSB) was proposed and applied on laboratory scale. The effects of backwashing on turbidity and suspended solid (SS) in backwashing efluent using this new backwashing process were compared with those of traditional backwashing process, namely air-water backwashing (AWB). In AWB, the turbidity of backwashing efluent maintained 100 NUT when consumed 60 min and 10.5 L water. However, in AWSB, it declined to 44 NUT, consumed 40 min, and 7 L water. The COD removal of BAF after backwashing was also analyzed. The average removal rate of COD in the reactor backwashed by AWB and AWSB was 89.34% and 90.91%, respectively. Compared with AWB, the backwashing interval had been prolonged 35%. The volume of backwashing water in that AWSB was only 66.7% of that in AWB. The results demonstrated that AWSB required less water and took shorter backwashing time relative to AWB to achieve the same turbidity of backwashing efluent, and AWSB was more effective in removing fouling than that of AWB. More significant advantage of AWSB was that the backwashing interval was effectively prolonged. | Jinshui Yang Weijie Liu Baozhen Li Hongli Yuana Meiping Tong Jinsong Gao | 2010 | Journal of Environmental Sciences2010，22，3： | 7 |
| 10 | Three-dimensional holographic vector of atomic interaction field for quantitative structure-retention relationship of purine bases显示文摘A newly developed descriptor, three- dimensional holographic vector of atomic interaction field (3D-HoVAIF), was used to describe the chemical structures of purine bases. After variable screening by stepwise multiple regression (SMR) technique, a partial least square (PLS) regression model was built with 3D-HoVAIF. The model was satisfactory com- paring to reference since correlation coefficients of molecular modeling ( Rc 2um), cross- validation ( Qc 2um) and standard deviation of estimation (SD) were 0.966, 0.860 and 0.112, respectively, showing that the model had favorable estimation and prediction capa- bilities. It was illustrated that information related to retention data of purine bases could preferably be expressed by 3D-HoVAIF with definite physico- chemical meanings and easy structural interpretation for purine bases. It was illustrated that 3D-HoVAIF was to preferably express retention data of purine bases and had definite physicochemical significance. So 3D-HoVAIF was a useful structural expression technique for quantitative structure activity (or prop- erty or retention) relationships (QSAR/QSPR/QSRR) study, such as structural characterization and chro- matographic retention prediction. | TONG Jianbo ZHOU Peng ZHANG Shengwan ZHOU Yuan MEI Hu ZENG Hui LI Meiping LI Zhiliang | 2006 | Chinese Science Bulletin2006，51，13： | 7 |
| 11 | Prediction of median survival time in sepsis patients by the SOFA score combined with different predictors显示文摘Background:Sepsis is the leading cause of intensive care unit(ICU)admission.The purpose of this study was to explore the prognostic value of the Sequential Organ Failure Assessment(SOFA)score,the Acute Physiological and Chronic Health Evaluation Ⅱ(APACHE Ⅱ)score,and procalcitonin(PCT),albumin(ALB),and lactate(LAC)levels in patients with sepsis.Methods:Consecutive adult patients with suspected or documented sepsis at ICU admission were recruited.Their basic vital signs and related auxiliary examinations to determine their PCT and ALB levels and APACHE Ⅱ score were recorded at ICU admission,and their LAC levels and SOFA scores were recorded for one week after admission.The influence of these variables on hospital mortality was evaluated.Logistic regression was used to derive the Sepsis Hospital Mortality Score(SHMS),a prediction equation describing the relationship between predictors and hospital mortality.The median survival time was calculated by the Kaplan–Meier method.In the validation group,the kappa value was calculated to evaluate the stability of the derived formula.Results:This study included 894 sepsis patients admitted to 18 ICUs in 16 tertiary hospitals.Patients were randomly assigned to an experimental group(626 cases)and validation group(258 cases).In addition,a nonsurvival group(248 patients)of the experimental group was established according to the outcome at the time of discharge.The hospital mortality rate in the experimental group was 39.6%(248/626).Univariate and multivariate regression analyses revealed that the APACHE Ⅱ score(odds ratio[OR]=1.178),△SOFA(OR=1.186),△LAC(OR=1.157),and SOFA mean score(OR=1.086)were independently associated with hospital mortality.The SHMS was calculated as logit(p)=4.715–(0.164×APACHE Ⅱ)–(0.171×△SOFA)–(0.145×△LAC)–(0.082×SOFA mean).A receiver operating characteristic curve was constructed to further investigate the accuracy of the SHMS,with an area under the curve of 0.851(95%confidence interval[CI]0.821–0.882;p<0.001)for hospital mortality.In the low-risk group and high-risk groups,the corresponding median survival times were 15 days and 11 days,respectively.Conclusion:The APACHE Ⅱ score,△SOFA,△LAC and SOFA mean score were independently associated with hospital mortality in sepsis patients and accurately predicted the hospital mortality rate and median survival time.Data on the median survival time in sepsis patients could be provided to clinicians to assist in the rational use of limited medical resources by facilitating prudent resource allocation.Trial registration:ChiCTR-ECH-13003934,retrospectively registered on August 03,2013. | Wen Li Meiping Wang Bo Zhu Yibing Zhu Xiuming Xi | 2020 | Burns & Trauma2020，8，1： | 7 |
| 12 | Hydrological processes of glacier and snow melting and runoff in the Urumqi River source region, eastern Tianshan Mountains, China显示文摘水文学过程被比较,有或没有分泌物上的降水的影响,到在 Urumqi 河来源区域识别 glacierized 和 non-glacierized 集水之间的差别在东方 Tianshan 山的北斜坡上,在在 2011 的融化的季节(MaySeptember ) 期间。学习基于在 10-min 间隔,在 15-min 间隔观察的气象学的数据,并且冰河从空冰斗, Zongkong,和计量车站的 Urumqi 冰河 No.1 融化和雪观察观察的水文学数据。结果显示分泌物在三之中显著地不同计量车站。每日的分泌物多于在计量车站的冰河 No.1 的夜里的分泌物,它形成对照,模式在计量车站的 Zongkong 和空冰斗观察了。在在三个计量车站的分泌物有一个清楚的每日的变化,与在山峰分泌物的大小和持续时间的差别。当降水没被考虑时,在最大的分泌物和最高的温度之间的时间落后是在分别地计量车站的冰河 No.1,空冰斗,和 Zongkong 的 13 h, 1016 h,和 511 h。当降水被考虑时,相应时间落后分别地是 01 h, 13 h,和 67 h。因此,从到融合的分泌物的产生的持续时间在 glacierized 集水是最短的并且在被雪主要盖住的集水最长。降水什么时候被考虑,也被显示出从到融合的分泌物的产生的水文学过程弄短。在三之中在分泌物影响变化计量车站的因素是不同的。为冰河 No.1 车站,分泌物被热条件主要在 glacierized 区域控制,并且当温度超过了 5 时,分泌物显示了加速的生长 ? 楷桴 ? 朿丠佩愠摮 ???? 噐? 攠畱癩污湥 ? 潴 ?? ┿瑷倠 ?? 湩眠楥桧 ? 祳瑮敨楳? 愠 ?? 整灭牥瑡牵 ? | SUN Meiping YAO Xiaojun LI Zhongqin ZHANG Mingjun | 2015 | Journal of Geographical Sciences2015，25，2： | 6 |
| 13 | A method of correlation analysis for space-based GEO object surveillance显示文摘A method of correlation analysis to determine the correlation between two too-short arcs is presented to monitor geosynchronous earth orbit objects on a space-based surveillance system.The necessary condition for a geosynchronous earth orbit object to be observed by a space-based visible sensor in two successive orbital periods is derived,and the principle for the selection of search fence parameters is proposed.The processing procedure of the correlation analysis for the two too-short arcs as well as two correlation judgment methods is given and the selection of the threshold value for the judgment is analyzed.Finally,a simulation is performed to demonstrate the applicability of the presented methods.Simulation results indicate that a surveillance system can acquire two observation arcs in two successive orbital periods by selecting the suitable search fence parameters,and that the two correlation judgment methods and the selected threshold are valid.The initial orbit of the uncorrelated objects can be determined by two observation arcs,and the accuracy of the initial orbit meets the requirements of re-acquiring the object. | TANG Yi WU MeiPing FU XiaoFeng | 2012 | Science China(Technological Sciences)2012，55，6： | 5 |
| 14 | The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation显示文摘Hepatocellular carcinoma(HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor suppressors.Transforming growth factor beta(TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple mechanisms.Furthermore, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process. | Kegui Zhang Meiping Zhang Zhijun Luo Zhili Wen Xiaohua Yan | 2020 | Journal of Genetics and Genomics2020，47，9： | 5 |
| 15 | Cotransport of graphene oxides/reduced graphene oxides with BPA in both bare and iron oxides coated quartz sand显示文摘This study investigated the cotransport behaviors of graphene oxides(GO) and reduced graphene oxides(RGO) with bisphenol A(BPA) in porous media in both NaCl(1 and 10 mmol/L) and CaCl2 solutions(0.5 and 1.5 mmol/L) at pH 6.5. Both bare and iron oxides-coated quartz sand were employed as porous media in present study. We found that under all examined solution conditions, the presence of BPA(100 μg/L) did not have obvious influence on the transport of both GO and RGO(8 mg/L as TOC) in both bare and iron oxides-coated quartz sand. Although the dissolved BPAwas the major form dominating the transport behaviors of total BPA in the presence of GO/RGO, yet the GO/RGO-associated BPA(due to the adsorption of BPA onto GO/RGO surfaces) also had some contribution to the transport of total BPA in the presence of GO/RGO in two types of porous media.Overall, due to the different transport behaviors of GO and RGO under different solution conditions, we found that the presence of GO/RGO decreased the transport of total BPA under all examined solution conditions in two types of porous media with the smallest decrease in 1 mmol/L NaCl solutions and the largest in 1.5 mmol/L CaCl2 solutions. The results of this study clearly indicated that when BPA was co-present with GO/RGO, the transport behaviors of GO/RGO in porous media would have great influences on the fate and transport of BPA in natural environments due to their adsorption onto GO/RGO. | LIU Xian Wei LI Meng LIU FuYang HE Lei TONG MeiPing | 2019 | Science China(Technological Sciences)2019，62，11： | 4 |
| 16 | Power flows of three non-conservatively series-coupled oscillators, Part Ⅱ: Numerical analysis显示文摘The direct and indirect power flows among three non-conservatively series-coupled oscillators subjected to random forces have been investigated by the numerical method. The relationship between the power flows and the parameters of the oscillators and couplings have been studied. It is shown that the indirect power flow is caused by the resonant transmission between the indirectly coupled oscillators. Once the parameters of the oscillator elements have been settled, the indirect power flow is mainly determined by the coupling stiffness k3 and k4, and is less infiuenced by coupling dampings c3 and c4. The indirect power flow cannot be ignored in strong coupling conditions. Because of the resonant transmission between the indirectly coupled oscillators, the indirect power flow still cannot be neglected even if the coupling stiffness is relatively small and the coupling damping is relatively | WANG Minqing(Xi’an Jiaotong University Xi’an 710049)SHENG Meiping Ren Keming SUN Jincai(Institute of Acoustics Engineering, Northwestern Polgtechnical University Xi’an 710072) | 1998 | Chinese Journal of Acoustics1998，17，3： | 4 |
| 17 | Analysis of the causes of formation of negative loss factors显示文摘Based on classical energy balance equations for two coupled systems in Statistical Energy Analyis (SEA), the possibility of causing negative loss factors in measuring SEA parameters by using the equations is analyzed. The physical causes of formation of negative loss factors are theoretically invstigated by vibration analysis of the two non-conservatively coupled oscillator sets. Mom the analytical results, it is shown that the necessary condition of foedng negatbo loss factors is that the coupling of the coupled systems is non-conservative and strong and the suffiient condition is that the excitation frequency of the external force is not equal to the natural frequencies of the two oscillators at the sam tAne or the parameters of the two oscillators are much different. The absolute values of the negative loss factors increase with the increase of the coupling pararneters. | SUN Zhaohui SUN Jincai WANG Chong and SHENG Meiping(Institute of Acoustic Engineering, Northwestern Polytechnical University Xi’an, 710072) | 1996 | Chinese Journal of Acoustics1996，15，3： | 4 |
| 18 | Physico-chemical characterization and source tracking of black carbon at a suburban site in Beijing显示文摘Particles from ambient air and combustion sources including vehicle emission, coal combustion and biomass burning were collected and chemically pretreated with the purpose of obtaining isolated BC(black carbon) samples. TEM(transmission electron microscopy)results indicate that BC from combustion sources shows various patterns, and airborne BC appears spherical and about 50 nm in diameter with a homogeneous surface and turbostratic structure. The BET(Barrett–Emmett–Teller) results suggest that the surface areas of these BC particles fall in the range of 3–23 m2/g, with a total pore volume of 0.03–0.05 cm3/g and a mean pore diameter of 7–53 nm. The nitrogen adsorption–desorption isotherms are indicative of the accumulation mode and uniform pore size. O2-TPO(temperature programmed oxidation)profiles suggest that the airborne BC oxidation could be classified as the oxidation of amorphous carbon, which falls in the range of 406–490°C with peaks at 418, 423 and 475°C,respectively. Generally, the BC characteristics and source analysis suggest that airborne BC most likely comes from diesel vehicle emission at this site. | Hailin Wang Lei Nie Dan Liu Meiping Gao Minyan Wang Zhengping Hao | 2015 | Journal of Environmental Sciences2015，27，7： | 4 |
| 19 | Vibration power flow in infinite stiffened-plate with force excitation applied on plate显示文摘The formula of the vibration response and power flow in beam-stiffened plate with force excitation applied on.the plate, have been obtained by using the Steepest Descent Integral method. The characteristics of the power flow have been studied through computer simulation.It is shown that the stiffener acts as an extra lineal excitation applied on the plate and changes the characteristics of the power flow of the infinite plate greatly The greater the stiffness and the smaller the distance between the exciting point and the stiffener is, the greater the induence is. Lastly, experiments have been carried out by using the dualaccelerometer measurement technique that based on cross spectrum, and the test data agree well with the theoretical | WANG Minqing (Xi’an Jiaotong University Xi’an 710049) SHENG Meiping SUN Jincai SUN Zhaohui (Institute of Acoustical Engineering, Northwestern Polytechnical University Xi’an 710072) HUANG Xieqing (Xi,an Jiaotong University Xi’an 710049) | 1998 | Chinese Journal of Acoustics1998，17，2： | 3 |
| 20 | The coupling loss factors for non-conservatively coupled structures显示文摘The method to calculate the coupling loss factors for non-conservatively coupled structures by using the mobilities of substructures is studied. By using the form of the energy balance equations of conservatively coupled systems, the relationship between the coupling loss factors and the energy ratios in non-conservatively coupled systems is derived. The method to calculate the energy ratios by using the mobilities of substructures is introduced, and experiment verification is carried out. The test data agree well with the predicted results. | SHENG Meiping(Institute of Acoustic Enmneering, Northwestern Polytechnzcal Uniuersity Xi’an 710072)Wang Minqing(Institute of Vibration and Noise Control, Xi ’an Jiaotong University Xi’an’ 710049)SUN Jincai(Institute of Aconstic Engineering, Northwestern P | 1998 | Chinese Journal of Acoustics1998，17，4： | 3 |
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