191 results on '"Chen, Peng-fei"'
Search Results
152. An Improved Query Technique for Embedded Database Based on S-B Tree
- Author
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Huang, Kai-yin, primary, He, Yan-shan, additional, Chen, Peng-fei, additional, Chen, Xiao-yun, additional, and Li, Long-jie, additional
- Published
- 2009
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153. A novel chaotic system with one source and two saddle-foci in Hopfield neural networks
- Author
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Chen Peng-fei, Wu Wen-Juan, and Chen Zengqiang
- Subjects
Mathematics::Dynamical Systems ,Phase portrait ,Artificial neural network ,Dynamical systems theory ,Computer science ,Chaotic ,General Physics and Astronomy ,Lyapunov exponent ,Topology ,Nonlinear Sciences::Chaotic Dynamics ,Hopfield network ,symbols.namesake ,Attractor ,symbols ,Saddle - Abstract
This paper presents the finding of a novel chaotic system with one source and two saddle-foci in a simple three-dimensional (3D) autonomous continuous time Hopfield neural network. In particular, the system with one source and two saddle-foci has a chaotic attractor and a periodic attractor with different initial points, which has rarely been reported in 3D autonomous systems. The complex dynamical behaviours of the system are further investigated by means of a Lyapunov exponent spectrum, phase portraits and bifurcation analysis. By virtue of a result of horseshoe theory in dynamical systems, this paper presents rigorous computer-assisted verifications for the existence of a horseshoe in the system for a certain parameter.
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- 2010
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154. Building an Online Game-Based Learning System for Elementary School
- Author
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Cheng, Yuh-Ming, primary and Chen, Peng-Fei, additional
- Published
- 2008
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155. A Statistical Study on the Filament Eruption Caused by New Emerging Flux
- Author
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Xu, Xiao-yan, primary, Fang, Cheng, additional, and Chen, Peng-fei, additional
- Published
- 2008
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156. Applied Software Agents mechanism to Mathematics Learning in Elementary School
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Cheng, Yuh-Ming, primary and Chen, Peng-Fei, additional
- Published
- 2007
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157. A Parametric Survey of the CME Triggering Process by Numerical Simulations
- Author
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Xu, Xiao-Yan, primary, Chen, Peng-Fei, additional, and Fang, Cheng, additional
- Published
- 2005
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158. Two Sympathetic Homologous CMEs on 2002 May 22
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Cheng, Jian-Xia, primary, Fang, Cheng, additional, Chen, Peng-Fei, additional, and Ding, Ming-De, additional
- Published
- 2005
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159. Waiting Time Distribution of Coronal Mass Ejections
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Yeh, Chin-Teh, primary, Ding, Ming-De, additional, and Chen, Peng-Fei, additional
- Published
- 2005
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160. Slow and Fast MHD Shocks Associated with a Giant Cusp-Shaped Arcade on 1992 January 24
- Author
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Shiota, Daikou, primary, Yamamoto, Tetsuya T., additional, Sakajiri, Takuma, additional, Isobe, Hiroaki, additional, Chen, Peng-Fei, additional, and Shibata, Kazunari, additional
- Published
- 2003
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161. Ellerman Bombs, Type II White-light Flares and Magnetic Reconnection in the Solar Lower Atmosphere
- Author
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Chen, Peng-Fei, primary, Fang, Cheng, additional, and Ding, Ming-De, additional
- Published
- 2001
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162. Double‐Neutral Genes, Sa‐n and Sb‐n, for Pollen Fertility in Rice to Overcome Indica × Japonica Hybrid Sterility.
- Author
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Shahid, Muhammad Qasim, Chen, Feng‐Yi, Li, Hong‐Yan, Wang, Si‐Zhe, Chen, Peng‐Fei, Lin, Shun‐Quan, Liu, Xiang‐Dong, and Lu, Yong‐Gen
- Abstract
A major obstacle in the development of superior intersubspecific hybrids between subspecies (indica and japonica) of Asian cultivated rice (Oryza sativa L.) is partial sterility of the F1 generation. Neutral genes, Sa‐n, Sb‐n, and Sc‐n, for pollen fertility have the potential to overcome F1 pollen sterility. The present study was planned to find double‐neutral genes for pollen fertility and to evaluate their effect on pollen fertility of intersubspecific hybrids. Five genotypes were crossed with eight isogenic lines to mine neutral genes for pollen fertility. Pollen fertility of hybrids was observed in F1 and F2, and segregation ratios were recorded in F2 to confirm the neutral genes. The results showed that DN18 and DN75 had double‐neutral genes (Sa‐n and Sb‐n) whereas DN22 had three neutral genes Sa‐n, Sb‐n, and Sc‐n at Sa, Sb, and Sc pollen sterility loci, respectively. Furthermore, we found a single neutral gene (Sc‐n) for pollen fertility at the Sc locus and neutral gene for embryo sac fertility at the S5 locus in DN13. DN18 and DN75 were crossed with numerous typical japonica and indica cultivars. Results showed that double‐neutral genes could overcome most of the intersubspecific hybrid pollen sterility. These lines could be used for the development of high yielding indica × japonica hybrids and neutral genes could be introgressed into elite cultivars of Asian cultivated rice for fertility restoration. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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163. Energy-saving analysis of equivalent index method for fresh air-cooling in communication room of China.
- Author
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ZHANG Ji-li, LU Zhen, and CHEN Peng-fei
- Subjects
ENERGY conservation ,AIR-cooled engines ,BUSINESS communication ,INVESTMENTS - Abstract
The issues of fresh air-cooling resources use for communication room which has cooling load through all year in China were analyzed. The system and operation sequence were given. The equivalent index method was applied to dividing China into 7 zones. The equivalent hours of fresh air-cooling was calculated in every zone. The energy-saving and investment cost were given for communication rooms of 20 main cities in China. The distribution of fresh air-cooling resources was analyzed. The results show that the equivalent hours are 5 425 h in Harbin and 248 235 kWh/a is saved, electricity saving rate is 24. 8%. The equivalent index method can evaluate the quality of fresh air-cooling resources and help to make a retrofit plan using fresh air-cooling. When communication room was retrofitted by fresh air-cooling, energy-saving rates of 2 cities are <20% and those of 4 cities are >40%, and those of most parts are between 20%-40% and energy-saving is considerable. [ABSTRACT FROM AUTHOR]
- Published
- 2011
164. Immobilization of BiFeO3 on Silica Fiber and its Photocatalytic Application
- Author
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Wu, Qiang, Han, Ruo Bing, and Chen, Peng Fei
- Abstract
Uniform immobilization of BiFeO
3 on silica fiber was successfully obtained by a combined impregnation method with carbon nanofibers (CNFs) template route. The physicochemical properties of the obtained material were characterized by means of X-ray diffraction, field emission scanning electron microscopy, and ultraviolet-visible diffuse reflectance spectroscopy. It turned out that BiFeO3 immobilized on silica fiber can exhibit visible light photocatalytic degradation of rhodamine B (RhB) to some extents. It is expected that such kind of material would possess many potential applications in photocatalysis.- Published
- 2014
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165. Double‐Neutral Genes, Sa‐nand Sb‐n, for Pollen Fertility in Rice to Overcome Indica× JaponicaHybrid Sterility
- Author
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Shahid, Muhammad Qasim, Chen, Feng‐Yi, Li, Hong‐Yan, Wang, Si‐Zhe, Chen, Peng‐Fei, Lin, Shun‐Quan, Liu, Xiang‐Dong, and Lu, Yong‐Gen
- Abstract
A major obstacle in the development of superior intersubspecific hybrids between subspecies (indicaand japonica) of Asian cultivated rice (Oryza sativaL.) is partial sterility of the F1generation. Neutral genes, Sa‐n, Sb‐n, and Sc‐n, for pollen fertility have the potential to overcome F1pollen sterility. The present study was planned to find double‐neutral genes for pollen fertility and to evaluate their effect on pollen fertility of intersubspecific hybrids. Five genotypes were crossed with eight isogenic lines to mine neutral genes for pollen fertility. Pollen fertility of hybrids was observed in F1and F2, and segregation ratios were recorded in F2to confirm the neutral genes. The results showed that DN18 and DN75 had double‐neutral genes (Sa‐nand Sb‐n) whereas DN22 had three neutral genes Sa‐n, Sb‐n, and Sc‐nat Sa, Sb, and Scpollen sterility loci, respectively. Furthermore, we found a single neutral gene (Sc‐n) for pollen fertility at the Sclocus and neutral gene for embryo sac fertility at the S5locus in DN13. DN18 and DN75 were crossed with numerous typical japonicaand indicacultivars. Results showed that double‐neutral genes could overcome most of the intersubspecific hybrid pollen sterility. These lines could be used for the development of high yielding indica× japonicahybrids and neutral genes could be introgressed into elite cultivars of Asian cultivated rice for fertility restoration.
- Published
- 2013
- Full Text
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166. High Consumption of Sweetened Beverages Might Increase the Risk of Inflammatory Bowel Diseases.
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Chen, Peng-Fei, He, Jian-Hua, and Yang, Xue-Ying
- Published
- 2019
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167. Real-time analysis of soil N and P with near infrared diffuse reflectance spectroscopy
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Chen, Peng-Fei, liuliangyun, Wang, Ji-Hua, Shen, Tao, Lu, An-Xiang, and Zhao, Chun-Jiang
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Diffusion ,Soil ,Spectroscopy, Near-Infrared ,Time Factors ,Nitrogen ,Calibration ,Phosphorus - Abstract
Improving the efficiency of fertilization is an effective method of enhancing income for farmers, but it depends on measuring the soil nutrients accurately and rapidly. Near infrared reflectance spectroscopy (NIRS) is a fast method to detect the soil nutrients. In order to evaluate the feasibility of using NIRS to determine the soil N and P contents, the soil samples were collected from different LULC (land use and land cover) types in Daxing district, Beijing, and their biochemical parameters were determined by traditional chemical method. Then, the near infrared reflectance spectra of the samples were acquired, and NIRS models were built using partial least square regression (PLS) and Fourier transform technology for the total N and total P. The determination coefficients of cross validation for the total N and total P were 0.862 6 and 0.668 5 respectively. Ten samples were used to test the performance of the models. The coefficients of correlation between the chemically determined value and the NIRS predicted one were 0.969 8(N) and 0.830 7(P) respectively. The root mean standard error of prediction for N and P were 0.009 5(%) and 0.008 6(%), respectively. The ratios of RMSEP to SD(RPD) were 3.78(N) and 1.69(P). The results showed that the NIRS could be used to evaluate the soil N accurately and the soil P roughly.
168. Substitution disorder and photoluminescent property of a new rare-earth borate: K3TbB6O12.
- Author
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Zhao, Dan, Ma, Fa-Xue, Zhang, Rui-Juan, Huang, Min, Chen, Peng-Fei, Zhang, Rong-Hua, and Wei, Wei
- Subjects
- *
BORATE crystals , *PHOTOLUMINESCENT polymers , *OPTICAL materials , *PHOTOLUMINESCENCE , *RARE earth metals - Abstract
A new rare-earth borate K3TbB6O12 has been prepared using the high temperature molten salt method and was structurally determined by single crystal X-ray diffraction analyses. The structure features a three-dimensional (3D) framework which is composed of isolated B5O10, KO6, KO8 and TbO6 groups. An atom site in the 32 screw axis is shared by K and Tb atoms with the molar ratio of 1:1. The self-activated photoluminescence (PL) property of K3TbB6O12 was studied. Under the excitation of 378 nm, the emission spectrum exhibits an intense green emission centered at 543-548 nm with the chromaticity coordinates (0.342, 0.590), which can be assigned to the 5D4→7F5 transition of Tb3+. The excitation spectra cover a wide range from 330 to 385 nm, which suggests that the K3TbB6O12 phosphors can be effectively excited by a near-UV light source. One may expect that compound K3TbB6O12 can be used as a green phosphor pumped by near-UV LED chips. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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169. AKTeO 2 (CO 3 ) (A = Li, Na): The First Carbonatotellurites Featuring a Zero-Dimensional [Te 2 C 2 O 10 ] 4- Cluster and a Wide Band Gap.
- Author
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Chen PF, Hu CL, Cao MY, Zhang XY, and Mao JG
- Abstract
The first carbonatotellurites, AKTeO
2 (CO3 ) (A = Li, Na), have been successfully synthesized by using boric acid as the mineralizer. AKTeO2 (CO3 ) (A = Li, Na) crystallize in the monoclinic space group P 21 / n (no. 14), and their structures exhibit the novel zero-dimensional (0D) [Te2 C2 O10 ]4- clusters, in which two [TeO4 ]4- groups form a [Te2 O6 ]4- dimer via edge-sharing, with each side of the dimer attached by a [CO3 ]2- group via a Te-O-C bridge. The alkali metal cations occupy the voids between the 0D clusters and maintain the charge balance. The ultraviolet-visible-near-infrared diffuse reflectance spectra show that the short absorption cut-off edges of LiKTeO2 (CO3 ) (LKTC) and NaKTeO2 (CO3 ) (NKTC) are 248 and 240 nm, respectively, and LKTC exhibits the largest experimental band gap (4.58 eV) among all of the tellurites containing the π-conjugated anionic groups reported. Theoretical calculations revealed that they exhibit moderate birefringences of 0.029 and 0.040@1064 nm, respectively.- Published
- 2023
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170. Free autologous internal limiting membrane transplantation in the treatment of large macular hole.
- Author
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Ma FY, Xi RJ, Chen PF, and Hao YH
- Abstract
We evaluated the clinical efficacy of free internal limiting membrane (ILM) flap transplantation for the treatment of large macular hole over 500 µm in 42 consecutive patients. Quantified evaluation of the post-operative macular anatomy restoration was performed by spectral-domain optical coherence tomography in the 12mo follow-up. The results showed 41 eyes achieved successful closure (97.6%). Postoperative best corrected visual acuity, ellipsoid layer, and external limiting membrane disruption were significantly improved at all follow-up time points. The central foveal thickness was significantly higher at 1mo. We concluded that free ILM flap transplantation proves to be effective to achieve anatomical and functional improvement for the treatment of large macular hole.
- Published
- 2019
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171. Atrial fibrosis associated with left ventricular apical hypoplasia.
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Chen PF, Peng R, Tang L, and Hu XQ
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- Chest Pain diagnosis, Chest Pain etiology, Dyspnea diagnosis, Dyspnea etiology, Echocardiography methods, Electrocardiography methods, Fibrosis pathology, Heart Atria diagnostic imaging, Humans, Hypoplastic Left Heart Syndrome pathology, Male, Rare Diseases, Young Adult, Cardiomyopathy, Hypertrophic diagnostic imaging, Cardiomyopathy, Hypertrophic pathology, Heart Atria pathology, Hypoplastic Left Heart Syndrome diagnostic imaging
- Published
- 2018
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172. Sucrose is involved in the regulation of iron deficiency responses in rice (Oryza sativa L.).
- Author
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Chen PF, Chen L, Jiang ZR, Wang GP, Wang SH, and Ding YF
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- Biological Transport drug effects, Biomass, Chlorophyll metabolism, Darkness, Oryza drug effects, Oryza physiology, Phloem drug effects, Phloem metabolism, Photosynthesis drug effects, Plant Leaves drug effects, Plant Leaves metabolism, Plant Roots drug effects, Plant Roots metabolism, Iron Deficiencies, Oryza metabolism, Sucrose pharmacology
- Abstract
Key Message: Sucrose signaling pathways were rapidly induced in response to early iron deficiency in rice plants, and the change of sucrose contents in plants was essential for the activation of iron deficiency responses. Sucrose is the main product of photosynthesis in plants, and it functions not only as an energy metabolite but also a signal molecule. However, a few studies have examined the involvement of sucrose in mediating iron deficiency responses in rice. In this study, we found that the decrease in photosynthesis and total chlorophyll concentration (SPAD values) in leaves occurred at a very early stage under iron deficiency. In addition, the sucrose was increased in leaves but decreased in roots of rice plants under iron deficiency, and also the sucrose transporter (SUT) encoded genes' expression levels in leaves were all inhibited, including OsSUT1, OsSUT2, OsSUT3, OsSUT4, and OsSUT5. The carbohydrate distribution was changed under iron deficiency and sucrose might be involved in the iron deficiency responses of rice plants. Furthermore, exogenous application of sucrose or dark treatment experiments were used to test the hypothesis; we found that the increased endogenous sucrose would cause the repression of iron acquisition-related genes in roots, while further stimulated iron transport-related genes in leaves. Compared to the exogenous application of sucrose, the dark treatment had the opposite effects. All the above results highlighted the important role of sucrose in regulating the responses of rice plants to iron deficiency.
- Published
- 2018
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173. Controversial role of alcohol consumption in the development of inflammatory bowel diseases.
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Yang XY, Wei WB, Zeng LR, He JH, and Chen PF
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- Humans, Alcohol Drinking, Inflammatory Bowel Diseases
- Published
- 2018
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174. Superior vena cava syndrome secondary to recurrent coronary artery fistula: A case report and literature review.
- Author
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Chen PF, Tang L, Liu ZZ, and Hu X
- Subjects
- Coronary Aneurysm diagnostic imaging, Female, Humans, Middle Aged, Recurrence, Arterio-Arterial Fistula diagnostic imaging, Coronary Vessels diagnostic imaging, Superior Vena Cava Syndrome etiology
- Abstract
Rationale: Coronary artery fistula (CAF) is characterized by an abnormal communication of a coronary artery with a cardiac chamber or a great vessel bypassing the capillary bed. Surgical closure of large or symptomatic CAF is the gold standard treatment. However the previously closed CAF still has the possibility to reopen. Superior vena cava syndrome (SVCS) is defined as a condition that occurs when the obstruction of the superior vena cava interrupts blood flow from the head, upper extremities, and thorax to the right atrium and can present a life-threatening situation. In this report, we described a case of SVCS, which was secondary to the compression by a huge aneurysm formed in a recurrent CAF, as a long-term complication associated with surgical treatment of CAF., Patient Concerns: A 47-year-old woman presented with chief complaint of progressive exertional dyspnea for one month., Diagnoses: Superior vena cava syndrome and recurrent coronary artery fistula., Interventions: Reoperation for ligation of the fistulous and excision of the aneurysm were performed., Outcomes: The patient made an uneventful recovery and her postoperative course through 1-year follow-up was uneventful., Lessons: First, SVCS is a rare but clinically important postoperative complication of surgical ligation of CAF. Second, surgical ligation of the fistula alone is unlikely to prevent the ectatic course. Therefore, long-term follow-up is mandatory for patients with CAF undergoing surgical closure., (Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2017
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175. Efficacy and safety of probiotic-supplemented triple therapy for eradication of Helicobacter pylori in children: a systematic review and network meta-analysis.
- Author
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Feng JR, Wang F, Qiu X, McFarland LV, Chen PF, Zhou R, Liu J, Zhao Q, and Li J
- Subjects
- Child, Dietary Supplements, Drug Therapy, Combination, Helicobacter Infections microbiology, Humans, Network Meta-Analysis, Probiotics adverse effects, Treatment Outcome, Helicobacter Infections drug therapy, Helicobacter pylori drug effects, Probiotics administration & dosage, Probiotics therapeutic use
- Abstract
Aim: The aim of this study was to identify the best probiotic supplementation in triple therapy for pediatric population with Helicobacter pylori infection., Methods: Eligible trials were identified by comprehensive searches. Relative risks with 95% confidence intervals and relative ranks with P scores were assessed., Results: Twenty-nine trials (3122 participants) involving 17 probiotic regimens were identified. Compared with placebo, probiotic-supplemented triple therapy significantly increased H. pylori eradication rates (relative ratio (RR) 1.19, 95% CI 1.13-1.25) and reduced the incidence of total side effects (RR 0.49, 95% CI 0.38-0.65). Furthermore, to supplemented triple therapy, Lactobacillus casei was identified the best for H. pylori eradication rates (P score = 0.84), and multi-strain of Lactobacillus acidophilus and Lactobacillus rhamnosus for total side effects (P score = 0.93). As for the subtypes of side effects, multi-strain of Bifidobacterium infantis, Bifidobacterium longum, L. acidophilus, L. casei, Lactobacillus plantarum, Lactobacillus reuteri, L. rhamnosus, Lactobacillus salivarius, Lactobacillus sporogenes, and Streptococcus thermophilus was the best to reduce the incidence of diarrhea; multi-strain of Bacillus mesentericus, Clostridium butyricum, and Streptococcus faecalis for loss of appetite; multi-strain of B. longum, Lactobacillus bulgaricus, and S. thermophilus for constipation; multi-strain of Bifidobacterium bifidum, B. infantis, L. acidophilus, L. bulgaricus, L. casei, L. reuteri, and Streptococcus for taste disturbance; Saccharomyces boulardii for bloating; and multi-strain of Bifidobacterium breve, B. infantis, L. acidophilus, L. bulgaricus, L. casei, L. rhamnosus, and S. thermophilus for nausea/vomiting., Conclusions: Probiotics are recommended to supplement triple therapy in pediatrics, and the effectiveness of triple therapy is associated with specific probiotic supplementation.
- Published
- 2017
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176. Fabrication of magnetically responsive HKUST-1/Fe 3 O 4 composites by dry gel conversion for deep desulfurization and denitrogenation.
- Author
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Tan P, Xie XY, Liu XQ, Pan T, Gu C, Chen PF, Zhou JY, Pan Y, and Sun LB
- Abstract
Selective adsorption by use of metal-organic frameworks (MOFs) is an effective method for purification of hydrocarbon fuels. In consideration that the adsorption processes proceed in liquid phases, separation and recycling of adsorbents should be greatly facilitated if MOFs were endowed with magnetism. In the present study, we reported for the first time a dry gel conversion (DGC) strategy to fabricate magnetically responsive MOFs as adsorbents for deep desulfurization and denitrogenation. The solvent is separated from the solid materials in the DGC strategy, and vapor is generated at elevated temperatures to induce the growth of MOFs around magnetic Fe
3 O4 nanoparticles. This strategy can greatly simplify the complicated procedures of the well-known layer-by-layer method and avoid the blockage of pores confronted by introducing magnetic Fe3 O4 nanoparticles to the pores of MOFs. Our results show that the adsorbents are capable of efficiently removing aromatic sulfur and nitrogen compounds from model fuels, for example removing 0.62mmolg-1 S and 0.89mmolg-1 N of thiophene and indole, respectively. In addition, the adsorbents are facile to separate from liquid phases by use of an external field. After 6 cycles, the adsorbents still show a good adsorption capacity that is comparable to the fresh one., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2017
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177. [Relationship between retention PM 2.5 and leaf surface AFM character of six greening trees during autumn in Beijing West Mountain.]
- Author
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Chen B, Liu HL, Zhao DB, Chen PF, Lu SW, and Li SN
- Subjects
- Acer, Adsorption, Air Pollutants, Beijing, Cities, Ginkgo biloba, Pinus, Populus, Salix, Seasons, Environmental Monitoring, Particulate Matter, Plant Leaves physiology, Trees physiology
- Abstract
This study investigated PM
2.5 adsorption by leaves of six tree species (Pinus bungeana, Pinus tabuliformis, Salix babylonica, Acer mono, Ginkgo biloba, Populus davidiana) in the West Mountain of Beijing. An aerosol generator was used for quantitative determination of PM2.5 adsorption. Atomic force microscopy (AFM) was used to determine micro morphology characteristics on the leaf surface, including roughness parameters and the PM2.5 absorption mechanism of tree leaves. The results showed that the PM2.5 adsorption capacity per unit leaf area was as follows: P. bungeana (2.44±0.22 μg·cm-2 ) > P. tabuliformis (2.40±0.23 μg·cm-2 ) > S. babylonica (1.62±0.09 μg·cm-2 ) > A. mono (1.23±0.01 μg·cm-2 ) > G. biloba (1.00±0.07 μg·cm-2 ) > P. davi-diana (0.97±0.03 μg·cm-2 ). In autumn, PM2.5 adsorption capacity per unit leaf area was as follows: November (2.33±0.43 μg·cm-2 ) > October (1.62±0.64 μg·cm-2 ) > September (1.51±0.50 μg·cm-2 ). The leaves of P. bungeana and P. tabuliformis were rugged with many recesses and protrusions, large relative height difference, and high roughness, and their absorption ability of PM2.5 was strong. The leaves of S. babylonica and A. mono had folded leaf lamina and were covered by fine hairs, and their roughness was relatively high, with many protrusions and fillisters on the leaf surface. Since G. biloba and P. davidiana had smooth leaves, mostly oblong stomata and low roughness, their PM2.5 absorption ability was weaker. The ranking of average roughness on the ada-xial and abaxial side of the leaves was as follows: P. bungeana (149.91±16.38 nm) > P. tabuliformis (124.47±10.52 nm) > S. babylonica (98.85±5.36 nm) > A. mono (93.74±21.75 nm) > G. biloba (80.84±0.88 nm) > P. davidiana (67.72±8.66 nm). This accorded with PM2.5 adsorption per unit leaf area, and leaf roughness had a significant positive correlation with PM2.5 adsorption amount per unit leaf area as well (R2 =0.9498). To improve the environmental effects of city vegetation, tree species with leaf surface morphology that facilitates absorption of PM2.5 and other particles should be selected.- Published
- 2016
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178. Outcomes of percutaneous coronary intervention in patients ≥ 75 years: one-center study in a Chinese patient group.
- Author
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Chen PF, Wang DN, Chen K, Liang C, Reng YS, Yang J, Ding R, Blackwell J, and Liao DN
- Abstract
Objective: To investigate the clinical and perioperative characteristics of patients ≥ 75 who undergoing percutaneous coronary intervention (PCI) and to evaluate the risk factors related to short-term post-PCI mortality in this specific patients group., Methods: 1,035 consecutive subjects who underwent PCI from December 2011 to November 2013 were divided into four categories: (1) patients with stable angina (SA) ≥ 75 years (n = 58); (2) patients with SA < 75 years (n = 218); (3) patients with acute coronary syndrome (ACS) ≥ 75 years (n = 155); (4) patients with ACS < 75 years (n = 604). A multivariable logistic regression analysis was conducted to detect risk factors of six-month mortality in patients ≥ 75 years who had undergone PCI. Clinical comorbidities, in-hospital biochemical indicators, perioperative data, in-hospital and six-month outcomes were analyzed and compared among the four groups., Results: Compared with the younger group, patients ≥ 75 years were more likely to have hypertension, history of stroke, chronic obstructive pulmonary disease, peripheral vascular disease, cardiogenic shock and malignant arrhythmia, and they were admitted to hospital with relative lower weight, hemoglobin, albumin, triglyceride, higher creatinine, uric acid, urea nitrogen and pro-BNP. Left main artery lesions, multi-vessel, calcified lesions, chronic totally occlusion were also more likely to be seen in the elderly group. Univariate analysis revealed that age ≥ 85 years, cardiogenic shock or severe arrhythmia at admission, emergency PCI, prior stroke and chronic kidney disease were related to six-month mortality in elderly patients ≥ 75 years who underwent PCI. Multivariable logistic regression showed that cardiogenic shock or severe arrhythmia at admission, chronic kidney disease and prior stroke were independent risk factors predicting six-month mortality in elderly patients ≥ 75 years who had undergone PCI., Conclusions: Our data showed that, compared with patients under 75 years, elderly patients (≥ 75 years) who had undergone PCI had a relative higher risk of mortality, and more often accompanied with multi-comorbidities, severer admission conditions and complex coronary lesions. Better evaluation of risk factors and more intensively care should be taken to patients ≥ 75 years who had undergone PCI therapy to reduce complications.
- Published
- 2015
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179. [Concentration and Source of Dissolved Organic Carbon in Snowpits of the Tibetan Plateau].
- Author
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Yan FP, Kang SC, Chen PF, Bai JK, Li Y, Hu ZF, and Li CL
- Subjects
- Biomass, Carbon Cycle, Ions, Tibet, Air Pollutants analysis, Carbon analysis, Environmental Monitoring, Ice Cover chemistry
- Abstract
Snowpit samples of three glaciers (Laohugou NO. 12 Glacier (LHG), Small Dongkemadi Glacier on Mount Tanggula (TGL) and East Ronghuk Glacier on Mount Everest (ZF)) in the Tibetan Plateau were collected. Concentrations of DOC and major ions were analyzed. The results showed that average DOC concentrations of the snowpits of LHG, TGL and ZF were (250.30 +/- 157.10), (216.92 +/- 142.82) and (152.50 +/- 56.11) microg x L(-1), respectively. DOC of TGL and ZF accounted for large parts of total values of DOC and ions. Correspondingly, DOC of LHG accounted for small part (only 5%), because LHG was located at north China and intensively influenced by natural mineral dust, which caused high concentrations of Ca2+ (the highest value could reach 5299.18 microg x L(-1)) and consequently low percentage of DOC of snowpit samples. Correlation and PCA analyses were used to study the sources of DOC. DOC was significantly correlated with Ca2+, Mg2+, K+ and SO4(2-). Additionally, PCA further indicated that the main potential source of DOC was the natural source of mineral dust. Meanwhile, anthropogenic pollutants (e.g., biomass, fossil combustion and agricultural related pollutants) could also not be ignored. Moreover, the carbon depositional fluxes of three snowpits were roughly estimated, and the values of LHG, TGL and ZF snowpits were 189.23, 132.76 and 128.44 mg (m2 x a)(-1), respectively, which played a significant role in the carbon cycle in this region and was also helpful for the study of glaciers fluctuation.
- Published
- 2015
180. Lower gastrointestinal bleeding: role of 64-row computed tomographic angiography in diagnosis and therapeutic planning.
- Author
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Ren JZ, Zhang MF, Rong AM, Fang XJ, Zhang K, Huang GH, Chen PF, Wang ZY, Duan XH, Han XW, and Liu YJ
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, China, Embolization, Therapeutic, Female, Gastrointestinal Hemorrhage etiology, Humans, Male, Middle Aged, Patient Selection, Predictive Value of Tests, Prospective Studies, Recurrence, Young Adult, Gastrointestinal Hemorrhage diagnostic imaging, Gastrointestinal Hemorrhage therapy, Hemostatic Techniques, Multidetector Computed Tomography
- Abstract
Aim: To determine the value of computed tomographic angiography (CTA) for diagnosis and therapeutic planning in lower gastrointestinal (GI) bleeding., Methods: Sixty-three consecutive patients with acute lower GI bleeding underwent CTA before endovascular or surgical treatment. CTA was used to determine whether the lower GI bleeding was suitable for endovascular treatment, surgical resection, or conservative treatment in each patient. Treatment planning with CTA was compared with actual treatment decisions or endovascular or surgical treatment that had been carried out in each patient based on CTA findings., Results: 64-row CTA detected active extravasation of contrast material in 57 patients and six patients had no demonstrable active bleeding, resulting in an accuracy of 90.5% in the detection of acute GI bleeding (57 of 63). In three of the six patients with no demonstrable active bleeding, active lower GI bleeding recurred within one week after CTA, and angiography revealed acute bleeding. The overall location-based accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the detection of GI bleeding by 64-row CTA were 98.8% (249 of 252), 95.0% (57 of 60), 100% (192 of 192), 100% (57 of 57), and 98.5% (192 of 195), respectively. Treatment planning was correctly established on the basis of 64-row CTA with an accuracy, sensitivity, specificity, PPV and NPV of 98.4% (248 of 252), 93.3% (56 of 60), 100% (192 of 192), 100% (56 of 56), and 97.5% (192 of 196), respectively, in a location-based evaluation., Conclusion: 64-row CTA is safe and effective in making decisions regarding treatment, without performing digital subtraction angiography or surgery, in the majority of patients with lower GI bleeding.
- Published
- 2015
- Full Text
- View/download PDF
181. [Chemical speciation and risk assessment of heavy metals in the middle part of Yarlung Zangbo surface sediments].
- Author
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Bai JK, Li CL, Kang SC, Chen PF, and Wang JL
- Subjects
- China, Risk Assessment, Environmental Monitoring, Geologic Sediments chemistry, Metals, Heavy chemistry, Rivers chemistry, Water Pollutants, Chemical chemistry
- Abstract
Nine heavy metals (Cd, Co, Ni, Cu, Zn, Pb, Cs, As, Cr) of surface sediments collected from the Middle Part of the Yarlung Zangbo River were analyzed by BCR sequential extraction procedure. Based on speciation distributions of these metals, ecological risk of heavy metals was assessed with methods of risk assessment code (RAC) and sediment quality guideline quotient (SQG-Q). The results show that: (1) Large part of Cr and As belong to residual fraction(87%-96%). Ni, Cu, Co and Cs have similar distribution characteristics (non-residual part accounts for approximate 20%). Correspondingly, mass fraction of Cd exists mainly in acid soluble and reducible faction (65% ) , indicating high ecological risk level. (2) Based on calculation of RAC method, Cd is of high risk to the environment (37. 38%). Accordingly, Co, Ni, Cu and Zn are of low risk, and Pb, Cs, As and Cr pose extreme low risk to the environment. According to evaluation of heavy metal speciation distributions, the potential ecological risk of heavy metals is in the descending order of Cd > Co > Ni > Cu > Zn > Pb > Cs > As > Cr. (3) The SQG index of sediments is 0. 804, indicating that studied river sediment has a moderate potential biological toxicity effect. Given most of heavy metals exists in residual fraction, the sediments of this region pose a low ecological risk to the environment.
- Published
- 2014
182. [An automatic peak detection method for LIBS spectrum based on continuous wavelet transform].
- Author
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Chen PF, Tian D, Qiao SJ, and Yang G
- Abstract
Spectrum peak detection in the laser-induced breakdown spectroscopy (LIBS) is an essential step, but the presence of background and noise seriously disturb the accuracy of peak position. The present paper proposed a method applied to automatic peak detection for LIBS spectrum in order to enhance the ability of overlapping peaks searching and adaptivity. We introduced the ridge peak detection method based on continuous wavelet transform to LIBS, and discussed the choice of the mother wavelet and optimized the scale factor and the shift factor. This method also improved the ridge peak detection method with a correcting ridge method. The experimental results show that compared with other peak detection methods (the direct comparison method, derivative method and ridge peak search method), our method had a significant advantage on the ability to distinguish overlapping peaks and the precision of peak detection, and could be be applied to data processing in LIBS.
- Published
- 2014
183. [Study on soil element background values of the Hoh Xil area in north Tibet].
- Author
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Bai JK, Wang JL, Li CL, Kang SC, and Chen PF
- Subjects
- Elements, Minerals chemistry, Tibet, Soil chemistry
- Abstract
Hoh Xil locates at northern part of the Tibetan Plateau. Twenty five surface soil samples were collected from this area in 2007 and 32 elements were analyzed and compared to the element contents of Yarlung Zangbo river sediment, background element value of the Tibetan surface soil and the Chinese Continental crust contents. The results showed that the element contents of the < 20 microm fraction were higher than those of bulk samples; Contents of many elements of this study were similar to those of the Tibetan soil. Meanwhile, contents of Ca and As of the studied area were higher than those of Chinese continental crust, resulting mainly from local alpine arid climate and widely distributed the rocks that enriched in As, respectively. The EOF analysis of the contents of bulk soil samples revealed the sources and chemical properties of studied elements: many elements such as Al, Fe, Ga inherit the characteristics of the parent rocks of this region. Meanwhile, elements with an active chemical property and the element Zr that specially existed in the heavy minerals also had a certain contribution to the contents. The contents of B and Cs revealed contribution of hot springs to the soil of studied area.
- Published
- 2014
184. Clinical analysis of 240 patients with HLA-B27 associated acute anterior uveitis.
- Author
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Zheng MQ, Wang YQ, Lu XY, Wang YL, Mao LP, Gu YF, and Chen PF
- Subjects
- Acute Disease, Adult, Age of Onset, Female, Humans, Incidence, Male, Middle Aged, Ophthalmology, Prevalence, Recurrence, Retrospective Studies, Spondylarthropathies epidemiology, Spondylitis, Ankylosing epidemiology, HLA-B27 Antigen, Uveitis, Anterior epidemiology, Uveitis, Anterior immunology
- Abstract
Purpose: To analyze the prevalence of HLA-B27 associated acute anterior uveitis and to identify its clinical features., Methods: A total of 240 patients with HLA-B27 associated acute anterior uveitis, who were admitted to Zhejiang Ophthalmologic Hospital between December 2006 and October 2012, were retrospectively analyzed. The age of onset, sex, affected eyes, HLA-B27 antigen detection, recurrence, joint involvement, and surgical complications were investigated., Results: The average age of onset was 37.0±12.0 years and the ratio of male to female patients was 2.4:1. Most cases had alternate unilateral or bilateral involvement. Among all participants, 234 cases (97.5%) were HLA-B27 positive, and 124 cases (51.7%) had spondyloarthropathies (SpA), dominated by 108 cases with ankylosing spondylitis (AS,45.0%), and mostly seen in male subjects (P<0.05). Six patients were HLA-B27 negative (2.5%) and no statistical significance was noted between male and female patients (P>0.05). A total of 193 cases (80.4%) presented with complications, mainly fibrinous exudation, posterior synechia, and vitreous opacity., Conclusion: HLA-B27 that is associated acute anterior uveitis with a relatively high incidence and recurrence presents with more severe clinical features than does idiopathic acute anterior uveitis, and it often accompanies systemic arthritic diseases. HLA-B27 antibody detection is associated with the diagnosis and treatment of acute anterior uveitis.
- Published
- 2012
- Full Text
- View/download PDF
185. [Temporal and spatial distribution of ozone concentration by aircraft sounding over Beijing].
- Author
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Chen PF, Zhang Q, Quan JN, Gao Y, and Huang MY
- Subjects
- Aircraft, China, Cities, Nitrogen Oxides analysis, Seasons, Spatio-Temporal Analysis, Air Pollutants analysis, Environmental Monitoring, Ozone analysis
- Abstract
Based on the aircraft sounding volume fraction concentration data of ozone (O3), nitrogen oxides (NO, NO2) and other data in Beijing from 2007 to 2010, temporal and spatial evolution of ozone concentration from the ground surface to 3.5 km altitude were studied. Results show that: (1) Vertical profiles of monthly average O3 concentration were in good agreement, with increasing altitude, the concentrations were first increased and then decreased, and then remained almost constant, and there was a clear dividing line at 1.5 km altitude, the vertical gradient of the O3 concentration changed greatly below which, there were O3 high-value areas, which were influenced by human activities near the ground; the change of vertical gradient of O3 concentration was significantly reduced above 1.5 km altitude, this space was above the mixing layer, where the air mass movement was less affected by underlying surface, and the advection-diffusion played a crucial role in the local accumulation process of air pollutants. (2) Changes of O3 concentration showed clear seasonal characteristics, O3 concentration was lower in spring and autumn, but higher in summer. In the months studied, no significant difference in monthly average O3 concentration from July to September was detected (P > 0.05), but there was significant difference in other months (P < 0.01). (3) In summer days (daytime), the variations in the vertical profiles of hourly O3 concentration were consistent with those of the monthly O3 concentration. The O3 concentration was lower near the surface within 1.5 km in the morning (09:00-10:00), and higher in the afternoon (15:00-16:00), with the maximum discrepancy of about 60 x 10(-9) in the same altitude; there was minor difference in O3 concentration in altitude range of 1.5-3.5 km, generally fluctuating among 70 x 10(-9) -80 x 10(-9). (4) For the regional distribution of O3 concentration, higher concentration within 0-2 km appeared near the Fourth Ring Road of city center and the surrounding areas, the main reasons for this distribution might be the presence of many strong sources of pollution emissions and low sink flow near the ground; within 2-4 km, in addition to the urban area of Beijing, higher O3 concentration areas were found in the north, the south-east (Beijing-Tianjin direction), the south-west (Beijing-Baoding direction). (5) There were significant correlation between O3 and NO, NO2 and NO2/NO within 0-3.5 km, O3 was negatively related with both NO and NO2, but positively correlated with the NO2/NO ratio.
- Published
- 2012
186. [Bone marrow mesenchymal stem cells contribute to liver fibrosis].
- Author
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Zhou W, Chen PF, Wu XL, Jiang R, and Xu YH
- Subjects
- Animals, Bone Marrow Cells, Liver Cirrhosis, Experimental pathology, Mesenchymal Stem Cells, Rats, Rats, Sprague-Dawley, Bone Marrow Transplantation, Liver Cirrhosis, Experimental surgery, Mesenchymal Stem Cell Transplantation
- Published
- 2011
- Full Text
- View/download PDF
187. [Indoor air pollution in the Nam Co and Ando Regions in the Tibetan Plateau].
- Author
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Chen PF, Li CL, Kang SC, Zhang QG, Guo JM, Mi J, Basang PC, and Luosang QZ
- Subjects
- Altitude, Environmental Monitoring methods, Tibet, Air Pollution, Indoor analysis, Carbon Monoxide analysis, Particulate Matter analysis
- Abstract
Concentrations and variations of fine particulate matter (PM2.5) and carbon monoxide (CO) within tents from the Nam Co and Ando regions were observed at summer 2009, in order to understand the concentrations and variations of PM2.5 and CO in these tents (or in rooms) and their main affect factors, as well as the exposure of different residents. The result indicates that the twenty-four hour average concentrations of PM2.5 and CO (V/V) in the tents without chimney are 1.272 mg x m(-3) and 5.035 x 10(-6), which are significantly higher than those of tents installed chimneys (0.097 mg x m(-3) and 0.089 x 10(-6)). Diurnal variations of PM2.5 and CO are similar and show multiple peaks, which is different with those in the eastern rural areas of China and closely connected with the behaviors of the residents within the tents. Generally, women and children spend three or four hours longer in tents than other family members every day. Children have the highest exposure of 0.972 mg x m(-3) and 0.132 x 10(-6) for PM2.5 and CO, respectively. Therefore, although the outdoor air in the Tibetan Plateau is very clean, the air of the Tibetan tents are seriously polluted and mainly caused by yak dung combustion.
- Published
- 2011
188. [New index for crop canopy fresh biomass estimation].
- Author
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Chen PF, Nicolas T, Wang JH, Philippe V, Huang WJ, and Li BG
- Subjects
- Models, Theoretical, Regression Analysis, Biomass, Plant Leaves, Remote Sensing Technology, Zea mays
- Abstract
The objective of the present study is to propose a new vegetation index for corn canopy fresh biomass estimation, which improves the ability to accurately estimate high biomass levels by remote sensing technology. For this purpose, hyperspectral reflectance data of corn canopies were collected using a ground-based spectroradiometer during different field campaigns in a region of Quebec (Canada), from 2004 to 2008. Corresponding fresh biomass values were obtained by destructive measurements, and a hyperspectral image was also acquired using the Compact Airborne Spectrographic Imager (CASI) in 2005. A new biomass index named red-edge triangular vegetation index (RTVI) was designed and compared to existing indices used for fresh biomass estimation. The results showed that RTVI was the best vegetation index for predicting canopy fresh biomass, with sustained sensitivity at high fresh biomass levels. The best regression model between RTVI and canopy fresh biomass was the power fit, with determination coefficient (R2) of 0.96. With the validation by CASI imagery in 2005, good results were obtained. The relationship between CASI predicted biomass and actual biomass was 0.58 (R2), with the RMSE of 0.44 kg x m(-2).
- Published
- 2010
189. [Evaluation of fermentation character of alfalfa silage through near infrared reflectance spectroscopy (NIRS)].
- Author
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Chen PF, Rong YP, and Han JG
- Subjects
- Fermentation physiology, Medicago sativa physiology, Silage, Spectroscopy, Near-Infrared
- Abstract
It is very important to evaluate the fermentation character of alfalfa silage using near infrared reflectance spectroscopy technology (NIRS) for animal production, including the content of NH3-N, lactic acid, acetic acid and butyric acid in silage. In order to evaluate the feasibility of using NIRS to analyze the formation character of alfalfa silage, the near infrared reflectance spectroscopy models were built for NH3-N, lactic acid, zcetic acid and butyric acid in this experiment. Partial least square regression (PLS), Fourier transform technology and sample preparation with liquid nitrogen technology were used to optimize the model. The analyzed samples were obtained with different cultivars, maturity, cuttings and ensiling method. The determination of cross validation was between 0.6024 and 0.9497. The standard errors of cross validation were between 5.59 x 10(-1) and 3.78 g x kg(-1) fresh weight. The validation samples were used to test the performance of the models. The correlation coefficients between the chemical value and the NIRS value were between 0.8826 and 0.9853, and the root mean square errors of prediction were between 5.71 x 10(-1) and 3.15 g x kg(-1) fresh weight. The results showed the NIRS could evaluate the fermentation of the fresh forage.
- Published
- 2008
190. [Real-time analysis of soil N and P with near infrared diffuse reflectance spectroscopy].
- Author
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Chen PF, Liu LY, Wang JH, Shen T, Lu AX, and Zhao CJ
- Subjects
- Calibration, Diffusion, Time Factors, Nitrogen analysis, Phosphorus analysis, Soil analysis, Spectroscopy, Near-Infrared methods
- Abstract
Improving the efficiency of fertilization is an effective method of enhancing income for farmers, but it depends on measuring the soil nutrients accurately and rapidly. Near infrared reflectance spectroscopy (NIRS) is a fast method to detect the soil nutrients. In order to evaluate the feasibility of using NIRS to determine the soil N and P contents, the soil samples were collected from different LULC (land use and land cover) types in Daxing district, Beijing, and their biochemical parameters were determined by traditional chemical method. Then, the near infrared reflectance spectra of the samples were acquired, and NIRS models were built using partial least square regression (PLS) and Fourier transform technology for the total N and total P. The determination coefficients of cross validation for the total N and total P were 0.862 6 and 0.668 5 respectively. Ten samples were used to test the performance of the models. The coefficients of correlation between the chemically determined value and the NIRS predicted one were 0.969 8(N) and 0.830 7(P) respectively. The root mean standard error of prediction for N and P were 0.009 5(%) and 0.008 6(%), respectively. The ratios of RMSEP to SD(RPD) were 3.78(N) and 1.69(P). The results showed that the NIRS could be used to evaluate the soil N accurately and the soil P roughly.
- Published
- 2008
191. [Evaluation of fresh sample of alfalfa silage through near infrared reflectance spectroscopy (NIRS)].
- Author
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Chen PF, Rong YP, Han JG, Wang JH, Zhang LD, and Xu XJ
- Subjects
- Animals, Dietary Fiber analysis, Least-Squares Analysis, Medicago sativa classification, Nutritive Value, Plant Proteins analysis, Reference Standards, Regression Analysis, Reproducibility of Results, Silage standards, Species Specificity, Medicago sativa chemistry, Silage analysis, Spectroscopy, Near-Infrared methods
- Abstract
It is very important to evaluate the fresh sample of alfalfa silage using near infrared reflectance spectroscopy technology (NIRS) for animal production. The nutrient content of forage means the contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the forage. Because of the high moisture content, it is difficult to make uniform samples for fresh forage and to get useful information from the spectrum. Therefore, it is hard to use NIRS analysis. In order to evaluate the feasibility of using NIRS to analyse the fresh alfalfa silage, the DM, CP, NDF and ADF contents of fresh alfalfa silage were evaluated by the near infrared reflectance spectroscopy model in this experiment using partial least square regression (PLS), Fourier transform technology and sample preparation with liquid nitrogen technology. The analysis samples were obtained through different cultivars, maturity, cuttings and ensiling method. The cross validation was determined between 0.884 6-0. 989 8. The standard error of cross validation was between 3.9 and 9.7 g x kg(-1) fresh weight. Fifty samples were used to test the performance of the models. The coefficients of correlation between the chemical value and the NIRS value are between 0.939 7 and 0.994 9, and the root mean square errors of prediction are between 1.9 and 8.3 g x kg(-1) fresh weight. The results showed that NIRS could be used to evaluate the nutrition of fresh forage.
- Published
- 2007
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