维普中文期刊产品整合服务
471篇 您的检索式:作者名="Anhui"
    题名 作者 年代 出处 被引量
1Homotopic mapping solving method for gain fluency of a laser pulse amplifier显示文摘The model for gain fluency of a laser pulse amplifier is studied. Using the homotopic mapping method, firstly, the system of the original model is packed up standardization; secondly, introducing a homotopic mapping, taking the property of the mapping, inducing a contrived parameter, the solving of a nonlinear problem translates into the solving of a linear problem. Then the approximate expressions of the solution for the corresponding model are obtained. And the precision for the approximate solution is compared. It illuminates that the obtained approximate solution using the homotopic mapping method possesses higher approximate degree. At one time, the expansion of solution through the homotopic mapping method can be kept in the analytic operation. Thus it also enables us through differential and integral operations to obtain other physics behavior for the gain fluency of laser pulse amplifier.MO JiaQi1,2 1 Anhui Normal University, Wuhu 241000, China 2 Division of Computational Science, E-Institutes of Shanghai Universities, at SJTU, Shanghai 200240, China 2009Science China(Physics,Mechanics & Astronomy)2009,52,7:124
2L^p-Boundedness of Marcinkiewicz Integrals with Hardy Space Function KernelsYong Ding Department of Mathematics, Beijing Normal University, Beijing 100875, P. R. China Dashan Fan Department of Mathematics, Anhui University and University of Wisconsin-Milwaukee. MW 53201 USA Yibiao Pan Department of Mathematics, University of Pittsburgh. Pittsburgh. Pennsylvania 15260. USA 2000Acta Mathematica Sinica,English Series2000,16,4:88
3Shock solution for quasilinear singularly perturbed Robin problem显示文摘The shock solution for the quasilinear singularly perturbed Robin problem is considered. Under suitable conditions and using the theory of differential inequalities the existence and asymptotic behavior of the shock solution for the original boundary value problems are studied.MO Jiaqi and WANG Hui(1. Anhui Normal University, Wuhu 241000, China 2. National Natural Science Foundation of China, Beijing 100085, China) 2002Progress in Natural Science:Materials International2002,12,12:70
4Prognostic significance of expression of cyclooxygenase-2 and vascular endothelial growth factor in human gastric carcinoma显示文摘AIM: To investigate the role of cyclooxygenase-2(COX-2)and vascular endothelial growth factor (VEGF) in the development of gastric carcinoma and correlation between expression of COX-2 and VEGF and clinicopathologic features in tissues from patients with gastric carcinoma.METHODS: 281 patients with gastric carcinoma who underwent surgical resection between 1990 and 1999 at the First Affiliated Hospital, Anhui Medical University, PRC, were followed up. Expression of COX-2 and VEGF was investigated retrospectively in 232 gastric carcinoma tissues and 60noncancerous specimens by using immunohistochemistry.RESULTS: The 5-year survival rates of early gastric carcinoma (EGC) and advanced gastric carcinoma (AGC) were 93.4 %and 59.0 %, respectively. Survival time was highly correlated with lymph node metastasis, vascular invasion, depth of invasion and treatment with chemotherapy. Compared with paired noncancerous tissues, expression of COX-2 and VEGF and microvessel density (MVD) value in carcinoma tissue were significantly higher. The MVD value was much higher in COX-2-positive group and VEGF-positive group than that in COX-2-negative group and VEGF-negative group.Expression of COX-2 and VEGF, as well as MVD value were highly correlated with lymph node metastasis and vascular invasion. The 5-year survival rate of patients with expression of COX-2 or VEGF was significantly lower than that of patients without COX-2 or VEGF expression. Multivariate analysis revealed that VEGF overexpression, lymph node metastasis,COX-2 overexpression, depth of invasion and vascular invasion were all independent prognostic factors of gastric carcinoma.CONCLUSION: Overexpression of COX-2 and VEGF in patients with gastric carcinoma can enhance the possibility of invasion and metastasis, implicating a poor prognosis.They may serve as the fairly good prognostic factors to indicate biologic behaviors of gastric carcinoma.Hai Shi Jian-Ming Xu Nai-Zhong Hu Hui-Jun Xie Department of Gastroenterology,the First Affiliated Hospital,Anhui Medical University,Hefei 23022,Anhui Province,China 2003World Journal of Gastroenterology2003,9,7:64
5A CLASS OF SINGULARLY PERTURBEDBOUNDARY VALUE PROBLEMS FOR NONLINEARDIFFERENTIAL SYSTEMS显示文摘The singularly perturbed nonlinear problem εy' = f(x, y’)y + g(x, y’), 0 MO Jiaqi (Department of Mathematics, Anhui Normal University, Wuhu 241000, China) 1999Systems Science and Mathematical Sciences1999,12,1:51
6L-forms of H. pylori显示文摘AIM: To study the occurrence of L-forms of H. pyloriinfection in patients with peptic ulcers and its association with possible changes of cellular immune function in the patients.METHODS: Endoscopic biopsy specimens of gastric antrum and gastric corpus were taken from 228 patients with peptic ulcers and inoculated into Skirrow selective medium for H.pylorivegetative forms and special medium for H. pylori Lforms, followed by bacterial isolation and identification. And peripheral venous blood of the patients was taken to detect the percentage of CD3+, CD4+ and CD8+ with biotin-streptavidin (BSA) and the level of IL-2, IL-6 and IL-8 with ElISA.RESULTS: (1) The detection rates of H. pyloriL-forms and vegetative forms in the patients were 50.88 % (116/228)and 64.91 % (148/228) respectively, and the co-infection rate of H. pyloriL-forms and vegetative forms was 78.38 % (116/148). To be more exact, the detection rates of H. pylori L-forms in male and female patients were 57.04 % (77/135) and 41.94 % (39/93) respectively, and statistics found significant difference between them (P<0.05). Furthermore, the detection rates of H. pyloriL-forms in patients aged 14 years-, 30 years-, 40 years- and 50 years- were 31.91%(15/47), 42.86 % (24/56), 56.94 % (41/72) and 67.92 %(36/53) respectively, and there was significant difference between them (P<0.011). (2) The percentages of CD3+, CD4+,CD8+, the ratio of CD4+/CD8+, and the level of IL-2, IL-6,IL-8 in H. pylori-positive patients were (52.59±5.44) %,(35.51±5.74) %, (27.77±8.64) %, (1.56±0.51), (2.66±0.47)mg/L, (108.62±5.85) ng/L and (115.79±7.18) ng/Lrespectively, compared with those in H. pylori-negative patients, the percentages of CD3+, CD4+ and the ratio of CD4+/CD8+ decreased, but the level of IL-2, IL-6 increased, and the difference was significant (P<0.001-P<0.011).Moreover, the percentages of CD3+, CD4+, CD8+, the ratio of CD4+/CD8+, and the level of IL-2, IL-6, IL-8 in the patients with mixed infection of bothH. pyloriL-forms and vegetative forms were (51.69±5.28) %, (34.75±5.89) %, (27.15±7.45) %, (1.48±0.47), (2.16±0.38) mg/L, (119.45±5.44) ng/L and (123.64±6.24) ng/L respectively, compared with those in patients with simple infection of H. pylorivegetative forms,the percentage of CD4+, the ratio of CD4+/CD8+ and the level of IL-2 increased, but the level of IL-6 and IL-8decreased, statistical difference was found between them (P<0.001-P<0.05).CONCLUSION: L-forms variation often occurs in patients with peptic ulcers who are infected byH. pylori, which is commonly found in male patients and related to ages. The L-forms variation of H. pylori can be an important factor causing disorder of cellular immune function in the patients with peptic ulcers who are infected by H. pylori.Ke-Xia Wang Chao-Pin Li Yu-Bao Cui Ye Tian Qing-Gui Yang School of Medicine, Anhui University of Science & Technology Huainan 232001, Anhui Province, China 2003World Journal of Gastroenterology2003,9,3:47
7Detection of T lymphocyte subsets and mIL-2R on surface of PBMC in patients with hepatitis B显示文摘AIM: To study the levels of T lymphocyte subsets andmembrane interleukin-2 receptor (mIL-2R) on surface ofperipheral blood mononuclear cells (PBMCs) of patients withhepatitis B and its role in the pathogenesis of hepatitis B.METHODS: The levels of T lymphocyte subsets and mIL-2R in PBMC before and after being stimulated with PHAwere detected by biotin-streptavidin (BSA) technique in 196cases of hepatitis B.RESULTS: In patients with hepatitis B, the levels of CD3+,CD4+ cells, and the ratio of CD4+ cells/CD8+ cells were lower,but the level of CD8+ cells was higher than those in normalcontrols (42.20±6.01 vs65.96±6.54, 38.17±5.93 vs41.73±6.40,0.91±0.28 vs 1.44±0.31, 39.86±6.36 vs30.02±-4.54, P<0.01).The total expression level of mIL-2R in PBMC before andafter being stimulated with PHA was also lower than thosein normal controls (3.47±1.55 vs4.52±1.49, 34.03±2.94 vs37.95±3.00, P<0.01). In all the patients with hepatitis B, thelevels of T lymphocyte subsets and mIL-2R in PBMC withHBV-DNA (+) were lower than those with HBV-DNA (-),which were significantly different (39.57±7.11 vs44.36±5.43,34.36±7.16 vs 40.75±5.87, 37.82±6.54 vs 41.72±6.21,0.88±0.33 vs0.99±0.27, 2.82±1.62 vs3.85±1.47, 31.56±3.00vs35.84±2.83, P<0.01). In addition, the levels of CD3+, CD4+,CD8+ cells, the ratio of CD4+ cells/CD8+ cells and mIL-2R amongdifferent courses of hepatitis B were all significantly different(F=3 723.18, P<0.01. F=130.43, P<0.01. F=54.01, P<0.01.F=2.99, P<0.05. F=7.16, P<0.01).CONCLUSION: Both cellular and humoral immune functionsare obviously in disorder in patients with hepatitis B, whichmight be closely associated with the chronicity in patients.Ke-Xia Wang Jiang-Long Peng Xue-Feng Wang Ye Tian Jian Wang Chao-Pin Li School of Medicine,Anhui University of Science and Technology,Huainan 232001,Anhui Province,China 2003World Journal of Gastroenterology2003,9,9:32
8Acaroid mite,intestinal and urinary acariasis显示文摘AIM: To investigate epidemiology and pathogenic mite species of intestinal and urinary acariasis in individuals with different occupations.METHODS: A total of 1994 individuals were tested in this study. History collection, skin prick test and pathogen identification were conducted. The mites were isolated from stool and urine samples by saturated saline flotation methods and sieving following centrifugation, respectively.RESULTS: Among the 1994 individuals examined, responses to the skin prick test of '+++', '++', '+','±' and '-' were observed at frequencies of 3.96 % (79), 3.21% (64), 2.31%(46), 1.25 % (25) and 89.27 % (1780), respectively. A total number of 161 (8.07 %) individuals were shown to carry mites, with 92 (4.61%) positive only for stool samples, 37(1.86 %) positive only for urine samples and 32 (1.60 %)for both. The positive rate of mites in stool samples was 6.22 % (124/1994), being 6.84 % (78/1140) for males and 5.39 % (46/854) for females. No gender difference was observed in this study (χ2=1.77, P>0.05). The mites from stool samples included Acarus siro, TynoPhagus putrescentiae,Dermatophagoides farinae, D. pteronyssinus, Glycyphagus domesticus, G.ornatus, Carpoglyphus lactis and Tarsonemus granaries. The positive rate of mites in urine samples was 3.46 % (69/1994). The positive rates for male and female subjects were found to be 3.95 % (45/1140) and 2.81%(24/854) respectively, with no gender difference observed (χ2=1.89, P>0.05). Mites species in urine samples included Acar us siro, Tynophagus putrescentiae, T. longior, Aleunocglyphus ovatus, Caloglyphus berlesei, C mycophagus, Suidasia nesbitti, Lardoglyphus konoi, Glycyphagus domesticus,Carpoglyphus lactis, Lepidoglyphus destructor,Dermatophagoides farinae, D. pteronyssinus, Euroglyphus magnei, Caloglyphus hughesi, Tarsonemus granarus and T.hominis. The species of mites in stool and urine samples were consistent with those separated from working environment. A significant difference was found among the frequencies of mite infection in individuals with different occupations (χ2=82.55, P<0.001), with its frequencies in those working in medicinal herb storehouses, those in rice storehouse or mills, miners, railway workers, pupils and teachers being 15.89 % (68/428), 12.96 % (53/409), 3.28 %(18/549), 2.54 % (6/236), 5.10 % (13/255) and 2.56 % (3/117), respectively.CONCLUSION: The prevalence of human intestinal and urinary acariasis was not associated with gender, and these diseases are more frequently found in individuals working in medicinal herb, rice storehouses or mills and other sites with high density of mites. More attention should be paid to the mite prevention and labor protection for these highrisk groups.Chao-Pin Li Yu-Bao Cui Jian Wang Qing-Gui Yang Ye Tian Department of Etiology and Immunology,School of Medicine,Anhui University of Science & Technology,Huainan 232001,Anhui Province,China 2003World Journal of Gastroenterology2003,9,4:30
9Selection of the Linear Regression Model According to the Parameter Estimation显示文摘In this paper,based on the theory of parameter estimation,we give a selection method and,in a sense or a good character of the parameter estimation,we think that it is very reasonable. Moreover,we offer a calculation method of selection statistic and an applied example.Sun Dao-de Department of Computer, Fuyang Teachers College, Anhui 236032,China 2000Wuhan University Journal of Natural Sciences2000,5,4:28
10mIL-2R,T cell subsets & hepatitis C显示文摘AIM: To study the levels of membrane interleukin-2 receptor(mIL-2R ) and T cell subsets in peripheral bloodmononuclear cells (PBMC) from patients with hepatitis Cand their role in the pathogenesis of hepatitis C.METHODS: The levels of mlL-2R and T cells subsets in PBMCWere detected by biotin- streptstividin (BSA) technique beforeand after stimulation with PHA in 203 patients with hepatitis Cwith HCV-RNA( + ), anti-HCV( + ), anti-HCV(-).RESULTS: The total expressive levels of mlL-2R before andafter stimulation with PHA(0.03 ± 0.01, 0.03 ± 0.02, 0.04 ± 0.02, 0.36±0.03), and Tcell subsets in PBMC (0.62±0.06,0.37 ± 0.05, 0.35 ± 0.07) were all lower in patients withhepatitis C than those in normal controls (0.66 ± 0.07, 0.41± 0.06, 0.31 ± 0.05, P < 0.01 ). Among the patients, thelevels of mlL-2R were lower in silence than those in situationof PHA inducting (P< 0.01). However, the levels of mlL-2Rwere similar in acute hepatitis C to that in chronic hepatitis C(P>0.05). The levels of CD3+, CD4+, CD4 +/CD8+ Were lov erand CD8 + was higher in patients with acute and chronichepatitis C with anti-HCV( + ) than those in normal controls (0.62±0.06, 0.37±0.05, 0.35±0.07, 1.18±0.30, 0.61±0.07, 0.37±0.05, 1.39±0.33, 0.31±0.05, P<0.05-P<0.01).CONCLUSION: The cellular immunity is obviously changed inpatients with hepatitis C. The levels of mlL-2R end activationof T cells am closely associated with chronicity of hepatitis C.Chao-Pin Li Ke-Xia Wang Jian Wang,Department of Aetiology and Immunology,School of Medicine,Huainan University of Technology,Huainan 232001,Anhui Province,China Bo-Rong Pan,the Fourth Military Medical University 2002World Journal of Gastroenterology2002,8,2:24
11Multipliers on Dirichlet Type SpacesPeng Yan HU Department of Mathematics. Normal College of Shenzhen University. Shenzhen. Guangdong 518060. P. R. China Ji Huai SHI Department of Mathematics. University of Science and Technology of China. Hefei. Anhui 230026, P. R. China 2001Acta Mathematica Sinica,English Series2001,17,2:23
12Quantum secret sharing between multiparty and multiparty with Bell states and Bell measurements显示文摘We present a quantum secret sharing scheme between multiparty (m members in Group 1) and multiparty (n members in Group 2), and analyze its security. This scheme takes EPR pairs in Bell states as quantum resources. In order to obtain the shared key, all members only need to perform Bell measurements, rather than perform any local unitary operation. The total efficiency in this scheme approaches 100% as the classical information exchanged is not necessary except for the eavesdropping checks.SHI RunHua 1,2* , HUANG LiuSheng 1,3 , YANG Wei 1,3 & ZHONG Hong 2 1 National High Performance Computing Center at Hefei, Department of Computer Science and Technology, University of Science and Technology of China, Hefei, 230027, China 2 School of Computer Science and Technology, Anhui University, Hefei 230039, China 3 Suzhou Institute for Advanced Study, USTC, Suzhou 215123, China 2010Science China(Physics,Mechanics & Astronomy)2010,53,12:17
13Some Concepts and Mathematical Consideration of Similarity System TheoryZHOU MeiliDepartment of Mechanical Engineering, Anhui Institute of Technology 111 Lu An Road, Hefei 230069, the People’s Republic of China 1992Systems Science and Systems Engineering1992,2,1:17
14A reconstruction method of porous media integrating soft data with hard data显示文摘The three-dimensional reconstruction of porous media is of great significance to the research of mechanisms of fluid flow. The real three-dimensional structural data of porous media are helpful to describe the irregular topologic structures in porous media. The reconstruction of porous media will be inaccurate while only hard data or no conditional data are available. Reconstructed results can be more accurate, using soft data during reconstruction. Integrating soft data with hard data, a method based on multiple-point geostatistics (MPS) is proposed to reconstruct three-dimensional structures of porous media. The variogram curves and permeability, computed by lattice Boltzmann method (LBM), of the reconstructed images and the target image obtained from real volume data were compared, showing that the structural characteristics of reconstructed porous media using both soft data and hard data as conditional data are most similar to those of real volume data.LU DeTang1,2,3, ZHANG Ting1,2,3, YANG JiaQing1,2,3, LI DaoLun1,2,3 & KONG XiangYan1,2,3 1 Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, China 2 Research Center of Oil and Natural Gas, University of Science and Technology of China, Hefei 230027, China 3 Key Laboratory of Software in Computing and Communication of Anhui Province, University of Science and Technology of China, Hefei 230027, China 2009Chinese Science Bulletin2009,54,11:16
15Invariant sets and solutions to the generalized thin film equation显示文摘The invariant sets and the solutions of the 1+2-dimensional generalized thin film equation are discussed. It is shown that there exists a class of solutions to the equations, which are invariant with respect to the set E0 = {u : ux = vxF(u), uy = vyF(u)}, where v is a smooth function of variables x, y and F is a smooth function of u. This extends the results of Galaktionov (2001) and for the l+l-dimensional nonlinear evolution equations.Chang-zheng QU & Chun-rong ZHU Center for Nonlinear Studies, Northwest University, Xi’an 710069, China Department of Mathematics, Northwest University, Xi’an 710069, China Department of Mathematics, Anhui Normal University, Wuhu 241000, China 2007Science China Mathematics2007,50,6:15
16Apoptosis of hepatoma cells SMMC-7721 induced by Ginkgo biloba seed polysaccharide显示文摘AIM: To study the apoptosis of hepatoma cells SMMC-7721induced by polysaccharide isolated from Ginkgo biloba seed.METHODS: Ginkgo biloba seed polysaccharide (GBSP) wasisolated by ethanol fractionation of Ginkgo biloba seed andpurified by Sephadex G-200 chromatography. The purity ofGBSP was verified by reaction with iodine-potassium iodideand ninhydrin and confirmed by UV spectrophotometer,cellulose acetate membrane electrophoresis and Sepharose4B gel filtration chromatography. The Scanning ElectronMicroscope (SEM) and Flow Cytometrv (FCM) were used toexamine the SMMC-7721 cells with and without GBSPtreatment at 500 mg/ml for 36 h.RESULTS: GBSP product obtained was of high purity withthe average molecular weight of 1.86 × 105. Quantitativeanalysis of SMMC-7721 cells in vitro with FCM showed thatthe percentages of G2-M cells without and with GBSPtreatment were 17.01±1.28 % and 11.77±1.50% (P<0.05),the debds ratio of the cells were 0.46±0.12 % and 0.06±0 .06 %(P<0.01), and the apoptosis ratio of cells was 3.84±0 .55 %and 9.13±1.48 %(P<0.01) respectively. Following GBSPtreatment, microvilli of SMMC-7721 cells appeared thinnerand the number of spherical cells increased markedly. Mostsignificantly, the apoptosis bodies were formed on andaround the spherical cells treated with GBSP.CONCLUSION: GBSP could potentially induce the apoptosisof SMMC-7721 cells.Gui-Wen Yang Li-Guo An Department of Biology,Shandong Normal University,Jinan 250014,Shandong Province,China Qun Chen Department of Biology & Chemistry,Huainan Teachers College,Huainan 232001,Anhui Province,China 2002World Journal of Gastroenterology2002,8,5:15
17Epidemiological survey of cryptosporidiosis in Anhui Province China显示文摘AIM: To provide scientific evidence for prevention and controlling of cryptosporidiosis, the infection of Cryptosporidium parvum and its epidemiological characteristics were studied in some areas of Anhui Province.METHODS: The oocyst of Cryptosporidium parvum in 5421fresh stool samples from eleven areas of Anhui Provincewas tested by auramine-phenol stain and improved anti-acidstain respectively. The specific antibody of IgG, IgM and Tsubsets of 41 patients with positive Cryptosporidium parvumin stools were detected by ELISA and biotin-streptavidin(BSA) respectively.RESULTS: The total infective rate of Cryptosporidiumparvum was 1.33 % (74/5421). Among them, the positiverates of oocyst in the areas of Huaibei (1. 82 % ) and Fuyang( 1. 80 % ) were higher. The positive rates of oocyst in stoolsof infants, pupils, middle school students, collegestudents, adults, patients with diarrhea, and those withimmunodeficiency were 3.15 % (28/889), 0.82 % (9/1098), 0.82 %(9/1092), 0.83 %(8/969), 0.85 % (9/1095), 2.88 %(8/27g) and 8.33 %(3/36) % respectively. The positive rates ofoocyst in infants and the patients with diarrhea andimmunodeficiency were significantly higher than those incontrols ( P < 0.01 ). The positive rate of oocyst in maleswas similar to that in females ( P> 0.05). The positive rateof oocyst in urban areas ( 1. 13 %) was significantly lowerthan those in rural areas ( 1. 72 %, P < 0.01 ). The positiverates of specific IgG, IgM and IgG + IgM in sera of thepatients with positive oocyst in stool were 63.4 % ( 26/41 ),17.1% (7/41), 19.5 % (8/41) respectively. The numberfractions of T subsets of CD3 + , CD4 + , CD8 + and CD4 +/CD8 + of the patients were 0.66 ± 0.07, 0.44 ± 0.06, 0.28 ± 0.04 and 1. 58 ± 0.32 respectively. The difference between thepatients and the controls was significant ( P < 0. 05). Themain manifestations of the patients were subclinicalinfection, in forms of slight abdominal pain, mild diarrhea,and loose stool.CONCLUSION: There are two infection peaks in infection ofCryptosporidium parvum and its infection can he foundmore often in infants, patients with diarrhea orimmunodeficiency, and in rural areas. Subclinical infectionis the main manifestation and might he easily misdiagnosed.When the therapeutic effectiveness is low for diarrhea, theinfection of Cryptosporidium parvum should he considered,conceming their age and immune function.Ke-Xia Wang Chao-Pin Li Jian Wang,Department of Aetiology and Immunology, School of Medicine, Huainan University of Technology,Huainan 232001,Anhui Province,China Bo-Rong Pan,Department of Oncology,Xijing Hospital,the Fourth Military Medical University,Xian,Shanxi Province,China 2002World Journal of Gastroenterology2002,8,2:15
18Distribution and fractionation mechanism of stable carbon isotope of coalbed methane显示文摘The stable carbon isotope values of coalbed methane range widely, and also are gener- ally lighter than that of gases in normal coal-formed gas fields with similar coal rank. There exists strong carbon isotope fractionation in coalbed methane and it makes the carbon isotope value lighter. The correlation between the carbon isotope value and Ro in coalbed methane is less obvious. The coaly source rock maturity cannot be judged by coalbed methane carbon isotope value. The carbon isotopes of coalbed methane become lighter in much different degree due to the hydrodynamics. The stronger the hydrodynamics is, the lighter the CBM carbon isotopic value becomes. Many previous investigations indicated that the desorption-diffusion effects make the carbon isotope value of coalbed methane lighter. However, the explanation has encountered many problems. The authors of this arti- cle suggest that the flowing groundwater dissolution to free methane in coal seams and the free methane exchange with absorbed one is the carbon isotope fractionation mechanism in coalbed methane. The flowing groundwater in coal can easily take more 13CH4 away from free gas and com- paratively leave more 12CH4. This will make 12CH4 density in free gas comparatively higher than that in absorbed gas. The remaining 12CH4 in free gas then exchanges with the adsorbed methane in coal matrix. Some absorbed 13CH4 can be replaced and become free gas. Some free 12CH4 can be ab- sorbed again into coal matrix and become absorbed gas. Part of the newly replaced 13CH4 in free gas will also be taken away by water, leaving preferentially more 12CH4. The remaining 12CH4 in free gas will exchange again with adsorbed methane in the coal matrix. These processes occur all the time. Through accumulative effect, the 12CH4 will be greatly concentrated in coal. Thus, the stable carbon isotope of coalbed methane becomes dramatically lighter. Through simulation experiment on wa- ter-dissolved methane, it had been proved that the flowing water could fractionate the carbon isotope of methane, and easily take heavy carbon isotope away through dissolution.QIN Shengfei1, TANG Xiuyi2, SONG Yan1 & WANG Hongyan3 1. Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China 2. Anhui Science and Technology College, Huainan 232000, China 3. Langfang Branch, Research Institute of Petroleum Exploration and Development, PetroChina, Langfang 065007, China 2006Science China Earth Sciences2006,49,12:14
19Characteristics of N Mineralization in Urban Soils of Hefei,East China显示文摘Nitrogen cycling has been poorly characterized in urban ecosystems.An in-situ buried bag incubation technique was used to quantify net rates of N mineralization and nitrification in soils of two urban sites,a street greening belt and a university campus,and a suburban site,a forest park,in Hefei,East China.The average concentration of extractable NO 3 in the surface soil (0-10 cm) was significantly higher at the urban sites than the suburban park site,whereas extractable NH + 4 concentration was significantly higher at the suburban park site than the urban sites.The forest park soil had greater potential N mineralization (148.1 μg N cm 3) than the soils from the campus (138.3 μg N cm 3) and street (99.8 μg N cm 3).The net mineralization rates varied between 1.63 and 2.69 μg N cm 3 d 1 and net nitrification rates between 0.82 and 1.02 μg N cm 3 d 1 at the suburban forest park site,but the rates varied from 1.27 to 2.41 μg N cm 3 d 1 and from 1.07 to 1.49 μg N cm 3 d 1,respectively,at the urban campus site.Both net mineralization and nitrification rates were lower during dry seasons.Results from regression analysis indicated that net N mineralization was significantly and positively correlated with soil moisture and soil C/N ratio,and was negatively correlated with soil pH.Relative nitrification was,however,significantly and negatively correlated with soil moisture and soil C/N ratio,and was positively correlated with soil pH.Mean relative nitrification was 0.763,indicating the dominance of nitrate cycling relative to ammonium cycling at the urban sites.The urban soils had the great potential for N losses compared to the suburban soils.ZHANG Kai,XU Xiao-Niu and WANG Qin School of Forestry and Landscape Architecture,Anhui Agricultural University,Hefei 230036 (China) 2010Pedosphere2010,20,2:13
20EXISTENCE AND UNIQUENESS OF ANTI-PERIODIC SOLUTIONS TO AN nTH-ORDER NONLINEAR DIFFERENTIAL EQUATION WITH MULTIPLE DEVIATING ARGUMENTS显示文摘In this paper,we use the Leray-Schauder degree theory to establish some new results on the existence and uniqueness of anti-periodic solutions to an nth-order nonlinear differential equation with multiple deviating arguments.Jianzhong Xu 1,2,Zongfu Zhou 1 (1.Dept.of Math.,Bozhou Teachers College,Bozhou 236800,Anhui,2.School of Mathematical Sciences,Anhui University,Hefei 230039) 2012Annals of Differential Equations2012,28,1:13
返回顶部 每页显示:
共24页 首页 上一页 第1页 下一页 末页 /24 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费