This paper is devoted to the nonlinear stress and strain analysis oftunneling and working conditions of Wanjiazhai Division Project No.7 Tunnel in Shanxi province ofChina. The initial geological stress of loess was si...This paper is devoted to the nonlinear stress and strain analysis oftunneling and working conditions of Wanjiazhai Division Project No.7 Tunnel in Shanxi province ofChina. The initial geological stress of loess was simulated by grading fill; the theory of unloadingproposed by Duncan and boundary stress of elasticity were used to calculate the excavation of thetunnel; Goodman joint elements were applied to simulate the joints of the liners; both loading andunloading tests have been performed to determine the parameters of Duncan-Chang's model and thecalculated results were compared; Terzaghi' s theory on loosening earth pressure was applied. Manyworking conditions were analyzed and some reasonable results were obtained. Based on the analyses,reparative measures were proposed and completed. The tunnel has functioned well since October, 2001.展开更多
Peltophorum dubium seeds provided by Anhembi, SP were scarified in 98% H2SO4 for 15 min to overcome mechani-cal dormancy. Seeds were primed in solutions of 0.2% Captan at 10 C and 27C, PEG 6000 -1.0 MPa at 10C and 27...Peltophorum dubium seeds provided by Anhembi, SP were scarified in 98% H2SO4 for 15 min to overcome mechani-cal dormancy. Seeds were primed in solutions of 0.2% Captan at 10 C and 27C, PEG 6000 -1.0 MPa at 10C and 27C, 0.5 mol KNO3, 0.75 Mol KNO3, 1.0 Mol KNO3. Eight treatments including the primed seeds and nonprimed seeds, five replicates with 100 seeds for each treatment, were set to 15-cm-Petri dish with double filter paper moistened with testing solution PEG in refrigerator at 27C. For the experiments of all the groups, osmotic potential were 0.0, -0.2, -0.4, -0.6, -0.8, -1.0, -1.2, and -1.4 MPa. P. dubium seeds were also set to water stress experiment in rolled paper with PEG solutions from 0.0 to -1.0 M Pa. Germination percentage decreased with the increase of PEG concentration. Control group had a better germination percentage than other groups. Germination hardly occurred in PEG -1.4 MPa.展开更多
[ Objective] This study was to investigate the pathogenic mechanism of rice sheath blight pathogen ( Rhizoctonia solani) and the bioactive components of toxin. [ Method ] Rice sheath blight pathogen was cultured in ...[ Objective] This study was to investigate the pathogenic mechanism of rice sheath blight pathogen ( Rhizoctonia solani) and the bioactive components of toxin. [ Method ] Rice sheath blight pathogen was cultured in the improved Richared medium; the culture filtrate was centrifuged and sterilized, then treated by activated carbon adsorption chromatography, distilled with methanol or water, and all were next concentrated, yielding the crude extracts of culture solution, crude extracts of methanol and crude extracts of water; the activities of these three extracts were determined, [ Result] The three extracts were russet pastes; activity determination showed that they had remarkable inhibitory effects on the growth of rice radicle and plantule, as well as the growth of four-foliage-young seedlings. They could also generate toxic effects on abscisic foliages and spots similar to the symptoms of sheath blight pathogen. [ Conclusion] Bioactive components of rice sheath blight pathogen toxin may be composed of various ingredients.展开更多
AIM: To study the effect of botulinum toxin in patients with chronic anal fissure after biliopancreatic diversion (BPD) for severe obesity. METHODS: Fifty-nine symptomatic adults with chronic anal fissure developed af...AIM: To study the effect of botulinum toxin in patients with chronic anal fissure after biliopancreatic diversion (BPD) for severe obesity. METHODS: Fifty-nine symptomatic adults with chronic anal fissure developed after BPD were enrolled in an open label study. The outcome was evaluated clinically and by comparing the pressure of the anal sphincters before and after treatment. All data were analyzed in univariate and multivariate analysis. RESULTS: Two months after treatment, 65.4% of the patients had a healing scar. Only one patient had mild incontinence to flatus that lasted 3 wk after treatment, but this disappeared spontaneously. In the multivariate analysis of the data, two registered months after the treatment, sex (P = 0.01), baseline resting anal pressure (P = 0.02) and resting anal pressure 2 mo after treatment (P < 0.0001) were significantly related to healing rate.CONCLUSION: Botulinum toxin, despite worse results than in non-obese individuals, appears the best alternative to surgery for this group of patients with a high risk of incontinence.展开更多
In most studies of tunnel boring machine(TBM)tunnelling, the groundwater pressure was not considered, or was simplified and exerted on the boundary of lining structure. Meanwhile, the leakage, which mainly occurs in t...In most studies of tunnel boring machine(TBM)tunnelling, the groundwater pressure was not considered, or was simplified and exerted on the boundary of lining structure. Meanwhile, the leakage, which mainly occurs in the segment joints, was often ignored in the relevant studies of TBM tunnelling. Additionally, the geological models in these studies were simplified to different extents, and mostly were simplified as homogenous bodies. Considering the deficiencies above, a 3D refined model of the surrounding rock of a tunnel is firstly established using NURBS-TIN-BRe P hybrid data structure in this paper. Then the seepage field of the surrounding rock considering the leakage in the segment joints is simulated. Finally, the stability of TBM water diversion tunnel is studied coupled with the seepage simulation, to analyze the stress-strain conditions, the axial force and the bending moment of tunnel segment considering the leakage in the segment joints. The results illustrate that the maximum radial displacement, the minimum principal stress, the maximum principal stress and the axial force of segment lining considering the seepage effect are all larger than those disregarding the seepage effect.展开更多
AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and tre...AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing glutamine,butyrate,or saline.Enemas were administered twice a week in the excluded segment of the colon from 4 to 12 wk after the surgical procedure.Follow-up colonoscopy was performed every 4 wk for 12 wk.The effect of treatment was evaluated using video-endoscopic and histologic scores and measuring interleukin-1β,tumor necrosis factor-alpha,and transforming growth factor beta production in organ cultures by enzyme linked immunosorbent assay.RESULTS:Colonoscopies of the diverted segment showed mucosa with hyperemia,increased number of vessels,bleeding and mucus discharge.Treatment with either glutamine or butyrate induced significant reductions in both colonoscopic(P < 0.02) and histological scores(P < 0.01) and restored the densities of collagen fibers in tissue(P = 0.015;P = 0.001),the number of goblet cells(P = 0.021;P = 0.029),and the rate of apoptosis within the epithelium(P = 0.043;P = 0.011) to normal values.The high levels of cytokines in colon explants from rats with diversion colitis significantly decreased to normal values after treatment with butyrate or glutamine.CONCLUSION:The improvement of experimental diversion colitis following glutamine or butyrate enemas highlights the importance of specific luminal nutrients in the homeostasis of the colonic mucosa and supports their utilization for the treatment of human diversion colitis.展开更多
The Western Route of the South-to-North Water Diversion Project is an important trans-basin diversion project to transfer water from the upstream Yangtze River and its tributaries (water-exporting area), to the upst...The Western Route of the South-to-North Water Diversion Project is an important trans-basin diversion project to transfer water from the upstream Yangtze River and its tributaries (water-exporting area), to the upstream of the Yellow River (water- importing area). The long-term hydrologieal data from 14 stream gauging stations in the Western Route area and techniques including the pre-whitening approach, non-parametric test, Bayes, law, variance analysis extrapolation, and Wavelet Analysis are applied to identify the streamflow eharacteristics and trends, streamflow time series cross-correlations, wetness-dryness encountering probability, and periodicities that occurred over the last 50 years. The results show that the water-exporting area, water- importing area, and the streteh downstream of the water-exporting have synehronization in high-low flow relationship, whereas they display non- synchronization in long-term evolution. This corresponds to the complicated and variable climate of the plateau region. There is no obvious increasing or decreasing trend in runoff at any gauging station. The best hydrological eompensation probability for rivers where water is diverted is about 25% to lO%, and those rivers influenced significantly by diversion are the Jinsha and Yalong rivers. Proper planning and design of compensation reservoirs for the water-exporting area and stretch downstream of the water- exporting area can increase the hydrological compensation possibility from water-exporting area to the water-importing area, and reduce the impact on the stretch of river downstream of the water- exporting area.展开更多
The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization b...The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization become one of the most important geological engineering problems. At the same time, it is also crucial to select a safe and economic excavation gradient for the construction. We studied the problem of how to select a safe and economic slope ratio by analyzing the geological condition of the high slope, including the lithology, slope structure, structural surface and their combinations, rock weathering and unloading, hydrology, and the natural gradient. The study results showed that the use of an excavation gradient larger than the gradient observed during site investigation and the gradient recommended in standards and field practice manuals is feasible. Then, we used the finite element method and rigid limit equilibrium method to evaluate the stability of the excavation slope under natural, rainstorm and earthquake conditions. The calculated results showed that the excavated slope only has limited failure, but its stability is greatly satisfactory. The research findings can be useful in excavation and slope stabilization projects.展开更多
Objective To assess the effects of suction drainage versus nondrainage on the post-operative rehabilitation of patients receiving primary bilateral total knee arthroplasties(TKA).Methods A prospective study including ...Objective To assess the effects of suction drainage versus nondrainage on the post-operative rehabilitation of patients receiving primary bilateral total knee arthroplasties(TKA).Methods A prospective study including 40 patients was conducted.These patients were diagnosed with osteoarthritis and underwent primary bilateral TKA between October 2007 and September 2009 with the same operation team.A suction drainage was placed by randomization in only one knee for each patient,while the other knee as self-control.Pain visual analogue scale score,extremity swelling,wound healing,range of motion and incidence of early post-operative complications between the drained and nondrained group were compared statistically.Results Each patient was followed up for 12 months.Placing drainage did not relieve the pain,extremity swelling,ecchymosis,or reduce the incidence of early complications(all P>0.05).Conclusions Suction drainage in TKA does not exhibit substantial advantages in promoting post-operative rehabilitation after unsophisticated TKA,compared with nondrainage.On the other hand,it might complicate the surgical operation,and increase the incidence of post-operative hemorrhage and retrograde infection.Thus we do not recommend suction drainage in unsophisticated TKA.展开更多
A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agre...A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin(except the North Indian Ocean, where the circulation is dominated by monsoons). The identifi ed nonSverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom(JEBAR) and mesoscale eddy nonlinearity.展开更多
Based on analyzing risk factors of diversion project,synthetic risk rate and engineering insurance period,the frequency and distribution law of loss are researched on the grounds that foundation pit is submerged after...Based on analyzing risk factors of diversion project,synthetic risk rate and engineering insurance period,the frequency and distribution law of loss are researched on the grounds that foundation pit is submerged after diversion project ceases to be effective.And then,the standpoint that these total loss is subject to non-homogeneous compound Poisson processes is put forward.Furthermore,the collective risk model of the total loss about engineering insurance is established on the basis of construction diversion project risk.Ultimately,insurance ratemaking method for construction engineering risk and its mathematical expression are presented,which provides theoretical method for the insurance ratemaking of hydropower engineering to some extent.展开更多
The authors examined the performance of version 3.4.1 of the Weather Research and Forecasting Model(WRF) with various land surface schemes in simulating a severe drought event in Southwest China. Five numerical experi...The authors examined the performance of version 3.4.1 of the Weather Research and Forecasting Model(WRF) with various land surface schemes in simulating a severe drought event in Southwest China. Five numerical experiments were completed using the Noah land surface scheme, the Pleim-Xiu land surface scheme, the Noah-MP land surface schemes, the Noah- MP scheme with dynamic vegetation, and the Noah-MP scheme with dynamic vegetation and groundwater processes. In general, all the simulations reasonably reproduced the spatial and temporal variations in precipitation, but significant bias was also found, especially for the spatial pattern of simulated precipitation. The WRF simulations with the Noah-MP series land surface schemes performed slightly better than the WRF simulation with the Noah and Pleim-Xiu land surface schemes in reproducing the severe drought events in Southwest China. The leaf area index(LAI) simulated by the different land surface schemes showed significant deviations in Southwest China. The Pleim-Xiu scheme overestimated the value of LAI by a factor of two. The Noah-MP scheme with dynamical vegetation overestimated the magnitude of the annual cycle of the LAI, although the annual mean LAI was close to observations. The simulated LAI showed a long-term lower value from autumn 2009 to spring 2010 relative to normal years. This indicates that the LAI is a potential indictor to monitor drought events.展开更多
In order to meet the needs of various tasks of water conservancy project, tunnel excavation under the ground, called hydraulic tunnel. Hydraulic tunnel according to the functions of flood discharge, water diversion, i...In order to meet the needs of various tasks of water conservancy project, tunnel excavation under the ground, called hydraulic tunnel. Hydraulic tunnel according to the functions of flood discharge, water diversion, irrigation, water supply, and the construction diversion tunnel of desilting emptying. Nowadays, water conservancy project on flood discharge runnel design requirements more and more high, so the factors taken into account the amount of spillway tunnel engineering, engineering cost, structure design and other factors to evaluate nature of the spillway tunnel is very important. Therefore, in actual construction, of spillway tunnel of optimization design, whether from the economic point of view, or from the point of view of safety and applicability are necessary. This article mainly from the overall layout of flood discharge tunnel, structure design and so on, and then discuss the optimization scheme.展开更多
Different results of seed purity identification for Gangyou 158, Ⅱ You 808, Wuyou 308 and Tianfengyou 316 were obtained using different SSR primers in our early work. To find out the reasons, the four hybrid combinat...Different results of seed purity identification for Gangyou 158, Ⅱ You 808, Wuyou 308 and Tianfengyou 316 were obtained using different SSR primers in our early work. To find out the reasons, the four hybrid combinations were grown in field to identify their purity according to their phenotypic traits. Then, the results of field identification were compared with that of laboratory tests using different SSR primers. The comparison revealed that only sterile lines (female parent) were distin- guished from true hybrids using the primers RM208, RM264, RM242 and RM164 for the purity identification of Gangyou 158, II You 808, Wuyou 308 and Tianfengyou 316, so the results were higher than that of field identification. In contrast, the primers RM341, RM297, RM21 and RM110 were able to distinguish not only the sterile plants but also the cross-pollinated ones from the true hybrids of Gangyou 158,Ⅱ You 808, Wuyou 308 and Tianfengyou 316, and the results of purity identifi- cation using them were close that of field identification, in summary, several pairs of primers should be used for the purity identification of rice hybrids to distinguish all the off-type plants and thus improve the accuracy.展开更多
Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronizati...Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronization attacks of QIM digital watermarking,a low density parity check (LDPC) code-aided QIM watermarking algorithm is proposed,and the performance of QIM watermarking system can be improved by incorporating LDPC code with message passing estimation/detection framework.Using the theory of iterative estimation and decoding,the watermark signal is decoded by the proposed algorithm through iterative estimation of amplitude scaling parameters and decoding of watermark.The performance of the proposed algorithm is closer to the dirty paper Shannon limit than that of repetition code aided algorithm when the algorithm is attacked by the additive white Gaussian noise.For constant amplitude scaling attacks,the proposed algorithm can obtain the accurate estimation of amplitude scaling parameters.The simulation result shows that the algorithm can obtain similar performance compared to the algorithm without desynchronization.展开更多
Effects of heat softening on the initiation of slide surface(shear banding) in clayey slopes during fast deformation were discussed.Controlling equations considering heat,pore pressure and mechanical movement were pre...Effects of heat softening on the initiation of slide surface(shear banding) in clayey slopes during fast deformation were discussed.Controlling equations considering heat,pore pressure and mechanical movement were presented.By perturbation method,the instability condition of localized zone(i.e.criterion for initiation of shear banding) for thermal related soils,such as clayey slope,was obtained.It is shown that slide surface initiates once the thermal-softening effects overcome the strain-hardening effects whether it is adiabatic or not.Without strain hardening effects,strain rate hardening obviously plays a role in initiation of shear band.During initiating process,heat is trapped inside the shear band,which leads rapidly to a pore pressure increase and fast loss of strength.The localized shear strain is concentrated in a narrow zone with a width of several centimeters at most and increases fast.This zone forms the sliding surface.Temperature can increase more than 2?C,pore pressure can increase 160% in about 0.1s inside this zone.These changes cause the fast decrease in friction-coefficient by about 36% over the initial value.That is how shear band initiated and developed in clayey slopes.展开更多
AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty...AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty-two patients received at least 2 wk of drug therapy before the procedure was carried out to reduce the risk of recurrence from spillage during the procedure.The procedure was performed under local anesthesia with a 19-gauge 20 cm long needle,the cyst was punctured,cystic content(approximately 30 mL) was aspirated by a 12-14 F pigtail catheter and aspirated fluids were sent for analysis.Once the cyst was almost empty,two-thirds of the net amount of material aspirated was replaced by hypertonic saline and left in the cavity for about 30 min,with the catheter left in place for reaspiration of most of the fluid.When the amount of fluid drained was less than 10 mL per 24 h,the drainage catheter was removed.RESULTS:All 32 cysts showed evidence of immediate collapse after completion of the procedure,and before discharge from hospital,ultrasound examination showed fluid reaccumulation in all cysts.Serial follow-up showed a progressive decrease in the size and change in the appearance of cysts.To confirm the sterility of these cystic cavities,seven cysts were reaspirated on average 3 mo after the procedure.Investigations revealed no viable scolices.CONCLUSION:PAIR using hypertonic saline is very effective and safe with proper precautions.展开更多
[Objective] This study aimed to establish a high-efficiency and stable SSR amplification system and screen polymorphic primers in order to further compare the tri-group probability analysis method and traditional QTL ...[Objective] This study aimed to establish a high-efficiency and stable SSR amplification system and screen polymorphic primers in order to further compare the tri-group probability analysis method and traditional QTL mapping method. [Method] In this study, we preliminarily screened the 605 pairs of primers evenly distributed on the 12 chromosomes through investigating their polymorphism performance in amplification, and established an optimized SSR-PCR reaction system. [Result] A 10μL SSR-PCR reaction system suitable for rice was set up as fol ows: 2 μl of 10 × Buffer, 2.0 mmol/L Mg2+ (final concentration), 0.5 mmol/L dNTPs, 1.0 μmol/L primers (final concentration), 1 μl of DNA template, 0.15 U Taq DNA polymerase. Among the SSR primers distributed over the genome, 142 pairs that were polymorphic upon the parents were screened. [Conclusion] This study lays a good foundation for sub-sequent QTL mapping studies.展开更多
文摘This paper is devoted to the nonlinear stress and strain analysis oftunneling and working conditions of Wanjiazhai Division Project No.7 Tunnel in Shanxi province ofChina. The initial geological stress of loess was simulated by grading fill; the theory of unloadingproposed by Duncan and boundary stress of elasticity were used to calculate the excavation of thetunnel; Goodman joint elements were applied to simulate the joints of the liners; both loading andunloading tests have been performed to determine the parameters of Duncan-Chang's model and thecalculated results were compared; Terzaghi' s theory on loosening earth pressure was applied. Manyworking conditions were analyzed and some reasonable results were obtained. Based on the analyses,reparative measures were proposed and completed. The tunnel has functioned well since October, 2001.
基金This work is Supported by CAPES Brazil. Open research laboratory of forest plant ecology NEFU. The State's tenth five-year "211 Project"-supported key academic discipline program of ECNU。
文摘Peltophorum dubium seeds provided by Anhembi, SP were scarified in 98% H2SO4 for 15 min to overcome mechani-cal dormancy. Seeds were primed in solutions of 0.2% Captan at 10 C and 27C, PEG 6000 -1.0 MPa at 10C and 27C, 0.5 mol KNO3, 0.75 Mol KNO3, 1.0 Mol KNO3. Eight treatments including the primed seeds and nonprimed seeds, five replicates with 100 seeds for each treatment, were set to 15-cm-Petri dish with double filter paper moistened with testing solution PEG in refrigerator at 27C. For the experiments of all the groups, osmotic potential were 0.0, -0.2, -0.4, -0.6, -0.8, -1.0, -1.2, and -1.4 MPa. P. dubium seeds were also set to water stress experiment in rolled paper with PEG solutions from 0.0 to -1.0 M Pa. Germination percentage decreased with the increase of PEG concentration. Control group had a better germination percentage than other groups. Germination hardly occurred in PEG -1.4 MPa.
基金Supported by National Scientific and Technological Project(30500335)Special Projects Fund of National Excellent Doctorial Dissertation of Education Ministry(2004061)~~
文摘[ Objective] This study was to investigate the pathogenic mechanism of rice sheath blight pathogen ( Rhizoctonia solani) and the bioactive components of toxin. [ Method ] Rice sheath blight pathogen was cultured in the improved Richared medium; the culture filtrate was centrifuged and sterilized, then treated by activated carbon adsorption chromatography, distilled with methanol or water, and all were next concentrated, yielding the crude extracts of culture solution, crude extracts of methanol and crude extracts of water; the activities of these three extracts were determined, [ Result] The three extracts were russet pastes; activity determination showed that they had remarkable inhibitory effects on the growth of rice radicle and plantule, as well as the growth of four-foliage-young seedlings. They could also generate toxic effects on abscisic foliages and spots similar to the symptoms of sheath blight pathogen. [ Conclusion] Bioactive components of rice sheath blight pathogen toxin may be composed of various ingredients.
文摘AIM: To study the effect of botulinum toxin in patients with chronic anal fissure after biliopancreatic diversion (BPD) for severe obesity. METHODS: Fifty-nine symptomatic adults with chronic anal fissure developed after BPD were enrolled in an open label study. The outcome was evaluated clinically and by comparing the pressure of the anal sphincters before and after treatment. All data were analyzed in univariate and multivariate analysis. RESULTS: Two months after treatment, 65.4% of the patients had a healing scar. Only one patient had mild incontinence to flatus that lasted 3 wk after treatment, but this disappeared spontaneously. In the multivariate analysis of the data, two registered months after the treatment, sex (P = 0.01), baseline resting anal pressure (P = 0.02) and resting anal pressure 2 mo after treatment (P < 0.0001) were significantly related to healing rate.CONCLUSION: Botulinum toxin, despite worse results than in non-obese individuals, appears the best alternative to surgery for this group of patients with a high risk of incontinence.
基金Supported by the Foundation for Innovation Research Groups of the National Natural Science Foundation of China(No.51321065)Tianjin Research Program of Application Foundation and Advanced Technology(No.12JCZDJC29200)Tianjin Natural Science Foundation(No.13JCYBJC19500)
文摘In most studies of tunnel boring machine(TBM)tunnelling, the groundwater pressure was not considered, or was simplified and exerted on the boundary of lining structure. Meanwhile, the leakage, which mainly occurs in the segment joints, was often ignored in the relevant studies of TBM tunnelling. Additionally, the geological models in these studies were simplified to different extents, and mostly were simplified as homogenous bodies. Considering the deficiencies above, a 3D refined model of the surrounding rock of a tunnel is firstly established using NURBS-TIN-BRe P hybrid data structure in this paper. Then the seepage field of the surrounding rock considering the leakage in the segment joints is simulated. Finally, the stability of TBM water diversion tunnel is studied coupled with the seepage simulation, to analyze the stress-strain conditions, the axial force and the bending moment of tunnel segment considering the leakage in the segment joints. The results illustrate that the maximum radial displacement, the minimum principal stress, the maximum principal stress and the axial force of segment lining considering the seepage effect are all larger than those disregarding the seepage effect.
基金Supported by Grants from the Brazilian Research CouncilFundao de Amparo à Pesquisa do Estado do Rio de Janeiro
文摘AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing glutamine,butyrate,or saline.Enemas were administered twice a week in the excluded segment of the colon from 4 to 12 wk after the surgical procedure.Follow-up colonoscopy was performed every 4 wk for 12 wk.The effect of treatment was evaluated using video-endoscopic and histologic scores and measuring interleukin-1β,tumor necrosis factor-alpha,and transforming growth factor beta production in organ cultures by enzyme linked immunosorbent assay.RESULTS:Colonoscopies of the diverted segment showed mucosa with hyperemia,increased number of vessels,bleeding and mucus discharge.Treatment with either glutamine or butyrate induced significant reductions in both colonoscopic(P < 0.02) and histological scores(P < 0.01) and restored the densities of collagen fibers in tissue(P = 0.015;P = 0.001),the number of goblet cells(P = 0.021;P = 0.029),and the rate of apoptosis within the epithelium(P = 0.043;P = 0.011) to normal values.The high levels of cytokines in colon explants from rats with diversion colitis significantly decreased to normal values after treatment with butyrate or glutamine.CONCLUSION:The improvement of experimental diversion colitis following glutamine or butyrate enemas highlights the importance of specific luminal nutrients in the homeostasis of the colonic mucosa and supports their utilization for the treatment of human diversion colitis.
基金supported by the China Meteorological Data Sharing Service System,the Bureau of Hydrology,and Water Resources of Sichuan Province,China
文摘The Western Route of the South-to-North Water Diversion Project is an important trans-basin diversion project to transfer water from the upstream Yangtze River and its tributaries (water-exporting area), to the upstream of the Yellow River (water- importing area). The long-term hydrologieal data from 14 stream gauging stations in the Western Route area and techniques including the pre-whitening approach, non-parametric test, Bayes, law, variance analysis extrapolation, and Wavelet Analysis are applied to identify the streamflow eharacteristics and trends, streamflow time series cross-correlations, wetness-dryness encountering probability, and periodicities that occurred over the last 50 years. The results show that the water-exporting area, water- importing area, and the streteh downstream of the water-exporting have synehronization in high-low flow relationship, whereas they display non- synchronization in long-term evolution. This corresponds to the complicated and variable climate of the plateau region. There is no obvious increasing or decreasing trend in runoff at any gauging station. The best hydrological eompensation probability for rivers where water is diverted is about 25% to lO%, and those rivers influenced significantly by diversion are the Jinsha and Yalong rivers. Proper planning and design of compensation reservoirs for the water-exporting area and stretch downstream of the water- exporting area can increase the hydrological compensation possibility from water-exporting area to the water-importing area, and reduce the impact on the stretch of river downstream of the water- exporting area.
基金financially supported by Chinese National Natural Science Foundation (Grant No. 41072229)State Key Laboratory of Hydraulics and Mountain River Engineering (Sichuan University) open fund (Grant No. 201110)Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education and National Engineering Research Center for Inland Waterway Regulation (Chongqing Jiaotong University) open fund (Grant No. SLK2011B04)
文摘The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization become one of the most important geological engineering problems. At the same time, it is also crucial to select a safe and economic excavation gradient for the construction. We studied the problem of how to select a safe and economic slope ratio by analyzing the geological condition of the high slope, including the lithology, slope structure, structural surface and their combinations, rock weathering and unloading, hydrology, and the natural gradient. The study results showed that the use of an excavation gradient larger than the gradient observed during site investigation and the gradient recommended in standards and field practice manuals is feasible. Then, we used the finite element method and rigid limit equilibrium method to evaluate the stability of the excavation slope under natural, rainstorm and earthquake conditions. The calculated results showed that the excavated slope only has limited failure, but its stability is greatly satisfactory. The research findings can be useful in excavation and slope stabilization projects.
文摘Objective To assess the effects of suction drainage versus nondrainage on the post-operative rehabilitation of patients receiving primary bilateral total knee arthroplasties(TKA).Methods A prospective study including 40 patients was conducted.These patients were diagnosed with osteoarthritis and underwent primary bilateral TKA between October 2007 and September 2009 with the same operation team.A suction drainage was placed by randomization in only one knee for each patient,while the other knee as self-control.Pain visual analogue scale score,extremity swelling,wound healing,range of motion and incidence of early post-operative complications between the drained and nondrained group were compared statistically.Results Each patient was followed up for 12 months.Placing drainage did not relieve the pain,extremity swelling,ecchymosis,or reduce the incidence of early complications(all P>0.05).Conclusions Suction drainage in TKA does not exhibit substantial advantages in promoting post-operative rehabilitation after unsophisticated TKA,compared with nondrainage.On the other hand,it might complicate the surgical operation,and increase the incidence of post-operative hemorrhage and retrograde infection.Thus we do not recommend suction drainage in unsophisticated TKA.
基金Supported by the National Basic Research Program of China(973 Program)(No.2012CB956001)the CMA(No.GYHY201306018)+2 种基金the Chinese Academy of Sciences(CAS)(No.XDA11010301)the National Natural Science Foundation of China(Nos.41176019,41421005,U1406401)the State Oceanic Administration(SOA)(No.GASI-03-01-01-05)
文摘A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin(except the North Indian Ocean, where the circulation is dominated by monsoons). The identifi ed nonSverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom(JEBAR) and mesoscale eddy nonlinearity.
基金Project of the National Eleventh Five-year Research Program of China (No.2008BAB29B02)National Natural Science Foundation of China(No.51079115)
文摘Based on analyzing risk factors of diversion project,synthetic risk rate and engineering insurance period,the frequency and distribution law of loss are researched on the grounds that foundation pit is submerged after diversion project ceases to be effective.And then,the standpoint that these total loss is subject to non-homogeneous compound Poisson processes is put forward.Furthermore,the collective risk model of the total loss about engineering insurance is established on the basis of construction diversion project risk.Ultimately,insurance ratemaking method for construction engineering risk and its mathematical expression are presented,which provides theoretical method for the insurance ratemaking of hydropower engineering to some extent.
基金support was provided by the National Basic Research Program of China (Project 2012CB956203)the Special Fund for Meteorological Research in the Public Interest (Grant No. GYHY201006023)+1 种基金the National Key Technologies R&D Program of China (Grant No. 2012BAC22B04)the National Natural Science Foundation of China (General Program, Grant No. 41105039)
文摘The authors examined the performance of version 3.4.1 of the Weather Research and Forecasting Model(WRF) with various land surface schemes in simulating a severe drought event in Southwest China. Five numerical experiments were completed using the Noah land surface scheme, the Pleim-Xiu land surface scheme, the Noah-MP land surface schemes, the Noah- MP scheme with dynamic vegetation, and the Noah-MP scheme with dynamic vegetation and groundwater processes. In general, all the simulations reasonably reproduced the spatial and temporal variations in precipitation, but significant bias was also found, especially for the spatial pattern of simulated precipitation. The WRF simulations with the Noah-MP series land surface schemes performed slightly better than the WRF simulation with the Noah and Pleim-Xiu land surface schemes in reproducing the severe drought events in Southwest China. The leaf area index(LAI) simulated by the different land surface schemes showed significant deviations in Southwest China. The Pleim-Xiu scheme overestimated the value of LAI by a factor of two. The Noah-MP scheme with dynamical vegetation overestimated the magnitude of the annual cycle of the LAI, although the annual mean LAI was close to observations. The simulated LAI showed a long-term lower value from autumn 2009 to spring 2010 relative to normal years. This indicates that the LAI is a potential indictor to monitor drought events.
文摘In order to meet the needs of various tasks of water conservancy project, tunnel excavation under the ground, called hydraulic tunnel. Hydraulic tunnel according to the functions of flood discharge, water diversion, irrigation, water supply, and the construction diversion tunnel of desilting emptying. Nowadays, water conservancy project on flood discharge runnel design requirements more and more high, so the factors taken into account the amount of spillway tunnel engineering, engineering cost, structure design and other factors to evaluate nature of the spillway tunnel is very important. Therefore, in actual construction, of spillway tunnel of optimization design, whether from the economic point of view, or from the point of view of safety and applicability are necessary. This article mainly from the overall layout of flood discharge tunnel, structure design and so on, and then discuss the optimization scheme.
基金Supported by Special Fund for the Screening and Breeding of Low-Cd-accumulating Crop Varieties~~
文摘Different results of seed purity identification for Gangyou 158, Ⅱ You 808, Wuyou 308 and Tianfengyou 316 were obtained using different SSR primers in our early work. To find out the reasons, the four hybrid combinations were grown in field to identify their purity according to their phenotypic traits. Then, the results of field identification were compared with that of laboratory tests using different SSR primers. The comparison revealed that only sterile lines (female parent) were distin- guished from true hybrids using the primers RM208, RM264, RM242 and RM164 for the purity identification of Gangyou 158, II You 808, Wuyou 308 and Tianfengyou 316, so the results were higher than that of field identification. In contrast, the primers RM341, RM297, RM21 and RM110 were able to distinguish not only the sterile plants but also the cross-pollinated ones from the true hybrids of Gangyou 158,Ⅱ You 808, Wuyou 308 and Tianfengyou 316, and the results of purity identifi- cation using them were close that of field identification, in summary, several pairs of primers should be used for the purity identification of rice hybrids to distinguish all the off-type plants and thus improve the accuracy.
基金National Natural Science Foundation of China(No.61272432)Qingdao Science and Technology Development Plan(No.12-1-4-6-(10)-jch)
文摘Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronization attacks of QIM digital watermarking,a low density parity check (LDPC) code-aided QIM watermarking algorithm is proposed,and the performance of QIM watermarking system can be improved by incorporating LDPC code with message passing estimation/detection framework.Using the theory of iterative estimation and decoding,the watermark signal is decoded by the proposed algorithm through iterative estimation of amplitude scaling parameters and decoding of watermark.The performance of the proposed algorithm is closer to the dirty paper Shannon limit than that of repetition code aided algorithm when the algorithm is attacked by the additive white Gaussian noise.For constant amplitude scaling attacks,the proposed algorithm can obtain the accurate estimation of amplitude scaling parameters.The simulation result shows that the algorithm can obtain similar performance compared to the algorithm without desynchronization.
基金funded by the National Natural Science Foundation of China (Grant No. 11272314 No. 51239010)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20133514110004)the Research Project of Chinese Ministry of Transport (Grant No. 201331849A130)
文摘Effects of heat softening on the initiation of slide surface(shear banding) in clayey slopes during fast deformation were discussed.Controlling equations considering heat,pore pressure and mechanical movement were presented.By perturbation method,the instability condition of localized zone(i.e.criterion for initiation of shear banding) for thermal related soils,such as clayey slope,was obtained.It is shown that slide surface initiates once the thermal-softening effects overcome the strain-hardening effects whether it is adiabatic or not.Without strain hardening effects,strain rate hardening obviously plays a role in initiation of shear band.During initiating process,heat is trapped inside the shear band,which leads rapidly to a pore pressure increase and fast loss of strength.The localized shear strain is concentrated in a narrow zone with a width of several centimeters at most and increases fast.This zone forms the sliding surface.Temperature can increase more than 2?C,pore pressure can increase 160% in about 0.1s inside this zone.These changes cause the fast decrease in friction-coefficient by about 36% over the initial value.That is how shear band initiated and developed in clayey slopes.
文摘AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty-two patients received at least 2 wk of drug therapy before the procedure was carried out to reduce the risk of recurrence from spillage during the procedure.The procedure was performed under local anesthesia with a 19-gauge 20 cm long needle,the cyst was punctured,cystic content(approximately 30 mL) was aspirated by a 12-14 F pigtail catheter and aspirated fluids were sent for analysis.Once the cyst was almost empty,two-thirds of the net amount of material aspirated was replaced by hypertonic saline and left in the cavity for about 30 min,with the catheter left in place for reaspiration of most of the fluid.When the amount of fluid drained was less than 10 mL per 24 h,the drainage catheter was removed.RESULTS:All 32 cysts showed evidence of immediate collapse after completion of the procedure,and before discharge from hospital,ultrasound examination showed fluid reaccumulation in all cysts.Serial follow-up showed a progressive decrease in the size and change in the appearance of cysts.To confirm the sterility of these cystic cavities,seven cysts were reaspirated on average 3 mo after the procedure.Investigations revealed no viable scolices.CONCLUSION:PAIR using hypertonic saline is very effective and safe with proper precautions.
基金Supported by the Governor Special Fund for Excellent Talents for Education of Science and Technology of Guizhou Province(2012093025)~~
文摘[Objective] This study aimed to establish a high-efficiency and stable SSR amplification system and screen polymorphic primers in order to further compare the tri-group probability analysis method and traditional QTL mapping method. [Method] In this study, we preliminarily screened the 605 pairs of primers evenly distributed on the 12 chromosomes through investigating their polymorphism performance in amplification, and established an optimized SSR-PCR reaction system. [Result] A 10μL SSR-PCR reaction system suitable for rice was set up as fol ows: 2 μl of 10 × Buffer, 2.0 mmol/L Mg2+ (final concentration), 0.5 mmol/L dNTPs, 1.0 μmol/L primers (final concentration), 1 μl of DNA template, 0.15 U Taq DNA polymerase. Among the SSR primers distributed over the genome, 142 pairs that were polymorphic upon the parents were screened. [Conclusion] This study lays a good foundation for sub-sequent QTL mapping studies.