This study aimed to gain more high-quality rice with less water and im- prove the level of national food security. Based on the optimized planting density of rice with drip irrigation, direct sowing technology for pla...This study aimed to gain more high-quality rice with less water and im- prove the level of national food security. Based on the optimized planting density of rice with drip irrigation, direct sowing technology for plastic-film-covered rice cultiva- tion with drip irrigation was proposed. Furthermore, sowing planter for plastic-film- covered drip-irrigation rice cultivation was developed in accordance with the require- ments for the combination of agricultural technique and agricultural machinery. Ac- cording to the large-scale field production evaluation, the film-punching direct-sowing technology for dry cultivation of rice can greatly reduce the labor consumption and results in neat emergence of seedlings. Productive practice shows that using the developed sowing planter for plastic-film-covered rice cultivation with drip irrigation leads to vacancy rate ≤3%, pass rate of grain number ≥85%, soil-covering rate ≥ 95%, and hole number per acre of 31 000-33 000. In addition, the sowing planter can adapt to the agronomic technical requirements for high-density cultivation of rice and provide technical support for the rice production in arid regions of China. Key words Fargesia murielae; Nutrition mechanism; Age grade; Nutrient distribution展开更多
A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypi...A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypical materials are simulated using different indicators in the centrifuge model.The silver sand,the shaft and the pile cap are simulated according to the natural density,the compressive stiffness and the bending stiffness,respectively.The finite element method(FEM)is implemented and analyzed in ANSYS,in which the stress field during the undisturbed soil stage,the boring stage,the concrete-casting stage and the curing stage are discussed in detail.Comparisons in terms of load-settlement,shaft axial force distribution and lateral friction between the numerical results and the test data are carried out to investigate the bearing behaviors of super-long rock-socketed bored pile groups under loading and unloading conditions.Results show that there is a good agreement between the centrifuge modeling tests and the FEM.In addition,the load distribution at the pile top is complicated,which is related to the stiffness of the cap,the corresponding assumptions and the analysis method.The shaft axial force first increases slightly with depth then decreases sharply,and the rate of decrease in rock is greater than that in sand and soil.展开更多
In this article, we have reviewed the hepatic perfusion disorder (HPD), etiopathogenesis of HPD and corresponding diseases. Review of the literature was based on computer searches (PubMed, Index Medicus) and perso...In this article, we have reviewed the hepatic perfusion disorder (HPD), etiopathogenesis of HPD and corresponding diseases. Review of the literature was based on computer searches (PubMed, Index Medicus) and personal experiences. We considered HPD reflects perfusion differences due to redistribution of arterial blood flow among segments, subsegments and lobes of the liver. The plain CT scan findings of HPD manifests as triangular or wedge-shaped areas of low attenuation. On contrast-enhanced CT scan, HPD manifests multiple (or single) transient wedge-shaped, rotundloid or irregular appearance, homogeneous hyperattenuation (in less cases, hypoattenuation) during the hepatic arterial phase (HAP) and isoattenuated or slightly hyperattenuated areas during the portal arterial phase. Dynamic enhanced magnetic resonance (MR) features are similar to enhanced CT scan. Angiographic findings include non-opacification of portal vein on portograms or wedge-shaped segmental staining in arterial and parenchymal phases on hepatic angiograms. The causes of HPD are arterioportal shunts (APS), intrahepatic vascular compressions and portal vein occlusion, steal phenomenon by hypervascular tumors, vascular variations and any other unknown reasons. It is very important for radiologists to be familiar with the various appearances of HPD to avoid false-positive diagnosis of pseudolesions and not to overestimate the extent of the disease.展开更多
This study aimed to explore the optimum drip irrigation belt arrangement mode for mechanically-harvested cotton in Xinjiang. The Xinluzao 61 was selected as the experiment material, and the effects of two different dr...This study aimed to explore the optimum drip irrigation belt arrangement mode for mechanically-harvested cotton in Xinjiang. The Xinluzao 61 was selected as the experiment material, and the effects of two different drip irrigation modes(6 cotton rows with 2 drip irrigation pipes under plastic film, 6 cotton rows with 3 drip irrigation pipes under plastic film) on the growth and yield of Xinluzao 61 were investigated under mechanical harvest. The results showed that under the mode of 6 cotton rows with 2 drip irrigation pipes, the growth rate of edge-row cotton was lower in the early growth period, and its emergence rate and agronomic traits were all lower than those of the interior-row cotton; under the mode of 6 cotton rows and 3 drip irrigation pipes, the difference in cotton growth between edge and interior rows was smaller. The yield and benefit under the mode of 6 cotton rows with 3 drip irrigation pipes were higher than those under the mode of 6 cotton rows and 2 drip irrigation pipes by 255 kg/hm^2 and 1 500 yuan/hm^2, respectively. Therefore, the cultivation mode of 6 cotton rows with 3 drip irrigation pipes under plastic film should be promoted in the production.展开更多
Abstract: Physical, chemical and biological soil properties in surface (0-5 cm) and subsurface soil (5-15 cm) were determined in a field experiment conducted with seven treatments consisted of different combinati...Abstract: Physical, chemical and biological soil properties in surface (0-5 cm) and subsurface soil (5-15 cm) were determined in a field experiment conducted with seven treatments consisted of different combinations of fertilizer N (0, 100 and 200 kg N ha^-1), P (0, 22 and 44 kg P2O5 ha^-1) and K (0, 41 and 82 kg K2O ha^-1) applied both to summer-grown maize (Zea mays L.) and winter-grown wheat (Triticum aestivum L.) crops continuously for 37 years under irrigated subtropical conditions. Application of N, P and K significantly increased water stable aggregates and had profound effects in increasing the mean weight diameter as well as the formation of macro-aggregates, which were highest in both surface (81%) and subsurface (74%) soil layers with application of 100 kg N + 22 kg P2O5 + 41 kg K2O ha^-1 (N100P22K41). The N100P22K41 treatment also enhanced total organic C (TOC) from 4.4 g kg^-1 in no-NPK control to 4.8 g kg^-1in surface layer and from 3.3 to 4.1 g kg1 in subsurface layer leading to the 20% higher TOC stocks in 0-15 cm soil. The labile C and N fractions such as water soluble C, particulate and light fraction organic matter, potentially mineralizable N and microbial biomass were also highest under the optimized balanced application of N100P22K41. Relatively higher increase in all labile fractions of C and N as proportion of TOC and total N, respectively suggested that these are potential indicators to reflect changes in management practices long before changes in TOC and TN are detectable. These results demonstrated that optimized balanced application of N, P and K is crucial for improving soil health ensuring long-term sustainability of farming systems in semiarid subtropical soils.展开更多
AIM: To study the effects of hepatic ischemia/ reperfusion (I/R) injury on store-operated calcium channel (SOC) currents (Isoc) in freshly isolated rat Kupffer cells, and the effects of Ca^2+ channel blockers,...AIM: To study the effects of hepatic ischemia/ reperfusion (I/R) injury on store-operated calcium channel (SOC) currents (Isoc) in freshly isolated rat Kupffer cells, and the effects of Ca^2+ channel blockers, 2-aminoethoxydiphenyl borate (2-APB), SK&F96365, econazole and miconazole, on Isoc in isolated rat Kupffer cells after hepatic I/R injury.METHODS: The model of rat hepatic I/R injury was established. Whole-cell patch-clamp techniques were performed to investigate the effects of 2-APB, SK&F96365, econazole and miconazole on Isoc in isolated rat Kupffer cells after hepatic I/R injury.RESULTS: I/R injury significantly increased Isoc from -80.4±25.2pA to -159.5±34.5pA (^bp 〈 0.01, n = 30). 2-APB (20, 40, 60, 80, 100 pmol/L), SK&F96365 (5, 10, 20, 40, 50 pmol/L), econazole (0.1, 0.3, 1, 3, 10 μmol/L) and miconazole (0.1, 0.3, 1, 3, 10 μmol/L) inhibited Isoc in a concentration-dependent manner with IC50 of 37.41 μmol/L (n = 8), 5.89 μmol/L (n = 11), 0.21 μmol/L (n = 13), and 0.28 μmol/L (n = 10). The peak value of Isoc in the I-V relationship was decreased by the blockers in different concentrations, but the reverse potential of Isoc was not transformed. CONCLUSION: SOC is the main channel for the influx of Ca^2+ during hepatic I/R injuries. Calcium channel blockers, 2-APB, SK&F96365, econazole and miconazole,have obviously protective effects on I/R injury, probably by inhibiting Isoc in Kupffer cells and preventing the activation of Kupffer cells.展开更多
AIM: To determine whether mild hypothermia could protect liver against ischemia and reperfusion injury in pigs. METHODS: Twenty-four healthy pigs were randomly divided into normothermia, mild hypothermia and normal co...AIM: To determine whether mild hypothermia could protect liver against ischemia and reperfusion injury in pigs. METHODS: Twenty-four healthy pigs were randomly divided into normothermia, mild hypothermia and normal control groups. The experimental procedure consisted of temporary interruption of blood flow to total hepatic lobe for different lengths of time and subsequent reperfusion. Hepatic tissue oxygen pressure (PtiO2) and aspartate aminotransferase (AST) values were evaluated, and ultrastructural analysis was carried out for all samples. RESULTS: Serum AST was significantly lower, and hepatic PtiO2 values were significantly higher in the mild hypothermia group than in the normothermia group during liver ischemia-reperfusion periods (P= 0.032, P= 0.028). Meanwhile, the histopathologic injury of liver induced by ischemia-reperfusion was significantly improved in the mild hypothermia group, compared with that in the normothermia group. CONCLUSION: Mild hypothermia can protect the liver from ischemia-reperfusion injury in pigs.展开更多
In order to study the uplifting effect of compensation grouting on ground surface and the upper structures,the ground heave induced by stratum expansion was considered as a stochastic process and the stochastic medium...In order to study the uplifting effect of compensation grouting on ground surface and the upper structures,the ground heave induced by stratum expansion was considered as a stochastic process and the stochastic medium theory was applied to determine the heave and deformation of ground surface under uniform and non-uniform expansion models of spherical grout bulb.The corresponding calculating formulas and simplified methods were derived based on the hypotheses of radial expansion.Then,a numerical model,in which radial velocity was imposed on the outer nodes of grout bulb to simulate the expansion process reaching a required volume strain,was established simultaneously.This new method avoids repeated trial calculation needed in the traditional method which applies a "fictitious" expanding pressure in the grouting elements.The results show that the numerical solutions have good consistency with the theoretical ones.Meanwhile,though the heave resulting from non-uniform expansion is larger than that from uniform expansion for shallow grouting,both of them tend to be convergent with the increasing of grouting depth.展开更多
AIM: To elucidate the mechanism of liver protection by inhibition of Kupffer cells (KCs) function.METHODS: All the animals were randomly divided into three groups. Blockade group (gadolinium chloride solution (G...AIM: To elucidate the mechanism of liver protection by inhibition of Kupffer cells (KCs) function.METHODS: All the animals were randomly divided into three groups. Blockade group (gadolinium chloride solution (GdCl3) injection plus ischemia/reperfusion (I/R) injury):GdCl3 solution was injected once every 24 h for 2 d via the tail vein before I/R injury. Non-blockade group (saline solution injection plus I/R injury): saline instead of GdCl3 as a control was injected as in the blockade group. Sham group: saline was injected without I/R injury. Liver samples were collected 4 h after blood inflow restoration. The blockade of the function of KCs was verified by immunostaining with an anti-CD68 mAb. Toll-like receptor2 (TLR2) was immunostained with a goat antimouse polydonal anti-TLR2 antibody. Membrane proteins were extracted from the liver samples and TLR2 protein was analyzed by Western blot. Portal vein serum and plasma were taken respectively at the same time point for further detection of the levels of tumor necrosis factor-α (TNF-α) and alanine aminotransferase (ALT), an indicator of liver function.I/R injury via downregulation of theexpression of TLR2.RESULTS: Compared to non-blockade group, CD^68+ cells significantly reduced in blockade group (OPTDI, optical density integral): 32.97±10.55 vs 185.65±21.88, P〈0.01) and the liver function impairment was relieved partially (level of ALT: 435.89±178.37 U/L vs 890.21±272.91 U/L,P〈0.01). The expression of TLR2 protein in blockade group significantly decreased compared to that in non- group(method of immunohistochemistry, OPDTI: 75.74±17.44 vs 170.58±25.14, P〈0.01; method of Western blot, A value: 125.89±15.49 vs 433.91±35.53, P〈0.02). The latter correlated with the variation of CD68 staining (r = 0.745,P〈0.05). Also the level of portal vein TNF-α decreased in blockade group compared to that in non-blockade group (84.45±14.73 ng/L vs 112.32±17.56 ng/L, P〈0.05), butwas still higher than that in sham group (84.45±14.73 ng/L vs 6.07±5.33 ng/L, P〈0.01).CONCLUSION: Inhibition of the function of KCs may protect liver against I/R injury via downregulation of the expression of TLR2.展开更多
The study investigated the response of Amaranth to irrigation depth and irrigation interval as well as poultry waste incorporation. A replicated 4 ×3 × 3 factorial arrangement with treatments consisting of p...The study investigated the response of Amaranth to irrigation depth and irrigation interval as well as poultry waste incorporation. A replicated 4 ×3 × 3 factorial arrangement with treatments consisting of percent organic matter incorporation (0%, 2%, 4% and 6% by weight), irrigation interval (1, 3 and 5 days) and irrigation depth (4, 6 and 8 mm) was used for the experiment which was conducted in pots in a green house. The result of the experiment showed that percent organic matter incorporation, irrigation interval, and irrigation depth significantly (P 〈 0.05) affected the dry matter yield of the vegetable. However, only the percent organic matter incorporation and irrigation interval were significant (P 〈 0.05) in their effects on the plant height. The highest plant height of 12.03 cm occurred when 2% organic matter was incorporated into the soil while the lowest plant height of 9.04 cm occurred with 6% organic matter incorporation. The maximum plant yield (47.44 kg/ha) occurred when 2% poultry litter was incorporated into the soil while the lowest plant yield (31.57 kg/ha) occurred with the control experiment. Irrigation interval of three days as well as irrigation depth of 6 mm resulted in the highest plant height and maximum dry matter yield of the vegetable. From the result of the experiment, the factor combination of 2% organic matter incorporation with 6 mm irrigation depth applied at three days irrigation interval resulted in the highest plant height of 16.7 cm above ground surface and maximum yield of 67.8 kg/ha.展开更多
The Heifangtai platform in Northwest China is famous for irrigation-induced loess landslides.This study conducted a centrifuge model test with reference to an irrigation-induced loess landslide that occurred in Heifan...The Heifangtai platform in Northwest China is famous for irrigation-induced loess landslides.This study conducted a centrifuge model test with reference to an irrigation-induced loess landslide that occurred in Heifangtai in 2011.The loess slope model was constructed by whittling a cubic loess block obtaining from the landslide site.The irrigation water was simulated by applying continuous infiltration from back of the slope.The deformation,earth pressure,and pore pressure were investigated during test by a series of transducers.For this particular study,the results showed that the failure processes were characterized by retrogressive landslides and cracks.The time dependent reductions of cohesion and internal friction angle at basal layer with increasing pore-water pressure were responsible for these failures.The foot part of slope is very important for slope instability and hazard prevention in the study area,where concentration of earth pressure and generation of high pore-water pressures would form before failures.The measurements of earth pressure and pore-water pressure might be effective for early warning in the study area.展开更多
文摘This study aimed to gain more high-quality rice with less water and im- prove the level of national food security. Based on the optimized planting density of rice with drip irrigation, direct sowing technology for plastic-film-covered rice cultiva- tion with drip irrigation was proposed. Furthermore, sowing planter for plastic-film- covered drip-irrigation rice cultivation was developed in accordance with the require- ments for the combination of agricultural technique and agricultural machinery. Ac- cording to the large-scale field production evaluation, the film-punching direct-sowing technology for dry cultivation of rice can greatly reduce the labor consumption and results in neat emergence of seedlings. Productive practice shows that using the developed sowing planter for plastic-film-covered rice cultivation with drip irrigation leads to vacancy rate ≤3%, pass rate of grain number ≥85%, soil-covering rate ≥ 95%, and hole number per acre of 31 000-33 000. In addition, the sowing planter can adapt to the agronomic technical requirements for high-density cultivation of rice and provide technical support for the rice production in arid regions of China. Key words Fargesia murielae; Nutrition mechanism; Age grade; Nutrient distribution
基金The Natural Science Foundation of Hubei Province(No.2007ABA094)
文摘A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypical materials are simulated using different indicators in the centrifuge model.The silver sand,the shaft and the pile cap are simulated according to the natural density,the compressive stiffness and the bending stiffness,respectively.The finite element method(FEM)is implemented and analyzed in ANSYS,in which the stress field during the undisturbed soil stage,the boring stage,the concrete-casting stage and the curing stage are discussed in detail.Comparisons in terms of load-settlement,shaft axial force distribution and lateral friction between the numerical results and the test data are carried out to investigate the bearing behaviors of super-long rock-socketed bored pile groups under loading and unloading conditions.Results show that there is a good agreement between the centrifuge modeling tests and the FEM.In addition,the load distribution at the pile top is complicated,which is related to the stiffness of the cap,the corresponding assumptions and the analysis method.The shaft axial force first increases slightly with depth then decreases sharply,and the rate of decrease in rock is greater than that in sand and soil.
文摘In this article, we have reviewed the hepatic perfusion disorder (HPD), etiopathogenesis of HPD and corresponding diseases. Review of the literature was based on computer searches (PubMed, Index Medicus) and personal experiences. We considered HPD reflects perfusion differences due to redistribution of arterial blood flow among segments, subsegments and lobes of the liver. The plain CT scan findings of HPD manifests as triangular or wedge-shaped areas of low attenuation. On contrast-enhanced CT scan, HPD manifests multiple (or single) transient wedge-shaped, rotundloid or irregular appearance, homogeneous hyperattenuation (in less cases, hypoattenuation) during the hepatic arterial phase (HAP) and isoattenuated or slightly hyperattenuated areas during the portal arterial phase. Dynamic enhanced magnetic resonance (MR) features are similar to enhanced CT scan. Angiographic findings include non-opacification of portal vein on portograms or wedge-shaped segmental staining in arterial and parenchymal phases on hepatic angiograms. The causes of HPD are arterioportal shunts (APS), intrahepatic vascular compressions and portal vein occlusion, steal phenomenon by hypervascular tumors, vascular variations and any other unknown reasons. It is very important for radiologists to be familiar with the various appearances of HPD to avoid false-positive diagnosis of pseudolesions and not to overestimate the extent of the disease.
基金Supported by Key Agricultural Program of Xinjiang Production and Construction Corps(2011BA001)Agricultural Science and Technology Achievement Transformation Fund of Ministry of Science and Technology(2014GB2G410111)~~
文摘This study aimed to explore the optimum drip irrigation belt arrangement mode for mechanically-harvested cotton in Xinjiang. The Xinluzao 61 was selected as the experiment material, and the effects of two different drip irrigation modes(6 cotton rows with 2 drip irrigation pipes under plastic film, 6 cotton rows with 3 drip irrigation pipes under plastic film) on the growth and yield of Xinluzao 61 were investigated under mechanical harvest. The results showed that under the mode of 6 cotton rows with 2 drip irrigation pipes, the growth rate of edge-row cotton was lower in the early growth period, and its emergence rate and agronomic traits were all lower than those of the interior-row cotton; under the mode of 6 cotton rows and 3 drip irrigation pipes, the difference in cotton growth between edge and interior rows was smaller. The yield and benefit under the mode of 6 cotton rows with 3 drip irrigation pipes were higher than those under the mode of 6 cotton rows and 2 drip irrigation pipes by 255 kg/hm^2 and 1 500 yuan/hm^2, respectively. Therefore, the cultivation mode of 6 cotton rows with 3 drip irrigation pipes under plastic film should be promoted in the production.
文摘Abstract: Physical, chemical and biological soil properties in surface (0-5 cm) and subsurface soil (5-15 cm) were determined in a field experiment conducted with seven treatments consisted of different combinations of fertilizer N (0, 100 and 200 kg N ha^-1), P (0, 22 and 44 kg P2O5 ha^-1) and K (0, 41 and 82 kg K2O ha^-1) applied both to summer-grown maize (Zea mays L.) and winter-grown wheat (Triticum aestivum L.) crops continuously for 37 years under irrigated subtropical conditions. Application of N, P and K significantly increased water stable aggregates and had profound effects in increasing the mean weight diameter as well as the formation of macro-aggregates, which were highest in both surface (81%) and subsurface (74%) soil layers with application of 100 kg N + 22 kg P2O5 + 41 kg K2O ha^-1 (N100P22K41). The N100P22K41 treatment also enhanced total organic C (TOC) from 4.4 g kg^-1 in no-NPK control to 4.8 g kg^-1in surface layer and from 3.3 to 4.1 g kg1 in subsurface layer leading to the 20% higher TOC stocks in 0-15 cm soil. The labile C and N fractions such as water soluble C, particulate and light fraction organic matter, potentially mineralizable N and microbial biomass were also highest under the optimized balanced application of N100P22K41. Relatively higher increase in all labile fractions of C and N as proportion of TOC and total N, respectively suggested that these are potential indicators to reflect changes in management practices long before changes in TOC and TN are detectable. These results demonstrated that optimized balanced application of N, P and K is crucial for improving soil health ensuring long-term sustainability of farming systems in semiarid subtropical soils.
基金the National Natural Science Foundation of China,No.30270532 Trans-Century Training Programme Foundation for the Talents by the Ministry of Education of China, No. 2002-48Shuguang Program Project of Shanghai Educational Committee,No.02SG20
文摘AIM: To study the effects of hepatic ischemia/ reperfusion (I/R) injury on store-operated calcium channel (SOC) currents (Isoc) in freshly isolated rat Kupffer cells, and the effects of Ca^2+ channel blockers, 2-aminoethoxydiphenyl borate (2-APB), SK&F96365, econazole and miconazole, on Isoc in isolated rat Kupffer cells after hepatic I/R injury.METHODS: The model of rat hepatic I/R injury was established. Whole-cell patch-clamp techniques were performed to investigate the effects of 2-APB, SK&F96365, econazole and miconazole on Isoc in isolated rat Kupffer cells after hepatic I/R injury.RESULTS: I/R injury significantly increased Isoc from -80.4±25.2pA to -159.5±34.5pA (^bp 〈 0.01, n = 30). 2-APB (20, 40, 60, 80, 100 pmol/L), SK&F96365 (5, 10, 20, 40, 50 pmol/L), econazole (0.1, 0.3, 1, 3, 10 μmol/L) and miconazole (0.1, 0.3, 1, 3, 10 μmol/L) inhibited Isoc in a concentration-dependent manner with IC50 of 37.41 μmol/L (n = 8), 5.89 μmol/L (n = 11), 0.21 μmol/L (n = 13), and 0.28 μmol/L (n = 10). The peak value of Isoc in the I-V relationship was decreased by the blockers in different concentrations, but the reverse potential of Isoc was not transformed. CONCLUSION: SOC is the main channel for the influx of Ca^2+ during hepatic I/R injuries. Calcium channel blockers, 2-APB, SK&F96365, econazole and miconazole,have obviously protective effects on I/R injury, probably by inhibiting Isoc in Kupffer cells and preventing the activation of Kupffer cells.
基金Supported by the Health Committee of Guangdong Province, No.A1998550
文摘AIM: To determine whether mild hypothermia could protect liver against ischemia and reperfusion injury in pigs. METHODS: Twenty-four healthy pigs were randomly divided into normothermia, mild hypothermia and normal control groups. The experimental procedure consisted of temporary interruption of blood flow to total hepatic lobe for different lengths of time and subsequent reperfusion. Hepatic tissue oxygen pressure (PtiO2) and aspartate aminotransferase (AST) values were evaluated, and ultrastructural analysis was carried out for all samples. RESULTS: Serum AST was significantly lower, and hepatic PtiO2 values were significantly higher in the mild hypothermia group than in the normothermia group during liver ischemia-reperfusion periods (P= 0.032, P= 0.028). Meanwhile, the histopathologic injury of liver induced by ischemia-reperfusion was significantly improved in the mild hypothermia group, compared with that in the normothermia group. CONCLUSION: Mild hypothermia can protect the liver from ischemia-reperfusion injury in pigs.
基金Project(2007AA11Z134) supported by the National High Technology Research and Development Program of ChinaProject(10JJ4035) supported by the Natural Science Foundation of Hunan Province,China Project(2010ybfz046) supported by the Fund of Excellent Doctoral Dissertation of Central South University,China
文摘In order to study the uplifting effect of compensation grouting on ground surface and the upper structures,the ground heave induced by stratum expansion was considered as a stochastic process and the stochastic medium theory was applied to determine the heave and deformation of ground surface under uniform and non-uniform expansion models of spherical grout bulb.The corresponding calculating formulas and simplified methods were derived based on the hypotheses of radial expansion.Then,a numerical model,in which radial velocity was imposed on the outer nodes of grout bulb to simulate the expansion process reaching a required volume strain,was established simultaneously.This new method avoids repeated trial calculation needed in the traditional method which applies a "fictitious" expanding pressure in the grouting elements.The results show that the numerical solutions have good consistency with the theoretical ones.Meanwhile,though the heave resulting from non-uniform expansion is larger than that from uniform expansion for shallow grouting,both of them tend to be convergent with the increasing of grouting depth.
基金Supported by the National Natural Science Foundation of China, No. 30200272
文摘AIM: To elucidate the mechanism of liver protection by inhibition of Kupffer cells (KCs) function.METHODS: All the animals were randomly divided into three groups. Blockade group (gadolinium chloride solution (GdCl3) injection plus ischemia/reperfusion (I/R) injury):GdCl3 solution was injected once every 24 h for 2 d via the tail vein before I/R injury. Non-blockade group (saline solution injection plus I/R injury): saline instead of GdCl3 as a control was injected as in the blockade group. Sham group: saline was injected without I/R injury. Liver samples were collected 4 h after blood inflow restoration. The blockade of the function of KCs was verified by immunostaining with an anti-CD68 mAb. Toll-like receptor2 (TLR2) was immunostained with a goat antimouse polydonal anti-TLR2 antibody. Membrane proteins were extracted from the liver samples and TLR2 protein was analyzed by Western blot. Portal vein serum and plasma were taken respectively at the same time point for further detection of the levels of tumor necrosis factor-α (TNF-α) and alanine aminotransferase (ALT), an indicator of liver function.I/R injury via downregulation of theexpression of TLR2.RESULTS: Compared to non-blockade group, CD^68+ cells significantly reduced in blockade group (OPTDI, optical density integral): 32.97±10.55 vs 185.65±21.88, P〈0.01) and the liver function impairment was relieved partially (level of ALT: 435.89±178.37 U/L vs 890.21±272.91 U/L,P〈0.01). The expression of TLR2 protein in blockade group significantly decreased compared to that in non- group(method of immunohistochemistry, OPDTI: 75.74±17.44 vs 170.58±25.14, P〈0.01; method of Western blot, A value: 125.89±15.49 vs 433.91±35.53, P〈0.02). The latter correlated with the variation of CD68 staining (r = 0.745,P〈0.05). Also the level of portal vein TNF-α decreased in blockade group compared to that in non-blockade group (84.45±14.73 ng/L vs 112.32±17.56 ng/L, P〈0.05), butwas still higher than that in sham group (84.45±14.73 ng/L vs 6.07±5.33 ng/L, P〈0.01).CONCLUSION: Inhibition of the function of KCs may protect liver against I/R injury via downregulation of the expression of TLR2.
文摘The study investigated the response of Amaranth to irrigation depth and irrigation interval as well as poultry waste incorporation. A replicated 4 ×3 × 3 factorial arrangement with treatments consisting of percent organic matter incorporation (0%, 2%, 4% and 6% by weight), irrigation interval (1, 3 and 5 days) and irrigation depth (4, 6 and 8 mm) was used for the experiment which was conducted in pots in a green house. The result of the experiment showed that percent organic matter incorporation, irrigation interval, and irrigation depth significantly (P 〈 0.05) affected the dry matter yield of the vegetable. However, only the percent organic matter incorporation and irrigation interval were significant (P 〈 0.05) in their effects on the plant height. The highest plant height of 12.03 cm occurred when 2% organic matter was incorporated into the soil while the lowest plant height of 9.04 cm occurred with 6% organic matter incorporation. The maximum plant yield (47.44 kg/ha) occurred when 2% poultry litter was incorporated into the soil while the lowest plant yield (31.57 kg/ha) occurred with the control experiment. Irrigation interval of three days as well as irrigation depth of 6 mm resulted in the highest plant height and maximum dry matter yield of the vegetable. From the result of the experiment, the factor combination of 2% organic matter incorporation with 6 mm irrigation depth applied at three days irrigation interval resulted in the highest plant height of 16.7 cm above ground surface and maximum yield of 67.8 kg/ha.
基金partially supported by the National Science Foundation of China (Grant No. 41572302)the Funds for Creative Research Groups of China (Grant No. 41521002)
文摘The Heifangtai platform in Northwest China is famous for irrigation-induced loess landslides.This study conducted a centrifuge model test with reference to an irrigation-induced loess landslide that occurred in Heifangtai in 2011.The loess slope model was constructed by whittling a cubic loess block obtaining from the landslide site.The irrigation water was simulated by applying continuous infiltration from back of the slope.The deformation,earth pressure,and pore pressure were investigated during test by a series of transducers.For this particular study,the results showed that the failure processes were characterized by retrogressive landslides and cracks.The time dependent reductions of cohesion and internal friction angle at basal layer with increasing pore-water pressure were responsible for these failures.The foot part of slope is very important for slope instability and hazard prevention in the study area,where concentration of earth pressure and generation of high pore-water pressures would form before failures.The measurements of earth pressure and pore-water pressure might be effective for early warning in the study area.