Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-...Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.展开更多
Sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that inv...Sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that investigated the influence of sand quality on the properties of fresh and hardened SCC (self-compacting concrete). The dune sands are very fine materials characterized by a high intergranular porosity, high surface area and low fineness modulus; on the other hand crushed (manufactured) sand has a high rate into thin and irregular shapes which influence the workability of concrete. The amount of dune sand varies from (0%, 50% to 100%) by weight of fine aggregates. The results show that the rheological properties favour the use of dune sands; however the mechanical properties support the use of crushed sand.展开更多
Objective: To investigate the imaging features of primary hepatic leiomyoma. Methods: 3 patients of primary hepatic leiomyoma confirmed by pathology without immunodeficiency were retrospectively analyzed about CT an...Objective: To investigate the imaging features of primary hepatic leiomyoma. Methods: 3 patients of primary hepatic leiomyoma confirmed by pathology without immunodeficiency were retrospectively analyzed about CT and MRI findings, clinical and pathological correlation. 2 cases had routine CT scan, 2 cases had routine MRI. Results: 2 case CT scans showed low-density lesions, 2 cases MRI showed lesions with long T1 and long T2 signal. One case of uniform density and signal showed homogeneous enhancement; two cases showed uneven density and signal, of which one case was inhomogeneous enhancement. 3 cases presented pseudocapsule without hepatic cirrhosis and venous tumor thrombus. Pathology showed spindle tumor cell proliferation and capillary hyperplasia; one case showed central hyalinization and one case central liquefaction necrosis. Conclusion: Primary hepatic leiomyoma is a hypervascular tumor, and CT and MRI help in the diagnosis.展开更多
OBJECTIVE:To systematically review the benefits of integrated traditional and Western medicine therapies based on the Hamilton depression scale(HAMD) following syndrome differentiation of depression.METHODS:We searche...OBJECTIVE:To systematically review the benefits of integrated traditional and Western medicine therapies based on the Hamilton depression scale(HAMD) following syndrome differentiation of depression.METHODS:We searched six English and Chinese electronic databases for randomized clinical trials(RCTs) on integrated traditional and Western medicine for treatment of depression.Two authors extracted data and independently assessed the trial quality.RevMan 5 software was used for data analyses with an effect estimate presented as weighted mean difference(WMD) with a 95% confidence interval(CI).RESULTS:Seven RCTs with 576 participants were identified for this review.All trials were eligible for the meta-analysis and were evaluated as unclear or having a risk of bias.Meta-analysis showed,compared with Western medicine alone,integrated traditional and Western medicine based on syndrome differentiation could improve the effect of treatment represented by the HAMD [WMD=-2.39,CI(-2.96,-1.83),Z=8.29,P<0.00001].There were no reported serious adverse effects that were related to integrated traditional and Western medicine based therapies in these trials.CONCLUSIONS:Integrated traditional and Western medicine based therapies for the syndrome differentiation of depression significantly improved the HAMD,illustrating that combining therapies from integrated traditional and Western medicine for treatment of depression is better than Western medicine alone.However,further large,rigorously designed trials are warranted due to the insufficient methodological rigor seen in the trials included in this study.展开更多
As the key components of nanopore-based nucleic acid sequencing systems, nanopores have drawn more and more scientific interests over these years. Although most of the early nanopore-based sequencers adopted biologica...As the key components of nanopore-based nucleic acid sequencing systems, nanopores have drawn more and more scientific interests over these years. Although most of the early nanopore-based sequencers adopted biological nanopores, solid-state nanopores have been gradually growing in popularity due to their increased robustness and durability, control over pore geometry and surface properties, as well as compatibility with the existing semiconductor and microfiuidics fabrication techniques. Besides acting as a platform for biomolecular analysis, solid-state nanopores also have great potential in many other fields such as near-field optics, nanostencil lithography and ionic logic circuitry, due to the possibility of parallel massive production. Therefore, many approaches for the fabrication of solid-state nanopores have been developed. This paper reviews the typical solid-state nanopore fabrication techniques reported to date and compares their advantages and disadvantages. The specific applications of each kind of solid-state nanopores are also summarized based on the carefully analysis of their unique morphologies and properties such as the feature size, inner structure and possibility of massive production.展开更多
This work presents the results of tribological investigations of lubricating substances composed of water and a nonionic surfactant:lauric acid random copolyether(LPE),as additive.At the current stage of investigation...This work presents the results of tribological investigations of lubricating substances composed of water and a nonionic surfactant:lauric acid random copolyether(LPE),as additive.At the current stage of investigation,aqueous solutions with LPE additives are prepared and subsequently the lowering friction and reducing wear behaviors are tested by means of friction/wear tester,in conjunction with that the film forming properties experiments are carried out with a nanoscale film thickness measure apparatus.The contact is under condition of steel-steel tribo-pair.The results show that the coefficient of friction measured decreases considerably to about over 60%relative to water.The film thickness data of friction process lubricated by aqueous solutions with LPE added show that the lubrication is in boundary lubrication regime.The results indicate that aqueous solutions with LPE added can be used to improve the lubricity and they may be applied to real tribological systems.展开更多
Seismic fluid identification works as an effective approach to characterize the fluid feature and distribution of the reservoir underground with seismic data. Rock physics which builds bridge between the elastic param...Seismic fluid identification works as an effective approach to characterize the fluid feature and distribution of the reservoir underground with seismic data. Rock physics which builds bridge between the elastic parameters and reservoir parameters sets the foundation of seismic fluid identification, which is also a hot topic on the study of quantitative characterization of oil/gas reservoirs. Study on seismic fluid identification driven by rock physics has proved to be rewarding in recognizing the fluid feature and distributed regularity of the oil/gas reservoirs. This paper summarizes the key scientific problems immersed in seismic fluid identification, and emphatically reviews the main progress of seismic fluid identification driven by rock physics domestic and overseas, as well as discusses the opportunities, challenges and future research direction related to seismic fluid identification. Theoretical study and practical application indicate that we should incorporate rock physics, numerical simulation, seismic data processing and seismic inversion together to enhance the precision of seismic fluid identification.展开更多
In this study,we theoretically investigate the dynamic indentation for measuring the loss (damping) factor of a linear viscoelastic material from its indentation response.A rigid indenter with arbitrary tip profile is...In this study,we theoretically investigate the dynamic indentation for measuring the loss (damping) factor of a linear viscoelastic material from its indentation response.A rigid indenter with arbitrary tip profile is assumed to indent into a viscoelastic substrate with arbitrary shape.We perform a theoretical analysis and identify the conditions under which the loss factor of the material can be determined from the phase angle between the applied harmonic indentation load and the corresponding harmonic displacement,a directly measurable quantity in a dynamic indentation test.To validate the conclusion drawn from our theoretical analysis,a series of numerical experiments are performed,including the spherical indentation of a soft layer with irregular surface morphology bonded to a rigid substrate,a conical indenter with tip defects indenting into a half-spherical particle,and the indentation of porous materials.This study may facilitate the use of the dynamic indentation technique to evaluate the damping properties of linear viscoelastic materials,including some advanced polymers and biological soft tissues.展开更多
This paper studies a class of variational problems which involving both bulk and surfaceenergies. The bulk energy is of Dirichlet type though it can be in very general forms allowingunknowns to be scalar or vectors.Th...This paper studies a class of variational problems which involving both bulk and surfaceenergies. The bulk energy is of Dirichlet type though it can be in very general forms allowingunknowns to be scalar or vectors.The surface energy is an arbitrary elliptic parametric integralwhich is defined on a free interface. One also allows other constraints such as volumes of partitioning sets. One establishes the existence and regularity theory, in particular, the regularityof the free interface of such problems.展开更多
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest of China(No.201203018)the National Key Technology Research and Development Program of China(No.2006BAD09A05)
文摘Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.
文摘Sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that investigated the influence of sand quality on the properties of fresh and hardened SCC (self-compacting concrete). The dune sands are very fine materials characterized by a high intergranular porosity, high surface area and low fineness modulus; on the other hand crushed (manufactured) sand has a high rate into thin and irregular shapes which influence the workability of concrete. The amount of dune sand varies from (0%, 50% to 100%) by weight of fine aggregates. The results show that the rheological properties favour the use of dune sands; however the mechanical properties support the use of crushed sand.
文摘Objective: To investigate the imaging features of primary hepatic leiomyoma. Methods: 3 patients of primary hepatic leiomyoma confirmed by pathology without immunodeficiency were retrospectively analyzed about CT and MRI findings, clinical and pathological correlation. 2 cases had routine CT scan, 2 cases had routine MRI. Results: 2 case CT scans showed low-density lesions, 2 cases MRI showed lesions with long T1 and long T2 signal. One case of uniform density and signal showed homogeneous enhancement; two cases showed uneven density and signal, of which one case was inhomogeneous enhancement. 3 cases presented pseudocapsule without hepatic cirrhosis and venous tumor thrombus. Pathology showed spindle tumor cell proliferation and capillary hyperplasia; one case showed central hyalinization and one case central liquefaction necrosis. Conclusion: Primary hepatic leiomyoma is a hypervascular tumor, and CT and MRI help in the diagnosis.
基金supported by the National Natural Science Foundation of China (81072756,30672578)the Chinese National Funds for Distinguished Young Scientists (30825046)+1 种基金the Hi-Tech Research and Development Program of China (2008AA02Z406)the Program for Innovative Research Teams in Beijing University of Chinese Medicine (2011CXTD-07)
文摘OBJECTIVE:To systematically review the benefits of integrated traditional and Western medicine therapies based on the Hamilton depression scale(HAMD) following syndrome differentiation of depression.METHODS:We searched six English and Chinese electronic databases for randomized clinical trials(RCTs) on integrated traditional and Western medicine for treatment of depression.Two authors extracted data and independently assessed the trial quality.RevMan 5 software was used for data analyses with an effect estimate presented as weighted mean difference(WMD) with a 95% confidence interval(CI).RESULTS:Seven RCTs with 576 participants were identified for this review.All trials were eligible for the meta-analysis and were evaluated as unclear or having a risk of bias.Meta-analysis showed,compared with Western medicine alone,integrated traditional and Western medicine based on syndrome differentiation could improve the effect of treatment represented by the HAMD [WMD=-2.39,CI(-2.96,-1.83),Z=8.29,P<0.00001].There were no reported serious adverse effects that were related to integrated traditional and Western medicine based therapies in these trials.CONCLUSIONS:Integrated traditional and Western medicine based therapies for the syndrome differentiation of depression significantly improved the HAMD,illustrating that combining therapies from integrated traditional and Western medicine for treatment of depression is better than Western medicine alone.However,further large,rigorously designed trials are warranted due to the insufficient methodological rigor seen in the trials included in this study.
基金supported by the National Natural Science Foundation of China (91023040 and 61273061)
文摘As the key components of nanopore-based nucleic acid sequencing systems, nanopores have drawn more and more scientific interests over these years. Although most of the early nanopore-based sequencers adopted biological nanopores, solid-state nanopores have been gradually growing in popularity due to their increased robustness and durability, control over pore geometry and surface properties, as well as compatibility with the existing semiconductor and microfiuidics fabrication techniques. Besides acting as a platform for biomolecular analysis, solid-state nanopores also have great potential in many other fields such as near-field optics, nanostencil lithography and ionic logic circuitry, due to the possibility of parallel massive production. Therefore, many approaches for the fabrication of solid-state nanopores have been developed. This paper reviews the typical solid-state nanopore fabrication techniques reported to date and compares their advantages and disadvantages. The specific applications of each kind of solid-state nanopores are also summarized based on the carefully analysis of their unique morphologies and properties such as the feature size, inner structure and possibility of massive production.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2013JBZ015)
文摘This work presents the results of tribological investigations of lubricating substances composed of water and a nonionic surfactant:lauric acid random copolyether(LPE),as additive.At the current stage of investigation,aqueous solutions with LPE additives are prepared and subsequently the lowering friction and reducing wear behaviors are tested by means of friction/wear tester,in conjunction with that the film forming properties experiments are carried out with a nanoscale film thickness measure apparatus.The contact is under condition of steel-steel tribo-pair.The results show that the coefficient of friction measured decreases considerably to about over 60%relative to water.The film thickness data of friction process lubricated by aqueous solutions with LPE added show that the lubrication is in boundary lubrication regime.The results indicate that aqueous solutions with LPE added can be used to improve the lubricity and they may be applied to real tribological systems.
基金supported by the National Basic Research Program of China(Grant No.2013CB228604)the National Grand Project for Science and Technology(Grant Nos.2011ZX05030-004-002,2011ZX05019-003,2011ZX05006-002)SINOPEC Key Laboratory of Geophysics+2 种基金Science Foundation for Post-doctoral Scientists of ChinaScience Foundation for Post-doctoral Scientists of Shandongthe Western Australian Energy Research Alliance(WA:ERA)
文摘Seismic fluid identification works as an effective approach to characterize the fluid feature and distribution of the reservoir underground with seismic data. Rock physics which builds bridge between the elastic parameters and reservoir parameters sets the foundation of seismic fluid identification, which is also a hot topic on the study of quantitative characterization of oil/gas reservoirs. Study on seismic fluid identification driven by rock physics has proved to be rewarding in recognizing the fluid feature and distributed regularity of the oil/gas reservoirs. This paper summarizes the key scientific problems immersed in seismic fluid identification, and emphatically reviews the main progress of seismic fluid identification driven by rock physics domestic and overseas, as well as discusses the opportunities, challenges and future research direction related to seismic fluid identification. Theoretical study and practical application indicate that we should incorporate rock physics, numerical simulation, seismic data processing and seismic inversion together to enhance the precision of seismic fluid identification.
基金supported by the National Natural Science Foundation of China(Grant Nos. 10972112,10525210,and 10732050)the National Basic Research Program of China(Grant Nos. 2010CB631005)
文摘In this study,we theoretically investigate the dynamic indentation for measuring the loss (damping) factor of a linear viscoelastic material from its indentation response.A rigid indenter with arbitrary tip profile is assumed to indent into a viscoelastic substrate with arbitrary shape.We perform a theoretical analysis and identify the conditions under which the loss factor of the material can be determined from the phase angle between the applied harmonic indentation load and the corresponding harmonic displacement,a directly measurable quantity in a dynamic indentation test.To validate the conclusion drawn from our theoretical analysis,a series of numerical experiments are performed,including the spherical indentation of a soft layer with irregular surface morphology bonded to a rigid substrate,a conical indenter with tip defects indenting into a half-spherical particle,and the indentation of porous materials.This study may facilitate the use of the dynamic indentation technique to evaluate the damping properties of linear viscoelastic materials,including some advanced polymers and biological soft tissues.
文摘This paper studies a class of variational problems which involving both bulk and surfaceenergies. The bulk energy is of Dirichlet type though it can be in very general forms allowingunknowns to be scalar or vectors.The surface energy is an arbitrary elliptic parametric integralwhich is defined on a free interface. One also allows other constraints such as volumes of partitioning sets. One establishes the existence and regularity theory, in particular, the regularityof the free interface of such problems.