The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro cracks and its composition were determined...The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro cracks and its composition were determined. The result demonstrates that only a few phosphides contribute to the spontaneous crumbling of the RE silicide alloy by reacting with water and forming oxide or phosphorus oxide. The phosphorus content is not the critical factor of disintegration in the alloy studied.展开更多
Rock masses without pre-existing macrocracks can usually be considered as granular materials with only microcracks.During the excavation of the tunnels,microcracks may nucleate,grow and propagate through the rock matr...Rock masses without pre-existing macrocracks can usually be considered as granular materials with only microcracks.During the excavation of the tunnels,microcracks may nucleate,grow and propagate through the rock matrix;secondary microcracks may appear,and discontinuous and incompatible deformation of rock masses may occur.The classical continuum elastoplastic theory is not suitable for analyzing discontinuous and incompatible deformation of rock masses.Based on non-Euclidean model of the discontinuous and incompatible deformation of rock masses,the distribution of stresses in the surrounding rock masses in deep tunnels is fluctuant or wave-like.The stress concentration at the tips of microcracks located in vicinity of stress wave crest is comparatively large,which may lead to the unstable growth and coalescence of secondary microcracks,and consequently the occurrence of fractured zones.On the other hand,the stress concentration at the tips of microcracks located around stress wave trough is relatively small,which may lead to the arrest of microcracks,and thus the non-fractured zones.The alternate appearance of stress wave crest and trough thus may induce the alternate occurrence of fractured and non-fractured zones in deep rock masses.For brittle rocks,the dissipated energy of microcrack growth is small,but the elastic strain energy stored in rock masses may be larger than the dissipated energy growths of pre-existing microcracks and secondary microcracks.The sudden release of the residual elastic strain energy may lead to rockburst.Based on this understanding,the criteria of rockburst are established.Furthermore,the relationship between rockbursts and zonal disintegration in the surrounding rock masses around deep tunnels is studied.The influences of the in-situ stresses and the physico-mechanical parameters on the distribution of rockburst zones and the ejection velocity of rock fragments are investigated in detail.展开更多
Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and environment.In this study,typical Benggang collapsing-wall soils were used as the study ar...Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and environment.In this study,typical Benggang collapsing-wall soils were used as the study area to investigate the effects of different initial moisture contents and dicranopteris linearis root weight densities,as well as their interactions on disintegration in orthogonal test method.The results showed that the rate of soil disintegration decreased as a linear function of the initial moisture content.The soil disintegration rate tended to rise and then fall as the root weight density increased,reflecting an optimum root weight density of 0.75-1.00 g/100 cm3.The incorporation of dicranopteris linearis roots was most effective for soil consolidation in the shallow layers of soil.In addition,the disintegration rate of the collapsing-wall soils increases as the soil layer deepened.The dicranopteris linearis root system and initial moisture content had an interactive effect that was more pronounced in deeper soils.However,the combined effect of these processes was always dominated by the initial moisture content.Moderate initial soil moisture content(0.20-0.24 g/g)and the addition of a high root density in dicranopteris linearis(0.75-1.00 g/100 cm3)were the optimal combinations that reduced the disintegration rate.In conclusion,maintaining a suitable natural moisture content in collapsing-wall soils and taking measures that use plants to consolidate soil can effectively prevent and control the occurrence of Benggang erosion.The results of this study provided further insight into the factors that influence soil disintegration and offered a scientific basis for soil erosion management in the southern China.展开更多
The main pathways of primary sludge(PS)ultrasonic disintegration were analyzed at the sonication frequency of 20 kH z and the thermal effect on PS disintegration was investigated.By adding Na HCO3as a scavenger to ent...The main pathways of primary sludge(PS)ultrasonic disintegration were analyzed at the sonication frequency of 20 kH z and the thermal effect on PS disintegration was investigated.By adding Na HCO3as a scavenger to entrap the free hydroxyl radicals,cavitation contributed to 82.91%of the total sonication effect.The power consumed by temperature rising accounted for more than40%of ultrasound power input at the power density of 0.215 W/m L and the sonication time of 10 min.With the thermal insulation of polyfoam coating during sonication,a 18.37%of soluble chemical oxygen demand(SCOD)increment was observed.With the process of pre-heating the PS before sonication,64.15%of SCOD increment was achieved.Compared with the particle size of 13.77μm for the sonicated PS,the sludge mean particle size decreased to 12.83 and11.98μm by applying polyfoam coating and pre-heating the PS to enhance the cavitation and thermal effect.It suggested that if thermal energy consumption was relieved during the sonication process of PS,more energy could be used to disintegrate the sludge.展开更多
't Hooft-Veltman Wilson dimensional regularization depends crucially upon Borel summability which entails strong links to the modern mathematical theory of transfinite sets and consequently to the fractal-Cantoria...'t Hooft-Veltman Wilson dimensional regularization depends crucially upon Borel summability which entails strong links to the modern mathematical theory of transfinite sets and consequently to the fractal-Cantorian spacetime proposal of Ord-Nottale-El Naschie. Starting from the above, we interpret the main step of the mathematical analysis in terms of elementary particles interaction. Thus 't Hooft-Veltman “perturbation” parameter which measures the deviation of the regulated space from the four dimensionality of spacetime is interpreted as an elementary particle with a topological mass charge equal to 0.18033989, i.e. double the magnitude of Hardy’s quantum entanglement. In turn, Hardy’s quantum entanglement which may be interpreted geometrically as a consequence of the zero set embedded in an empty set could also be interpreted as an exchange of pseudo elementary particles with a topological mass charge equal to Hardy’s entanglement where is the Hausdorff dimension of the zero set of the corresponding 't Hooft-Veltman spacetime.展开更多
Objective:The influence of two experimental starches - ginger starch obtained from Zingiber officinale and banana starch from Musa sapientum - on the mechanical and disintegration properties of chloroquine tablets hav...Objective:The influence of two experimental starches - ginger starch obtained from Zingiber officinale and banana starch from Musa sapientum - on the mechanical and disintegration properties of chloroquine tablets have been studied in comparison with the influence of official corn starch.Methods:Chloroquine tablets were formulated using various concentarions of the starches as binding agent.The mechanical properties of the tablets were assessed in terms of crushing strength and friability and the crushing strength-friability ratio(CSFR) while drug release properties were evaluated based on disintegration and the time of tablets.Results:The ranking for crushing strength and CSFR was corn】banana】ginger starch while the ranking was reverse for friability.The disintegration time increased with packing fraction and starch concentration in the rank order of formulations containing corn】banana】ginger starch.The CSFR/DT values increased with concentration of starch binder indicating an improved balance between binding and disintegrant properties of the starches.Statistical analysis showed that there were significant(P【0.001) difference in the CSFR/DT for tablets containing the various starch binders.Conclusion:The mechanical and disintegration properties of the experimental starches compared favorably with those of corn starch and ginger starch could be more useful when faster tablet disintegration is desired.展开更多
TC11 titanium alloy samples with lamellar microstructrue were compressed on a Gleeble 1500D Simulator.Compression tests were carried out at 950 ℃ and a strain rate of 0.1 s-1 with height reduction of 20%,40% and 60%,...TC11 titanium alloy samples with lamellar microstructrue were compressed on a Gleeble 1500D Simulator.Compression tests were carried out at 950 ℃ and a strain rate of 0.1 s-1 with height reduction of 20%,40% and 60%,respectively.Microstruture of the compressed TC11 alloy was obeserved and analyzed by optical microscopy(OM),transmission electron microscope(TEM),electron back-scattered diffraction(EBSD).The lamellar disintegration mechanism of the TC11 titanium alloy was deduced.The results indicated that the compressive deformation promoted the phase transformation in bi-phase area.βphase layers were formed along the gliding planes inα phase,and α slivers were disintegrated into many small flakes through theα/βinterface slipping.展开更多
The disintegration of granite residual soil is especially affected by variations in physical and chemical properties. Serious geologic hazards or engineering problems are closely related to the disintegration of grani...The disintegration of granite residual soil is especially affected by variations in physical and chemical properties. Serious geologic hazards or engineering problems are closely related to the disintegration of granite residual soil in certain areas. Research on the mechanical properties and controlling mechanisms of disintegration has become a hot issue in practical engineering. In this paper, the disintegration characteristics of improved granite residual soil are studied by using a wet and dry cycle disintegration instrument, and the improvement mechanism is analyzed. The results show that the disintegration amounts and disintegration ratios of soil samples treated with different curing agents are obviously different. The disintegration process of improved granite residual soil can be roughly divided into 5 stages:the forcible water intrusion stage, microcrack and fissure development stage, curing and strengthening stage, stable stage, and sudden disintegration stage. The disintegration of granite residual soil is caused by the weakening of the cementation between soil particles under the action of water. When the disintegration force is greater than the anti-disintegration force of soil, the soil will disintegrate. Cement and lime mainly rely on ion exchange agglomeration, the inclusion effect of curing agents on soil particles, the hard coagulation reaction and carbonation to strengthen granite residual soil. Kaolinite mainly depends on the reversibility of its own cementation to improve and strengthen granite residual soil. The reversibility of kaolinite cementation is verified by investigating pure kaolinite with a tensile, soaking, drying and tensile test cycle. Research on the disintegration characteristics and disintegration mechanism of improved granite residual soil is of certain reference value for soil modification.展开更多
To investigate the zonal disintegration form of the surrounding rock in deep tunnels,model tests were performed in the simulation set-up of fracture mechanism and support technology of surrounding rock in deep tunnel....To investigate the zonal disintegration form of the surrounding rock in deep tunnels,model tests were performed in the simulation set-up of fracture mechanism and support technology of surrounding rock in deep tunnel.The test results illustrate that the first fracture of the surrounding rock occurred at the intersection of the tunnel floor and the side wall.After more serious destruction,the side wall and the vault were destroyed.Although the fracture width of each surrounding rock mass was distinct,they were relatively uniform with a nearly continuous fracture form.The width of the split bodies of the model tunnels(i.e.,the annular zonal disintegration area)developed with an increasing load.It was observed from the fitting curves of the data that all radial strain values of the surrounding rock were more symmetric with a smooth fitting curve,and the maximum value occurred near the tunnel wall before reducing instantly.The circumferential strain values were dispersed and the data were inconsistent with the fitting curve,which caused some data to be unreliable.The phenomenon of zonal disintegration was primarily caused by radial tension strain of the surrounding rock.This phenomenon would not extend indefinitely as the rupture range would be limited to a certain extent,because the maximum radial tension strain of the surrounding rock was less than the limiting value.展开更多
Irreparable consequences to Middle East geopolitics ensued as the political systems in the Islamic world declined in a process that began under the persistent infiltration and influence of the Western ideal of nation-...Irreparable consequences to Middle East geopolitics ensued as the political systems in the Islamic world declined in a process that began under the persistent infiltration and influence of the Western ideal of nation-state.Three progressive stages in this conceptual transformation show how longstanding multinational imperial systems in the Islamic world disintegrated after the introduction of uone nation,one staten forced upon Middle East states an unrealistic model and eroded the principle of supremacy of sovereignty that had just been established.Interventionist theories that took hold meant that the Islamic world's self-transformation has never caught up with the demand of Western strategies.The Islamic realm has failed to achieve what it set out to do because political systems that would have been adaptive to the reality of the Islamic world had collapsed.展开更多
A pathophysiological model of the loss of reality comprehension in schizophrenia is proposed. Based on a formalism it is hypothesized that astroglial domains exert an information-categorizing function which becomes pr...A pathophysiological model of the loss of reality comprehension in schizophrenia is proposed. Based on a formalism it is hypothesized that astroglial domains exert an information-categorizing function which becomes progressively lost in the schizophrenic process, caused by functional and structural disintegration of astroglial domains. Unconstrained synaptic neurotransmission functionally disintegrates the astroglial domains. Microdomains located between perisynaptic astroglial processes and the synaptic membrane are interpreted as elementary functional units categorizing synaptic information processing. Unconstrained diffusion of neurotransmitters into the extrasynaptic space leads to the dysfunction of microdomain formation. In parallel, atrophic processes of astroglia progressively break up the connectivity between synaptic and extrasynaptic compartments disrupting astroglial domains. Basically, the organization of astroglia into definite functional and structural units (modules) of astroglial-synaptic information processing may enable the brain to comprehend ontological realms such as subjects and objects in the environment and their distinct qualities. This fundamental capability of cognition is lost in schizophrenia. It is suggested that this ontological confusion of astroglial domain boundaries progressively disorganizes reality comprehension and may represent the basic pathology in schizophrenia underlying the main symptoms of the disorder. Finally, the testing of the model is shortly discussed.展开更多
The Arab Spring in the spring of 2011 soon brought the Middle East into an abyss of chaos,instability,terrorism and civil war.Over the past six years,the Syria conflict in some areas tended to cool down.President Trum...The Arab Spring in the spring of 2011 soon brought the Middle East into an abyss of chaos,instability,terrorism and civil war.Over the past six years,the Syria conflict in some areas tended to cool down.President Trump reached an agreement with Russian President Putin on building a new"conflict relegation zone"on July 7,2017.After three years of展开更多
Zonal disintegration is the phenomenon of cyclical rupture zone and nonrupture zone in the surrounding rock of a deep-buried chamber,which is different from that of a shallow chamber.Based on the finite difference sof...Zonal disintegration is the phenomenon of cyclical rupture zone and nonrupture zone in the surrounding rock of a deep-buried chamber,which is different from that of a shallow chamber.Based on the finite difference software FLAC3D,the numerical simulation of surrounding rock with different mechanical parameters was conducted by using the SU model(Bilinear Strain-Softening Ubiquitous-Joint).The influences of buried depth,cohesion,and internal friction angle of surrounding rock on zonal disintegration were analyzed to reveal the influence law.The results show that:(1)after the chamber excavation,multiple rupture zones gradually extend from the chamber surface or adjacent periphery to the deep surrounding rock.In the extension process,a single rupture zone may be forked into two or even multiple rupture zones,which cross each other and form the zonal disintegration zone.(2)Zonal disintegration is affected by bothσ(in situ stress)and U_(cs)(uniaxial compression strength).Smaller U_(cs)and largerσwill lead to zonal disintegration.(3)The zoning fracture is not obvious in the case ofσ≤U_(cs).In the reverse case,zoning fracture appears remarkably in the surrounding rock around the chamber.These results reveal the influence law of zonal disintegration and provide theoretical support for the design of deep-buried chambers.展开更多
The purpose of this research was to evaluate the effect of starch- and xanthan gum-based food thickeners on the bitterness and dissolution of amlodipine besilate (AMPB) loaded orally disintegrating tablets (ODT) for p...The purpose of this research was to evaluate the effect of starch- and xanthan gum-based food thickeners on the bitterness and dissolution of amlodipine besilate (AMPB) loaded orally disintegrating tablets (ODT) for potential use with patients with dysphagia. A conventional dissolution test simulating the oral cavity was performed and the taste sensor output of the dissolved sample was evaluated over a 60-seconds period. When four types of AMPB loaded ODTs were tested alone, at 60 seconds, branded product (A) was the least bitter, followed by generic product (B)/generic product (C) which were equal, and finally generic product (D) which was the most bitter. Inhibition of bitterness of AMPB loaded ODTs mixed thickeners, 1.0 (w/v) % xanthan gum-based food thickener solution was significantly strong. The 7.1 (w/v) % and 4.7 (w/v) % starch-based food thickeners solution also effective in bitterness inhibition compared to the 2.4 (w/v) % starch-based food thickener solution. The dissolution test under pH 1.2 in related to 7.1 (w/v) % and 4.7 (w/v) % starch-based thickener contained each of AMPB loaded ODTs were associated with an almost complete amlodipine (AMP) dissolution (almost 90% at 10 minutes), whereas the 1.0, 2.0, 3.0 (w/v) % xanthan gum-based food thickener solution containing AMPB loaded ODTs did not show complete AMP dissolution and there were large variations in the initial dissolution stage. This suggests that a mixture of xanthan gum-based thickener and AMPB loaded ODT poses a risk of reduction of bioavailability. In conclusion, a mixture of 4.7 (w/v) % or 7.1 (w/v) % starch-based thickener with ODTs provides complete release of AMP and superior bitterness inhibition, so is the best choice for administration to patients with dysphagia.展开更多
The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has claimedmillions of lives and caused innumerable economic losses worldwide.Unfortunately,state-of...The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has claimedmillions of lives and caused innumerable economic losses worldwide.Unfortunately,state-of-the-art treatments still lag behind the continual emergence of new variants.Key to resolving this issue is developing antivirals to deactivate coronaviruses regardless of their structural evolution.Here,we report an innovative antiviral strategy involving extracellular disintegration of viral proteins with hyperanion-grafted enediyne(EDY)molecules.The core EDY generates reactive radical species and causes significant damage to the spike protein of coronavirus,while the hyperanion groups ensure negligible cytotoxicity of the molecules.The EDYs exhibit antiviral activity down to nanomolar concentrations,and the selectivity index of up to 20,000 against four kinds of human coronavirus,including the SARS-CoV-2 Omicron variant,suggesting the high potential of this new strategy in combating the COVID-19 pandemic and a future“disease X.”展开更多
Identifying critical nodes or sets in large-scale networks is a fundamental scientific problem and one of the key research directions in the fields of data mining and network science when implementing network attacks,...Identifying critical nodes or sets in large-scale networks is a fundamental scientific problem and one of the key research directions in the fields of data mining and network science when implementing network attacks, defense, repair and control.Traditional methods usually begin from the centrality, node location or the impact on the largest connected component after node destruction, mainly based on the network structure.However, these algorithms do not consider network state changes.We applied a model that combines a random connectivity matrix and minimal low-dimensional structures to represent network connectivity.By using mean field theory and information entropy to calculate node activity,we calculated the overlap between the random parts and fixed low-dimensional parts to quantify the influence of node impact on network state changes and ranked them by importance.We applied this algorithm and the proposed importance algorithm to the overall analysis and stratified analysis of the C.elegans neural network.We observed a change in the critical entropy of the network state and by utilizing the proposed method we can calculate the nodes that indirectly affect muscle cells through neural layers.展开更多
Both HIV-1 integrase (IN) and the central catalytic domain of IN (IN-CCD) catalyze the disintegration reaction in vitro.In this study,IN and IN-CCD proteins were expressed and purified,and a high-throughput format enz...Both HIV-1 integrase (IN) and the central catalytic domain of IN (IN-CCD) catalyze the disintegration reaction in vitro.In this study,IN and IN-CCD proteins were expressed and purified,and a high-throughput format enzyme-linked immunosorbent assay (ELISA) was developed for the disintegration reaction.IN exhibited a marked preference for Mn2+ over Mg2+ as the divalent cation cofactor in disintegration.Baicalein,a known IN inhibitor,was found to be an IN-CCD inhibitor.The assay is sensitive and specific for the study of disintegration reaction as well as for the in vitro identification of antiviral drugs targeting IN,especially targeting IN-CCD.展开更多
The mechanical behaviors of deep rock mass are different from those of shallow rock mass.Through cases of Jinping II Hydropower Station,the special phenomenon of zonal disintegration in the surrounding rock mass aroun...The mechanical behaviors of deep rock mass are different from those of shallow rock mass.Through cases of Jinping II Hydropower Station,the special phenomenon of zonal disintegration in the surrounding rock mass around the diversion tunnels,is analyzed.On the basis of fracture mechanics,a new strength criterion for deep rock mass is derived.The new nonlinear strength criterion that is relative to the rock mass rating classification can be applied to the study of the tensile failure of deep rock mass.Subsequently,zonal disintegration model is established,and the radius of fractured zone and none-fractured zone of deep surrounding rock mass around cylindrical tunnel are obtained,their exact positions and the evolution law of zonal disintegration of surrounding rock mass is determined.To validate the present model,comparison between calculation results and the experiment observation on facture and failure around underground openings is carried out.It is found that the numerical simulation result is in good agreement with the experimental one on failure modes around the hole.Through sensitivity analysis,the effects of stress condition,cohesion and the angle of internal friction on the phenomenon of zonal disintegration are determined.Finally,the present model is adopted in the analysis of the zonal disintegration in the surrounding rock mass around the diversion tunnels in Jinping II Hydropower Station.Meanwhile,the magnitude and distributions of fractured zones are determined by numerical simulation.展开更多
How to solve the hypersonic aerothermodynamics around large-scale uncontrolled spacecraft during falling disintegrated process from outer space to earth,is the key to resolve the problems of the uncontrolled Tiangong-...How to solve the hypersonic aerothermodynamics around large-scale uncontrolled spacecraft during falling disintegrated process from outer space to earth,is the key to resolve the problems of the uncontrolled Tiangong-No.1 spacecraft reentry crash.To study aerodynamics of spacecraft reentry covering various flow regimes,a Gas-Kinetic Unified Algorithm(GKUA)has been presented by computable modeling of the collision integral of the Boltzmann equation over tens of years.On this basis,the rotational and vibrational energy modes are considered as the independent variables of the gas molecular velocity distribution function,a kind of Boltzmann model equation involving in internal energy excitation is presented by decomposing the collision term of the Boltzmann equation into elastic and inelastic collision terms.Then,the gas-kinetic numerical scheme is constructed to capture the time evolution of the discretized velocity distribution functions by developing the discrete velocity ordinate method and numerical quadrature technique.The unified algorithm of the Boltzmann model equation involving thermodynamics non-equilibrium effect is presented for the whole range of flow regimes.The gas-kinetic massive parallel computing strategy is developed to solve the hypersonic aerothermodynamics with the processor cores 500~45,000 at least 80%parallel efficiency.To validate the accuracy of the GKUA,the hypersonic flows are simulated including the reentry Tiangong-1 spacecraft shape with the wide range of Knudsen numbers of 220~0.00005 by the comparison of the related results from the DSMC and N-S coupled methods,and the low-density tunnel experiment etc.For uncontrolling spacecraft falling problem,the finite-element algorithm for dynamic thermalforce coupling response is presented,and the unified simulation of the thermal structural response and the hypersonic flow field is tested on the Tiangong-1 shape under reentry aerodynamic environment.Then,the forecasting analysis platform of end-of-life largescale spacecraft flying track is established on the basis of ballistic computation combined with reentry aerothermodynamics and deformation failure/disintegration.展开更多
The effects of two solid-based hydrogen peroxides sodium percarbonate(SPC) and calcium peroxide(CP)on waste activated sludge(WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration f...The effects of two solid-based hydrogen peroxides sodium percarbonate(SPC) and calcium peroxide(CP)on waste activated sludge(WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration for the synergistic effect of alkaline and oxidation. The strong alkaline condition led to the leakage of ammonia and the existence of abundant calcium ions accelerated the fixation of phosphorus via precipitation in CP WAS disintegration process. However, the spongy-like layer and low p H condition retarded the release of gaseous ammonia in SPC group. Hydroxyl radical was the main oxygen reactive species in SPC approaches which were more intense than CP by electron spin resonance(ESR) analysis.CP treated WAS contented more small particle size matter and total suspended solids(TSS) increased dramatically. In conclusion, CP pretreated sludge was more suitable for fertilization, while SPC was in favor of anaerobic digestion. This study clarified the differences between these two oxidants and their intermediates on nutrients release in sludge disintegration.展开更多
文摘The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro cracks and its composition were determined. The result demonstrates that only a few phosphides contribute to the spontaneous crumbling of the RE silicide alloy by reacting with water and forming oxide or phosphorus oxide. The phosphorus content is not the critical factor of disintegration in the alloy studied.
基金Supported by the National Natural Science Foundation of China (51078371,51021001)the Natural Science Foundation Project of CQ CSTC (2009BA4046,2009AB6194)
文摘Rock masses without pre-existing macrocracks can usually be considered as granular materials with only microcracks.During the excavation of the tunnels,microcracks may nucleate,grow and propagate through the rock matrix;secondary microcracks may appear,and discontinuous and incompatible deformation of rock masses may occur.The classical continuum elastoplastic theory is not suitable for analyzing discontinuous and incompatible deformation of rock masses.Based on non-Euclidean model of the discontinuous and incompatible deformation of rock masses,the distribution of stresses in the surrounding rock masses in deep tunnels is fluctuant or wave-like.The stress concentration at the tips of microcracks located in vicinity of stress wave crest is comparatively large,which may lead to the unstable growth and coalescence of secondary microcracks,and consequently the occurrence of fractured zones.On the other hand,the stress concentration at the tips of microcracks located around stress wave trough is relatively small,which may lead to the arrest of microcracks,and thus the non-fractured zones.The alternate appearance of stress wave crest and trough thus may induce the alternate occurrence of fractured and non-fractured zones in deep rock masses.For brittle rocks,the dissipated energy of microcrack growth is small,but the elastic strain energy stored in rock masses may be larger than the dissipated energy growths of pre-existing microcracks and secondary microcracks.The sudden release of the residual elastic strain energy may lead to rockburst.Based on this understanding,the criteria of rockburst are established.Furthermore,the relationship between rockbursts and zonal disintegration in the surrounding rock masses around deep tunnels is studied.The influences of the in-situ stresses and the physico-mechanical parameters on the distribution of rockburst zones and the ejection velocity of rock fragments are investigated in detail.
基金supported by the Special Projects of the Central Government Guiding Local Science and Technology Development in China(Guike.ZY21195022)the National Natural Science Foundation of China(No.42007055 and 42107350)。
文摘Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and environment.In this study,typical Benggang collapsing-wall soils were used as the study area to investigate the effects of different initial moisture contents and dicranopteris linearis root weight densities,as well as their interactions on disintegration in orthogonal test method.The results showed that the rate of soil disintegration decreased as a linear function of the initial moisture content.The soil disintegration rate tended to rise and then fall as the root weight density increased,reflecting an optimum root weight density of 0.75-1.00 g/100 cm3.The incorporation of dicranopteris linearis roots was most effective for soil consolidation in the shallow layers of soil.In addition,the disintegration rate of the collapsing-wall soils increases as the soil layer deepened.The dicranopteris linearis root system and initial moisture content had an interactive effect that was more pronounced in deeper soils.However,the combined effect of these processes was always dominated by the initial moisture content.Moderate initial soil moisture content(0.20-0.24 g/g)and the addition of a high root density in dicranopteris linearis(0.75-1.00 g/100 cm3)were the optimal combinations that reduced the disintegration rate.In conclusion,maintaining a suitable natural moisture content in collapsing-wall soils and taking measures that use plants to consolidate soil can effectively prevent and control the occurrence of Benggang erosion.The results of this study provided further insight into the factors that influence soil disintegration and offered a scientific basis for soil erosion management in the southern China.
基金National Natural Science Foundation of China(No.51478099)Scientific Research Foundation for Returned Overseas Chinese Scholars of China(No.SEM-11W11329)
文摘The main pathways of primary sludge(PS)ultrasonic disintegration were analyzed at the sonication frequency of 20 kH z and the thermal effect on PS disintegration was investigated.By adding Na HCO3as a scavenger to entrap the free hydroxyl radicals,cavitation contributed to 82.91%of the total sonication effect.The power consumed by temperature rising accounted for more than40%of ultrasound power input at the power density of 0.215 W/m L and the sonication time of 10 min.With the thermal insulation of polyfoam coating during sonication,a 18.37%of soluble chemical oxygen demand(SCOD)increment was observed.With the process of pre-heating the PS before sonication,64.15%of SCOD increment was achieved.Compared with the particle size of 13.77μm for the sonicated PS,the sludge mean particle size decreased to 12.83 and11.98μm by applying polyfoam coating and pre-heating the PS to enhance the cavitation and thermal effect.It suggested that if thermal energy consumption was relieved during the sonication process of PS,more energy could be used to disintegrate the sludge.
文摘't Hooft-Veltman Wilson dimensional regularization depends crucially upon Borel summability which entails strong links to the modern mathematical theory of transfinite sets and consequently to the fractal-Cantorian spacetime proposal of Ord-Nottale-El Naschie. Starting from the above, we interpret the main step of the mathematical analysis in terms of elementary particles interaction. Thus 't Hooft-Veltman “perturbation” parameter which measures the deviation of the regulated space from the four dimensionality of spacetime is interpreted as an elementary particle with a topological mass charge equal to 0.18033989, i.e. double the magnitude of Hardy’s quantum entanglement. In turn, Hardy’s quantum entanglement which may be interpreted geometrically as a consequence of the zero set embedded in an empty set could also be interpreted as an exchange of pseudo elementary particles with a topological mass charge equal to Hardy’s entanglement where is the Hausdorff dimension of the zero set of the corresponding 't Hooft-Veltman spacetime.
基金supported by University of Ibadan Senate Research Grant to O.A.Odeku
文摘Objective:The influence of two experimental starches - ginger starch obtained from Zingiber officinale and banana starch from Musa sapientum - on the mechanical and disintegration properties of chloroquine tablets have been studied in comparison with the influence of official corn starch.Methods:Chloroquine tablets were formulated using various concentarions of the starches as binding agent.The mechanical properties of the tablets were assessed in terms of crushing strength and friability and the crushing strength-friability ratio(CSFR) while drug release properties were evaluated based on disintegration and the time of tablets.Results:The ranking for crushing strength and CSFR was corn】banana】ginger starch while the ranking was reverse for friability.The disintegration time increased with packing fraction and starch concentration in the rank order of formulations containing corn】banana】ginger starch.The CSFR/DT values increased with concentration of starch binder indicating an improved balance between binding and disintegrant properties of the starches.Statistical analysis showed that there were significant(P【0.001) difference in the CSFR/DT for tablets containing the various starch binders.Conclusion:The mechanical and disintegration properties of the experimental starches compared favorably with those of corn starch and ginger starch could be more useful when faster tablet disintegration is desired.
基金Funded by the National Key Natural Science Foundation of China(No.5131903ZT1)
文摘TC11 titanium alloy samples with lamellar microstructrue were compressed on a Gleeble 1500D Simulator.Compression tests were carried out at 950 ℃ and a strain rate of 0.1 s-1 with height reduction of 20%,40% and 60%,respectively.Microstruture of the compressed TC11 alloy was obeserved and analyzed by optical microscopy(OM),transmission electron microscope(TEM),electron back-scattered diffraction(EBSD).The lamellar disintegration mechanism of the TC11 titanium alloy was deduced.The results indicated that the compressive deformation promoted the phase transformation in bi-phase area.βphase layers were formed along the gliding planes inα phase,and α slivers were disintegrated into many small flakes through theα/βinterface slipping.
基金supported by the National Natural Science Foundation of China (Nos. 41877228, 41877229 and 42102303)Guangdong Basic and Applied Basic Research Foundation (Nos. 2018B030311066 and 2019A1515010554)+1 种基金China Postdoctoral Science Foundation (No. 2019M663241)Science and Technology Program of Guangzhou, China (No. 201904010136)。
文摘The disintegration of granite residual soil is especially affected by variations in physical and chemical properties. Serious geologic hazards or engineering problems are closely related to the disintegration of granite residual soil in certain areas. Research on the mechanical properties and controlling mechanisms of disintegration has become a hot issue in practical engineering. In this paper, the disintegration characteristics of improved granite residual soil are studied by using a wet and dry cycle disintegration instrument, and the improvement mechanism is analyzed. The results show that the disintegration amounts and disintegration ratios of soil samples treated with different curing agents are obviously different. The disintegration process of improved granite residual soil can be roughly divided into 5 stages:the forcible water intrusion stage, microcrack and fissure development stage, curing and strengthening stage, stable stage, and sudden disintegration stage. The disintegration of granite residual soil is caused by the weakening of the cementation between soil particles under the action of water. When the disintegration force is greater than the anti-disintegration force of soil, the soil will disintegrate. Cement and lime mainly rely on ion exchange agglomeration, the inclusion effect of curing agents on soil particles, the hard coagulation reaction and carbonation to strengthen granite residual soil. Kaolinite mainly depends on the reversibility of its own cementation to improve and strengthen granite residual soil. The reversibility of kaolinite cementation is verified by investigating pure kaolinite with a tensile, soaking, drying and tensile test cycle. Research on the disintegration characteristics and disintegration mechanism of improved granite residual soil is of certain reference value for soil modification.
基金This work was financially supported by the Chinese National key R&D project(No.2016YFC0801402)the Chinese National Natural Science Foundation Project(No.51627804).
文摘To investigate the zonal disintegration form of the surrounding rock in deep tunnels,model tests were performed in the simulation set-up of fracture mechanism and support technology of surrounding rock in deep tunnel.The test results illustrate that the first fracture of the surrounding rock occurred at the intersection of the tunnel floor and the side wall.After more serious destruction,the side wall and the vault were destroyed.Although the fracture width of each surrounding rock mass was distinct,they were relatively uniform with a nearly continuous fracture form.The width of the split bodies of the model tunnels(i.e.,the annular zonal disintegration area)developed with an increasing load.It was observed from the fitting curves of the data that all radial strain values of the surrounding rock were more symmetric with a smooth fitting curve,and the maximum value occurred near the tunnel wall before reducing instantly.The circumferential strain values were dispersed and the data were inconsistent with the fitting curve,which caused some data to be unreliable.The phenomenon of zonal disintegration was primarily caused by radial tension strain of the surrounding rock.This phenomenon would not extend indefinitely as the rupture range would be limited to a certain extent,because the maximum radial tension strain of the surrounding rock was less than the limiting value.
基金This paper is a part of the National Social Science Fund project,The Islamic World of the Middle East in the International System(Approval No.:17FGJ009).
文摘Irreparable consequences to Middle East geopolitics ensued as the political systems in the Islamic world declined in a process that began under the persistent infiltration and influence of the Western ideal of nation-state.Three progressive stages in this conceptual transformation show how longstanding multinational imperial systems in the Islamic world disintegrated after the introduction of uone nation,one staten forced upon Middle East states an unrealistic model and eroded the principle of supremacy of sovereignty that had just been established.Interventionist theories that took hold meant that the Islamic world's self-transformation has never caught up with the demand of Western strategies.The Islamic realm has failed to achieve what it set out to do because political systems that would have been adaptive to the reality of the Islamic world had collapsed.
文摘A pathophysiological model of the loss of reality comprehension in schizophrenia is proposed. Based on a formalism it is hypothesized that astroglial domains exert an information-categorizing function which becomes progressively lost in the schizophrenic process, caused by functional and structural disintegration of astroglial domains. Unconstrained synaptic neurotransmission functionally disintegrates the astroglial domains. Microdomains located between perisynaptic astroglial processes and the synaptic membrane are interpreted as elementary functional units categorizing synaptic information processing. Unconstrained diffusion of neurotransmitters into the extrasynaptic space leads to the dysfunction of microdomain formation. In parallel, atrophic processes of astroglia progressively break up the connectivity between synaptic and extrasynaptic compartments disrupting astroglial domains. Basically, the organization of astroglia into definite functional and structural units (modules) of astroglial-synaptic information processing may enable the brain to comprehend ontological realms such as subjects and objects in the environment and their distinct qualities. This fundamental capability of cognition is lost in schizophrenia. It is suggested that this ontological confusion of astroglial domain boundaries progressively disorganizes reality comprehension and may represent the basic pathology in schizophrenia underlying the main symptoms of the disorder. Finally, the testing of the model is shortly discussed.
文摘The Arab Spring in the spring of 2011 soon brought the Middle East into an abyss of chaos,instability,terrorism and civil war.Over the past six years,the Syria conflict in some areas tended to cool down.President Trump reached an agreement with Russian President Putin on building a new"conflict relegation zone"on July 7,2017.After three years of
基金National Natural Science Foundation of China,Grant/Award Number:52079068State Key Laboratory of Hydroscience and Hydraulic Engineering,Grant/Award Number:2021-KY-04Key Research and Development Plan of Ningxia Hui Autonomous Region,Grant/Award Number:2018BCG01003。
文摘Zonal disintegration is the phenomenon of cyclical rupture zone and nonrupture zone in the surrounding rock of a deep-buried chamber,which is different from that of a shallow chamber.Based on the finite difference software FLAC3D,the numerical simulation of surrounding rock with different mechanical parameters was conducted by using the SU model(Bilinear Strain-Softening Ubiquitous-Joint).The influences of buried depth,cohesion,and internal friction angle of surrounding rock on zonal disintegration were analyzed to reveal the influence law.The results show that:(1)after the chamber excavation,multiple rupture zones gradually extend from the chamber surface or adjacent periphery to the deep surrounding rock.In the extension process,a single rupture zone may be forked into two or even multiple rupture zones,which cross each other and form the zonal disintegration zone.(2)Zonal disintegration is affected by bothσ(in situ stress)and U_(cs)(uniaxial compression strength).Smaller U_(cs)and largerσwill lead to zonal disintegration.(3)The zoning fracture is not obvious in the case ofσ≤U_(cs).In the reverse case,zoning fracture appears remarkably in the surrounding rock around the chamber.These results reveal the influence law of zonal disintegration and provide theoretical support for the design of deep-buried chambers.
文摘The purpose of this research was to evaluate the effect of starch- and xanthan gum-based food thickeners on the bitterness and dissolution of amlodipine besilate (AMPB) loaded orally disintegrating tablets (ODT) for potential use with patients with dysphagia. A conventional dissolution test simulating the oral cavity was performed and the taste sensor output of the dissolved sample was evaluated over a 60-seconds period. When four types of AMPB loaded ODTs were tested alone, at 60 seconds, branded product (A) was the least bitter, followed by generic product (B)/generic product (C) which were equal, and finally generic product (D) which was the most bitter. Inhibition of bitterness of AMPB loaded ODTs mixed thickeners, 1.0 (w/v) % xanthan gum-based food thickener solution was significantly strong. The 7.1 (w/v) % and 4.7 (w/v) % starch-based food thickeners solution also effective in bitterness inhibition compared to the 2.4 (w/v) % starch-based food thickener solution. The dissolution test under pH 1.2 in related to 7.1 (w/v) % and 4.7 (w/v) % starch-based thickener contained each of AMPB loaded ODTs were associated with an almost complete amlodipine (AMP) dissolution (almost 90% at 10 minutes), whereas the 1.0, 2.0, 3.0 (w/v) % xanthan gum-based food thickener solution containing AMPB loaded ODTs did not show complete AMP dissolution and there were large variations in the initial dissolution stage. This suggests that a mixture of xanthan gum-based thickener and AMPB loaded ODT poses a risk of reduction of bioavailability. In conclusion, a mixture of 4.7 (w/v) % or 7.1 (w/v) % starch-based thickener with ODTs provides complete release of AMP and superior bitterness inhibition, so is the best choice for administration to patients with dysphagia.
基金the National Natural Science Foundation of China(grant no.21871080)the Eastern Scholar Professorship(for A.H.)the Natural Science Foundation of Shanghai(grant no.20ZR1463900)(for J.L.).
文摘The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has claimedmillions of lives and caused innumerable economic losses worldwide.Unfortunately,state-of-the-art treatments still lag behind the continual emergence of new variants.Key to resolving this issue is developing antivirals to deactivate coronaviruses regardless of their structural evolution.Here,we report an innovative antiviral strategy involving extracellular disintegration of viral proteins with hyperanion-grafted enediyne(EDY)molecules.The core EDY generates reactive radical species and causes significant damage to the spike protein of coronavirus,while the hyperanion groups ensure negligible cytotoxicity of the molecules.The EDYs exhibit antiviral activity down to nanomolar concentrations,and the selectivity index of up to 20,000 against four kinds of human coronavirus,including the SARS-CoV-2 Omicron variant,suggesting the high potential of this new strategy in combating the COVID-19 pandemic and a future“disease X.”
基金Project supported by the National Natural Science Foundation of China (Grant Nos.72071153 and 72231008)Laboratory of Science and Technology on Integrated Logistics Support Foundation (Grant No.6142003190102)the Natural Science Foundation of Shannxi Province (Grant No.2020JM486)。
文摘Identifying critical nodes or sets in large-scale networks is a fundamental scientific problem and one of the key research directions in the fields of data mining and network science when implementing network attacks, defense, repair and control.Traditional methods usually begin from the centrality, node location or the impact on the largest connected component after node destruction, mainly based on the network structure.However, these algorithms do not consider network state changes.We applied a model that combines a random connectivity matrix and minimal low-dimensional structures to represent network connectivity.By using mean field theory and information entropy to calculate node activity,we calculated the overlap between the random parts and fixed low-dimensional parts to quantify the influence of node impact on network state changes and ranked them by importance.We applied this algorithm and the proposed importance algorithm to the overall analysis and stratified analysis of the C.elegans neural network.We observed a change in the critical entropy of the network state and by utilizing the proposed method we can calculate the nodes that indirectly affect muscle cells through neural layers.
基金supported by the National Natural Science Foundation of China (Grant No. 30670497)the Beijing Natural Science Foundation (Grant No. 5072002)
文摘Both HIV-1 integrase (IN) and the central catalytic domain of IN (IN-CCD) catalyze the disintegration reaction in vitro.In this study,IN and IN-CCD proteins were expressed and purified,and a high-throughput format enzyme-linked immunosorbent assay (ELISA) was developed for the disintegration reaction.IN exhibited a marked preference for Mn2+ over Mg2+ as the divalent cation cofactor in disintegration.Baicalein,a known IN inhibitor,was found to be an IN-CCD inhibitor.The assay is sensitive and specific for the study of disintegration reaction as well as for the in vitro identification of antiviral drugs targeting IN,especially targeting IN-CCD.
基金supported by the National Natural Science Foundation of China(Grant Nos.51078371,50878218,and 51027004)
文摘The mechanical behaviors of deep rock mass are different from those of shallow rock mass.Through cases of Jinping II Hydropower Station,the special phenomenon of zonal disintegration in the surrounding rock mass around the diversion tunnels,is analyzed.On the basis of fracture mechanics,a new strength criterion for deep rock mass is derived.The new nonlinear strength criterion that is relative to the rock mass rating classification can be applied to the study of the tensile failure of deep rock mass.Subsequently,zonal disintegration model is established,and the radius of fractured zone and none-fractured zone of deep surrounding rock mass around cylindrical tunnel are obtained,their exact positions and the evolution law of zonal disintegration of surrounding rock mass is determined.To validate the present model,comparison between calculation results and the experiment observation on facture and failure around underground openings is carried out.It is found that the numerical simulation result is in good agreement with the experimental one on failure modes around the hole.Through sensitivity analysis,the effects of stress condition,cohesion and the angle of internal friction on the phenomenon of zonal disintegration are determined.Finally,the present model is adopted in the analysis of the zonal disintegration in the surrounding rock mass around the diversion tunnels in Jinping II Hydropower Station.Meanwhile,the magnitude and distributions of fractured zones are determined by numerical simulation.
基金The National Key Basic Research and Development Program(2014CB744100)and the National Natural Science Foundation of China(91530319 and 11325212)support the present researches in the design of the study and collection,analysis,and interpretation of data and in writing the manuscript.
文摘How to solve the hypersonic aerothermodynamics around large-scale uncontrolled spacecraft during falling disintegrated process from outer space to earth,is the key to resolve the problems of the uncontrolled Tiangong-No.1 spacecraft reentry crash.To study aerodynamics of spacecraft reentry covering various flow regimes,a Gas-Kinetic Unified Algorithm(GKUA)has been presented by computable modeling of the collision integral of the Boltzmann equation over tens of years.On this basis,the rotational and vibrational energy modes are considered as the independent variables of the gas molecular velocity distribution function,a kind of Boltzmann model equation involving in internal energy excitation is presented by decomposing the collision term of the Boltzmann equation into elastic and inelastic collision terms.Then,the gas-kinetic numerical scheme is constructed to capture the time evolution of the discretized velocity distribution functions by developing the discrete velocity ordinate method and numerical quadrature technique.The unified algorithm of the Boltzmann model equation involving thermodynamics non-equilibrium effect is presented for the whole range of flow regimes.The gas-kinetic massive parallel computing strategy is developed to solve the hypersonic aerothermodynamics with the processor cores 500~45,000 at least 80%parallel efficiency.To validate the accuracy of the GKUA,the hypersonic flows are simulated including the reentry Tiangong-1 spacecraft shape with the wide range of Knudsen numbers of 220~0.00005 by the comparison of the related results from the DSMC and N-S coupled methods,and the low-density tunnel experiment etc.For uncontrolling spacecraft falling problem,the finite-element algorithm for dynamic thermalforce coupling response is presented,and the unified simulation of the thermal structural response and the hypersonic flow field is tested on the Tiangong-1 shape under reentry aerodynamic environment.Then,the forecasting analysis platform of end-of-life largescale spacecraft flying track is established on the basis of ballistic computation combined with reentry aerothermodynamics and deformation failure/disintegration.
基金financially supported by the National Natural Science Foundation of China (No. 51978201)the State Key Laboratory of Urban Water Resource and Environment (No.2020DX08)。
文摘The effects of two solid-based hydrogen peroxides sodium percarbonate(SPC) and calcium peroxide(CP)on waste activated sludge(WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration for the synergistic effect of alkaline and oxidation. The strong alkaline condition led to the leakage of ammonia and the existence of abundant calcium ions accelerated the fixation of phosphorus via precipitation in CP WAS disintegration process. However, the spongy-like layer and low p H condition retarded the release of gaseous ammonia in SPC group. Hydroxyl radical was the main oxygen reactive species in SPC approaches which were more intense than CP by electron spin resonance(ESR) analysis.CP treated WAS contented more small particle size matter and total suspended solids(TSS) increased dramatically. In conclusion, CP pretreated sludge was more suitable for fertilization, while SPC was in favor of anaerobic digestion. This study clarified the differences between these two oxidants and their intermediates on nutrients release in sludge disintegration.
