[Objective] The aim was to research and identify starch grain microfossil found in archaeological sites in China, and to find appropriate procedures for the starch grain analysis experiment.[Method] Wheat starch grain...[Objective] The aim was to research and identify starch grain microfossil found in archaeological sites in China, and to find appropriate procedures for the starch grain analysis experiment.[Method] Wheat starch grain size distribution was analyzed, and some simulated experiments were carried out, like mortar grinding, ultrasonic treatment, hydrochloric acid and hydrogen peroxide immersion, drying treatment, and so on. [Result] The mean size of wheat starch grains had increased in the growth process. Mortar grinding would make wheat starch grains larger than untreated sample. Long time of ultrasonic treatment can also make the starch grain size larger. 10% HCl and 6% H2O2 would have little effects on morphological feature of wheat starch grains. Low temperature heating did not cause starch grains to be gelatinized. [Conclusion] These experiment results can improve the accuracy of starch grain microfossil identification in the archaeological site. Starch grain analysis may be a utility and effective analytical tool in studying the origin of agriculture and the dispersal of crops in China.展开更多
The pitting corrosion behaviors of 7A60 aluminum alloy in the retrogression and re-aging (RRA) temper were investigated by electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques, ...The pitting corrosion behaviors of 7A60 aluminum alloy in the retrogression and re-aging (RRA) temper were investigated by electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques, and the microstructure and the second phase content of the alloy were observed and determined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that there exist two different corrosion stages for 7A60 alloy in 3.5%NaCl solution, and the corrosion process can be detected by the appearance of EIS spectrum with two capacitive time constants and the wavelet fractal dimension D extracted from EN. SEM and EDS results also demonstrate that severe pitting corrosion in 7A60 alloy is mainly caused by electrochemical active MgZn2 particles, secondly by Al2MgCu and Mg2Si. Al7Cu2Fe particles make little contribution to the pitting corrosion of 7A60 alloy.展开更多
Buckling is the primary cause of failure of a side member in condition of overloading,so buckling stability should be taken into consideration in the design optimization of side member.On the other hand,lightweight is...Buckling is the primary cause of failure of a side member in condition of overloading,so buckling stability should be taken into consideration in the design optimization of side member.On the other hand,lightweight is always a pursuing objective of manufacturer of automobile seat.Thus both the buckling stability and lightweight are considered in the suggested design optimization method of the side member of automobile seats.The method has two design phases.Firstly,the optimal shape of back curve by using shape optimization was obtained in which the lightweight of the side member was set to be the design objective.Secondly,optimal size and distribution of grooves on side member was obtained by topography optimization in which the buckling critical load was set to be the design objective.A typical design example shows that the buckling critical load of the optimal side member is increased by 25.98%,and the weight is decreased by 3.7% simultaneously.展开更多
AIM: To make drug sera of Salvia miltiorrhiza and Yigankang, both of which are Chinese herbs that activate bleeding and eliminate stasis, in normal rats and those with liver fibrosis, respectively. To investigate and ...AIM: To make drug sera of Salvia miltiorrhiza and Yigankang, both of which are Chinese herbs that activate bleeding and eliminate stasis, in normal rats and those with liver fibrosis, respectively. To investigate and compare the effects of the two different drug sera on the proliferation and activation of hepatic stellate cells (HSCs). METHODS: Some rats were induced with liver fibrosis: 40% carbon tetrachloride (CCI4) subcutaneous injection, twice a week for 9 wk. Salvia miltiorrhiza, Yigankang, colchicines and normal saline were administered into the stomachs of normal rats and those with liver fibrosis. Drug sera were extracted 5 d later. HSCs in vitro were cultivated in different drug sera for 24 h. The rates of proliferation and expression of a-smooth muscle actin (α-SMA) were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and immunocyt-ochemistry stain, respectively. RESULTS: The drug sera from normal and liver fibrotic rats could be used to cultivate HSCs and to observe the effects of the corresponding components of herbs on HSCs. Salvia miltiorrhiza and Yigankang had better inhibitory effects on HSCs than colchicines (MTT: normal drug serum: Salvia miltiorrhiza 0.42 ±0.08, Yigankang 0.32±0.10 vs colchicines 0.45±0.12 pathological drug serum: Salvia miltiorrhiza 0.33±0.02, Yigankang 0.26±0.01 vs colchicines 0.41±0.09. P<0.05). The drug sera of Salvia miltiorrhiza, Yigankang from liver fibrotic rats had a stronger inhibitory effect than the same ones from normal rats (MTT: Salvia miltiorrhiza: normal drug serum 0.42±0.08 vs pathological drug serum 0.33±0.02. Yigankang: normal drug serum 0.32±0.10 vs pathological drug serum 0.26±0.01. P<0.05) CONCLUSION: Salvia miltiorrhiza and Yigankang could inhibit the expression of a-SMA and the proliferation of HSCs. The drug sera from normal and liver fibrotic rats had different effects on HSCs, probably due to different metabolic processes, effective components and different quantities of drug contents in drug sera from rats with different states of liver.展开更多
Rifapentine, an important antibiotic, was crystallized from methanol solvent in the form of its methanol solvate. The crystal structure of rifapentine methanol solvate belongs to monoclinic, space group P21, with the ...Rifapentine, an important antibiotic, was crystallized from methanol solvent in the form of its methanol solvate. The crystal structure of rifapentine methanol solvate belongs to monoclinic, space group P21, with the unit cell parameters of a = 1.2278(3) nm, b = 1.9768(4) rim, c = 1.2473(3) nm, Z= 2, and β = 112.35(3). The parallelepiped.morphology was also predicted by Materials Studio simulation program.. The influence of intermolecular in-teraction was taken into account in the attachment energy model. The crystal shape fits the calculated morphology well, which was performed on the potential energy minimized model using a generic DREIDING 2.21 force fieldand developed minimization protocol with derived'partial charges.展开更多
The relationship between microspore developmental stages and morphological characteristics of floral organ in balsam pear was studied. The results showed that flower buds developed a series of morphological changes at...The relationship between microspore developmental stages and morphological characteristics of floral organ in balsam pear was studied. The results showed that flower buds developed a series of morphological changes at different microspore developmental stages, and morphological characteristics of floral organ were significantly different when sampling from different part or cultivar of balsam pear. Anther at late-uninucleate stage was best for culture, in which stage flower buds swelled obviously, and white floss on the surface reduced. In addition, calyxes were obvious but did not spread, and the most of anthers were light green.展开更多
AIM:To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.METHODS:Resected small bowel specimens from small bowel atresia patients(n = 12) were divided int...AIM:To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.METHODS:Resected small bowel specimens from small bowel atresia patients(n = 12) were divided into three sections(proximal,atretic and distal).Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers-smooth muscle actin(SMA) and desmin using conventional paraffin sections of the proximal and distal bowel.Small bowel from agematched patients(n = 2) undergoing Meckel's diverticulum resection served as controls.RESULTS:The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue,but the distal bowel was unchanged.Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue.There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel.The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers.CONCLUSION:Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia.展开更多
Notable for the completeness with which it surrenders formally and artistically to the textual dictates of Twitter, Jennifer Egan's 2012 short science fiction Black Box is one of the most triumphant and fully-fledged...Notable for the completeness with which it surrenders formally and artistically to the textual dictates of Twitter, Jennifer Egan's 2012 short science fiction Black Box is one of the most triumphant and fully-fledged fictions written in the form of new media. This paper explores the Twitter narrative employed in Black Box, pointing out that the serialized tweeting format of the story released via computer, mobile phone, or other electronic equipments brings readers immediate reading experience, allowing readers to sense the same feelings as the protagonist does. Through the experimental serialization of"Twitter" narrative, Egan expresses her concerns and worries about the security of the American security as well as the whole world in the post-"9.11" period and at the same time she embraces the virtues and pleasures of traditional storytelling delivered through a wholly new digital format. This paper concludes that Black Box is perhaps one of the boldest experiments of narrative form and is direct exploration into the contemporary image culture.展开更多
The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures (nucleoplasm, chromatin, nuclear ...The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures (nucleoplasm, chromatin, nuclear matrix) as possible zones affecting the conformational rearrangements of the total interphase chromatin at the induction of increasing morphogenesis of mature embryos-germs of spring and transformed from its winter wheat. Germinated embryos-germs were detached from endosperm after 24 hours from the start of soaking. Cell nuclei have been allocated from embryos-germs and cleared, and then from their heteropolymer suprastructures (nucleoplasm, chromatin loosely bound with nuclear matrix and chromatin tightly bound with nuclear matrix, and nuclear matrix) were extracted by increasing ionic strength of solution. From isolated nuclear suprastructures, non-histone proteins were separated from histones using ion exchange chromatography. Trypsin-like complexes from non-histone proteins and histone blocks were isolated using the affinity chromatography. The Arg-X (tryptase) activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine. Hypersensitivity to the Arg-X proteolysis in trypsin-like complexes detected at the level suprastructures of chromatin tightly bound with the nuclear matrix was shown. The most active changes of the nuclear proteome have occurred at the level of the non-histone proteins and the core histones (H2A + H2B) (H3 + H4) of induced to growth embryos-seedlings of winter wheat (compared to the initial spring form of wheat). Perhaps hypersensitivity to the Arg-X activity of the trypsin-like complexes in the non-histone proteins and the core blocks of chromatin tightly bound with nuclear matrix have been entrenched during the transforming of the winter wheat from the initial spring wheat.展开更多
Objective:To study the changes of the expression of bone morphogenetic protein-7(BMP-7) and its receptors(BMPR-Ⅱ,ALK2,ALK3 and ALK6) in the renal tubulointerstitial fibrosis induced with unilateral ureteral obstructi...Objective:To study the changes of the expression of bone morphogenetic protein-7(BMP-7) and its receptors(BMPR-Ⅱ,ALK2,ALK3 and ALK6) in the renal tubulointerstitial fibrosis induced with unilateral ureteral obstruction in rats. Methods: Sixty Wistar male rats were divided randomly into the normal control,sham-operation and unilateral ureteral obstruction(UUO) groups and the rats were killed on the 1st,3rd,7th and 14th postoperative days respectively.The mRNA level of BMP-7,BMPR-Ⅱ,ALK2,ALK3 and ALK6 was determined with RT-PCR.The site and level of protein expression of BMP-7 were observed with immunohistochemical staining. Results: The mRNA level of BMP-7,BMPR-Ⅱ,ALK2 and ALK3 was significantly decreased in the rats of UUO group than in those of the sham-operation group but the mRNA level of ALK6 showed no obvious changes in all the rats.Immunohistochemical staining revealed that the protein of BMP-7 was mainly expressed in the renal tubules and interstitial tissue of the kidneys in normal rats but it was decreased gradually along with the unilateral ureteral obstruction. Conclusion: It is found that the loss of BMP-7 and its receptors including BMPR-Ⅱ,ALK2 and ALK3 occurs in the early phase of renal tubulointerstitial fibrosis before the appearance of other pathological changes in the kidney and may play an important role in the occurrence and progress of renal tubulointerstitial fibrosis.展开更多
A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained v...A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained via localized timing optimization. Then, through evaluating each potential insertion against design objectives, potential optimal buffer insertion locations and sizes for the whole routing tree were determined. At last, by removing redundant buffer insertion operations which do not maximize S ( so ), given timing requirements are finally fulfilled through minimum number of buffers.展开更多
Like for most parts of High Asia,researches concerning the Pleistocene landscape evolution of the Leh Basin(34°03' N/77°38' E) have also left contradictions.To push this topic,three up to now unexplo...Like for most parts of High Asia,researches concerning the Pleistocene landscape evolution of the Leh Basin(34°03' N/77°38' E) have also left contradictions.To push this topic,three up to now unexplored Ladakh Range tributaries of the Leh Basin(Stagmo-,Arzu-and Nang-Valley) have been investigated.U-shaped profiles,transfluence passes,moraine mantled and glacially rounded peaks and ridges,roches moutonnées,glacial flank polishings and ground moraines document the former glaciation of the study area.The ice fillings of these tributaries reached a minimum thickness up to 540 m.Even at the valley outlets and on the orographic right side of the Leh Basin,the glaciation was more than 350 m thick.Based on these empirically extracted results,theoretical snow line considerations lead to the conclusion that the whole Leh Basin was filled up by a former Indus-Valley glacier.An ice injection limited to the nourishment areas of the Ladakh Range valleys could not have caused the reconstructed ice cover(down to 3236 m a.s.l.),which is proved by extended ground moraine complexes.Only an Indus ice stream network(most likely during the LGP),nourished by inflowing glaciers of the Ladakh-and Stok Range,explains the widespread existence of the glacial sediments at the outlets of the investigated valleys.展开更多
The paper traces back women like Celie, Shug, Sofia or Nettie engaged in journeys of self-discovery and development, ones that follow predicted feminist patterns, who try to get free from any dominance, either be it m...The paper traces back women like Celie, Shug, Sofia or Nettie engaged in journeys of self-discovery and development, ones that follow predicted feminist patterns, who try to get free from any dominance, either be it male, social or cultural. The colour purple signifies a metaphysical, social and personal rebirth reflected into different shades by their inner self. The social oppression for black women in their quest for freedom is the main theme of Walker's novel The Color Purple, written in the epistolary technique of Samuel Richardson's in the XVIllth century English novel. In our attempt to analyse the theme and the female characters of the novel we are also trying to cross a bridge from the slave woman of the past belonging to a completely different culture and race to the contemporary paradigm of the liberated woman. The movement in time encompasses possible similitudes and differences.展开更多
Typical isolation models are studied and a New Application Security Isolation model called NASI is proposed, which is based on trusted computing technology and least privilege principle. This paper introduces the desi...Typical isolation models are studied and a New Application Security Isolation model called NASI is proposed, which is based on trusted computing technology and least privilege principle. This paper introduces the design ideas of NASI, gives out formal description and safety analysis for the model, and finally describes the implementation of prototype system based on NASI.展开更多
This paper attempts to focus on Jorge Luis Borges’ short story The Gospel according To Mark. Borges, an Argentina short storywriter and translator, whose motherland is under long-term western colonization, identifi e...This paper attempts to focus on Jorge Luis Borges’ short story The Gospel according To Mark. Borges, an Argentina short storywriter and translator, whose motherland is under long-term western colonization, identifi es himself unconsciously with the western culture. Hisworks mostly touch upon the themes of religion and philosophy. Along with post-colonialism theory’s springing up, critics began to analyze hisworks from the post-colonial perspective. The author thinks that this short story with religious implication parallels to the cultural invasion in theperiod of colonization, from powerful culture to weaker one. The author, thus, aims to use Michael Foucault’s viewpoints concerning power andknowledge to probe into the western cultural hegemony and ideological invasion refl ected in this story. Besides, the loss and construction of theethnic identity of the colonized will be discussed in details.展开更多
Based on constructal theory and entransy theory,the optimal designs of constant-and variable-cross-sectional cylindrical heat sources are carried out by taking dimensionless equivalent resistance minimization as optim...Based on constructal theory and entransy theory,the optimal designs of constant-and variable-cross-sectional cylindrical heat sources are carried out by taking dimensionless equivalent resistance minimization as optimization objective.The effects of the cylindrical height,the cylindrical shape and the ratio of thermal conductivity of the fin to that of the heat source are analyzed.The results show that when the volume of the heat source is fixed,there exists an optimal ratio of the center-to-centre distance of the fin and the heat source to the cylinder radius which leads to the minimum dimensionless equivalent thermal resistance.With the increase in the height of the cylindrical heat source and the ratio of thermal conductivity,the minimum dimensionless equivalent thermal resistance decreases gradually.For the heat source model with inverted variable-cross-sectional cylinder,there exist an optimal ratio of the center-to-centre distance of the fin and the heat source to the cylinder radius and an optimal radius ratio of the smaller and bigger circles of the cylindrical fin which lead to a double minimum dimensionless equivalent thermal resistance.Therefore,the heat transfer performance of the cylindrical heat source is improved by adopting the cylindrical model with variable-cross-section.The optimal constructs of the cylindrical heat source based on the minimizations of dimensionless maximum thermal resistance and dimensionless equivalent thermal resistance are different.When the thermal security is ensured,the optimal construct of the cylindrical heat source based on minimum equivalent thermal resistance can provide a new alternative scheme for the practical design of heat source.The results obtained herein enrich the work of constructal theory and entransy theory in the optimal design field of the heat sources,and they can provide some guidelines for the designs of practical heat source systems.展开更多
Based on construtal theory, a nonuniform heat generation problem in a rectangular body is investigated in this paper. Entransy dissipation rate(EDR) is taken as the optimization objective. The optimal body shapes with...Based on construtal theory, a nonuniform heat generation problem in a rectangular body is investigated in this paper. Entransy dissipation rate(EDR) is taken as the optimization objective. The optimal body shapes with constant and variable widths of the high conductivity channel(HCC) are derived. For the rectangular first order assembly(RFOA) with constant cross-section HCC, the shape of the RFOA and width ratio of the HCCs are optimized, and the double minimum EDR is obtained. The heat transfer performance of the RFOA becomes worse when the nonuniform coefficient increases. For the RFOA with variable cross-section HCC, the EDR of the RFOA can be minimized for four times. Compared the optimal construct based on minimum EDR of the RFOA with that based on minimum maximum temperature difference, the shape of the former optimal construct is tubbier, and the average temperature difference is lower. In the practical design of electronic devices, when the thermal safety is ensured, the constructal design scheme of the former optimal construct can be adopted to improve the global heat transfer performance of an electronic device.展开更多
Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is...Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is obtained. The results show that the heat conductance performance of the assembly becomes ever worse with ever greater number of elemental cylindrical fins,the umbrella-shaped assembly reduces to cylindrical fin in some values of design parameters,and the diameters’ dependence on design parameters is weak for the optimized assembly. An equivalent thermal resistance defined based on entransy dissipation rate (EDR) reflects an average heat transfer effect of the assembly. The constructal design corresponding to the minimum EDR (or MTR) should be adopted for designing an assembly of fins in engineering at the limit safe condition.展开更多
Based on constructal theory,the constructs of the leaf-like fins are optimized by taking minimum entransy dissipation rate(for the fixed total thermal current,i.e.,the equivalent thermal resistance) as optimization ob...Based on constructal theory,the constructs of the leaf-like fins are optimized by taking minimum entransy dissipation rate(for the fixed total thermal current,i.e.,the equivalent thermal resistance) as optimization objective.The optimal constructs of the leaf-like fins with minimum dimensionless equivalent thermal resistance are obtained.The results show that there exists an optimal elemental leaf-like fin number,which leads to an optimal global heat conduction performance of the first order leaf-like fin.The Biot number has little effects on the optimal elemental fin number,optimal ratios of length and width of the elemental and first order leaf-like fins;with the increase of the thermal conductivity ratio of the vein and blade,the optimal elemental fin number and optimal ratio of the length and width of the elemental leaf-like fin increase,and the optimal shape of the first order leaf-like fin becomes tubbier.The optimal construct based on entransy dissipation rate minimization is obviously different from that based on maximum temperature difference minimization.The dimensionless equivalent thermal resistance based on entransy dissipation rate minimization is reduced by 11.54% compared to that based on maximum temperature difference minimization,and the global heat conduction performance of the leaf-like fin is effectively improved.For the same volumes of the elemental and first order leaf-like fins,the minimum dimensionless equivalent thermal resistance of the first order of the leaf-like fin is reduced by 30.10% compared to that of the elemental leaf-like fin,and the global heat conduction performance of the first order leaf-like fin is obviously better than that of the elemental leaf-like fin.Essentially,this is because the temperature gradient field of the first order leaf-like fin based on entransy dissipation rate minimization is more homogenous than that of the elemental leaf-like fin.The dimensionless equivalent thermal resistance defined based on entransy dissipation rate reflects the average heat transfer performance of the leaf-like fin,and can provide some guidelines for the thermal design of the fins from the viewpoint of heat transfer optimization.展开更多
基金Supported by National Natural Science Foundation of China(41072140)Chinese Academy of Sciences Strategic Priority Research Program(XDA05130402,XDA05130603)~~
文摘[Objective] The aim was to research and identify starch grain microfossil found in archaeological sites in China, and to find appropriate procedures for the starch grain analysis experiment.[Method] Wheat starch grain size distribution was analyzed, and some simulated experiments were carried out, like mortar grinding, ultrasonic treatment, hydrochloric acid and hydrogen peroxide immersion, drying treatment, and so on. [Result] The mean size of wheat starch grains had increased in the growth process. Mortar grinding would make wheat starch grains larger than untreated sample. Long time of ultrasonic treatment can also make the starch grain size larger. 10% HCl and 6% H2O2 would have little effects on morphological feature of wheat starch grains. Low temperature heating did not cause starch grains to be gelatinized. [Conclusion] These experiment results can improve the accuracy of starch grain microfossil identification in the archaeological site. Starch grain analysis may be a utility and effective analytical tool in studying the origin of agriculture and the dispersal of crops in China.
基金Project(13JCZDJC29500)supported by the Key Project of Tianjin Natural Science Foundation,ChinaProjects(2011CB610505,2014CB046801)supported by the National Basic Research Program of ChinaProject(20120032110029)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘The pitting corrosion behaviors of 7A60 aluminum alloy in the retrogression and re-aging (RRA) temper were investigated by electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques, and the microstructure and the second phase content of the alloy were observed and determined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that there exist two different corrosion stages for 7A60 alloy in 3.5%NaCl solution, and the corrosion process can be detected by the appearance of EIS spectrum with two capacitive time constants and the wavelet fractal dimension D extracted from EN. SEM and EDS results also demonstrate that severe pitting corrosion in 7A60 alloy is mainly caused by electrochemical active MgZn2 particles, secondly by Al2MgCu and Mg2Si. Al7Cu2Fe particles make little contribution to the pitting corrosion of 7A60 alloy.
基金National Natural Science Foundation of China(No.50875174)Shanghai Leading Academic Discipline Project,China(No.S30504)The Innovation Fund Project for Graduate Student of Shanghai,China(No.J WCXSL1002)
文摘Buckling is the primary cause of failure of a side member in condition of overloading,so buckling stability should be taken into consideration in the design optimization of side member.On the other hand,lightweight is always a pursuing objective of manufacturer of automobile seat.Thus both the buckling stability and lightweight are considered in the suggested design optimization method of the side member of automobile seats.The method has two design phases.Firstly,the optimal shape of back curve by using shape optimization was obtained in which the lightweight of the side member was set to be the design objective.Secondly,optimal size and distribution of grooves on side member was obtained by topography optimization in which the buckling critical load was set to be the design objective.A typical design example shows that the buckling critical load of the optimal side member is increased by 25.98%,and the weight is decreased by 3.7% simultaneously.
文摘AIM: To make drug sera of Salvia miltiorrhiza and Yigankang, both of which are Chinese herbs that activate bleeding and eliminate stasis, in normal rats and those with liver fibrosis, respectively. To investigate and compare the effects of the two different drug sera on the proliferation and activation of hepatic stellate cells (HSCs). METHODS: Some rats were induced with liver fibrosis: 40% carbon tetrachloride (CCI4) subcutaneous injection, twice a week for 9 wk. Salvia miltiorrhiza, Yigankang, colchicines and normal saline were administered into the stomachs of normal rats and those with liver fibrosis. Drug sera were extracted 5 d later. HSCs in vitro were cultivated in different drug sera for 24 h. The rates of proliferation and expression of a-smooth muscle actin (α-SMA) were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and immunocyt-ochemistry stain, respectively. RESULTS: The drug sera from normal and liver fibrotic rats could be used to cultivate HSCs and to observe the effects of the corresponding components of herbs on HSCs. Salvia miltiorrhiza and Yigankang had better inhibitory effects on HSCs than colchicines (MTT: normal drug serum: Salvia miltiorrhiza 0.42 ±0.08, Yigankang 0.32±0.10 vs colchicines 0.45±0.12 pathological drug serum: Salvia miltiorrhiza 0.33±0.02, Yigankang 0.26±0.01 vs colchicines 0.41±0.09. P<0.05). The drug sera of Salvia miltiorrhiza, Yigankang from liver fibrotic rats had a stronger inhibitory effect than the same ones from normal rats (MTT: Salvia miltiorrhiza: normal drug serum 0.42±0.08 vs pathological drug serum 0.33±0.02. Yigankang: normal drug serum 0.32±0.10 vs pathological drug serum 0.26±0.01. P<0.05) CONCLUSION: Salvia miltiorrhiza and Yigankang could inhibit the expression of a-SMA and the proliferation of HSCs. The drug sera from normal and liver fibrotic rats had different effects on HSCs, probably due to different metabolic processes, effective components and different quantities of drug contents in drug sera from rats with different states of liver.
基金Supported by Open Fund of Mineral Resources Chemistry Key Laboratory of Scihuan Higher Education Institutions
文摘Rifapentine, an important antibiotic, was crystallized from methanol solvent in the form of its methanol solvate. The crystal structure of rifapentine methanol solvate belongs to monoclinic, space group P21, with the unit cell parameters of a = 1.2278(3) nm, b = 1.9768(4) rim, c = 1.2473(3) nm, Z= 2, and β = 112.35(3). The parallelepiped.morphology was also predicted by Materials Studio simulation program.. The influence of intermolecular in-teraction was taken into account in the attachment energy model. The crystal shape fits the calculated morphology well, which was performed on the potential energy minimized model using a generic DREIDING 2.21 force fieldand developed minimization protocol with derived'partial charges.
文摘The relationship between microspore developmental stages and morphological characteristics of floral organ in balsam pear was studied. The results showed that flower buds developed a series of morphological changes at different microspore developmental stages, and morphological characteristics of floral organ were significantly different when sampling from different part or cultivar of balsam pear. Anther at late-uninucleate stage was best for culture, in which stage flower buds swelled obviously, and white floss on the surface reduced. In addition, calyxes were obvious but did not spread, and the most of anthers were light green.
文摘AIM:To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.METHODS:Resected small bowel specimens from small bowel atresia patients(n = 12) were divided into three sections(proximal,atretic and distal).Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers-smooth muscle actin(SMA) and desmin using conventional paraffin sections of the proximal and distal bowel.Small bowel from agematched patients(n = 2) undergoing Meckel's diverticulum resection served as controls.RESULTS:The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue,but the distal bowel was unchanged.Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue.There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel.The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers.CONCLUSION:Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia.
文摘Notable for the completeness with which it surrenders formally and artistically to the textual dictates of Twitter, Jennifer Egan's 2012 short science fiction Black Box is one of the most triumphant and fully-fledged fictions written in the form of new media. This paper explores the Twitter narrative employed in Black Box, pointing out that the serialized tweeting format of the story released via computer, mobile phone, or other electronic equipments brings readers immediate reading experience, allowing readers to sense the same feelings as the protagonist does. Through the experimental serialization of"Twitter" narrative, Egan expresses her concerns and worries about the security of the American security as well as the whole world in the post-"9.11" period and at the same time she embraces the virtues and pleasures of traditional storytelling delivered through a wholly new digital format. This paper concludes that Black Box is perhaps one of the boldest experiments of narrative form and is direct exploration into the contemporary image culture.
文摘The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures (nucleoplasm, chromatin, nuclear matrix) as possible zones affecting the conformational rearrangements of the total interphase chromatin at the induction of increasing morphogenesis of mature embryos-germs of spring and transformed from its winter wheat. Germinated embryos-germs were detached from endosperm after 24 hours from the start of soaking. Cell nuclei have been allocated from embryos-germs and cleared, and then from their heteropolymer suprastructures (nucleoplasm, chromatin loosely bound with nuclear matrix and chromatin tightly bound with nuclear matrix, and nuclear matrix) were extracted by increasing ionic strength of solution. From isolated nuclear suprastructures, non-histone proteins were separated from histones using ion exchange chromatography. Trypsin-like complexes from non-histone proteins and histone blocks were isolated using the affinity chromatography. The Arg-X (tryptase) activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine. Hypersensitivity to the Arg-X proteolysis in trypsin-like complexes detected at the level suprastructures of chromatin tightly bound with the nuclear matrix was shown. The most active changes of the nuclear proteome have occurred at the level of the non-histone proteins and the core histones (H2A + H2B) (H3 + H4) of induced to growth embryos-seedlings of winter wheat (compared to the initial spring form of wheat). Perhaps hypersensitivity to the Arg-X activity of the trypsin-like complexes in the non-histone proteins and the core blocks of chromatin tightly bound with nuclear matrix have been entrenched during the transforming of the winter wheat from the initial spring wheat.
文摘Objective:To study the changes of the expression of bone morphogenetic protein-7(BMP-7) and its receptors(BMPR-Ⅱ,ALK2,ALK3 and ALK6) in the renal tubulointerstitial fibrosis induced with unilateral ureteral obstruction in rats. Methods: Sixty Wistar male rats were divided randomly into the normal control,sham-operation and unilateral ureteral obstruction(UUO) groups and the rats were killed on the 1st,3rd,7th and 14th postoperative days respectively.The mRNA level of BMP-7,BMPR-Ⅱ,ALK2,ALK3 and ALK6 was determined with RT-PCR.The site and level of protein expression of BMP-7 were observed with immunohistochemical staining. Results: The mRNA level of BMP-7,BMPR-Ⅱ,ALK2 and ALK3 was significantly decreased in the rats of UUO group than in those of the sham-operation group but the mRNA level of ALK6 showed no obvious changes in all the rats.Immunohistochemical staining revealed that the protein of BMP-7 was mainly expressed in the renal tubules and interstitial tissue of the kidneys in normal rats but it was decreased gradually along with the unilateral ureteral obstruction. Conclusion: It is found that the loss of BMP-7 and its receptors including BMPR-Ⅱ,ALK2 and ALK3 occurs in the early phase of renal tubulointerstitial fibrosis before the appearance of other pathological changes in the kidney and may play an important role in the occurrence and progress of renal tubulointerstitial fibrosis.
文摘A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained via localized timing optimization. Then, through evaluating each potential insertion against design objectives, potential optimal buffer insertion locations and sizes for the whole routing tree were determined. At last, by removing redundant buffer insertion operations which do not maximize S ( so ), given timing requirements are finally fulfilled through minimum number of buffers.
文摘Like for most parts of High Asia,researches concerning the Pleistocene landscape evolution of the Leh Basin(34°03' N/77°38' E) have also left contradictions.To push this topic,three up to now unexplored Ladakh Range tributaries of the Leh Basin(Stagmo-,Arzu-and Nang-Valley) have been investigated.U-shaped profiles,transfluence passes,moraine mantled and glacially rounded peaks and ridges,roches moutonnées,glacial flank polishings and ground moraines document the former glaciation of the study area.The ice fillings of these tributaries reached a minimum thickness up to 540 m.Even at the valley outlets and on the orographic right side of the Leh Basin,the glaciation was more than 350 m thick.Based on these empirically extracted results,theoretical snow line considerations lead to the conclusion that the whole Leh Basin was filled up by a former Indus-Valley glacier.An ice injection limited to the nourishment areas of the Ladakh Range valleys could not have caused the reconstructed ice cover(down to 3236 m a.s.l.),which is proved by extended ground moraine complexes.Only an Indus ice stream network(most likely during the LGP),nourished by inflowing glaciers of the Ladakh-and Stok Range,explains the widespread existence of the glacial sediments at the outlets of the investigated valleys.
文摘The paper traces back women like Celie, Shug, Sofia or Nettie engaged in journeys of self-discovery and development, ones that follow predicted feminist patterns, who try to get free from any dominance, either be it male, social or cultural. The colour purple signifies a metaphysical, social and personal rebirth reflected into different shades by their inner self. The social oppression for black women in their quest for freedom is the main theme of Walker's novel The Color Purple, written in the epistolary technique of Samuel Richardson's in the XVIllth century English novel. In our attempt to analyse the theme and the female characters of the novel we are also trying to cross a bridge from the slave woman of the past belonging to a completely different culture and race to the contemporary paradigm of the liberated woman. The movement in time encompasses possible similitudes and differences.
文摘Typical isolation models are studied and a New Application Security Isolation model called NASI is proposed, which is based on trusted computing technology and least privilege principle. This paper introduces the design ideas of NASI, gives out formal description and safety analysis for the model, and finally describes the implementation of prototype system based on NASI.
文摘This paper attempts to focus on Jorge Luis Borges’ short story The Gospel according To Mark. Borges, an Argentina short storywriter and translator, whose motherland is under long-term western colonization, identifi es himself unconsciously with the western culture. Hisworks mostly touch upon the themes of religion and philosophy. Along with post-colonialism theory’s springing up, critics began to analyze hisworks from the post-colonial perspective. The author thinks that this short story with religious implication parallels to the cultural invasion in theperiod of colonization, from powerful culture to weaker one. The author, thus, aims to use Michael Foucault’s viewpoints concerning power andknowledge to probe into the western cultural hegemony and ideological invasion refl ected in this story. Besides, the loss and construction of theethnic identity of the colonized will be discussed in details.
基金supported by the National Natural Science Foundation of China(Grant Nos.5120618451176203&51356001)
文摘Based on constructal theory and entransy theory,the optimal designs of constant-and variable-cross-sectional cylindrical heat sources are carried out by taking dimensionless equivalent resistance minimization as optimization objective.The effects of the cylindrical height,the cylindrical shape and the ratio of thermal conductivity of the fin to that of the heat source are analyzed.The results show that when the volume of the heat source is fixed,there exists an optimal ratio of the center-to-centre distance of the fin and the heat source to the cylinder radius which leads to the minimum dimensionless equivalent thermal resistance.With the increase in the height of the cylindrical heat source and the ratio of thermal conductivity,the minimum dimensionless equivalent thermal resistance decreases gradually.For the heat source model with inverted variable-cross-sectional cylinder,there exist an optimal ratio of the center-to-centre distance of the fin and the heat source to the cylinder radius and an optimal radius ratio of the smaller and bigger circles of the cylindrical fin which lead to a double minimum dimensionless equivalent thermal resistance.Therefore,the heat transfer performance of the cylindrical heat source is improved by adopting the cylindrical model with variable-cross-section.The optimal constructs of the cylindrical heat source based on the minimizations of dimensionless maximum thermal resistance and dimensionless equivalent thermal resistance are different.When the thermal security is ensured,the optimal construct of the cylindrical heat source based on minimum equivalent thermal resistance can provide a new alternative scheme for the practical design of heat source.The results obtained herein enrich the work of constructal theory and entransy theory in the optimal design field of the heat sources,and they can provide some guidelines for the designs of practical heat source systems.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51506220, 51579244 and 51356001)
文摘Based on construtal theory, a nonuniform heat generation problem in a rectangular body is investigated in this paper. Entransy dissipation rate(EDR) is taken as the optimization objective. The optimal body shapes with constant and variable widths of the high conductivity channel(HCC) are derived. For the rectangular first order assembly(RFOA) with constant cross-section HCC, the shape of the RFOA and width ratio of the HCCs are optimized, and the double minimum EDR is obtained. The heat transfer performance of the RFOA becomes worse when the nonuniform coefficient increases. For the RFOA with variable cross-section HCC, the EDR of the RFOA can be minimized for four times. Compared the optimal construct based on minimum EDR of the RFOA with that based on minimum maximum temperature difference, the shape of the former optimal construct is tubbier, and the average temperature difference is lower. In the practical design of electronic devices, when the thermal safety is ensured, the constructal design scheme of the former optimal construct can be adopted to improve the global heat transfer performance of an electronic device.
基金supported by the National Natural Science Foundation of China (Grant No.10905093)the Program for New Century Excellent Talents in University of China (Grant No.NCET-04-1006)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No.200136)
文摘Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is obtained. The results show that the heat conductance performance of the assembly becomes ever worse with ever greater number of elemental cylindrical fins,the umbrella-shaped assembly reduces to cylindrical fin in some values of design parameters,and the diameters’ dependence on design parameters is weak for the optimized assembly. An equivalent thermal resistance defined based on entransy dissipation rate (EDR) reflects an average heat transfer effect of the assembly. The constructal design corresponding to the minimum EDR (or MTR) should be adopted for designing an assembly of fins in engineering at the limit safe condition.
基金supported by the National Natural Science Foundation of China (Grant No. 51176203)the Natural Science Foundation of Naval University of Engineering (Grant No. HGDYDJJ10011)the Natural Science Foundation for Youngsters of Naval University of Engineering (Grant No. HGDQNJJ10017)
文摘Based on constructal theory,the constructs of the leaf-like fins are optimized by taking minimum entransy dissipation rate(for the fixed total thermal current,i.e.,the equivalent thermal resistance) as optimization objective.The optimal constructs of the leaf-like fins with minimum dimensionless equivalent thermal resistance are obtained.The results show that there exists an optimal elemental leaf-like fin number,which leads to an optimal global heat conduction performance of the first order leaf-like fin.The Biot number has little effects on the optimal elemental fin number,optimal ratios of length and width of the elemental and first order leaf-like fins;with the increase of the thermal conductivity ratio of the vein and blade,the optimal elemental fin number and optimal ratio of the length and width of the elemental leaf-like fin increase,and the optimal shape of the first order leaf-like fin becomes tubbier.The optimal construct based on entransy dissipation rate minimization is obviously different from that based on maximum temperature difference minimization.The dimensionless equivalent thermal resistance based on entransy dissipation rate minimization is reduced by 11.54% compared to that based on maximum temperature difference minimization,and the global heat conduction performance of the leaf-like fin is effectively improved.For the same volumes of the elemental and first order leaf-like fins,the minimum dimensionless equivalent thermal resistance of the first order of the leaf-like fin is reduced by 30.10% compared to that of the elemental leaf-like fin,and the global heat conduction performance of the first order leaf-like fin is obviously better than that of the elemental leaf-like fin.Essentially,this is because the temperature gradient field of the first order leaf-like fin based on entransy dissipation rate minimization is more homogenous than that of the elemental leaf-like fin.The dimensionless equivalent thermal resistance defined based on entransy dissipation rate reflects the average heat transfer performance of the leaf-like fin,and can provide some guidelines for the thermal design of the fins from the viewpoint of heat transfer optimization.