外置硬盘中的银色法拉力——元谷3．5寸Pleiades硬盘盒全面评测

不论在出片公司，还是在广告公司，相信大家一定会经常用到移动硬盘盒。不过老式的移动硬盘盒不论从安全性还是数据读写速度都已经无法满足目前日益增长的数据业务需求。我们有时很难想象将一块原始的塑料移动硬盘接到PowerMac G5或者PowerBook上时的那种感觉。今天小编将向大家推荐一款全新的元谷3．5寸Pleiades硬盘盒，它出色的外观设计以及优秀的性能一定会让你爱不释手。

财富源泉 创意谷地

比尔·盖茨曾说,"创意具有裂变效应,一盎司创意能够带来无以数计的商业利益和奇迹。"如火如荼的世博会在中国上海汇集了来自全世界的创意智慧,通过展会,不同的国家、地区。

创意繁花在古运河畔竞相璀璨绽放

近年来,拱墅区紧紧围绕打造杭州文化创意产业示范区的战略目标,依托运河文化,以工业遗产保护利用为特色,把文创产业作为重点打造的四大经济之一。

Surface Morphology of Soil Cracks in Yuanmou Dry-hot Valley Region,Southwest China

Surface morphology of soil cracks is one of the important factors influencing the water evaporation rate in cracked soil in Yuanmou Dry-hot Valley Region,Southwest China. Quantitative study of the complicated surface morphology of soil cracks is a prerequisite for further studies of soil-cracking mechanisms. The present paper establishes a quantitative indicator system by application of concepts and methods originating from Fractal Geometry and Network Analysis. These indicators can effectively express the complicated features of soil-crack network structure. Furthermore,a series of values related to soil-crack morphology was obtained by image processing on field photos of soil-crack quads,and gradation criteria for the degree of development of soil cracks were determined. Finally,the changes in values of the morphological indicators under different degrees of development were analyzed in detail. Our results indicate that (1) the degree of development of soil cracks can be divided into five grades,i.e.,feeble development,slight development,medium development,intensive development and extremely intensive development; (2) the values of the indicators change predictably with increasing degree of development of soil cracks. The area density (Dc) increases,and both the area-weighted mean ratio of crack area to perimeter (AWMARP),which reflects the intensity of cracking,and the index r,which is related to the connectivity of a soil crack,grow uniformly (albeit with different forms). AWMRAP increases at a geometric rate while r shows logarithm-mic growth,indicating a gradual increase in theconnectivity of a soil crack. Nevertheless,the area-weighted mean of soil-crack fractal dimension (AWMFRAC) shows a decreasing trend,indicating a gradual decline in the complexity of cracks as area density increases.

Differential effects of glutamate receptor antagonists on dorsal horn neurons responding to colorectal distension in a neonatal colon irritation rat model

AIM: To investigate and compare the effects of spinal D-(-)-2-amino-7-phosphonoheptanoic acid (AP-7) and 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX),two glutamate receptor antagonists, on the responses of dorsal horn neurons to colorectal distension (CRD) in adult rats exposed to neonatal colon irritation (CI).METHODS: Hypersensitive SD rats were generated by CI during postnatal days 8, 10 and 12. Experiments on adult rats were performed using extracellular single-unit recording. The effects of spinal application of AP-7 (0.001,0.01, 0.1, 1 mmoL) were tested on the CRD-evoked neuronal responses in 16 controls and 17 CI rats. The effects of CNQX (0.2, 2, 5, 10 μmoL) were also tested on the CRD-evoked responses of 17 controls and 18 CI neurons.RESULTS: (1) The average responses of lumbosacral neurons to all intensities of CRD in CI rats were significantly higher than those in control rats; (2) In control rats, AP-7 (0.01 mmoL) had no significant effect on the neuronal response to all intensities of CRD (20,40, 60, 80 mmHg); while AP-7 (0.1 mmoL) inhibited the neuronal response to 80-mmHg CRD. By contrast, in CI rats, AP-7 (0.01-1 mmoL) attenuated the CRD-evoked neuronal responses to all distention pressures in a dosedependent manner; (3) In control rats, CNQX (2 μmoL)had no significantly effect on the neuronal response to all intensities of CRD; however, CNQX (5 μmoL) significantly attenuated the responses to CRD in the 40-80 mmHg range. By contrast, CNQX (2-10 μmoL)significantly decreased the neuronal responses in CI rats to non-noxious and noxious CRD in a dose-dependent manner.CONCLUSION: Our results suggest that spinal N-methyl-D-aspartate (NMDA) and non-NMDA receptors may contribute to the processing of central sensitivity in a neonatal CI rat model, but they may play different roles in it.

Effective stress law for rock masses and its application in impoundment analysis based on deformation reinforcement theory

Reservoir impoundment is related to several hydraulic engineering concerns,including irreversible valley contractions,landslides and reservoir-induced earthquakes.However,these phenomena,such as valley contractions,are hardly to be explained by the conventional method.The scientific understanding of water effects during impoundment and their hazards to hydraulic structure are needed.The effective stress law for fissured rock masses is introduced in the elasto-plastic model employing the Drucker-Prager criterion and implemented in the three dimension(3D)nonlinear finite element method(FEM)program Three-dimensional FINite Element(TFINE).The slope deforms towards river-way during impoundment since the increasing pore pressure in fissures changes stress state and leads to additional plastic deformation in the rock materials.The value of Biot coefficient and the influence of water on rock materials are discussed in detail.Thus,the mechanism of slope deformation during the impoundment of Jinping-I arch dam is revealed,and the deformation is accurately measured.The application of the effective stress law provides a method to consider stress assessment,deformation evaluation and stability estimate of hydraulic structures during the impoundment process.This is a beneficial exploration and an improvement of hydraulic engineering design.

Morphology and controlling factors of the longitudinal profile of gullies in the Yuanmou dry-hot valley

The morphology of the gully longitudinal profile （GLP） is an important topographic index of the gully bottom associated with the evolution of the gullies. This index can be used to predict the development trend and evaluate the eroded volumes and soil losses by gullying. To depict the morphology of GLP and understand its controlling factors, the Global Positioning System Real-time Kinematic （GPS RTK） and the total station were used to measure the detail points along the gully bottom of 122 gullies at six sites of the Yuanmou dry-hot Valley. Then, nine parameters including length （Lt）, horizontal distance （Dh）, height （H）, vertical erosional area （A）, vertical curvature （Co）, concavity （Ca）, average gradient （Ga）, gully length-gradient index （GL）, normalized gully length-gradient index （Ngl）, were calculated and mapped using CASS, Excel and SPSS. The results showed that this study area is dominated by slightly concave and medium gradient GLPs, and the lithology of most gullies is sandstone and siltstone. Although different types of GLPs appear at different sites, all parameters present a positively skewed distribution. There are relatively strong correlations between several parameters： namely Lt and H, Dh and H, Lt and A, Dh and A, H and GL. Most GLPs, except three, have a best fit of exponential functions with quasi- straight shapes. Soil properties, vegetation coverage, piping erosion and topography are important factors to affect the GLP morphology. This study provides useful insight into the knowledge of GLP morphology and its influential factors that are of critical importance to prevent and control gully erosion.

Simulation of Morphological Development of Soil Cracks in Yuanmou Dry-hot Valley Region, Southwest China

Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the close relationship between the soil cracking process and water movement in such semi-arid regions. Here we report regular changes on surface morphology of soil cracks with decreasing water in four different soils (Typ-Ustic Ferrisols,Ver-Ustic Ferrisols,Tru-Ustic Vertisols and Typ-Ustic Vertisols) through simulation experiments. Our results indicate the following: 1) Different soils ultimately have different development degrees of soil cracks,according to their various values of crack area density. Soil cracks in Typ-Ustic Ferrisols can only develop to the feeble degree,while those in the other three soils are capable of developing into the intensive degree,and even into the extremely intensive degree. 2) Soil crack complexity,as expressed by the value of the area-weighted mean of crack fractal dimension (AWMFRAC),is found to continuously decrease as a whole through the whole cracking process in all the studied soils. 3) Soil crack connectivity shows a uniform trend in the studied soils,that is to say,connectivity gradually increases with soil crack development.

2.5D scattering of incident plane SH waves by a canyon in layered half-space

This paper presents 2.5D scattering of incident plane SH waves by a canyon in layered half-space by the indirect boundary element method (IBEM). The free field response is carried out to give the displacements and stresses on the line which forms boundary of the canyon. The fictitious uniform moving loads are applied to the same line to calculate the Green's functions for the displacements and stresses. The amplitudes of the loads are determined by the boundary conditions. The displacements due to the free field and from the fictitious uniform moving loads have to be added to obtain the whole motion. The numerical results are carried out for the cases of a canyon in homogenous and in one layer over bedrock. The results show that the 2.5D wave scattering problem is essentially different from the 2D case, and there exist distinct differences between the wave amplification by a canyon in layered half-space and that in homogeneous half-space. The reasons for the distinct difference are explored, and the effects of the thickness and stiffness of the layer on the amplification are discussed.

Evaluation of Gold Geochemical Anomalies in the Liaodong Paleorift

89 Au geochemical anomalies are delineated by using 1/200000 regional geochemical exploration data. By researching regional geochemical characteristics and the relationship with the geological background, the author points out that： the main factors causing high background of Au geochemical anomalies are Gaixian and Dashiqiao formation of Liaohe group, intrusions of Mesozoic intermediate-acid intrusive rocks. The elements combination types of typical anomalies are determined by using factorial analysis,cluster analysis and other mathematical methods with the combination of elements association in typical anomalies：the composite anomaly of Baiyun gold deposits is Au-As-Sb, Maoling gold deposit is Au-As- Bi-Mo, Wulong gold deposits is Au-As-Bi-W, Xiaotongjiapuzi gold deposit is Au-As-Bi-Mo-Sb. By using multivariate statistical analysis method,62 ore-caused anomaly are preferred in 89 Au geochemical anomalies delineated. On this basis, the 62 anomalies are divided into 4 kinds of anomaly types reference to elements combination types of typical anomalies,the classification results of ore-caused anomalies are： 4 geochemical anomalies of Baiyun type,36 geochemical anomalies of Maoling type,11 geochemical anomalies of Wulong type, 11 geochemical anomalies of Xiaotongjapuzi type. According to the results, the prospecting direction is provided for the futme of gold exploration.

Three-dimensional Scattering of Obliquely Incident Plane SH Waves by an Alluvial Valley in a Layered Half-space

The indirect boundary element method （IBEM） is used to study three-dimensional scattering of obliquely incident plane SH waves by an alluvial valley embedded in a layered half-space. The free-field response of the layered half-space is calculated by the direct stiffness method, and dynamic Green＇s functions of moving distributed loads acting on inclined lines in a layered half-space are calculated to simulate the scattering wave field. The presented method yields very accurate results since the three-dimensional dynamic stiffness matrix is exact and the moving distributed loads can act directly on the valley boundary without singularity. Numerical results and analyses are performed for amplification of obliquely incident plane SH waves around an alluvial valley in a uniform half-space and in single layer over half-space. The results show that the three-dimensional responses are distinctly different from the two-dimensional responses, and the displacement amplitudes around alluvial valleys in a uniform haft-space are obviously different from those in a layered half-space.

我省开始实行高中毕业会考制度

我省从今年夏季开始,实行高中毕业会考制度,这是普通教育考试制度的一项重大改革。根据我省的会考方案,从1991年秋季入学的新生开始,普通高中全体学生都要参加毕业会考,1991年入学新生6月27日,首次举行高中毕业历史、生物会考。明年6月下旬举行外语、化学会考。1991年3月下旬举行政治、语文、数学会考。另外,理、化。

Glutamate enhances the surface distribution and release of Munc18 in cerebral cortical neurons

Objective Munc18 is considered as an intracellular protein that plays an important role in exocytosis of neurotransmitters.Previous studies have demonstrated the presence of autoantibodies against Munc18 in a subgroup of Rasmussen’s encephalitis patients.However,the machinery of Munc18 autoimmunity is still elusive.The present study was aimed to investigate Munc18 release from primary cultured neurons,Munc18 distribution on the outer plasma membrane of neurons,and the neurotoxicity of Munc18 antibody.Methods The cerebral cortical neurons from embryonic day 17 SpragueDawley rats were prepared and cultured in neurobasal medium.The proteins in culture medium were precipitated with 10% trichloroacetic acid,and analyzed by immunoblotting.The proteins on neuronal surface were biotinylated with EZ-Link-sulfoNHS-LC-Biotin,and collected with avidin-conjugated agarose beads followed by immunoblotting analysis.For cell surface immunofluorescent staining,the living neurons were labeled with anti-Munc18 antibody at 4 °C.Neuronal injury was assessed by lactate dehydrogenase（LDH） release.Results Munc18 was detected in culture medium by immunoblotting analysis.After treatment with 50 μmol/L glutamate for 1 h,Munc18 content in medium was increased.Meanwhile,β-actin and syntaxin1 were not detected in culture medium,and LDH release was not significantly increased.Moreover,glutamate enhanced Munc18 distribution on outer plasma membrane.Living neuron staining also demonstrated the localization of Munc18 on neuronal surface after glutamate treatment,especially at contacting regions between neurons.Glutamate-induced increase of surface Munc18 distribution was suppressed by NMDA receptor antagonist MK801,but not by AMPA receptor antagonist NBQX.Moreover,compared with c-Fos antibody,Munc18 antibody could induce neuronal injury,when culture medium contained the components of serum.Conclusion A portion of Munc18 can be released from neurons or distributed on neuronal surface,which can be enhanced by glutamate treatment via activation of NMDA receptors.Besides,Munc18 antibody-induced neuronal injury depends on the serum components.

Opening time and filling pattern of the Neoproterozoic Kangdian Rift Basin,western Yangtze Continent,South China

The Neoproterozoic Kangdian Rift Basin is a continental rift basin in the western Yangtze Continent.Determining its time of opening and subsequent filling pattern is an important aspect of understanding the formation and evolution of the Yangtze Continent,South China.The Luliang Formation is the early filling in the eastern part of this rift basin,and its deposition age and filling sequence are significant for studies of the regional stratigraphic correlation,opening time,and filling pattern of this basin.Having been correlated to the upper part of the Mesoproterozoic Kunyang Group or to the Neoproterozoic Chengjiang Formation,the age and regional stratigraphic correlation of the Luliang Formation have long been uncertain.This is due to a lack of reliable absolute age constraints.To address this issue,the first zircon SHRIMP U-Pb geochronology has been established for this formation,yielding two high-precision isotopic ages of 818.6±9.2 and 805±14 Ma for the tuff layers at the bottoms of the lower and upper members of the Luliang Formation,respectively.Given the error factor,the bottom age of the lower member of the Luliang Formation can be interpreted as ca.820 Ma,corresponding to the bottom age of the lower part of the Banxi Group,which is the early filling of the Neoproterozoic Xianggui Rift Basin,a representative basin of the Neoproterozoic rift basins in the Yangtze Continent,South China.The bottom age of the upper member of the Luliang Formation can be interpreted as ca.800±5 Ma,corresponding to the bottom age of the Chengjiang Formation in the western part of the Neoproterozoic Kangdian Rift Basin and also corresponding to the bottom age of the upper part of the Banxi Group in the Neoproterozoic Xianggui Rift Basin.These ages indicate that the Neoproterozoic Kangdian Rift Basin shares the same opening time and filling sequences as those of the other Neoproterozoic rift basins in South China.Basin analysis shows that the Neoproterozoic Kangdian Rift Basin is a typical half-graben basin,with its main boundary fault in the west and basin center in the east.This basin consisted of mini unidirectional half-graben basins in its juvenile stage and simplified to become a large united half-graben basin in its mature stage,i.e.,a supradetachment basin.

The prefer red-site tendency of alloying element Nb in Fe γ phase and its effect on grain boundary cohesion

The discrete variational (DV) and DMol methods within the framework of density functional theory are used to study the effect of alloying element Nb on Fe γ phase.The impurity formation energy in bulk and segregation energies at grain boundary and free surface are calculated.The results show that Nb prefers to segregate at grain boundary.The difference in segregation energies between the grain boundary and the corresponding free surface is -0.39 eV for solute Nb.According to Rice-Wang model,it can be predicted that Nb can enhance grain boundary cohesion.The calculated results of interatomic energy and charge density show that charge would be redistributed,and the bonds across grain boundary are strengthened by the substitution of Nb for Fe.As a result,it is difficult for the grain boundary to move.Thus the dragging effect of Nb is explained electronically.

Weathering reflected by the chemical composition of alluvial soils from the Zeya and Selemdzha river valleys

The paper examines the chemical composition of alluvial soils from the Zeya and Selemdzha River valleys, one of the branch rivers in the Amur River basin. It has been established that the compositions of these soils are characterized by a relative shortage of practically all analyzed macro-and microelements as compared with UCC(upper continental crust) and PAAS(postArhean Australian average shale) compositions. The chemical composition of alluvial soils approximates that of the soils in NE China and Korea due to similar climatic and geographic conditions. On the basis of relationships between major and trace elements and peculiarities of trace elements concentration it is shown that the alluvial soils in the middle reaches of the Zeya River were formed by the sources largely transformed by chemical weathering processes. By comparison, the soils in the Selemdzha River and lower reaches of the Zeya River(below the Selemdzha River mouth) are dominated by material to a large degree reworked by the physical processes rather than chemical ones. This inference conforms with specific geological settings of the water-collector.