对微孔吸附常用经典分析模型的比较

文章采用列表对比的方式,简要介绍了微孔吸附常用经典模型的出处、应用范围、发展历史和各自的特点。为了方便系统了解和掌握物理吸附中的微孔经典分析方法,文章将其分成三类:(1)由标准等温线发展出的方法,包括t-图法、αs-图法、n-图法和MP法;(2)基于微孔填充理论的方法,包括D-R方法、D-A方法和D-R-S方法;(3)目前普遍使用的方法,包括原始HK方法(狭缝型孔)、HK-SF方法(圆柱型孔)和HK-CY方法(球型孔)以及三种改进后的HK方法。

An Investigation of College English Autonomous Learning in Network Multimodal Context

In the current society, based on the growing development of network information technology, the teaching in many colleges and universities has also introduced it to adapt to the situation. This trend can provide more useful conditions for students to learn, which requires students to master enough self-learning abilities to adapt to this model. The study in the paper shows that students are usually interested in autonomous learning in a multimodal environment, but the degree of strategy choice is relatively low, and the learning process is blind and passive with the lack of self-confidence. Facing the future, schools should actively integrate into network thinking, and teachers should change their roles and train and guide students’ learning strategies and learning motivations, so as to achieve better teaching results.

t图方法解读吸附参数

介绍了用仪器配套软件获取t图的一般方法、注意事项和要点。介绍了在没有合适的膜厚度方程、选用参比吸附线时的数值处理方法。着重介绍了用origin软件插值方法从吸附等温线转换成t图的方法和技巧。

防范风险 提高效率——以改变高压吸附仪周边设备为例

文章列举了高压吸附实验室在日常测试中普遍存在的各种风险,提出了改变高压吸附仪外围设备的具体措施,经过实践验证,这些措施能有效防范风险发生,同时减轻了工作强度、提高了测试效率。

Reliable and Load Balance-Aware Multi-Controller Deployment in SDN

Software Defined Networking(SDN) provides flexible network management by decoupling control plane and data plane. However, such separation introduces the issues regarding the reliability of the control plane and controller load imbalance in the distributed SDN network, which will cause the low network stability and the poor controller performance. This paper proposes Reliable and Load balance-aware Multi-controller Deployment(RLMD) strategy to address the above problems. Firstly, we establish a multiple-controller network model and define the relevant parameters for RLMD. Then, we design the corresponding algorithms to implement this strategy. By weighing node efficiency and path quality, Controller Placement Selection(CPS) algorithm is introduced to explore the reliable deployments of the controllers. On this basis, we design Multiple Domain Partition(MDP) algorithm to allocate switches for controllers according to node attractability and controller load balancing rate, which could realize the reasonable domain planning. Finally, the simulations show that, compared with the typical strategies, RLMD has the better performance in improving the reliability of the control plane and balancing the distribution of the controller loads.

A Distributed Decision Mechanism for Controller Load Balancing Based on Switch Migration in SDN

Software Defined Networking(SDN) provides flexible network management by decoupling control plane from data plane. And multiple controllers are deployed to improve the scalability and reliability of the control plane, which could divide the network into several subdomains with separate controllers. However, such deployment introduces a new problem of controller load imbalance due to the dynamic traffic and the static configuration between switches and controllers. To address this issue, this paper proposes a Distribution Decision Mechanism(DDM) based on switch migration in the multiple subdomains SDN network. Firstly, through collecting network information, it constructs distributed migration decision fields based on the controller load condition. Then we choose the migrating switches according to the selection probability, and the target controllers are determined by integrating three network costs, including data collection, switch migration and controller state synchronization. Finally, we set the migrating countdown to achieve the ordered switch migration. Through verifying several evaluation indexes, results show that the proposed mechanism can achieve controller load balancing with better performance.

Cisplatin-induced vestibular hair cell lesion-less damage at high doses

Cisplatin, a widely used anticancer drug, damages hair cells in cochlear organotypic cultures at low doses, but paradoxically causes little damage at high doses resulting in a U-shaped dose-response function. To determine if the cisplatin dose-response function for vestibular hair cells follows a similar pattern, we treated vestibular organotypic cultures with doses of cisplatin ranging from 10 to 1000 μM. Vestibular hair cell lesions progressively increased as the dose of cisplatin increased with maximum damage occurring around 50-100 μM, but the lesions progressively decreased at higher doses resulting in little hair cell loss at 1000 μM. The U-shaped doseresponse function for cisplatin-treated vestibular hair cells in culture appears to be regulated by copper transporters, Ctrl, ATP7A and ATP7B, that dose-dependently regulate the uptake, sequestration and extrusion of cisplatin.

Effects of Vibration Characteristics on the Atomization Performance in the Medical Piezoelectric Atomization Device Induced by Intra-Hole Fluctuation

Oral inhalation of aerosolized drugs has be widely applied in healing the affected body organs including lesions of the throat and lungs and it is more effiicient than those conventional therapies,such as intravenous drip,intramuscular injection and external topical administration in the aspects of the dosage reduction and side effects of drugs.Never-theless,the traditional atomization devices always exhibit many drawbacks.For example,non-uniformed atomization particle distribution,the instability of transient atomization quantity and difficulties in precise energy control would seriously restrict an extensive use of atomization inhalation therapy.In this study,the principle of intra-hole fluctua-tion phenomenon occurred in the hole is fully explained,and the produced volume change is also estimated.Addi-tionally,the mathematical expression of the atomization rate of the atomizing device is well established.The mecha-nism of the micro-pump is further clarified,and the influence of the vibration characteristics of the atomizing film on the atomization behavior is analyzed theoretically.The curves of sweep frequency against the velocity and amplitude of the piezoelectric vibrator are obtained by the Doppler laser vibrometer,and the corresponding mode shapes of the resonance point are achieved.The influence of vibration characteristics on atomization rate,atomization height and atomization particle size are also verified by experiments,respectively.Both the experimental results and theoretical calculation are expected to provide a guidance for the design of this kind of atomization device in the future.

Magnetochronology of Mid-Miocene mammalian fauna in the Lanzhou Basin,northeastern Tibetan Plateau:Implications for Asian mammal migration

The Quantougou(QTG) Fauna in central Lanzhou Basin is an important late Mid-Miocene fauna on the northeastern Tibetan Plateau margin,but its numerical age remains a matter of debate.Here,we present a new magnetostratigraphic record for a fluvio-lacustrine section to further constrain the age of the QTG Fauna.Results suggest that the studied section spans from polarity chrons C5Cn.2n to C5 n.2n or C5 An.1n,with ages of ca.16.5 Ma to 10 Ma or 16.5 Ma to 12 Ma.The QTG Fauna is located at the top of polarity chron C5r.3 r or C5 Ar.2 r,which corresponds to an age of 11.7 Ma or 12.8 Ma for the fauna.Accordingly,the associated Myocricetodontinae(a subfamily of Gerbillidae,Rodentia) is suggested to have appeared in the Lanzhou Basin at 11.7 Ma or 12.8 Ma,which is the oldest Myocricetodontinae in East Asia but is still much younger than the ~20 Ma appearance of this subfamily in West and South Asia.Our age data support the interpretation that East Asian Myocricetodontinae originated from South Asia.The QTG fauna further suggest a dry and open grassland environment,which is consistent with global cooling after the Mid-Miocene Climatic Optimum.

Study on the Formation and Separation Process of Droplets in the Medical Piezoelectric Atomization Device Induced by Intra‑hole Fluctuation

Traditional atomization devices always exhibit many drawbacks,such as non-uniform atomization particle sizes,instability of transient atomization quantity and uncontrollability of precise energy,which seriously restrict further practical application of atomization inhalation therapy.The formation and separation process of droplets belongs to a microphenomenon of atomization.The investigation of the droplet formation and separation process will be favorable for understanding the atomization mechanism.In present work,the Conservative Level Set Method(CLSM)is successfully applied on the simulation of the formation and separation of droplets in a medical piezoelectric atomization device induced by intra-hole fluctuation.The intra-hole fluctuation mechanism is systematically explored and analyzed,and also the expression of the volume change in the micro cone hole is built and evaluated.Both the control equation and simulation model of droplet formation and separation process have been well established by meshing the simulation model,and thereby the process of droplet formation and separation is simulated.The corresponding results demonstrate that the breaking time of droplets is decreased with the inlet velocity and liquid temperature rising,while enhanced with the liquid concentration increasing.Meanwhile,the volume of droplet is decreased with the inlet velocity and liquid concentration increasing,but increased with the liquid temperature rising.The velocity of droplet is enhanced with the inlet velocity and liquid temperature rising,and reduced with the increase of liquid concentration.When the large side diameter of micro-cone hole is set as 79μm,the breaking time of the droplet reaches a minimum value of 38.7μs,whereas the volume and the velocity of droplet reach a maximum value of 79.8 pL and 4.46 m/s,respectively.This study provides theoretical guidance for the design of medical piezoelectric atomization devices and contributes to the promotion of inhalation therapy in practical use.

Recovery of photoacoustic images based on accurate ultrasound positioning

Photoacoustic microscopy is an in vivo imaging technology based on the photoacoustic effect.It is widely used in various biomedical studies because it can provide high-resolution images while being label-free,safe,and harmless to biological tissue.Polygon-scanning is an effective scanning method in photoacoustic microscopy that can realize fast imaging of biological tissue with a large field of view.However,in polygon-scanning,fluctuations of the rotating motor speed and the geometric error of the rotating mirror cause image distortions,which seriously affect the photoacoustic-microscopy imaging quality.To improve the image quality of photoacoustic microscopy using polygon-scanning,an image correction method is proposed based on accurate ultrasound positioning.In this method,the photoacoustic and ultrasound imaging data of the sample are simultaneously obtained,and the angle information of each mirror used in the polygon-scanning is extracted from the ultrasonic data to correct the photoacoustic images.Experimental results show that the proposed method can significantly reduce image distortions in photoacoustic microscopy,with the image dislocation offset decreasing from 24.774 to 10.365μm.

Efficacy and Safety of Tirofiban in Thrombolytic Therapyfor Ischemic Stroke

Objective:To evaluate the efficacy and safety of tirofiban hydrochloride in the treatment of ischemic stroke with thrombolytic therapy.Method:Two hundred patients with acute ischemic stroke thrombolysis were randomly divided into the experimental group and the control group.The experimental group was given tirofiban with the addition of rtpa in the control group and the therapeutic effects of the two groups were compared.Results:In comparison with the control group,the NIHSS improvement rate was 98%in the experimental group within 14 days.The platelet aggregation rate and efficacy in the experimental group were significantly reduced than the control group(P<0.01).The major adverse reaction in the two groups was hemorrhage with an incidence rate of 3%.Conclusion:Tirofiban hydrochloride is a highly effective and selective platelet glycoprotein Ⅱb/Ⅲa receptor inhibitor,which is safe and effective in combination with heparin and aspirin.

Synthesis of High-Density Vertically Aligned Carbon Nanotubes Using Ultrasonic Nebulizer

Vertically aligned carbon nanotubes (VACNTs) array with high density have been synthesized from a mixture of ferrocene and ethanol using ultrasonic nebulizer techniques. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as well as Raman spectroscopy, investigations reveal that the vertically aligned CNTs are multi-wall CNTs with well-ordered graphene sheets and are about 20 - 50 nm in diameter. We found that high density vertically aligned CNTs can be synthesized at 750℃ - 850℃ and that the length and density of vertically aligned CNTs increase with increasing growth temperatures. In addition, the single-walls CNTs have well-ordered graphene sheet and are about 2 nm in diameter on silicon substrates at 650℃.

Synthesis of Zirconia Oxide (ZrO₂) Nanofibers on Zirconnia Substrates by Ultrasonic Spray Pyrolysis

Zirconia oxide (ZrO2) nanofibers were synthesized using Phosphorus/water mixture as catalyst by ultrasonic spray pyrolysis CVD on the zirconia substrate at 900°C for 1 h in N2 gas. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) examinations show that all the synthesized nanofibers have uniform surface morphology and their diameters are in the range of 100 nm. The HRTEM selected-area electron diffraction pattern (SAED) shows that crystalline ZrO2 phase exist in the nanofibers, and the energy-dispersive x-ray spectroscopy (EDS) results show that the elements of Zr and O are uniformly distributed across the nanofiber matrix. The phosphorus atoms corroded the entire Zirconia substrate surface, and the Zirconia-Phosphorus liquid-catalyzed the solid-liquid-solid mechanism is proposed to explain the growth of the nanofibers.

Microstructure and Properties of Micro-Alloyed Mg-2.0Nd-0.2Sr by Heat Treatment and Extrusion

Magnesium(Mg)and its alloys have broad application prospects in the fields such as biomedical materials and automobile manufacturing.A micro-alloyed Mg-2.0Nd-0.2Sr(wt.%)magnesium alloy is designed and obtained through semicontinuous casting.The evolution of microstructures and tensile properties are investigated with different heat treatments and extrusion treatments.The grain sizes decrease significantly after extrusion,thus changing the fracture mode during the tensile testing process.The ultimate tensile strength(UTS),yield strength(YS)and elongation(EL)of the properly processed extrusion alloy(referred to as MNS-E2)reach to 247 MPa,228 MPa and 24%,respectively.The dramatical improvement of mechanical properties results from the refined grains and interactions between dislocations and precipitates.Some nanoparticle bands blocking the slippage and movement of dislocations are also found in the MNS-E2 alloy.The above causes combined result in an integrated effect of grain boundary strengthening,dislocation strengthening,precipitation strengthening and nanoparticle band strengthening.The contribution of strengthening mechanisms of MNS-E2 alloy consists of grain boundary with around 96 MPa,dislocations with around 3.4 MPa,precipitation strengthening with around 45 MPa and the nanoparticle band with around 18 MPa,respectively.

铜渣基草酸盐水泥的制备及其性能

以铜渣和草酸为原料,按一定比例混合,通过酸碱反应制备铜渣基草酸盐水泥,考察了铜渣与草酸质量比(CS/OA)、水灰质量比(W/C)、缓凝剂种类及掺量对所制水泥力学性能和凝结时间的影响,用扫描电镜和X射线粉末衍射仪分析了水泥的微观形貌和物相组成。结果表明,随质量比CS/OA和W/C增加,水泥的抗压强度呈先增大后减小的趋势,凝结时间随CS/OA增大而减小,随W/C增大而增大。硼砂和三聚磷酸钠对水泥的抗压强度影响较大,随其掺量增加,水泥的力学性能降低,适量的硼酸可提高水泥的抗压强度,且具有较好的缓凝效果,可将硼酸作为较佳缓凝剂。当质量比CS/OA=4和W/C=0.16～0.17、硼酸掺量为2.5wt%时,材料性能最优,养护28 d抗压强度可达38.5 MPa,凝结时间为24 min。水泥主要水化产物是结构密实、结晶良好的柱形FeC_2O_4·2H_2O,添加硼砂和三聚磷酸钠会使水泥出现孔隙,而硼酸会促进水化反应使水化产物结晶更优,且不会破坏水泥的密实度。

The rice OsV4 encoding a novel pentatricopeptide repeat protein is required for chloroplast development during the early leaf stage under cold stress

Pentatricopeptide repeat （PPR） proteins, charac- terized by tandem arrays of a 35 amino acid motif, have been suggested to play central and broad roles in modulating the expression of organelle genes in plants. However, the molecular mechanisms of most rice PPR genes remains unclear. In this paper, we isolated and characterized a temperature-conditional virescent mutant, OsV4, in rice （Oryza sativa cultivar Jiahual （WT, japonica rice variety））. The mutant displays albino phenotype and abnormal chloroplasts at the three leaf stage, which gradually turns green after the four leaf stage at a low temperature （20℃）. But the mutant always develops green leaves and well-developed chloroplasts at a high temperature （32℃）. Genetic and molecular analyses uncovered that OsV4 encodes a novel chloroplast-targeted PPR protein including four PPR motifs. Further investigations show that the mutant phenotype is associated with changes in chlorophyll content and chloroplast development. The OsV4 transcripts only accumulate to high levels in young leaves, indicating that its expression is tissue-specific. In addition, transcript levels of some ribosomal components and plastid- encoded polymerase-dependent genes are dramatically re- duced in the albino mutants grown at 20℃. These findings suggest that OsV4 plays an important role during early chloroplast development under cold stress in rice.

Electron-ion collider in China

Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei.As a future high energy nuclear physics project,an Electron-ion collider in China(EicC)has been proposed.It will be constructed based on an upgraded heavy-ion accelerator,High Intensity heavy-ion Accelerator Facility(HIAF)which is currently under construction,together with a new electron ring.The proposed collider will provide highly polarized electrons(with a po-larization of 80%)and protons(with a polarization of 70%)with variable center of mass energies from 15 to 20 GeV and the luminosity of(2–3)×1033 cm^(−2)·s^(−1).Polarized deuterons and Helium-3,as well as unpolarized ion beams from Carbon to Uranium,will be also available at the EicC.The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region,including 3D tomography of nucleon;the partonic structure of nuclei and the parton interaction with the nuclear environment;the exotic states,especially those with heavy flavor quark contents.In addition,issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC.In order to achieve the above-mentioned physics goals,a hermetical detector system will be constructed with cutting-edge technologies.This document is the result of collective contributions and valuable inputs from experts across the globe.The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States.The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.

Characterization and Fine Mapping of a Novel Rice Albino Mutant low temperature albino 1

Albino mutants are useful genetic resource for studying chlorophyll biosynthesis and chloroplast development and cloning genes involved in these processes in plants. Here we report a novel rice mutant low temperature albino I （ltal） that showed albino leaves before 4-leaf stage when grown under temperature lower than 20℃, but developed normal green leaves under temperature higher than 24℃ or similar morphological phenotypes in dark as did the wild-type （WT）. Our analysis showed that the contents of chlorophylls and chlo- rophyll precursors were remarkably decreased in the Ital mutant under low temperature compared to WT. Transmission electron microscope observation revealed that chloroplasts were defectively developed in the albino ltal leaves, which lacked of well-stacked granum and contained less stroma lamellae. These results suggested that the ltal mutation may delay the light-induced thylakoid assembly under low temperature. Genetic analysis indicated that the albino phenotype was controlled by a single recessive locus. Through map-based approach, we finally located the Ltal gene to a region of 40.3 kb on the short arm of chromosome 11. There are 8 predicted open reading frames （ORFs） in this region and two of them were deleted in ltal genome compared with the WT genome. The further characterization of the Ltal gene would provide a good approach to uncover the novel molecular mechanisms involved in chloroplast development under low temperature stress.

A spiral-tube-type valveless piezoelectric pump with gyroscopic effect

The valveless piezoelectric pump integrates driving and transmitting into one operating element,and characterizes easy micro-miniaturization.But,there is the original sin of low pressure and low flow.Thus,it must avoid weakness to choose applications field.This paper analyzes the flow characteristics in the rotary spiral-tube,which will cause the Coriolis force,and subsequently influence the fluid moving.The principle of the pump is deduced,and the spiral-tube-type valveless piezoelectric pump is invented.The angular velocity variation can be obtained when the pump attitude changes,which theoretically verifies the gyroscopic effect of the pump.A pump is fabricated for experimental testing.Experiments has shown that when Archimedes spiral h?4p is selected for the tube design,and the rotation speed of the plate is 70 r/min,the pressure differential is 9 mm H2O,which is 1.5 times that of 0 r/min rotation speed.If introduced the low-cost and miniaturized gyroscope,then this may promise potential application in these areas such as smart cars,robots,and home health care.