及物性效应对推理的制约作用——英汉语篇的实验研究之二

及物性效应对推理的制约作用———英汉语篇的实验研究之二索玉柱１背景从功能和认知两个角度来探讨语篇推理具有深刻的理论意义。这一点可以从功能语言学的“不完备原则”加以说明。不完备原则的主要思路是：任何一个说明语言功能的理论系统，无论看起来是多么充分和完...

过热合金熔体的几种物性滞后效应

过热处理的合金熔体会使熔体结构状态发生不可逆变化。这种不可逆变化与合金熔体中结构不均匀性有关 ,即熔体过热处理引起非均匀形核中心数量的不可逆变化 ,导致熔体粘滞性 η和溶质扩散系数DL

传感器技术在工程机器人中的应用

文中首先阐述了发展工程机器人的行业需求。就工程机器人中的传感器问题展开研究。首先探讨了传感器的定义、原理,和基本特征。并且按照不同的分类标准,重点筛选和梳理了传感器的种类。又按照工作原理,细分了传感器,并且列举了各类传感器的典型应用。同时,又根据信号输入量与信号输出量(电),以及转换原理重新编排和筛分传感器。因传感器的基本原理是利用物理、化学,和生物等现象,所以重点给出了六种常见的能量转换时的物理效应。随后,阐述了工程机器人的概念与分类,重点描述适用于工程机器人的各种类型的传感器。重点研究了适合工程机器人的机器视觉和机器触觉,由此最终探讨了各类传感器在工程机器人的应用前景。

压电式传感器与测力仪研发回顾与展望

较系统、扼要地回顾了作者 2 0余年来在压电式传感器与测力仪、压电式执行器等方面的理论研究与产品开发情况 .其中对压电效应的理论研究成果 ,如切向灵敏度分布、石英晶体扭转效应、多种能量间的物性效应等 ,作了比较详细的介绍 .对所研发的压电式传感器与测力仪产品作了宏观介绍 .最后 ,对作者目前在上述领域所做的工作和对未来研究工作的想法作了简要阐述 .

脊状表面减阻机理研究

针对脊状表面流场的特点,通过实验测量和数值模拟的方法对脊状表面微观流场进行了深入研究,获得了脊状表面湍流边界层的时均速度分布曲线、湍流度分布曲线和微观流场结构.为了得到脊状结构对壁面物性的影响,对脊状表面进行了疏水性测试,获得了液滴在脊状表面上的表观接触角,并通过水洞试验验证了脊状表面的减阻效果.研究表明,与光滑表面相比,脊状表面微观流场结构中存在"二次涡",近壁区的黏性底层厚度比平板的要厚得多,湍流度显著降低,且脊状表面表现出明显的疏水性.由此提出了基于壁面隔离效应、增大湍流阻尼效应和改变壁面物性效应的减阻机理.

超临界水通道内压降特性分析

超临界水冷堆是以超临界水作为冷却剂和慢化剂的第4代核能系统之一,超临界水在拟临界区附近剧烈的物性变化会给通道内的压降特性带来影响。本文分析了超临界条件下重力压降、加速压降和摩擦压降的特点,并对具体的计算方式提供了一些建议和参考:重力压降需考虑沿程的积分效应;基于隐式PKN公式得到了显式PKN公式,用于求解等温流动摩擦系数;采用CFD数值分析工具比较了超临界条件下不同摩擦关系式的异同,发现Kirillov公式与CFD计算结果较为接近。

Stndy on Soil Magnetic Effect

A study on the effect of applied magnetic field was performed with six types of soils collected fromnortheastern China. Magnetic field was found to cause changes of soil physicc-chemical properties and soilenzyme activities. An appropriate applied magnetic field could cut down soil zeta-potential, soil specificsurface, soil water potential and soil swelling capacity; raise the charge density on soil colloids and theactivities of invertase, hydrogen peroxidase and amylase in the soils; enhance soil aggregation and improvesoil structural status and soil water-releasing capability.

Property alterations of Sn-0.6Cu-0.05Ni-Ge lead-free solder by Ag, Bi, In and Sb addition

The Sn-Cu-Ni-Ge solder is a strong challenger to the Sn-Ag-Cu（SAC） solders as a replacement for the Sn-Pb eutectic solder. This research investigated the effects of addition of Ag, Bi, In, and Sb on the physical properties of the Sn-0.6 Cu-0.05 Ni-Ge（SCNG） lead-free solder and the interfacial reaction with the Cu substrate. The melting behavior, microstructure, tensile strength, and wettability of the SCNG-x（x=Ag, Bi, In, Sb） solders were examined. The findings revealed that the introduction of Ag, Bi, In, and Sb minimally altered the solidus temperature, liquidus temperature, and tensile strength of the solder. However, the cooling behavior and solidified microstructure of the solder were affected by the concentration of the alloying elements. The wettability of the SCNG solder was improved with the doping of the alloying elements except Sb. The thickness of intermetallic layer was increased by the addition of the alloying elements and was related to the cooling behavior of the solder. The morphology of intermetallic layer between the SCNG-x solders and the Cu substrate was different from that of the typical SAC solders. In conclusion, alloying the SCNG solder with Ag, Bi, In or Sb is able to improve particular properties of the solder.

Physically based analytical model for plateau in gate C-V characteristics of strained silicon pMOSFET

A physically based analytical model was developed to predict the performance of the plateau observed in the gate C-V characteristics of strained-Si/SiGe pMOSFET.Experimental results were used to validate this model.The extracted parameters from our model were tOX=20 nm,ND=1×1016cm 3,tSSi=13.2 nm,consistent with the experimental values.The results show that the simulation results agree with experimental data well.It is found that the plateau can be strongly affected by doping concentration,strained-Si layer thickness and mass fraction of Ge in the SiGe layer.The model has been implemented in the software for strained silicon MOSFET parameter extraction,and has great value in the design of the strained-Si/SiGe devices.

Toxic Effects of Seed Methanolic Extracts of Endemic Albizia Species （Fabaceae） from Madagascar on Animals

In order to find natural compounds of interest such as pesticides and therapeutic molecules, toxicological properties of seed methanolic extracts （SME） of nine Malagasy Albizia species were investigated. Toxicity was assessed on living animals by intraperitoneal and oral route, and pharmacological effects on isolated organs. All SME induced various disorders in mice but the signs of the nervous system disturbs were the earliest and the most often observed. The main organ lesions, examined on histological sections, induced vasodilatation, inflammatory infiltrate of neutrophil polymorphonuclears and hemorrhagic areas. At low concentrations （until 20 p.g/mL）, A. masikororum and A. viridis provoked on isolated auricular a positive inotrope effect followed by a progressive inhibition of the contraction and a complete atrial arrhythmia. Besides, A. viridis and A. bernieri induced some hepatic functional impairment after a chronic treatment during one month. Albizia greveana with a LD50 of 1.13-2 mg/kg was the most toxic and Albizia bernieri the least one with a LD50 of 52 mg/kg. Alkaloids and/or saponins, the major chemical groups found by phytochemical screening on these extracts, could be responsible of their toxicity.

Incorporation of flexible ionic polymers into a Lewis acid-functionalized mesoporous silica for cooperative conversion of CO2 to cyclic carbonates

A rational integration of multiple reactive centers into a combined unit to facilitate their cooperative effects is a smart approach for accelerating the catalytic activity.Here,to achieve this goal,linear imidazolium-based ionic polymers were confined into the nanopores of mesoporous silica nanospheres anchored with homogeneously distributed zinc salts.Owing to the flexible character and the reinforced cooperative effects of the ionic liquid(nucleophile)and zinc species(Lewis acid)in the confined mesoporous structure,the resultant composite exhibited dramatically improved catalytic performance in the cycloaddition of CO2 with epoxides to form cyclic carbonates.This was in contrast to that observed for the individual catalytic components.Moreover,such a solid catalyst could be easily recovered and reused four times without a significant loss of activity.

Construction of mTNFR1shRNA Plasmid and its Biological Effects on MHV-3 Induced Fulminant Hepatitis in BALB/cJ Mice

Previous study on TNFRl-mediated hepatocyte apoptosis has been implicated in the development of fulminant viral hepatitis. To interfere with the potentially effective target, plasmid named p-mTNFRlshRNA complimentary to the sequence responsible for mTNFR1 was also constructed and further confirmed by sequence analysis. To investigate the effect of mTNFRlshRNA plasmid on mTNFR1 expression in vivo and the disease progress in MHV-3 induced fulminant hepatitis mice model. By hydrodynamic injection of mTNFRlshRNA plasmid, the survival rate of mice, hepatic pathological change were examined and compared between mice with/without mTNFRlshRNA plasmid intervention. The expression of mTNFR1 was detected by Real-time PCR, immunohistochemistry staining. The mTNFRlshRNA plasmid significantly reduced mTNFR1 expression in vivo, markedly ameliorates inflammatory infiltration, prolonged the survival time period and elevated the survival rate from 0 up to 13.3% in Balb/cJ mice with MHV-3 induced fulminant hepatitis. This study was designed to explore the opportunity of RNA interference technique in inhibiting TNFR1 expression, which has been reported to be involved in the development of a variety of diseases including fulminant viral hepatitis and severe chronic hepatitis B.

Characterization of a full-length infectious clone of bovine foamy virus 3026

The biological features of most foamy viruses(FVs) are poorly understood, including bovine foamy virus(BFV). BFV strain 3026(BFV3026) was isolated from the peripheral blood mononuclear cells of an infected cow in Zhangjiakou, China. A full-length genomic clone of BFV3026 was obtained from BFV3026-infected cells, and it exhibited more than 99% amino acid(AA) homology to another BFV strain isolated in the USA. Upon transfection into fetal canine thymus cells, the full-length BFV3026 clone produced viral structural and auxiliary proteins, typical cytopathic effects, and virus particles. These results demonstrate that the full-length BFV3026 clone is fully infectious and can be used in further BFV3026 research.

Fabrication of Pd-based metal-acid-alkali multifunctional catalysts for one-pot synthesis of MIBK

The one-pot synthesis of methyl isobutyl ketone（MIBK） from acetone using multifunctional catalysts is an important sustainable organic synthesis method with high atom and energy efficiency.Herein. we report a series of Pd supported on mixed metal oxide（MMO） catalysts with controllable acidic/basic/metallic sites on the surface. We study the relationship between the nature, synergy,and proximity of active sites and the catalytic performance of the multifunctional catalyst in the tandem reaction, in detail. In the existence of Lewis acid and base sites, the catalysts with medium-strength acidic/basic sites show preferred activity and/or MIBK selectivity. For multifunctional catalysts, the catalytic properties are more than just a collection of active sites, and the Pd/Mg_3Al-MMO catalyst possessing 0.1% Pd loading and ~0.4 acid/base molar ratio exhibits the optimal 42.1% acetone conversion and 37.2% MIBK yield, which is among the best reported so far for this tandem reaction under similar conditions. Moreover, the proximity test indicates that the intimate distance between acidic/basic/metallic sites can greatly shorten the diffusion time of the intermediate species from each active site, leading to an enhancement in the catalytic performance.

Hydrogen Bonding Effects on the Photophysical Properties of 2,3-dihydro-3-keto- 1H-pyrido[3,2,1-kl] phenothiazine

Time-dependent density functional theory （TDDFT） and femtosecond transient absorption spectroscopy were used to investigate the photophysical properties of 2,3-dihydro-3-keto-lH- pyrido[3,2,1-kl]phenothiazine （PTZ4） and 3-keto-lH-pyrido[3,2,1-kl]phenothiazine （PTZ5）. The calculated results obtained from TDDFT suggest that the red-shifts of the absorption spectra of these two fluorophores in methanol are due to the formation of hydrogen-bonded complexes at the ground state. Four conformers of PTZ4 were obtained by TDDFT. The two fluorescence peaks of PTZ4 in tetrahydrofuran （THF） came from the ICT states of the four conformers. The fluorescence of PTZ4 in THF showed a dependence on the excitation wavelength because of butterfly bending. The excited state dynamics of PTZ4 in THF and methanol were obtained by transient absorption spectroscopy. The lifetime of the excited PTZ4 in methanol was 53.8 ps, and its relaxation from the LE state to the ICT state was completed within several picoseconds. The short lifetime of excited PTZ4 in methanol was due to the formation of out-of-plane model hydrogen bonds between PTZ4 and methanol at the excited state.

Efficient Syntheses of Permethylated Derivatives of Neolamellarin A,a Pyrrolic Marine Natural Product

The pyrrole-derived alkaloids with marine origin, especially their permethyl derivatives, have unique structures and promising biological activities. Marine natural product neolamellarins are a collection of lamellarin-like phenolic pyrrole compounds, which can inhibit hypoxia-induced HIF-1 activation. Many pyrrole-derived lamellarin-like alkaloids show potent MDR reversing activity. In this study, five permethylated derivatives of neolamellarin A were synthesized with their MDR reversing activity studied in order to identify new MDR reversal agents. A convergent strategy was adopted to synthesize the permethylated derivatives of neolamellarin A. Pyrrole was first converted into a corresponding N-trisisopropylsilyl （TIPS）-substituted derivative, then through iodination afforded 3,4-diiodinated pyrrole compound. The key intermediate, 3,4-disubstituent-lH-pyrrole, was obtained through desilylation of 3,4-disubstituent-l-TIPS pyrrole, which was prepared from 3,4-diiodinated pyrrole derivative and aryl boronic acid ester through Suzuki cross-coupling reaction between them. Then, the intermediate, 3,4-disubstituent-lH-pyrrole, reacted with fresh phenylacetyl chloride under n-BuLi/THF condition afforded the target compounds. Finally, we obtained five novel pyrrolic com- pounds, permethylated derivatives ofneolamellarin A 16a-e, in 30%-37% yield through five step reactions. The bioactivity testing of these compounds are in process.

DESIGN OF POLYMER-SUPPORTEDCHIRAL CATALYSTS

Some structural factors to the design of polymer-supported Chiral Catalysts arediscussed, and some new approaches for designing of polymer-supported catalysts arereviewed in this paper

On the Interpretation of the Foundations of Quantum Mechanics

This study discusses the information space, the wave function phase, the Berry phase and its relationship to quantization, discriminability of states and macroscopic quantum effects caused by localization of the particle, followed by a possible entropy change during its transition into a new thermodynamic state. This work addresses interference： it is the information waves which interfere; the particles follow their roadmap, and the measurement of their coordinates introduces an additional uncertainty into the momentum. It is not particles （matter） which manifest these wave properties but fluctuations of the physical space-time coordinates. Physical characteristics corresponding to the fluctuating variables, energy, momentum, etc., determine the magnitude of the respective fluctuations rather than the wave properties of matter. Matter possesses no wave properties. This work also discusses the difference between the objective information and knowledge.

Coastal afforestation effects on soil properties at Hatiya in Bangladesh

An exploratory study was conducted in the coastal plantation (12-and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noakhali district, in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0-10, 10-30 and 30-40 cm across three different land strips viz. inland, middle and sea side in 12-and 17-year-old keora (Sonneratia apetala) plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, K, Na, Ca and Mg were significantly (p≤0.05, p≤0.01, p≤0.001) higher, and soil salinity significantly (p≤0.001) lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, K, Na, Ca and Mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g·cm-3, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS·cm-1, 28.06 mg·L-1, 0.50 mg·L-1 11.5 mg·L-1, 3.30 mg·L-1 and 2.7 mmol·kg-1, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g·cm-3, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS·cm-1, 13.07mg·L-1, 0.30 mg·L-1, 1.4 mg·L-1, 0.30 mmol·kg-1 and 0.50 mg·L-1, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, K and Ca decreased, and soil salinity, available Na and Mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly (p≤0.01) lower and silt particle significantly (p≤0.001) in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.

Mutagenic Effect of Three Invasive Species through Allium Cepa Bioassay

Invasive alien species are a global threat to biodiversity that affects protected areas around the world. The occupation of new environments by these plants is a problem to be solved and it is essential to investigate all the aspects that allow this successful to find solutions to this question, such as its mutagenic effects. Thus, this study aimed to evaluate the mutagenic effect of leaves extracts of Acacia mangium Willd, Artocarpus heterophyllus Lam and Eriobothrya japonica （Thunb.） Lindl through Allium cepa bioassay. For this, A. cepa seeds were submitted to continuous and discontinuous （acute and chronic） treatments in medium with water （negative control） or four concentration of each extract （1, 5, 10 and 50 mg/mL）. The mitotic index was affected at all concentrations of three extracts tested in all treatments, continuous and discontinuous. Aneugenic effects were not related to any treatment tested. E. japonica extract induced clastogenic effects at 1, 5 and 10 mg/mL in continuous treatment, 5 and 10 mg/mL in acute discontinuous treatment and at 10 mg/mL in chronic discontinuous treatment. Clastogenic effect was also observed at 10 mg/mL ofA. heterophyllus extract in continuous and acute discontinuous treatments.