^(12)C^(16)O精确的半经验势能面、振转光谱及温度压强效应研究

伴随高超音速飞行器、无接触诊断等技术的快速发展,更多分子谱带被激发,对高温高压下的振转光谱数据需求急剧增加,加之高灵敏、高分辨激光光腔衰荡(CRDS)、可调谐半导体激光吸收(TDLAS)等光谱技术的快速进步,相应分子的振转光谱研究被进一步推进。CO作为高温燃烧的重要产物,对其研究首当其冲。首先利用实验决定的(ν<41)^(12)C ^(16)O基态Dunham参数,通过Rydberg-Klein-Rees(RKR)方法,反演出分子平衡核间距附近的局域离散势能点;接着将其拟合到十多个常见的解析势能函数(PEF),发现SPF和Morse函数具有较好的拟合精度,但在长程上依然不符合物理要求;在此基础上结合实验获得的解离能对长程进行校正,构建了一个全新的、半经验、全局、解析势函数Revised-Morse,并通过多参考组态相互作用理论(MRCI)确认了其合理性,该函数既能精确再现低振动态能级,也能合理预测未知高振动态能级,且具有精确的解离极限。接着通过multireference averaged coupled-pair functional(ACPF)理论方法结合差分技术,得到了三种电场下^(12)C ^(16)O基态(ν<63)的偶极矩面(DMs)。基于构建的Revised-Morse势函数和DMs,通过求解一维薛定谔方程得到了直到解离极限的振转能级,计算结果与文献值十分吻合,表明Revised-Morse函数是十分可靠的。基于此得到了常温下所有的跃迁谱线位置,ν<63时的爱因斯坦系数、谱线强度等光谱数据,计算值与HITRAN数据库中的结果几乎完全一致,同时振动跃迁偶极矩、辐射寿命、离心畸变等光谱常数也被一并获取。该研究不仅完美再现了已知谱带,还预期了几十万条新的跃迁谱线,一些新的光谱参数也被报道,可为光谱探测提供参考。为建立基于^(12)C ^(16)O的测温模型,继续考察了温度直到9000 K的配分函数,模拟了不同温度下的振转光谱,以20000 cm^(-1)(对数坐标)以下和ν0-1带(线性坐标)的线状谱图为示例说明了谱线随温度的变化情况,并提出了几种可能的测温方案线索。最后考察了压强对振转谱线的影响。

大气负荷格林函数的压强效应

定义了大气压强负荷勒夫数 ,给出了大气压强引起的地球变形格林函数的表达式 。

多层电流片中双撕裂模耦合的压强效应

应用边界层理论研究了等离子体压强对多层电流片中m≥ 2的双撕裂模耦合的线性和非线性发展行为的影响 .考虑等离子体的压强效应 ,在一阶近似下 ,解析求得了环位形中双撕裂模的外区匹配参数Δ′.结果表明 ,当等离子体 β 1时 ,等离子体压强对双撕裂模的两有理面模之间通过撕裂模外区发生耦合作用的线性行为没有定性影响 .虽然等离子体压强将影响双撕裂模耦合的非线性行为 ,但是主要表现在对其单模项的影响 ,而对由于两有理面模之间的耦合作用产生的耦合项的影响却很小 .

压强对纳米铝粉点火和燃烧特性的影响

为了揭示压强对纳米铝(n-Al)粉点火和燃烧特性的影响,利用高压燃烧实验台对n-Al粉堆进行了0.1~3.5 MPa的激光点火实验研究。采用高速摄像仪、三色测温仪和光谱分析仪同步获取颗粒堆着火、火焰演变、表面辐射温度和特征辐射光谱等信息,分析了n-Al粉堆点火和燃烧特性。结果表明,空气气氛中的n-Al粉堆在1.5 MPa时,燃烧时间最短且最充分,剧烈燃烧阶段占比最大。随着压强的增加,n-Al粉的燃烧火焰强度和特征辐射光谱均增强,三个燃烧阶段时间从常压下的254.03、864.24、922.69 ms分别缩短至1.0 MPa时的118.85、435.69、452.50 ms,总燃烧时间缩短了50.65%。点火延迟时间和燃烧时间均随压强增加呈现非线性曲线的变化趋势,在0.1~1.5 MPa范围内,提高空气压强可以减小n-Al粉的燃烧时间,增大火焰锋面,提升最高燃烧火焰温度,促进气相燃烧。但过高的压强(1.5~2.5 MPa)会阻碍n-Al粉点火及火焰发展,减小剧烈燃烧阶段占比进而增大燃烧时间,引起中压熄火现象。

Strength criterion for crystalline rocks considering grain size effect and tensile-compressive strength ratio

The macroscopic mechanical properties of rocks are significantly influenced by their microstructure.As a material bonded by mineral grains,the grain morphology of crystalline rock is the primary factor influencing the strength.However,most strength criteria neglect the strength variations caused by different grain characteristics in rocks.Furthermore,the traditional linear criteria tend to overestimate tensile strength and exhibit apex singularity.To address these shortcomings,a piecewise strength criterion that considers the grain size effect has been proposed.A part of an ellipse was employed to construct the envelope of the tensive-shear region on the meridian plane,to accurately reproduce the low tensile-compressive strength ratio.Based on the analysis of experimental data,both linear and exponential modification functions that account for grain size effects were integrated into the proposed criterion.The corresponding finite element algorithm has been implemented.The accuracy and applicability of the proposed criterion were validated by comparing with the experimental data.

二氧化碳激光治疗外眼肿瘤

二氧化碳激光（以下简称CO2激光）对生物体的主要作用原理是热效应，它使组织细胞失活，蛋白变性，进而发生凝固性坏死，炭化和气化。此外，压强效应，光化效应和电磁场效应亦起一定作用。为了摸索它在眼科临床方面的应用，自1978年以来，我们应用CO2激光器共治疗外眼肿瘤75例，取得了较好的疗效，现初步小结如下；

应用He-Cd激光诊断耳鼻咽喉科肿瘤

激光具有方向性强。能量集中。单色性和相干性好的特点，因此已成为现在重要的先进技术之一，它对生物作用的机制，至今尚未完全清楚，现已公认的有热效应、压强效应，光化效应，电磁场效应和刺激效应。我们利用光化效应的原理，对临床病理进行的研究，

岩溶地面塌陷机制、预测及整治研究

本研究采用模型试验、现场试验及野外调查等多种方法,得出了当地下水位变动时产生的压强差效应是导致塌陷的主要成因机理的新概念.对岩溶地面塌陷提出了定性预测。半定量预测指标及定量预测的数学表达式和整治措施.

水城抽水致塌试验

本文根据试验结果探索因抽水而产生岩溶地面塌陷的形成机理。阐述了塌陷产生的规律性及相关因素。

Influence of Device Narrowing on HALO-pMOSFETs' Degradation Under V_g= V_d/2 Stress Mode

The degradation characteristics of both wide and narrow devices under V _g= V _d/2 stress mode is investigated.The width-enhanced device degradation can be seen with devices narrowing.The main degradation mechanism is interface state generation for pMOSFETs with different channel width.The cause of the width-enhanced device degradation is attributed to the combination of width-enhanced threshold voltage and series resistance.

Size effect on compressive strength of reactive powder concrete

In this paper the coefficient and law of the size effect of RPC were studied through experiments and theoretical analysis. The size-effect coefficients for the compressive strength of RPC are deduced through experiments.They indicate that RPC without fiber behaves quite the same as normal or high strength concrete.The size effect on compressive strength is more prominent in RPC containing fiber.Bazant's size effect formula of compressive strength applies to RPC.A formula is given to predict the compressive strength of cubic RPC specimens 100 mm on a side where the fiber dosage ranges from 0-2%.

Macro mechanical parameters’ size effect of surrounding rock of Shuibuya project’s underground power station

Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, classification of engineering rock mass, nu- merical simulation test and back analysis based on surrounding rock’s displacement monitoring results of Shuibuya Project’s underground power station, rock mass deforma- tion module’s size effect of surrounding rock of Shuibuya Project’s undegroud power sta- tion was studied. It’s shown that rock mass deformation module’s scale effect of sur- rounding rock of Shuibuya Project’s undeground power station is obvious, the rock mass deformation module to tranquilization is 20% of intact rock’s. Finally the relation between rock mass deformation modules and the scale of research was established.

Size effect on cubic and prismatic compressive strength of cement paste

A series of compression tests were conducted on 150 groups of cement paste specimens with side lengths ranging from 40 mm to 200 mm. The specimens include cube specimens and prism specimens with height to width ratio of 2. The experiment results show that size effect exists in the cubic compressive strength and prismatic compressive strength of the cement paste, and larger specimens resist less in terms of strength than smaller ones. The cubic compressive strength and the prismatic compressive strength of the specimens with side length of 200 mm are respectively about 91% and 89% of the compressive strength of the specimens with the side length of 40 mm. Water to binder ratio has a significant influence on the size effect of the compressive strengths of the cement paste. With a decrease in the water to binder ratio, the size effect is significantly enhanced. When the water to binder ratio is 0.2, the size effects of the cubic compressive strength and the prismatic compressive strength of the cement paste are 1.6 and 1.4 times stronger than those of a water to binder ratio of 0.6. Furthermore, a series of formulas are proposed to calculate the size effect of the cubic compressive strength and the prismatic compressive strength of cement paste, and the results of the size effect predicted by the formulas are in good agreement with the experiment results.

Science Letters:New solutions of shear waves in piezoelectric cubic crystals

Acoustic wave propagation in piezoelectric crystals of classes 43m and 23 is studied. The crystals Tl3VS4 and Tl3TaSe4 （43m） of the Chalcogenide family and the crystal Bi12TiO20 （23） possess strong piezoelectric effect. Because the surface Bleustein-Gulyaev waves cannot exist in piezoelectric cubic crystals, it was concluded that new solutions for shear-horizontal surface acoustic waves （SH-SAWs） are found in the monocrystals using different electrical boundary conditions such as electrically ＂short＂ and ＂open＂ free-surfaces for the unique [ 101 ] direction of wave propagation. For the crystal Tl3TaSe4 with coefficient of electromechanical coupling （CEMC） Ke^2=e^2/（C×g）-1/3, the phase velocity Vph for the new SH-SAWs can be calculated with the following formula： Vph=（Vα＋Vt）/2, where Vt is the speed of bulk SH-wave, Vt=Vt4（1＋Ke^2）^1/2, Vα=αKVt4, αK=2[Ke（1＋Ke^2）^1/2-Ke^2]^1/2, and Vt4=（C44/p）^1/2. It was found that the CEMC K2 evaluation for Tl3TaSe4 gave the value of K^2=2（Vf-Vm）/Vf-0.047 （-4.7%）, where Vf-848 m/s and Vm-828 m/s are the new-SAW velocities for the free and metallized surfaces, respectively. This high value of KZ（Tl3TaSe4） is significantly greater than K2（Tl3VS4）-3% and about five times that of K2（Bi12YiO20）.

In situ strength of coal bed based on the size effect study on the uniaxial compressive strength

In the early 1990 s, the Foundation for Science and Technology of Rio Grande do Sul State(CIENTEC)developed a pioneering study in Brazil, related to the simultaneous mining of multiple coal seams.One of the activities included detailed studies on the geomechanical characterization of materials present in the Irapua coal seam, under exploitation in the A-Sangao Mine, located near the city of Criciuma-SC,within the South-Catarinense coalfield. The goal of the laboratory tests was to define the behavior of the uniaxial compressive strength of the Irapua coal seam and establish a first approximation for the in situ strength value of this coal seam, since existing knowledge is solely based on practical mining experience over the years. Large samples of the coal seam were collected, using special techniques to maintain the integrity of the material, and a set of 56 uniaxial compression tests in cubic specimens, with side length ranging from 4.5 to 31 cm, were conducted in laboratory. This paper describes the experimental techniques used in the assays, and also presents the uniaxial compression strength results obtained.Moreover, important aspects of this type of study are considered, highlighting the size effect for the carbonaceous bed and the estimation of in situ strength values for the Irapua coal seam.

Dynamic characteristics of high stressed red sandstone subjected to unloading and impact loads

In the process of deep projects excavation,deep rock often experiences a full stress process from high stress to unloading and then to impact disturbance failure.To study the dynamic characteristics of three-dimensional high stressed red sandstone subjected to unloading and impact loads,impact compression tests were conducted on red sandstone under confining pressure unloading conditions using a modified split Hopkinson pressure bar.Impact disturbance tests of uniaxial pre-stressed rock were also conducted(without considering confining pressure unloading effect).The results demonstrate that the impact compression strength of red sandstone shows an obvious strain rate effect.With an approximately equal strain rate,the dynamic strength of red sandstone under confining unloading conditions is less than that in the uniaxial pre-stressed impact compression test.Confining pressure unloading produces a strength-weakening effect,and the dynamic strength weakening factor(DSWF)is also defined.The results also indicate that the strain rate of the rock and the incident energy change in a logarithmic relation.With similar incident energies,unloading results in a higher strain rate in pre-stressed rock.According to the experimental analysis,unloading does not affect the failure mode,but reduces the dynamic strength of pre-stressed rock.The influence of confining pressure unloading on the shear strength parameters(cohesion and friction angle)is discussed.Under the same external energy impact compression,prestressed rock subjected to unloading is more likely to be destroyed.Thus,the effect of unloading on the rock mechanical characteristics should be considered in deep rock project excavation design.

Strength weakening effect of high static pre-stressed granite subjected to low-frequency dynamic disturbance under uniaxial compression

This study aimed to elucidate the strength weakening effect of high static pre-stressed rocks subjected to low-frequency disturbances under uniaxial compression.Based on the uniaxial compressive strength(UCS)of granite under static loading,70%,80%,and 90%of UCS were selected as the initial high static pre-stress(σ_(p)),and then the pre-stressed rock specimens were disturbed by sinusoidal stress with amplitudes of 30%,20%,and 10%of UCS under low-frequency frequencies(f)of 1,2,5,and 10 Hz,respectively.The results show that the rockburst failure of pre-stressed granite is caused by low-frequency disturbance,and the failure strength is much lower than UCS.When theσp or f is constant,the specimen strength gradually decreases as the f or σ_(p) increases.The experimental study illustrates the influence mechanism of the strength weakening effect of high static pre-stress rocks under low-frequency dynamic disturbance,that is,high static pre-stress is the premise and leading factor of rock strength weakening,while low-frequency dynamic disturbance induces rock failure and affects the strength weakening degree.

Light Actuation of Liquid in Optofluidics

Optofluidics is the integration of optics and microfluidics(so-called lab on the chip). Wherein the actuation of liquid is a key technic. In a variety of methods for controlling microscale liquid, the light actuation is particularly interesting. The light actuation offers a novel way to control the flow of fluids for biomedical and biotechnological applications, etc.. The complexity and cost of devices sometimes may be greatly reduced by using complete optical control and may be more flexible in operation than other methods. However the light actuation of liquid is a burgeoning field as well as optofluidics. There is lots of work to do. Here we systematically describe four mechanisms for the light actuation of liquid based on the following points: optoelectrowetting, photothermal effect, radiation pressure, photosensitive substance.

Experimental study on dimension-form effect for compressive strength of coal

The uniaxial compression tests of cylinder standard specimens and different dimension cube specimens of No.13 coal seam of Jianxin Colliery were carried out using MTS, and the basic mechanics parameters of Jianxin Colliery 13 coal were studied. The dimension-form effect of uniaxial compression strength was analyzed. The exponent formula σc=6.928＋130.269 8 exp（-0.105 95D）of dimension effect was fitted. While the side length of specimen reaches 80 mm, its unaxial strength tends to a stable value which is called to be the strength of coal mass. Studies indicates that since the cube specimen suffered more shake than the cylinder one during machining and processing and the stress is centralized at four corners of cube during compressive experiment, the coal strength of standard cylinder specimen is higher than that of cube one.

Active earth pressure for subgrade retaining walls in cohesive backfills with tensile strength cut-off subjected to seepage effects

The commonly used Mohr-Coulomb(M-C) failure condition has a limitation that it overestimates the tensile strength of cohesive soils. To overcome this limitation, the tensile strength cut-off was applied where the predicted tensile strength is reduced or eliminated. This work then presented a kinematical approach to evaluate the active earth pressure on subgrade retaining walls in cohesive backfills with saturated seepage effects. An effective rotational failure mechanism was constructed assuming an associative flow rule. The impact of seepage forces, whose distribution is described by a closed-form solution, was incorporated into the analysis. The thrust of active earth pressure was derived from the energy conservation equation, and an optimization program was then coded to obtain the most critical solution. Several sets of charts were produced to perform a parameter analysis. The results show that taking soil cohesion into account has a distinct beneficial influence on the stability of retaining walls, while seepage forces have an adverse effect. The active earth pressure increases when tensile strength cut-off is considered, and this increment is more noticeable under larger cohesion.