Short-term Return of New Share in China

Initial return and short-term return are two totally different conceptions. When the anticipated year return is evaluated, we should stand on the conception of short-term return not the initial return. Based on the primary conception of the investment return, and considering the cost of purchasing, this paper gives the method of calculating the rate of short-term return. After the experienced analyses, we think there is excess return in the primary market. However, influenced by the low hit rate, only those investors, whose capital over some limit, can get it. The result explains the phenomena that why little investors leave the primary market for the secondary market. From the other way, the result proves that the investors are rational.     

THE APPLICATION OF THE INTEGRAL EQUATION OF RING SHELLS IN INITIAL PARAMETER FORM TO THE PROBLEMS OF S-TYPE CORRUGATED TUBES

By means of the method of integral equation of ring shells ininitial parameter form,the problems of S-type corrugated tubes are studied inthis paper.Two calculating examples are given,and compared with the exactsolutions.     

桃‘豫农矮砧1号’快繁体系初代培养基的初探

通过对不同完全培养基的筛选,进而探寻能够提高桃‘豫农矮砧1号’萌芽率的初代培养基,为桃‘豫农矮砧1号’快繁体系的建立打下坚实的基础,以桃‘豫农矮砧1号’的茎段为外植体,进行离体培养中初代培养基的筛选,以MS为基本培养基,附加不同浓度生长素IBA（3-吲哚丁酸）与细胞分裂素6-BA（6-苄基腺嘌呤）。结果表明：桃‘豫农矮砧1号’快繁体系中最佳初代培养基为MS+1.6 mg/L 6-BA+0.4 mg/L IBA,芽诱导率在IBA 0.1~1.0 mg/L,6-BA 0.8~1.6 mg/L的浓度范围内随激素浓度的上升而上升,并且以MS+1.6 mg/L 6-BA+0.4 mg/L IBA的芽诱导率最高。     

Development and experiments of direct resistance heating in hot forging

A new hot-forging method by means of direct resistance heating is investigated aiming at the long produce time and large energy consumption of traditional hot forging. The hot upsetting experiments with cylindrical billet of 42CrMo4 are performed. The influences of initial contact force, surface quality of the billet and current intensity on the heating temperature are researched. The results of the experiments show that the billet can be heated quickly to forming temperature by the approach. The relatively low initial contact force is useful to increase the heating temperature. The heating temperature is proportional to the square of the current intensity, and the heating temperature is seriously affected by the surface quality. During the forming process the billet cooling rate is effectively decreased and the forming time is extended in relation to the resistance heating.     

Impact Mechanism of Member Initial Stress on Space Truss

To reveal distribution characteristics of member initial stresses, nine experimental prototypes in span of 4 m, 5 m and 6 m were employed. To analyze effects of member initial stresses on ultimate capacity of space truss, a prototype in span of 6m was applied. Meanwhile, the results were compared with those of Abaqus nonlinear FEM which were based on elastic-perfectly plastic model and Marshall Mode. Initial stress test shows that some initial stresses approach or even exceed stability stress. It is shown that the test ultimate capacity decreases by 17.9% than that of Marshall Mode, and the safety margin of structure is just 1.25. The impact mechanism of member initial stress consists in damaging structure initial symmetry, producing member initial bending and prompting press member buckling in advance. Member initial stress must be taken into account when space truss design, especially Fully-Stress design, is conducted.     

Improved Least Square Method for the Consolidation Coefficient Evaluation

At present, the logarithm of time and the square root of time methods are usually used to compute consolidation coefficient, from which only a few data were adopted for the consolidation coefficient. At the same time, the two solutions depend on the initial value from the curves and influenced the exactitude of consolidation coefficient directly. So, in this paper, an improved least square method is supposed to compute the consolidation coefficient with testing data. According to the derived formulae, a program is used to compute consolidation coefficient based on Matlab language and to eliminate human error. The computation results show a good effect and give a reduction of errors.     

A Review of Set- retarding and Retarding Measures of Alkali- slag Cement and Concrete

In this paper,the influence of set- retarding on applications of alkali- slag cement and concrete is analysed.Set character of alkali- slag cement and suitability of measures used at home and abtord are discussed.On the basis of above mentioned,it is proposed that the only way to solve the fast- set problem of alkali- slag cement is by incorporating efficient retarders,and researches on mechanism of retarders along with deve loping new composite retarders are the most important topics in the research field of alkali- slag cement and concrete.     

AN ANALYSIS OF AXISYMMETRY SHELLS OF SUSPENSION CROSS SECTION BY A METHOD OF INTEGRAL EQUATION IN INITIAL PARAMETER FORM

In this paper,the axisymmetrical shells of suspension crosssection is studied by means of integral equation in initial parameter form.An example of the shells under uniformly distributed load is calculated.     

Influence of fine aggregate on initial shrinkage of high performance concrete

The type and percentage of sand affect the gradation of coarse fine aggregate and the amount of spare mortar in concrete, which further affects the resistance of fresh concrete to initial plastic shrinkage. Taking into account the engineering characteristics of sand in the area of Chongqing, P. R. China, three fine aggregates composed of superfine, medium, mixed and manufactured sand, are used to prepare high performance concrete (HPC). The effects of these three fine aggregates on initial plastic shrinkage crack are investigated. The results show that the HPC prepared with superfine sand possesses a higher initial shrinkage value than HPC prepared with mixed or medium sand. An optimal sand percentage is necessary to reduce the initial shrinkage cracking of HPC prepared with mixed or medium sand.     

INVESTIGATION OF INITIAL STRESS FIELD IN COMPOSITE STRATIFIED ROCK MASS

According to the weight stress field, the seismic stress field, the temperature stress field in the composite stratified rock mass, the initial stress field in rock mass is discussed theoretically in this paper. The obtained results are useful to make a recognition of the initial stress field in the composite stratified rock mass caused by influencing each other with different physical and mechanical properties between the rock beams.     

不同重金属胁迫对绿豆种子萌发和幼苗初期生长影响的差异

研究了不同浓度的重金属Cu2 、Cr6 、Pb2 胁迫对绿豆(Phaseolus radiatusL.)种子萌发和幼苗初期生长的影响。结果表明:低浓度抑或高浓度Cu2 、Pb2 胁迫对绿豆种子发芽率的抑制不明显,但较高浓度(100mg/L)Cr6 胁迫严重抑制种子萌发率,在400mg/L抑制高达66%(表1)。低浓度抑或高浓度Cu2 、Pb2 胁迫对绿豆初期生长抑制不明显,而Cr6 胁迫的抑制效应在浓度为50mg/L极为明显,并随浓度升高而加重。在400mg/L浓度时抑制其主根长、侧根数、株高及生物量分别高达93%、96%、75%、76%(鲜重计)57%(干重计)(表2~表6)。研究结果表明:3种重金属胁迫对绿豆种子萌发和幼苗初期生长影响有差异,其毒害能力顺序为Cr6 >Cu2 >Pb2 。     

造林初植密度对翅荚木幼龄林木材热值影响的研究

为了研究造林初植密度对翅荚木木材热值等的影响,笔者采用造林初植密度试验与木材采样测试相结合的方法对幼龄翅荚木的生长量、生物量、热值等进行研究。结果表明：4年生翅荚木胸径、树高、生物量等生长量密度效应显著。木材热值密度效应不显著,当翅荚木造林初植密度为10001~40002株/hm2时,其单木热值约18200 J/g;当初植密度为3334~6667株/hm2时,其单木热值约19000 J/g。当翅荚木造林初植密度达40002株/hm2时,4年生翅荚木每hm2生物量达94.2 t,生物总量相当于58.69 t标煤。翅荚木是较好的纤维能源植物。     

盾壳霉固态发酵基质筛选和发酵条件优化

为了探索盾壳霉固体发酵的条件,提高其生防效果,比较了6种天然培养基对盾壳霉固体发酵的影响,测定了在不同发酵培养基、温度、初始湿度、接种比例条件下盾壳霉的产孢量。结果表明：盾壳霉在麦粒和谷粒培养基上产孢量最大;而在麸皮和棉籽培养基上生长和产孢也较好,且成本低,成为后续试验的发酵材料。在含麦麸、棉籽壳及无机盐的培养料作为基质时,采用温度为20℃,发酵料初始湿度为60%,接种比例为7%,最终孢子含量可达109个/g以上。同时对发酵的条件做了进一步优化,发现麦粒与谷粒的混合比例、光照条件、甘露糖和甘氨酸含量对盾壳霉产孢量的影响较大。     

New Method to Study In-situ Stress of Rock Mass by AE and Structure Analysis of Rock Mass

In this paper, the authors adopt a method of structural analysis and stereography in combination with acoustic emission Kaiser Effect test in laboratory to find out the main direction of initial stresses. For overcoming the shortcomings of Kaiser effect by comparing it with traditional methods of measuring in-situ stresses, it is shown that this method is simpler, more economical and convenient for a large number of measurements and for studying the law of changes of regional in-situ stresses.     

Experimental and Numerical Analysis on Rupture of Rock Bridge with Non-Coplanar Intermittent Joints Under Direct Shear

By using servo control shear loading system, specimens with non-coplanar rock-like intermittent joints were tested by the way of forward and reverse direct shear, rupture mechanism and shearing law for rock bridge with non-coplanar intermittent joints were studied under direct shear. The experimental studies showed that five apparent stages are presented in the process of rock bridge rupture under direct shear, which are linear elastic stage, initiation and extension of crack, fracture and transfixion of rock bridge, climbing and occlusion of shear plane and residual friction. Rock bridge presented profile fracture plane under forward direct shear. While under reverse direct shear, band form fracture plane is showed which penetrated along with the direction of forward shear, and the shear strength of initiation and peak shear strength under reverse direct shear are bigger than that under forward shear. Crack angle, normal stress and lap proportion among adjacent joint are the main factors that influence the initiation strength and peak shear strength. The FLAC 3D simulation for the process of non-coplanar intermittent joints rock bridge rupture and formation of shear rupture surface under forward and reverse direct shear was conducted. The results of numerical simulation agreed well with those of experiment. The simulation results revealed tension crack failure of non-coplanar intermittent joints rock bridge and shear yielding mechanism of fracture plane.     

前处理及初始油炸温度对油炸薯片品质的影响

通过一系列实验及定量分析,探讨了不同的漂烫温度、漂烫时间和初始煎炸温度对油炸薯片的含油率、色泽及质构的影响。     

The Operator Solution of Liouville-Hill Equation and Its Applications

With operator solution. recursion formula of series solution to Liouville-Hill equation is given, furthermore the paper discusses the remainder term of the series and its estimation. and the existence and uniqueness of the solution is obtianed. Next,we discuss the inital problem of the n on homogeneous Hill equation with damping terms, which is a forced oscillation problem, and the series sloution and the sufficient conditions of its convergence are also given.     

Analysis of comprehensive evaluation method on safety of mountain tunnel initial support

Through collecting and collating information of 62 tunnels with initial support fracture,the risk grade is summed up,the factors causing initial support fracture are divided into two types：objective factors and subjective factors. The statistical results show that the proportion of controlled subjective factors’ reached as large as 25%. The comprehensive evaluation model on safety of mountain tunnel initial support by analytic hierarchy process (AHP)and fuzzy comprehensive evaluation is established. On this basis,the science rational risk response method is required. Then the evaluation model is proved credible by field measurements.     

Fastener-style Formwork Support System Initial Imperfection Classification and Defect Sensitivity Analysis

For the ultimate bearing capacity of steel tubular scaffold with couplers, influences and computation methods considering initial imperfections are analyzed in this paper. Initial imperfections are classified into four type defects: mechanical defects, ma