Research on the cutting force of a pick

Cutting tests were done using a test bed designed to measure pick cutting forces when cutting coal and rock.The test equipment has a drum with two starting helical vanes.Cutting forces on a pick were measured as a function of coal compressive strength,pick carbide tip diameter and the cutting depth per drum revolution.The results show that the cutting force is linearly related to the compressive strength.The relationship between the cutting force and both the carbide tip diameter and the cutting depth are exponential.Fluctuation in the cutting force does not increase with coal compressive strength but it has a linear relationship to tip diameter.A plot of cutting force fluctuations versus the cutting depth follows a sigmoidal curve.Based on the analysis of these test results a theoretical basis is supplied for design and effective use of shearer drums.

Local Data Analysis for Eliminating End Restraint of Triaxial Specimen

A data processing method was proposed for eliminating the end restraint in triaxial tests of soil. A digital image processing method was used to calculate the local deformations and local stresses for any region on the surface of triaxial soil specimens. The principle and implementation of this digital image processing method were introduced as well as the calculation method for local mechanical properties of soil specimens. Comparisons were made between the test results calculated by the data from both the entire specimen and local regions, and it was found that the deformations were more uniform in the middle region compared with the entire specimen. In order to quantify the nonuniform characteristic of deformation, the non-uniformity coefficients of strain were defined and calculated. Traditional and end-lubricated triaxial tests were conducted under the same condition to investigate the effects of using local region data for deformation calculation on eliminating the end restraint of specimens. After the statistical analysis of all test results, it was concluded that for the tested soil specimen with the size of 39.1 mm × 80 ram, the utilization of the middle 35 mm region of traditional specimens in data processing had a better effect on eliminating end restraint compared with end lubrication. Furthermore, the local data analysis in this paper was validated through the comparisons with the test results from other researchers.

Mechanical behaviour analysis and support system field experiment of confined concrete arches

Soft rock control is a big challenge in underground engineering.As for this problem,a high-strength support technique of confined concrete(CC)arches is proposed and studied in this paper.Based on full-scale mechanical test system of arch,research is made on the failure mechanism and mechanical properties of CC arch.Then,a mechanical calculation model of circular section is established for the arches with arbitrary section and unequal rigidity;a calculation formula is deduced for the internal force of the arch;an analysis is made on the influence of different factors on the internal force of the arch;and a calculation formula is got for the bearing capacity of CC arch through the strength criterion of bearing capacity.With numerical calculation and laboratory experiment,the ultimate bearing capacity and internal force distribution is analyzed for CC arches.The research results show that:1)CC arch is 2.31 times higher in strength than the U-shaped steel arch and has better stability;2)The key damage position of the arch is the two sides;3)Theoretical analysis,numerical calculation and laboratory experiment have good consistency in the internal force distribution,bearing capacity,and deformation and failure modes of the arch.All of that verifies the correctness of the theoretical calculation.Based on the above results,a field experiment is carried out in Liangjia Mine.Compared with the U-shaped steel arch support,CC arch support is more effective in surrounding rock deformation control.The research results can provide a basis for the design of CC arch support in underground engineering.

Modification of B3 Model for Sealed Concrete with Additives Based on Experimental Observations

Thirteen specimens were tested out of which nine were for creep of sealed concrete and four for shrinkage test,for a period of 700 d under controlled temperature condition.The experimental results for creep and shrinkage were compared with creep and shrinkage computation model B3 and distinct discrepancies between observed and calculated creep and shrinkage strains were observed.Based on regression analysis,modification on B3 model has been formulated which will be applicable at least for concrete of characteristics strength of C40 and C50 with additives.Besides,on the basis of observation on identical specimens with varied stress strength ratio,a function is generated which accounts effect of stress strength ratio on creep.Finally,Civil Engineering community is suggested not to follow the creep prediction models without correction at least for modern concrete,as they do not account the effect of additives on its compliance function.

Network Management of Food Additives Quality Analysis and Inspection

In this paper, on the basis of the implementation of the national chemical industry standard analytical test methods and analysis of test items, a food additive quality analysis and inspection of network management applications are developed using the development technology of Visual Basic language and computer system operating environment, to achieve a network management software for users on food additives of quality analytical testing. The software sets up an information sharing network platform for enterprise and quality management departments, which is a major innovation in the food additive quality analysis on test management methods and tools.

Damage Analysis of Circulating Soaked Rock Sample Based on Sonic-test Trials

Circulating soaked sandstone and mudstone samples sonic parameters were tested and analyzed, using RSM-SY5 sonic instrument, the variation between soaked times and the velocity of longitudinal wave and shear wave was studied, calculation and analysis of the damage variable of circulating soaked rock samples were taken, with sonic measurement results and the empirical formula, the damage variable formulas associated with cycle times was established. The results showed that： the attenuation of sonic velocity basically in line with the exponential relationship, with cycle times increasing; The results of the critical calculation of damage variables and the strength test are well matched, which further confirms that the occurrence and expansion of new crack inside the rock mass resulted from circulating soaked lead to the decrease of the rock strength; The trend of sonic parameters attenuation and damage variable growth are good correspondence.

Present and future of prophylactic antibiotics for severe acute pancreatitis

AIM: To investigate the role of prophylactic antibiotics in the reduction of mortality of severe acute pancreatitis (SAP) patients, which is highly questioned by more and more randomized controlled trials (RCTs) and metaanalyses. METHODS: An updated meta-analysis was performed. RCTs comparing prophylactic antibiotics for SAP with control or placebo were included for meta-analysis. The mortality outcomes were pooled for estimation, and re-pooled estimation was performed by the sensitivity analysis of an ideal large-scale RCT. RESULTS: Currently available 11 RCTs were included. Subgroup analysis showed that there was significant reduction of mortality rate in the period before 2000, while no significant reduction in the period from 2000 [Risk Ratio, (RR ) = 1.01, P = 0.98]. Funnel plot indi-cated that there might be apparent publication bias in the period before 2000. Sensitivity analysis showed that the RR of mortality rate ranged from 0.77 to 1.00 with a relatively narrow confidence interval (P < 0.05). However, the number needed to treat having a minor lower limit of the range (7-5096 patients) implied that certain SAP patients could still potentially prevent death by antibiotic prophylaxis. CONCLUSION: Current evidences do not support prophylactic antibiotics as a routine treatment for SAP, but the potentially benefited sub-population requires further investigations.

Investigating Iranian Test-takers＇ Performance Over Taking Different Modalities of Listening Comprehension Test

Visual and pictorial materials are extensively used in teaching listening comprehension textbooks. Although the use of still image is currently implemented in some distinguished testing systems, video test is not a popular modality due to the fact that this kind of test may result in test-takers＇ confusion during the test. In the present study, a sample of 80 Iranian EFL （English as a Foreign Language） students was selected to compare their performance on three different modalities of listening test： audio-only test, pictorial （listening with still image test）, and visual （video） listening test. The analysis of one-way repeated measure ANOVA （Analysis of Variance） was used to compare the students＇ scores. The results of Bonferroni Post Hoc Test confirm that there were significant differences in scores among audio-only, pictorial, and visual tests. The results of this study highlight the greater performance of students in pictorial listening test which is statistically significant.

Test and analysis of the influence of the transformer insulation resistance and dielectric loss

In view of long-term transformer insulation resistance and dielectric loss measurement, measurement and according to the national standard formula conversion values are not completely consistent, in this paper, a variety of transformers are studied, and the applicable scope of the conversion formula is discussed emphatically, combined with the test results are analyzed of transformer insulation resistance value to temperature and oiliness and dielectric loss tangent to temperature and oiliness, and puts forward suggestions on how to improve the insulation performance of transformer.

Measurement Module for Young for Thermal Insulation Composite Polymeric

To analyze the feasibility of application of composite material as the insulating material, it is necessary to have knowledge of some of its mechanical properties. An insulating material may suffer from the most different efforts, but the major applications suggest mechanical bending and compression tests because the insulation can be applied on roofs of homes, liners similar to, in the form of plates. Thus, the product is continually flexed. When the material is used on a floor, it suffers constant compressions over its use. For tests performed in this study, we used the ASTM D695-96 for compression, an example of literature. Using such a standard test, specimens were produced for compression test, with specimens made of cylindrical shapes, respecting the condition that the height of the specimen corresponds to twice the diameter of the base. Polyurethane castor without charge vermiculite and mass loads of 10%, 15% and 20% matrix： four specimens for each type of material were produced. The composites were tested in a universal testing machine at a speed of 2 mm/s. The results are average values of four test samples, and initially show the behavior of castor oil polyurethane during the compression test, which is detailed in the stress versus strain curve. The achieved results are promising, and detailed in this paper.

A Test Items Knowledge Library System for Adaptive Learning

A test items knowledge library system of for adaptive learning is proposed in this paper. The first step is to carry out the quantity and quality analysis of the test items by using the Bloom＇s revised taxonomy and scale anchoring respectively to produce the characteristics for test items. A smoothing method of arbitrary anchoring revised from scale anchoring is first proposed to make tests more accurate in distinguishing test levels. In addition, raised three dimensional indicators based on the Bloom＇s revised taxonomy are adopted to validate test contents and therefore it concretely describes the examining function of items. The items obtained have the precise and concrete properties; an item knowledge library is therefore constructed combining teaching materials and items using the technologies of ontology and knowledge management. Finally, a knowledge library system of test items is established to achieve the purpose of adaptive learning for learners.

Airborne test flight of HY-2A satellite microwave scatterometer and data analysis

This paper introduces the background, aim, experimental design, configuration and data processing for an airborne test flight of the HY-2 Microwave scatterometer(HSCAT). The aim was to evaluate HSCAT performance and a developed data processing algorithm for the HSCAT before launch. There were three test flights of the scatterometer, on January 15, 18 and 22, 2010, over the South China Sea near Lingshui, Hainan. The test flights successfully generated simultaneous airborne scatterometer normalized radar cross section(NRCS), ASCAT wind, and ship-borne-measured wind datasets, which were used to analyze HSCAT performance. Azimuthal dependence of the NRCS relative to the wind direction was nearly cos(2w), with NRCS minima at crosswind directions, and maxima near upwind and downwind. The NRCS also showed a small difference between upwind and downwind directions, with upwind crosssections generally larger than those downwind. The dependence of airborne scatterometer NRCS on wind direction and speed showed favorable consistency with the NASA scatterometer geophysical model function(NSCAT GMF), indicating satisfactory HSCAT performance.

Simulation analysis for O-cell test of pile and the interaction of upper pile and lower pile

In this paper,the soil-pile system of O-cell test of pile is simplified as an axi-symmetric problem.By using aggregation of quadrilateral isoparametric elements to simulate pile and soil,setting Goodman's elements between pile and soils,a method of numerical simulation analysis on O-cell test of pile is presented with the consideration of nonlinear mechanical behavior of soils and pile-soil interface.The method is applied to the analysis of a case of O-cell test of pile.The load-displacement curves and axial force curves of upper pile and lower pile obtained from the O-cell test of pile are fitted,and parameters of the mechanical model of soils and interface are determined.Analysis results validate that the numerical simulation analysis method put forward in this paper is applicable.Furthermore,the interaction and influence of upper pile and lower pile in the O-cell test are also studied with the method.The result shows that if load box is located in a soil layer with fine mechanical behavior,the interaction of upper pile and lower pile in O-cell test can be ignored generally.

Test evaluation for vertical fracture wells in low permeability reservoir

As flow environment is poor in low permeability reservoirs, wells are always fractured in order to gain better economic benefits. Well testing analysis is very necessary for fracturing wells. However, available test analysis methods are of slow fitting speed and low fitting precision. In this paper, we first use a comprehensive evaluation method of analytical well testing, numerical well testing and well testing design. Many dynamic parameters such as fracture length, fracture conductivity, skin factor, etc are obtained. An example to illustrate accurate results of this method is given.

探究幼儿园课程游戏化背景下的自然角课程建设

本文主要从探究幼儿园课程游戏化背景下的自然角课程建设出发,并结合当下幼儿园的自然角课程开展进行阐述说明,并且根据幼儿身心的特点、学习特征合理的创建游戏化为背景的自然角课程,从而有效的激发幼儿对课程学习的兴趣,积极的参与到活动当中,并且实现在玩中学习的教学目的。

Effect of Yiqi Yangyin prescription in treatment of dilated cardiomyopathy： a Meta-analysis of randomized controlled trials

OBJECTIVE: To evaluate the therapeutic effect of Yiqi Yangyin prescription for dilated cardiomyopathy(DCM).METHODS: Electronic databases were searched for relevant clinical randomized controlled trials of DCM treatment using Yiqi Yangyin prescription(Shengmai and Zhigancao decoction). Databases searched included Pub Med, EMBASE, the Cochrane Library, China National Knowledge Infrastructure Database, Wanfang Database, China Science and Technology Journal Database, and Chinese Biological Medicine from January 1, 1985, to October 31,2015. After literature screening and data extraction according to previously determined exclusion criteria, data were analyzed using Rev Man 5.3 and Stata12.0. Study heterogeneity was evaluated using the I2 test and Cochran's Q test. Egger's test was used to detect publication bias.RESULTS: Nineteen trials involving 1024 partici-pants were included in the Meta-analysis. Of these,15 used Shengmai(treatment group: 421 cases;control group: 344 cases) and 4 used Zhigancao decoction(treatment group: 133 cases; control group:126 cases). A Meta-analysis demonstrated that the total curative effect was significantly improved by combining Shengmai with conventional treatment[relative risk(RR) = 1.32, 95% confidence intervals(CI)(1.22, 1.43), P < 0.01]. Left ventricular ejection fraction [standard mean difference(SMD) = 1.13,95% CI(0.55, 1.70), P < 0.01] and left ventricular end diastolic [SMD =-0.46, 95% CI(-0.70,-0.23), P <0.01] were also improved. Adding Zhigancao decoction achieved the same effect [total efficiency of RR = 1.34, 95% CI(1.16, 1.54), P < 0.01].CONCLUSION: Compared with conventional therapy, Yiqi Yangyin prescription can significantly improve the curative effect, increase left ventricular ejection fraction, and reduce left ventricular end diastolic. Thus, it can effectively improve heart function in patients with DCM.

Predictors of functional outcome after hanging injury

Purpose： Suicide becomes a serious problem in today＇s society and hanging is a common method of suicide. We want to find the factors which can predict the final functional outcomes of these cases. Methods： All patients who presented to Accident and Emergency Department （ED） of the National Cheng Kung University Hospital from 1st January 2005 to 31th December 2013 with a hanging injury were included in this study. All cases were divided into good outcome group and bad outcome group according to Glasgow Outcome Scale （GOS）. Data was analyzed by Mann-Whitney test and chi-square test. Results： Glasgow Coma Scale （GCS） 〈 3, pupil dilation and no pupillary light reflex both at the scene and ED were the factors to indicate poor functional outcome. Out-hospital cardiac arrest （OHCA）, acidosis （pH 〈 Z2） and the need for intubation once arriving at ED were also related to poor functional outcome. OHCA cases all had poor functional outcome, Conclusion： GCS, pupil size, pupiUary light reflex, OHCA and acidosis are useful as prognostic factors. GCS= 3 lead to a very poor outcome. However, the functional outcome seems good in patients with GCS〉3. There parameters can help to predict the outcome before treatment.