“果实法”在高中地理课堂练习教学中的应用

课堂练习"果实法"教学就是在生本课堂的基础上,师生共同审视课堂练习"果皮"的地理情景表象,掌握练习中"果肉"的地理知识原理,培养基于"果核"的地理核心素养.

A New Non-enzymatic Method to Isolate Immature Embryos of Capsella bursa-pastoris (L.) Medic.

[Objective] The aim of this study was to manually isolate the microstructures such as ovule and embryo of Capsella bursa-pastoris (L.) Medic. by the non-enzymatic method. [Method] With the gum block and dissecting microscope, its floral characteristics, ovule and embryo were manually isolated and observed by the non-enzymatic method. [Result] C. bursa-pastoris had four calyces, four petals, tetradynamous stamen and silicle, while its embryogenesis contained globular embryo, heart-shaped embryo and torpedo-shaped embryo. [Conclusion] The microstructures such as ovule and embryo of plants become easier to be isolated manually with the viscosity of gum block, which has small damage on embryo or disadvantages of keeping original shapes, and also can used in multi fields studies. This test can also be accomplished in labs with poor experiment facilities.

Detection and Analysis of Squalene in Oil from Olive Fruits of Different Varieties and of Different Degrees of Maturity

[Objective] This study aimed to identify the difference in squalene content among different olive varieties and the law of squalene content change in the same olive variety of different degrees of maturity, with the objective to provide technical support for the harvest and processing of olive fruits. [Method] Taking 13 introduced olive varieties including three varieties of eight different grades of maturity, fat acid w3s first extracted by Soxhlet extraction and then squalene was quantitatively and qualitatively analyzed by gas chromatography-mass spectrometry （GC-MS） method. [Result] The results showed that squalene content was the highest in CG-32, and the lowest in Leccino among the 13 olive varieties. And squalene content increased with the degree of maturity in the three olive varieties including CG-32, Frantoio and Ascolana Tenera. [Conclusion] A more simple and rapid method for the determina- tion of squatene content was established.

Effect of Stirring on Oil-Water Separation in Rare Earth Mixer-Settler

Oil-water separation is critical to solvent extraction process of rare earth, which can directly affect the yield and quality of the product. The experiments measure the two-phase separation time in a beaker, mixing uniformity of two phases in the mixer and the oil phase entrainment at oil exit by the Karl Fischer method and numerical simulation for the mixersettler to study the combined effect of gravity and stirring. Experimental results show that relative to the static situation, the separation efficiency resulted from low-speed stirring is increased by 25%. The water content in the oil is a minimum at an offset distance L of 10 cm and the clearance off the tank bottom z of 10 cm is as low as 0.49%. Distribution images of oilwater separation at 2 s indicates that stirring is very conducive to the separation of the oil-water phase.

Antioxidant Activity and Anti-Hyperglycemic Effect of Lagenaria Siceraria Fruit Extract

Lagenaria siceraria （Molina） Standl., known as bottle gourd is widely available throughout Vietnam as an edible vegetable. Bottle gourd is a commonly fruit but there are little reports about its biological activities. The aim of the present study was to evaluate antioxidant activity and anti-hyperglycemic potential of ethanolic extract of bottle gourd. The ethanolic extract was tested for its antioxidant activity on chelating power, the ferric reducing/antioxidant power assay （FRAP） and the 1, 1-diphenyl-2-picryl-hydrazyl （DPPH） free radical scavenging assay. The results showed that chelating activity was 80.02%, FRAP value was 92.84 μmol Fe^2＋/g and active radical scavenging which showed an IC50 was 49.50 μg/ml. The five different doses of ethanolic extract were treated by oral tolerance to mice body before oral glucose tolerance and blood glucose level was measured using glucose oxidase method. The result indicated that inhibition percentage of ethanolic extract of bottle gourd at the dose of 400 mg/kg in glucose-induced hyperglycemic mice was effectively similar to standard drug glibenclamide. The results obtained indicate that ethanolic extract from bottle gourd is the potential antioxidant and anti-hyperglycemic agent.

Computer simulation of flow and mixing at the duodenal stump after gastric resection

AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A and B） were modeled. Case A was defined with a shorter and almost straight duodenal section, while case B has a much longer and curved duodenal section. Velocity, pressure and food concentration distribution were determined and the numerical results were compared with experimental observations. RESULTS： The pressure distribution obtained by numerical simulation was in the range of the recorded experimental results. Case A had a more favorable pressure distribution in comparison with case B. However, case B had better performance in terms of food transport because of more continual food distribution, as well as better emptying of the duodena section. CONCLUSION： This study offers insight into the transport process within the duodenal stump section after surgical intervention, which can be useful for future patient-specific predictions of a surgical outcome.

Timedelay based all-frequency correction method for discrete spectrum

Many spectrum correction methods have been developed, but their performance degrades significantly when they are applied to the correction of low frequency component （ LFC ）. It owns to that the model underlying the conventional approaches neglects the interference of the negative frequency in the real signal. A new approach for the correction of the LFC is proposed, which suits all kinds of symmetrical windows. It divides a signal into three sections and makes use of the first spectrum line of each section. Then this approach is modified so that it is also applicable to the correction of the high frequency component. Thus a timedelay-based all-frequency correction method is proposed. The simulation results show that this method is simple and feasible. By this method, the accurate frequency, amplitude and phase of the spectral line can be obtained whether it is close to or far from OHz.

The Research of Fractal Characteristics of the Electrocardiogram in a Real Time Mode

The article presents the results of recent investigations into Holter monitoring of ECG, using non-linear analysis methods. This paper discusses one of the modern methods of time series analysis--a method of deterministic chaos theory. It involves the transition from study of the characteristics of the signal to the investigation of metric （and probabilistic） properties of the reconstructed attractor of the signal. It is shown that one of the most precise characteristics of the functional state of biological systems is the dynamical trend of correlation dimension and entropy of the reconstructed attractor. On the basis of this it is suggested that a complex programming apparatus be created for calculating these characteristics on line. A similar programming product is being created now with the support of RFBR. The first results of the working program, its adjustment, and further development, are also considered in the article.

The Implementation Effects of a Nationwide Sloping Farmland Soil Erosion Control Project in China

To understand implementation of a nationwide sloping farmland soil erosion comprehensive control project during China＇s 12 th Five-Year Plan we used data collection and expert consultation. We selected 24 indexes across three aspects including project management, engineering construction and implementation benefit and used AHP-grey correlation analysis methods. We found that the scores for engineering construction were greater than 0.65 in most of the provinces, autonomous regions and municipalities. These scores are high and scores for project management and implementation benefit are between 0.45–0.65; however, overall scores are low. The comprehensive evaluation results are normally distributed. The composite scores for Sichuan, Yunnan and Guizhou are 0.71, 0.68 and 0.68 respectively, indicating that the implementation effects are good. The scores for Jilin and Liaoning are 0.38 and 0.42 respectively, indicating that the implementation effects need improvement. Scores for other provinces are between 0.45–0.65 and the effects are medium. The evaluation results show certain zonal rules spatially and the implementation effect in karst regions of Southwest China is the highest, followed by the purple soil region in Southwest China, Loess Plateau region of Northwest China, earth-rock mountain region of North China and red soil hilly region of South China. The implementation effect in the black soil region of Northeast China suggests that improvement is needed in this region.

Simulation and Experiment Research of Aerodynamic Performance of Small Axial Fans with Struts

Interaction between rotor and struts has great effect on the performance of small axial fan systems. The small axial fan systems are selected as the studied objects in this paper, and four square struts are downstream of the rotor. The cross section of the struts is changed to the cylindrical shapes for the investigation： one is in the same hy- draulic diameter as the square struts and another one is in the same cross section as the square struts. Influence of the shape of the struts on the static pressure characteristics, the internal flow and the sound emission of the small axial fans are studied. Standard K-s turbulence model and SIMPLE algorithm are applied in the calculation of the steady fluid field, and the curves of the pressure rising against the flow rate are obtained, which demonstrates that the simulation results are in nice consistence with the experimental data. The steady calculation results are set as the initial field in the unsteady calculation. Large eddy simulation and PISO algorithm are used in the transient calculation, and the Ffowcs Williams-Hawkings model is introduced to predict the sound level at the eight monitoring points. The research results show that： the static pressure coefficients of the fan with cylindrical struts increase by about 25% compared to the fan with square strum, and the efficiencies increase by about 28.6%. The research provides a theoretical guide for shape optimization and noise reduction of small axial fan with struts.

小南瓜卖出大价钱

他，曾带着淘金者的梦从河北农村南下广州，倾其所有做起了一个南瓜梦；他，怀揣奇思妙想一路走来，把一个南瓜最高卖到8000元，4年赚到300万元。

Correction of Wave Surge Forces to Improve Surf-Riding/Broaching Vulnerability Criterion Check Accuracy

Surf-riding/broaching is one of the five stability failure modes to be included into the International Maritime Organization (IMO) second generation intact stability criteria (which are risk-based stability criteria) that can ensure the safety of ships in actual seaways more effectively. This study focuses on the influence of wave surge force prediction accuracy on surf-riding/broaching vulnerability criterion check result. Firstly, it is demonstrated that the wave surge force prediction method adopted in the current vulnerability criterion check procedure is not accurate and may lead to wrong conclusions. The experimental data from captive model test and the numerical result based on 3D panel method both indicate that the diffraction effect must be considered to correctly predict the wave surge forces. Besides, sophisticated methods are not suitable for Level 2 vulnerability criterion check due to their complexity. Therefore, an empirical formula for wave surge force correction based on sample ship calculation results is proposed. The proposed empirical correction formula can effectively improve the vulnerability criterion check accuracy and thus contribute to the design and safety of the ships which are vulnerable to this stability failure mode. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany.