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With the development of science and technology , the position of the strength measurement[1] in national economic development is more and more important, In recent years, along with the computer technology, electronic technology and the development of numerical control technology, force standard machine also obtained the rapid development[2-6],dead weight force standard machine strength measuring accuracy is the highest power source device by far, in the process of weight loading, considering the axial load affect the performance of the whole machine and in order to guarantee the machine safe and reliable, it is necessary to eccentric loading conditions for mechanical properties analysis.

Eriocheir sinensis should cultivate in high water quality ponds, which is affected by many combined factors such as physics, chemistry, biology etc. Using the real-time water quality monitoring historical data to test one of the water quality indexes and predict this index in the next time has great significance. The dissolved oxygen is one of the most important indexes in aquaculture, such as in the Eriocheir sinensis pond. This paper established a dissolved oxygen prediction model of water quality monitoring system based on BP neural network. The forecast data which is predicted by the established model could fit the actual monitoring data very well.

The aim of this research was to investigate the inhibitory effect of bacteriocin for use as a biological control agent against Listeria monocytogenes in refrigerated meat products. And this bacteriocin was evaluated for their effectiveness as a preservative on pork. The bacteriocin-treated pork was compared with a control pork sample regarding the number of listeria colony count. After 10 days of storage at 4 °C, the population of Listeria monocytogenes was increased from 5.7×105 to 3.7×108 CFU/mL in control samples. In test samples, the population of Listeria monocytogenes underwent a slight increased from 5.7×103 to 6.0×105 CFU/mL. During 10 days of storage, the percentage of growth inhibition ranged from 82.6% to 99.8%, bacteriocin showed their inhibitory effect on Listeria monocytogenes. These results indicated that the studied bacteriocin exhibited bactericidal effect against Listeria monocytogenes strain at refrigerated temperatures, and bacteriocin could be used as antimicrobial agent to preserve the shelf life of refrigerated meat products.

Monacolin K is a secondary metabolite of Monascus fermentation with lowering blood fat, cholesterol and blood sugar. The culture substrates and fermentation conditions were optimized by means of L9 (33) orthogonal experiments. The optimized fermentation conditions were studied and concluded: initial moisture content 50%, material thickness 4 cm and fermentation time 13 days. Using rice as substrate, the maximum yield of monacolin K was 2.50 mg/g in the optimized conditions. Using glutinousrice as substrate, the maximum yield of monacolin K was 2.71 mg/g in the optimized conditions. The founding determined that glutinousrice was used as substrate in solid state fermentation by Monascus purpureus to produce monacolinK.

In this paper, the theory of flow and method of ripple control of the external gear pump group are studied with two same-parameter external gear pumps which are installed in the form of parallel and different phase. In this thesis, the external gear pump group is known as a low ripple gear pump group, and the theory of ripple control is based on the theory that two periodic and quadratic function curves of different phase superposition can reduce the amplitude variation. According to this method, the thesis starts to analyze the instantaneous flow of the low ripple gear pump group, moreover which are compared with the instantaneous flow of a single gear pump. Finally, it is concluded that the flow pulsation rate of low ripple pump group is equal to 1/4 times of a single pump flow pulsation.

In the test enginery, using reverse frame put the pulling force into the pressure is the most commonly structure method. This paper analyzed the buckling problem of the process of reverse frame working, established the finite element model , stability analyzed , putted forward and proved the critical condition of reverse frame in the course of stability, Verified in 10kN deadweight force standard machine.

According to the hypoid gear tooth surface forming principle, a generating-line will be formed in round-plane while a cone and its tangent circle plane do pure rolling, and the hypoid gear is cutting according to the motion equation as hypoid gears generating-line. to tools shape. The milling processing equation of the hypoid left-hand gear tooth surface on the right side gear tooth surface and on the left side gear tooth surface.There are a detailed description of the adjusting-tool , cutting out from ends, dividing, cycle cutting the whole process. The above method can realizes hypoid gearwheel right tooth surface processing.

In this paper, the low-velocity impact behavior of the 3D angle-interlock woven glass-fiber/epoxy composites (3DAWCs) were tested and analyzed under several levels of impact energies. The energy-time curves, deflection-time curves and load-deflection curves were obtained to show the impact damage behavior. It was found that the damage magnitude increases with the impact energy, and the composite structure can effectively reduce the in-plane shear failure. In addition, the failure modes were also photographed to illustrate the damage mechanisms of the3DAWCs.

This paper reports the ballistic penetration behavior of 2D basalt fiber plain woven composite (2DPWC). The residual velocity vs. strike velocity curve was recorded. The dissipated energy was also calculated for each strike velocity. Furthermore, the impact damage morphologies of the tested 2DPWC coupons were given to indicate the damage modes and the mechanisms of energy absorption.

Styrene/Sodium allyl sulfonate copolymer (St-c-SAS) were prepared using soap-free emulsion polymerization method and boiling at high-speed stirring, and it was acided to obtain an efficient, stable, reusable new solid acid catalyst styrene/acrylic acid copolymer (St-c-AS). Elemental analysis and acid–base titration techniques showed that St-c-AS have high concentration of sulfonic groups. Differential thermal analysis (DTA) and thermogravimetric analysis (TG) results showed that the sulfonic of copolymer was hard to fall off at high temperature. Esterifications of acetic acid with ethanol showed that St-c-AS has high catalytic activity, and the catalyst can be reused without separation of 10 times, the esterification yields close to or exceed 100%. The superior performance of St-c-AS is attributed to their unique features including large surface area, high content of sulfonic groups as well as high temperature resistance.