Nonreciprocity of energy transfer in a nonlinear asymmetric oscillator system with various vibration states

The nonreciprocity of energy transfer is constructed in a nonlinear asymmetric oscillator system that comprises two nonlinear oscillators with different parameters placed between two identical linear oscillators.The slow-flow equation of the system is derived by the complexification-averaging method.The semi-analytical solutions to this equation are obtained by the least squares method,which are compared with the numerical solutions obtained by the Runge-Kutta method.The distribution of the average energy in the system is studied under periodic and chaotic vibration states,and the energy transfer along two opposite directions is compared.The effect of the excitation amplitude on the nonreciprocity of the system producing the periodic responses is analyzed,where a three-stage energy transfer phenomenon is observed.In the first stage,the energy transfer along the two opposite directions is approximately equal,whereas in the second stage,the asymmetric energy transfer is observed.The energy transfer is also asymmetric in the third stage,but the direction is reversed compared with the second stage.Moreover,the excitation amplitude for exciting the bifurcation also shows an asymmetric characteristic.Chaotic vibrations are generated around the resonant frequency,irrespective of which linear oscillator is excited.The excitation threshold of these chaotic vibrations is dependent on the linear oscillator that is being excited.In addition,the difference between the energy transfer in the two opposite directions is used to further analyze the nonreciprocity in the system.The results show that the nonreciprocity significantly depends on the excitation frequency and the excitation amplitude.

Detection of Chlorpyrifos Residues in Akesu Red Fuji Apple based on Near Infrared Spectrum

[Objective] The paper was to explore a method for detecting chlorpyrifos residues in red Fuji apple. [Method] The original spectral data of apple samples sprayed with different volume fractions of chlorpyrifos were collected using near infrared spectrometer at the band of 4 000-10 000 cm^（-1）. The original spectra were pre-treated by a variety of methods, and partial least squares（PLS） model was established for predictive analysis. [Result] Near infrared spectrum showed sensitivity to apple samples sprayed with different volume fractions of chlorpyrifos, but had low precision on pesticide-free samples. Data of blank control group were further eliminated for modeling prediction. The results showed that the results were the best when pre-treated with first derivative（FD）： R=0.987 9; the square error of prediction（SEP） was 0.173 6; the root-mean-square error of cross-validation（RMSECV） was 0.120 5; and the precision was 0.923 4. [Conclusion] Near infrared spectrum can better predict chlorpyrifos residue, providing a new method for detecting chlorpyrifos residues in Akesu red Fuji apple.

Comparative Analysis of the Purchase Price of Raw Milk in the World

This paper selects 20 countries from the major dairy producing continents such as Oceania,the Americas,Europe and Asia,for the comparative analysis of the purchase price of raw milk in the world. Based on the summarization of general features of the world raw milk prices,this paper elaborates the fluctuations in the purchase price of raw milk in Oceania,the Americas,Europe and Asia,respectively,and carries out the comparative study of the gap between the domestic purchase price of raw milk and the world purchase price of raw milk.

Development of portable user-interactive holographic information collector for agricultural product markets

The efficient and accurate collection of agricultural product market information serves as the basis for the effective regulation of agricultural product markets.To achieve a comprehensive,accurate,and timely collection of agricultural product market information,this study puts forth a technique for collecting holographic information of agricultural product markets.A portable human-machine interaction device with an Advanced RISC(reduced instruction set computer)Machines(ARM)-based processor as the core is developed.Holographic information such as agricultural product market trading time,trading place,product name,price,and trading volume can be collected.Via embedded technology and component technology,innovative agricultural product market positioning,and matching,standardized collection,and data processing,and in combination with intelligent algorithms for analysis and early warning,a mobile application terminal for information collection is developed,namely,a holographic information collector for agricultural product markets(named Nongxincai).By using a layered structure,the hardware integrates microprocessor,storage,power,application and communication interface,and human-machine interaction modules.The device has the advantages of miniaturization,the whole-machine power consumption of less than 0.5 W,and continuous operating time of at least 10 h.A supporting software system for Nongxincai has also been developed,in which Microsoft Windows Mobile 6.5 is employed as the operating system,and the CPU frequency is up to 600 MHz.This configuration fully meets the computing requirements of map processing and large-volume data processing and has high compatibility.Nongxincai has been popularized and applied in 12 provinces/municipalities in China.It has played an important role in the monitoring and early warning of different varieties of agricultural products and target prices of soybean and cotton.

Strip rotary tillage with subsoiling increases winter wheat yield by alleviating leaf senescence and increasing grain filling

Sustainable agriculture in the Huang–Huai–Hai Plain of China is threatened by subsoil compaction and the decline of winter wheat productivity induced by inappropriate tillage regimes. We investigated the effects of optimizing the tillage regime on grain filling and its relationship with flag leaf senescence post-anthesis in winter wheat. Four treatments were compared: rotary tillage, strip rotary tillage, strip rotary tillage with a 2-year subsoiling interval(STS), and conventional plowing tillage. STS produced higher chlorophyll content and leaf area indexes than other treatments, resulting in a greater photosynthetically active radiation capture ratio. The net photosynthesis rate of flag leaves from 14 to 28 days after anthesis and dry matter accumulation at maturity were higher in STS than in other treatments. Sucrose content and sucrose phosphate synthase activity of flag leaves first increased and then decreased during grain filling and were highest in STS. STS increased superoxide dismutase activity, increased soluble protein content, and reduced malondialdehyde concentrations in flag leaves after the middle grain-filling stages,resulting in reduced premature senescence. This consequence extended the active grain filling period and increased grain weight. The highest yields were observed in STS, reaching10,451 kg ha-1 in 2014–2015 and 10,074 kg ha-1 in 2015–2016, owing to increased spike numbers and 1000-kernel weight. Overall, our study suggested that STS could substantially increase photosynthetic capacity and delay leaf senescence, thus promoting grain filling rate and increasing winter wheat yields.

Urban Residents' Consumption Risk Perception about the Dairy Products

Based on the continuous downturn puzzle of Chinese dairy consumption,with the perception of consumption risk as a starting point,the paper deeply analyzes the main factors which cause the downturn of dairy product consumption of Chinese residents. The results show that the income elasticity of dairy consumption of Chinese urban residents is still notable; the occurrence of dairy safety incidents improves the perception of consumption risk,and accordingly it reduces the promoting role of income to the dairy consumption; the safety incident is the key factor which leads to the fall of dairy consumption of urban residents in recent years,and the perception of consumption risk of lower income group is clearly higher than that of higher income group.

Analytical bi-level multi-local-world complex network model on fresh agricultural products supply chain

Lately,in some regions and seasons in China,urban consumers have paid high in buying fresh agricultural products while farmers get unreasonable income from producing them.To seek the reason for the phenomenon and explore ways to simulate it,this study constructed and implemented a complex network model named the Bi-Level Multi-Local-World(BI-MLW model)with characteristics of an interdependent coupling relationship between its participants.To verify the validity of the model,this study implemented an experimental simulation under Small Decentralized Operation Mode(SDOM)and Large Centralized Operation Mode(LCOM)scenarios using Cucurbita pepo and Cucumber in the Tianjin area of China as sample empirical products.Results indicate that nodes do not increase edges rapidly which reflects that even large firms in agricultural business cannot occupy markets fleetly.Furthermore,under the SDOM scenario the BI-MLW model exposes scale-free features with a small average degree value and low average clustering coefficient,while under the LCOM scenario,the model displays a rising average clustering coefficient and a lowered average path length.Both of which are consistent with the common view in literature and features of reality.Thus,the BI-MLW model specially designed for fresh agricultural products supply chain can improve the descriptive ability than conventional Erdös-Rényi(ER),Barabási-Albert(BA),Bianconi-Barabási(BB)network models.