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1–Naphthaleneacetic acid (NAA), having high-quality biological activity and great yield-increasing potential in agricultural production, is a broad-spectrum plant growth regulator. Although NAA is of low toxicity, it can affect the balance of the human metabolism and damage the body if it is used in high quantity for a long time. In this study, the interaction of NAA with calf thymus DNA (ctDNA) was investigated under simulated human physiological acidity (pH 7.4) using fluorescence, ultraviolet-visible absorption, and circular dichroism spectroscopy combined with viscosity measurements and molecular simulation techniques. The quenching of the endogenous fluorescence of NAA by ctDNA, observed in the fluorescence spectrum experiment, was a mixed quenching process that mainly resulted from the formation of the NAA–ctDNA complex. NAA mainly interacted with ctDNA through hydrophobic interaction, and the binding constant and quenching constant at room temperature (298 K) were 0.60 × 105 L mol−1 and 1.58 × 104 L mol−1, respectively. Moreover, the intercalation mode between NAA and ctDNA was verified in the analysis of melting point, KI measurements, and the viscosity of ctDNA. The results were confirmed by molecular simulation, and it showed that NAA was enriched near the C–G base of ctDNA. As shown in circular dichroism spectra, the positive peak intensity of ctDNA intensified along with a certain degree of redshift, while the negative peak intensity decreased after binding with NAA, suggesting that the binding of NAA induced the transformation of the secondary structure of ctDNA from B-form to A-form. These researches will help to understand the hazards of NAA to the human body more comprehensively and concretely, to better guide the use of NAA in industry and agriculture.

To achieve the intelligent, scientific management of the family pot, we design a remote intelligent watering system based on Internet of things. Firstly, the collection system of potted environment information is constructed by using soil moisture sensor and air temperature and humidity sensor. Secondly, based on STM32 microcontroller, ESP8266WIFI module and Internet of things technology, the potted information and watering command transmission system is realized. Finally, the web page of the system is developed by using JavaWeb technology and Mina communication framework to achieve the fundamental purpose of real-time display of potted environment information and remote intelligent watering. Tests show that the remote intelligent watering system works stably and has strong practicability, which ensures the healthy growth of family green plants.

An optic fiber refractive index (RI) sensor based on SMF-MMF-TMCF-SMF (SMTmS) structure is proposed. The MMF segment is introduced and confirmed theoretically and experimentally to act as an efficient optical coupler to launch the light from the center core to the cladding. Experimental results demonstrate that SMTmS is highly sensitive (1435.76 nm/RIU) to low surrounding RI in the range of 1.3330–1.3451. The temperature sensing has been implemented and the total wavelength shift of only 1.83 nm is achieved for the range of 30 °C–100 °C, implying a relatively low temperature cross-sensitivity of 2.01 × 10−5 RIU/°C. The developed sensor with high RI sensitivity and low temperature cross-sensitivity could be rather suitable and applicable in the fields of seawater sensing and environmental monitoring.

In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heights respectively. The study showed that water waves propagating over silty seabed can induce significant change of pore water pressure, and the amplitude of pore pressure depends on depth of buried soil layer, clay content and wave height, which are considered as the three influencing factors for pore water pressure change. The pressure will attenuate according to exponential law with increase of soil layer buried depth, and the attenuation being more rapid in those soil layers with higher clay content and greater wave height. The pore pressure in silty seabed increases rapidly in the initial stage of wave action, then decreases gradually to a stable value, depending on the depth of buried soil layer, clay content and wave height. The peak value of pore pressure will increase if clay content or depth of buried soil layer decreases, or wave height increases. The analysis indicated that these soils with 5% clay content and waves with higher wave height produce instability in bed easier, and that the wave energy is mostly dissipated near the surface of soils and 5% clay content in soils can prevent pore pressure from dissipating immediately.

Parking space monitoring algorithm serves to constantly and correctly update parking information which is vulnerable to the influences of shadows of surrounding objects and weather conditions through image processing. By analyzing and comparing various parking space detection algorithms, this paper selects the most suitable algorithm to achieve parking space detection in Nios II soft core embedded in FPGA. The algorithm can accurately and quickly reflect the change of state of parking spaces and can ensure real-time processing. After detection of parking spaces, real time status of parking spaces and parking guidance information will be displayed via VGA.