A Review of Research on Agroecosystem Services Based on Bibliometric Analysis

Agricultural ecosystem is one of the most important ecosystems in the world, which provides multiple ecosystem services such as grain production, climate regulation, water conservation and biodiversity. The degradation of ecosystem services has become an important factor that severely restricts the sustainable development of agriculture. Agroecosystem services have become the core and hot topic of ecological research. In recent years, countries and related institutions have been increasing their research on agricultural ecosystem service. Based on Web of Science(WoS) and China Knowledge Resource Integrated (CNKI) databases, the development characteristics and trends of agroecosystem services research were analyzed by bibliometric methods. The results show that: (1) The number of papers on agroecosystem services is increasing, which shows that the research on it is developing. (2) Developed countries are the main research forces in the field of ecosystem services, and the developed countries in Europe and the United States occupy the absolute leading position; China Agricultural University and the University of California in the United States are the main research institutions. (3) At present, eight research hotspots in this field are the study of ecosystem services mechanism, protection management and sustainability, sustainable development, biodiversity, land use and landscape change, value assessment, climate change, sustainable development of agriculture, ecological compensation. From the overall distribution of research hotspots in each period, the international research focuses more on the interdependence between ecosystem services and ecosystem services and human well-being, while the research in China focuses more on ecosystem services assessment. (4) In recent years, there is a big gap between China and foreign countries in the field of ecosystem services research. It is necessary to strengthen cooperation with research institutions in developed countries in Europe and the United States, and further improve the research content, research vision and research method

Sensor assembly, method, and device for monitoring shear force and pressure on a structure

Shear force and pressure on a structure are simultaneously monitored using signals received from sensors with antennas on the structure. For example, sensors and systems for monitoring shear force and pressure have applications including ulcer prevention associated with structures including shoes, prosthetics, wheel-chairs, and beds of bed-bound patients.Board of Regents, University of Texas Syste

Passive wireless antenna sensor for strain, temperature, crack and fatigue measurement

An apparatus and method is provided for monitoring a condition of a structure using a passive wireless antenna sensor having a known resonant frequency when mounted on the structure. A series of radio frequency signals are transmitted with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor. The passive wireless antenna sensor includes a dielectric substrate disposed between an antenna pattern and a ground plane such that a change in the condition of the structure will cause a change in one or more characteristics of the passive wireless sensor. A signal is received from the passive wireless antenna sensor and a resonant frequency of the passive wireless antenna sensor is determined based on the received signal. The determined resonant frequency is then compared to the known resonant frequency, whereby a change in the resonant frequency indicates a change in the condition of the structure.Board of Regents, University of Texas Syste

Structural characterization of the Fddd phase in a diblock copolymer thin film by electron microtomography

A 3-dimensional Fddd network structure of a polystyrene-block-polyisoprene (PS-b-PI) diblock copolymer (M(n) = 31 500, f(PI) = 0.645) was observed for the first time in real space by transmission electron microtomography (TEMT). In a 650 nm thick film of the PS-b-PI thin film on a silicon wafer, the Fddd phase was developed after annealing at 215 degrees C for 24 h. The single network structure consists of the connected tripodal units of minor PS block domains. The {111}(Fddd) plane, the densest plane of the minor PS phase, was found to orient parallel to the film plane. The transitional structure from the wetting layer at the free surface to the internal {111}(Fddd) plane via a perforated layer structure was also observed.X111313sciescopu

Research on the Artillery Shell Motion Parameters Automatic Detection Technology Based on Image Processing

AbstractTo realize automatic test of the shell motion parameters in the artillery experiment, the digital high-speed camera is used to gather the shell motion images. By applying digital image processing technique the characteristic images of shell are extracted accurately. Combined with the measuring principle of the shell motion parameters, a image test system is designed and realized automatic test of the shell motion parameters. The test results of shell motion images indicated that, the image extraction algorithm presented in this paper is easy to use and universal, and the precision of data measurement is increased. At present, the image test system has been applied in the data analysis in the artillery experiment and obtained good performance