Lifeng Fan

• Ph.D
• China Agricultural University

Research in plant electrophysiology has been developed for more than 100 years. However, even today, there are still many researchers may be puzzled by the results of different amplitude waveforms when recording plant potential signals. It is necessary to make a discussion of plant electrical potential recording method. In this paper, the history o...

The root zone of a plant is an important system that provides a base for use of nutrients and water and has been the focus of many researchers’ work. This paper examines a new electrical impedance spectroscopy (EIS) measurement approach within the 100 Hz–2 MHz range in the substrate root zone that uses an adjacent stimulation and measurement patter...

A highly reproducible plant electrical signal–light-induced bioelectrogenesis (LIB) was obtained by means of periodic illumination/darkness stimulation of broad bean (Vicia faba L.) leaves. By stimulating the same position of the same leaf with different concentrations of NaCl, we observed that the amplitude and waveform of the LIB was correlated w...

Kernel moisture content is an important factor in mechanized corn harvesting. However, rapid and nondestructive in situ detection of the kernel moisture content within an intact corn ear in the field remains challenging. In this work, we designed a novel handheld device with a double-ring sensing probe for nondestructive and convenient kernel moist...

The moisture content of intact pork meat was determined employing near-infrared non-destructive reflectance spectroscopy. The effects of various factors, namely the shape of the probe, the contact between the probe and sample and the modelling method, were also evaluated. Wavelengths in the range from 600 to 1100 nm, two spectra collection methods...

We present a novel, to the best of our knowledge, frequency shift mechanism in the optically detected atomic clock. This frequency shift is analogous to the light shift that is associated with a detecting light power. However, this shift arises from the inhomogeneity of the magnetic field (C-field) and the detecting light intensity. We call this sh...

The optically detected magnetic-state-selected cesium beam clock is a new type of compact cesium clock developed by Peking University. The principle and performance of our clock are introduced in the article as well as our recent researches on beam optics, signal-to-noise ratio, spectrum linewidth and light shift.

Electrical impedance tomography can reconstruct the complex conductivity distribution by injecting a current or voltage at a specific frequency into the target domain. The complex conductivity spectroscopy of numerous biological tissues is frequency-dependent. A suitable excitation frequency is vital to high-quality imaging over a wide frequency ra...

The RLCG parameters model and one‐port measurement model of the closed‐double ring electrodes have been established to obtain the dielectric properties of two‐layer medium in radio frequency. The accuracy of these models was verified by electromagnetic simulation experiments and the permittivity measurement experiments under 160 MHz. Results showed...

Electrical impedance tomography (EIT) has been used by researchers across several areas because of its low-cost and no-radiation properties. Researchers use complex conductivity in bioimpedance experiments to evaluate changes in various indicators within the image target. The diverse volumes and edges of biological tissues and the large impedance r...

We perform a new scheme of magnetic state selection in optically detected compact cesium beam clocks. Unlike the conventional method, we select atoms in the ground state | F = 4, m F ≠ −4⟩ by pointing the atomic collimator to the convex pole of the magnet realizing the two-wire magnetic field and detect atoms in | F = 3⟩ after interacting with the...

The moisture distribution in maize ears during the growth period has a major impact on crop quality and post-harvest production costs and is an important indicator for plant breeding. An electrical impedance tomography system with a resilient electrode array was designed to fit around a maize ear, and featured an adjustable diameter that can be ada...

Among all kinds of compact cesium beam clocks, the optically detected magnetic-state-selected cesium beam clock (OMCC) combines the advantages of the magnetic state selecting scheme and fluorescence detecting method. This paper presents an overview of the OMCC. Technical issues, noise sources, frequency shifts and improvements of OMCC are reviewed....

To improve the spatial resolution for mapping of small-scale cylindrical plant root zones using electrical impedance tomography, this paper presents a novel sensor structure, where a ring of 16 external electrodes and an inner ring of 8 internal electrodes are included in an electrode layer. To assess the ability of the structure in the electrode p...

Electrical imaging studies of laboratory- and small-scale plant root zones are gaining increasing attention. However, for essential moisture–conductivity calibrations on numerous substrate columns with variability in dry density, the use of one conventional strategy is relatively laborious or complicated. Thus, in this work, a relatively convenient...

Soil water potential is a key variable that determines water flow and indicates water availability and content. Although diverse techniques and methods have been developed for water potential measurement in unfrozen soils, most commercial techniques such as dielectric soil water potential (DSWP) sensors are not applicable for frozen soils due to po...

Plant electrical signals, an early event in the plant–stimulus interaction, rapidly transmit information generated by the stimulus to other organs, and even the whole plant, to promote the corresponding response and trigger a regulatory cascade. In recent years, many promising state-of-the-art technologies applicable to study plant electrophysiolog...

Corn kernel moisture content is the most frequently used indicator for kernel maturity prediction and determination of the appropriate mechanized harvesting time. Corn varieties with lower moisture contents and thus faster dehydration of the corn kernels after physiological maturity are suitable for high plant density and mechanized harvesting. How...

An accurate forecast of daily meteorological factors throughout the year is not only of great significance for the study of climate trends in a certain area but also enables the prediction of crop growth stages. Moreover, the prediction of crop growth stages is related to the scheduling of planting and tillage, the determination of machine harvest...

Imaging of the root zone of a plant is extremely important for studies of the root growth and development, root moisture and nutrient absorption, and water and nutrient transport in the root zone. Many noninvasive methods have been proposed for mapping, characterization or monitoring of the generally invisible and complex root zone. Benefiting sign...

Unlike animals, few vascular plants are known to spontaneously generate rhythmic electrical signals. In plants electrical signals triggered in response to external environmental changes are of physiological significance. However, plant electrical signals require experimental skill to measure, are stimulus-pattern dependent, and show poor quantitati...

Simultaneous detection of both ion flux and membrane potential in vivo and in situ in plants is a challenging research task. To explore the mechanisms of plant electrical activity, researchers urgently need to understand and determine the types of ions and the ion fluxes that pass in and out of cells during polarization and repolarization, but the...

Robot navigation in the environment with obstacles is still a challenging problem. In this paper, the navigation problems with wheeled mobile robots (WMRs) are reviewed, the navigation mechanism of WMRs is analyzed in detail, the methods of solving the sub problems such as mapping, localization and path planning which all both related to robot navi...

Many physiology and bioinformatics research institutions and websites have opened their own data analysis services and other related Web services. It is therefore very important to be able to quickly and effectively select and extract features from the Web service pages to learn about and use these services. This facilitates the automatic discovery...

Moisture content is an important meat quality trait. The fast and low-cost detection for the moisture content of meat or meat products is continuously concerned by researchers. At radio frequencies, the dielectric properties of meat are strongly affected by its moisture content. Therefore, we proposed a fast detection method for moisture content of...

To estimate crop water requirement state accurately, a remote system was built. It makes irrigation decision based on various information when water deficit stress occurs. To meet demand of remote monitoring and automatic control, the system adopted master-slave structure, implemented remote view and control. It integrated crop physiological state...

Moisture content is an important factor in corn breeding and cultivation. A corn breed with low moisture at harvest is beneficial for mechanical operations, reduces drying and storage costs after harvesting and, thus, reduces energy consumption. Nondestructive measurement of kernel moisture in an intact corn ear allows us to select corn varieties w...

Moisture content of corn directly affects its quality and storage time, and the rapid on-line detection of the moisture content of corn ears not threshed or in vivo in the fields is required. Because of the special shape of corn ear, the rapid, low cost and non-destructive bioelectrical impedance measurement is more suitable for its moisture conten...

The existing researches focused on using the commercial full wavelength spectrometer to determine the quality parameters of meat by detecting the meat emulsion, which were difficult to achieve online and non-destructive detection of the moisture content of intact meat. Moreover, the accuracy of pieces moisture detection is low, and people did not c...

The pulling of the glass microelectrode is a necessary technology in the electrophysiological measurement techniques. In order to better meet the requirements of electrophysiological experiments, we designed a multi-functional microelectrode puller, and gave the design of functional modules, and discussed its controlling effect. In this paper, we a...