Publications by authors named "Zefeng Sun"

The imaging quality of a rotational reflection high-speed tracking system is greatly affected by the optical characteristics of the reflector and the depth of field limitations of the imaging system, especially for tracking systems working in small distances. In order to improve the imaging quality, this paper focused on two factors that affect the imaging quality: double vision caused by the optical characteristics of reflectors and blurring caused by the depth of field of imaging systems. This paper quantified the impact of these two factors on imaging through theoretical analysis, proposed a method of changing the hardware position, and conducted a simulation and experiments.

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High-speed tracking technology has wide applications in the military and aerospace industry. However, existing approaches, such as camera arrays or Doppler radar systems, suffer from high cost and inconvenience. This paper reports a high-speed target tracking control system based on short-time rotational reflection imaging, specifically aimed at overcoming certain limitations.

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To investigate the potential of H2-calponin (CNN2) as a serum biomarker for hepatocellular carcinoma (HCC), this study employed the serological analysis of recombinantly expressed cDNA clone (SEREX) technique to identify the presence of CNN2 antibody in the serum of patients with HCC and other tumors. The CNN2 protein was produced through genetic engineering and used as an antigen to determine the positive rate of serum CNN2 autoantibodies via indirect enzyme-linked immunosorbent assay (ELISA). In addition, the mRNA and protein expressions of CNN2 in cells and tissues were evaluated using RT-PCR, in situ RT-PCR, and immunohistochemistry methods.

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The parameter calibration of a digital fringe projection profilometry (DFPP) system is a fundamental step and directly related to 3D measurement accuracy. However, existing solutions based on geometric calibration (GC) suffer from the weakness of limited operability and practicality. In this Letter, a novel, to the best of our knowledge, dual-sight fusion target is designed for flexible calibration.

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Motivated by the increasing demands on the precision of 3D large-scale measurement, the extrinsic parameters calibration with high accuracy of the bistatic non-orthogonal shafting laser theodolite (N-theodolite) system is required. A two-step method is proposed to achieve the extrinsic parameters calibration with high accuracy in this paper. In the first step, by analyzing and setting the approximate emitted point during the motion of the laser axis in local space, the calculation of the initial extrinsic parameters can be simplified.

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Compared to a conventional fixed focus lens, a zoom lens is more flexible and adaptable. However, the challenges involved in precise calibration for a zoom camera prevent its widespread use in close-range photogrammetry. A practical calibration method for a zoom camera is proposed.

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Tumor hypoxia and systemic toxicity seriously affect the efficacy of photodynamic therapy (PDT) and are considered as the "Achilles' heel" of PDT. Herein, to combat such limitations, an intelligent orthogonal emissions LDNP@SiO -CaO and folic acid-polyethylene glycol-Ce6 nanodrug is rationally designed and fabricated not only for relieving the hypoxic tumor microenvironment (TME) to enhance PDT efficacy, but also for determining the optimal triggering time through second near-infrared (NIR-II) fluorescence imaging. The designed nanodrug continuously releases a large amount of O , H O , and Ca ions when exposed to the acidic TME.

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Low temperature during the vegetative stage depresses rice tillering. Zinc (Zn) can promote rice tiller growth and improve plant resistance to abiotic stress. Consequently, Zn application after low temperature might be an effective approach to promote rice tiller recovery.

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The nonorthogonal shaft laser theodolite (N-theodolite) measurement system is a new kind of instrument that can be applied to large-scale metrology. Different from traditional theodolites, the three axes of the N-theodolite have no requirements on the orthogonality and intersection. For the measurement in laser scale, the parameters of the system on a large scale must be known.

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A laser beam used as a visualizing measuring axis is an important technique in 3D shape measurement. A highly accurate calibration method of a laser beam based on discrete point interpolation is proposed in this paper. A flexible control field constructed by a laser tracker, a theodolite and a target plane with 5 high-precision machining holes is presented.

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