Height Range Research Articles

A Swing Self‐Regulated Triboelectric Nanogenerator for High‐Entropy Ocean Breaking Waves Energy Harvesting

AbstractMultidirectional irregular breaking wave is the most prominent feature of the ocean surface and bears tremendous amounts of sustainable high‐entropy energy. However, the commercial utilization and harvesting efficiency are very limited low due to its low‐frequency and low‐amplitude. Here, a swing self‐regulated triboelectric nanogenerator (SSR‐TENG) is proposed, which can convert collected low‐grade breaking waves energy into electrical energy by regulating the oscillation frequency and resonance effect. Benefiting from simple and efficient structural strategy, SSR‐TENG outputs a peak power of 0.14 mW under wave height range of 6–11 cm, that the open‐circuit voltage, short‐circuit current and transferred charge increases is 5.8, 4, and 3.7 times compared to without self‐regulated design, respectively. This work gives a practical solution to the problems faced by harvesting high‐entropy ocean breaking waves energy, which exhibits large potential for building the self‐powered ocean assessment and meteorology system in the future.

Effect of Femtosecond Laser-Irradiated Titanium Plates on Enhanced Antibacterial Activity and Preservation of Bacteriophage Stability.

Titanium (Ti) is widely recognized for its exceptional properties and compatibility with medical applications. In our study, we successfully formed laser-induced periodic surface structures (LIPSS) on Ti plates with a periodicity of 520-740 nm and a height range of 150-250 nm. To investigate the morphology and chemical composition of these surfaces, we employed various techniques, including field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Additionally, we utilized a drop-shape analyzer to determine the wetting properties of the surfaces. To evaluate the antibacterial activity, we followed the ISO 22196:2011 standard, utilizing reference bacterial cultures of Gram-positive Staphylococcus aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922). The results revealed enhanced antibacterial properties against Staphylococcus aureus by more than 99% and Escherichia coli by more than 80% in comparison with non-irradiated Ti. Furthermore, we conducted experiments using the Escherichia coli bacteriophage T4 (ATCC 11303-B4) and the bacterial host Escherichia coli (ATCC 11303) to investigate the impact of Ti plates on the stability of the bacteriophage. Overall, our findings highlight the potential of LIPSS on Ti plates for achieving enhanced antibacterial activity against common bacterial strains while maintaining the stability of bacteriophages.

Preliminary quantification of the available solar power near the lunar South Pole

The lunar South Pole is an area of great interest for human bases and for the mining of water from the nearby permanently shadowed regions (PSRs) that remain below 110 K at all times. To provide power for these activities, only solar and nuclear fission are currently feasible options. Solar power is nearly continuously available from vertically deployed solar panels from some quite restricted high illumination regions (HIRs) close to the PSRs. One factor in determining the choice between solar and nuclear power sources is an assessment of the total solar power available. If solar power is found to be inadequate, even in a best-case scenario, for the demands of a base or, more challenging, of mining, then nuclear fission will become the only option. Local topography means that the amount of solar power available from the HIRs depends in a non-trivial way on the height of the solar panels deployed. Here we use average illumination maps for a range of heights above the local topography from 2 m to 20 m (for near-term deployment) and up to 2 km (for long-term consideration) to determine the total solar power that is potentially available from the HIRs as a function of time of lunar day. Overshadowing of highly illuminated areas by solar panels placed in sunward locations (at a given time of day) limits the total power to significantly smaller values than the highly illuminated area would suggest. The answers depend on the percentage illumination demanded by the application. We find that for near-term realizable vertical solar panels (up to 20 m), the upper limit to the time-averaged power available is ∼55–63 MW at >70% illumination, reducing to ∼6 MW at >90% illumination. This is sufficient to power thermal mining requirements at a rate of 1600–2450 tonnes/year of water. For the more distant future, for towers up to 2 km in height, a maximum time-averaged power of order 22,000 MW at >70% illumination could be realizable and ∼15,500 MW at 90% illumination. The variation in generated power with lunar time of day ranges from a factor of 1.1–∼3. These results suggest that sufficient solar power could be available for currently anticipated base or mining needs. Ensuring this power supply may require careful governance agreements.

A study of the capabilities for inferring atmospheric information from high-spatial-resolution simulations

In this work, we study the accuracy that can be achieved when inferring the atmospheric information from realistic numerical magneto-hydrodynamic simulations that reproduce the spatial resolution we will obtain with future observations made by the 4m class telescopes DKIST and EST. We first study multiple inversion configurations using the SIR code and the Fe I transitions at 630 nm until we obtain minor differences between the input and the inferred atmosphere in a wide range of heights. Also, we examine how the inversion accuracy depends on the noise level of the Stokes profiles. The results indicate that when the majority of the inverted pixels come from strongly magnetised areas, there are almost no restrictions in terms of the noise, obtaining good results for noise amplitudes up to 1 × 10−3 of Ic. At the same time, the situation is different for observations where the dominant magnetic structures are weak, and noise restraints are more demanding. Moreover, we find that the accuracy of the fits is almost the same as that obtained without noise when the noise levels are on the order of 1 × 10−4of Ic. We, therefore, advise aiming for noise values on the order of or lower than 5 × 10−4 of Ic if observers seek reliable interpretations of the results for the magnetic field vector reliably. We expect those noise levels to be achievable by next-generation 4m class telescopes thanks to an optimised polarisation calibration and the large collecting area of the primary mirror.

Anthropometric Study of Facial Index and its Clinical Implications among Medical Students in Devdaha Medical College and Research Institute, Rupandehi, Nepal

Background: The human facial contour has always been an interesting subject for anatomists, anthropologists, plastic surgeons and artists. The purpose of study was to create and evaluate data on face anthropometry. Methods: A descriptive cross-sectional study was conducted in 200 medical students studying at a ter­tiary care hospital during the period of 5th September 2022 to 5th February 2023 after ethical clearance from the institutional review committee (Ref. No: 194/079/080). Simple random sampling was done. Data were collected, entered in Statistical Package for Social Sciences version 20. Results: We observed that mean indices of the facial height was10.43± 0.84, facial width was 12.40±0.68,range of facial height was 9.31-13.01 and range of facial width was11.10-15.13 cm. Mesoprosopic face was predominant among female whereas leptoprosopic face type was more common among male population of the study. The most common face type was mesoprosopic and the uncommon was hyperleptoprosopic. The least common face among men was Europrosopic while among women was hyperleptoprosopic type. There was significant difference in the male and the female facial index. Conclusions: A higher index for all the parameters was seen among males than females. The data obtained may be useful in anthropological research, forensic, genetic research, as well as in medical clinical practice.

Heat transfer mechanism in vibrational turbulent Rayleigh–Bénard convection with rough plates

The joint effect of rectangular-type roughness and horizontal vibration on two-dimensional (2D) turbulent Rayleigh–Bénard convection (RBC) is investigated by using the thermal lattice Boltzmann method (LBM) in this article. The present work focuses on the Nusselt number and plume dynamics of the convection in the range of dimensionless vibration frequency 0 ≤ ω* ≤ 1000 and the range of dimensionless roughness height 0 ≤ h* ≤ 0.05. The Rayleigh number is 108 and Prandtl number is 4.38. Our numerical results indicate that the relationship between the Nusselt number and roughness height is mostly proportional, and the relationship between the Nusselt number and the vibration frequency is exponential. It is further found that heat transfer enhances by 3.06 times under the joint effect of horizontal vibration and rectangular roughness on turbulent RBC. It provides significant physical insight into the mechanism of cooperative heat transfer enhancement.

Experimental study on thermal characteristics of pure water flashing evaporation from thin-liquid film

An experimental investigation on thermodynamic phenomena of liquid film flash evaporation is presented. During experiments the pure waterfilm is flashed at an initial temperature range of 60–85 °C, an initial liquid film height range of 3–20 mm, and a superheat range of 2–22 K. The results show that the enthalpy difference is the dominant parameter for flashing phenomena and process. The static pressure distribution in the liquid film has an obvious impact on flashing evaporation process since the water static pressure can cause the change of saturation temperature. The liquid film height during the flash can be reached many times of the initial heightand it represents the intensity of the flashing. The flashing evaporation can be stepped more rapidly to the mild evaporation due to the lower water film. The NEF(non-equilibrium fraction) and the intensity of the flashing increased with the height of water film.

Profile-based diffuse reflectance corrections for improved optical property measurement of spherical fruit with spatial frequency domain imaging

Diffuse reflectance (Rd), demodulated from spatial frequency domain imaging (SFDI), is strongly influenced by the surface profile of target sample, and the optical properties (absorption coefficient μa and reduced scattering coefficient μ's) extracted from the Rd are prone to large estimation errors caused by curved surface of the fruit. This study proposes a profile-based Rd correction method, aiming to improve the accuracy of optical property measurement for spherical fruit, such as apples, as well as enhance fruit bruise detection through improved optical properties. Firstly, the surface height of the test object was obtained by performing the phase-measuring profilometry (PMP) in SFDI. Secondly, the object surface reflection angle was calculated using the proposed angle calculation method for spherical samples. The Modified Lambertian Correction (MLC) method was then refined to minimize the effect of the incident angle on the Rd correction. The performance of the Rd correction method was validated using standard reflector and Teflon spheres. The results showed that the average error of the PMP measurement with the height range of 0–50 mm was within 1 mm, the relative error of the corrected Rd was within 2 %, and the standard deviation of the Rd for the Teflon sphere was reduced by about 60 % after correction. Finally, the proposed Rd correction method was applied to measure the optical properties of four spherical fruit (‘Golden Delicious’, ‘Red Fuji’ apples, lemons, and oranges). The results revealed that the standard deviations of the measured μa and μ's of the spherical fruit were greatly reduced by about 70 % and 40 % after correction. The improved optical property mappings enhanced the early bruise detection of apples due to the fact that the optical property contrast between the non-bruised and bruised tissues were significantly increased.

Design of all-sky airglow imaging spectrometers in the middle and upper atmosphere

In order to detect the distribution of gravity waves in the middle and upper atmosphere, an all-sky airglow imaging spectrometer is designed to measure the airglow. It has the detection advantages of ultrawide field of view (FOV), large relative aperture and high signal-to-noise ratio (SNR). It can obtain the spectral images of OH (715–850 nm / 880–930 nm) and OI (630 nm) in the height range of 87–250 km. The whole design method of telecentric objective splicing relay zoom group is used to effectively suppress the spectral drift less than 0.2 nm, which meets the requirements of narrow bandwidth filters. The field experiments in northwest China show that the all-sky airglow imaging spectrometer can continuously acquire airglow spectral images with high SNR in both OH channel and OI channel without focusing in the temperature range of 0–45 ℃, and the images obtained in OH channel have obvious gravity wave phenomenon after star point removal and geometric correction.

Dynamics of coupled rotors in external fields

Coupled hindered rotor model is crucial for exploring the rotational dynamics of complex molecules under different external environments. When coupled hindered rotor molecules are subjected to the combined action of static electric and laser fields, their rotational dynamics get significantly modified, leading to interesting physics. In this study, we solve the time-independent Schrödinger equation for the coupled pair of rotors in the combined action of static electric and laser fields using the nine-point finite difference method and obtain rotational energy spectra and eigenvectors. We then use the partition function approach to understand thermal behaviour by studying thermal properties like heat capacity and entropy. We also explore the impact of temperature, coupling strength, and external fields strength parameters on these properties. The orientation of the coupled rotor is strongly dependent on the coupling strength between the coupled rotors as well as the hindrance. We analyse this directional parameter under a broad range of barrier height, coupling strength, and external fields strength parameters. Our analysis may provide insight into the rich and interesting physics, which may pave the way for future experimental and theoretical studies in this area.

New Insights from Imaging Spectroscopy of Solar Radio Emission

Newly available high-resolution imaging of solar radio emission at many closely spaced frequencies and times provides new physical insight into the processes, structure, and dynamics of the solar atmosphere. The observational advances have spurred renewed interest in topics dating from the early days of solar radio astronomy and have led to considerable advances in our knowledge. Highlights of recent advances include the following: ▪Quantitatively measuring the dynamic magnetic field strength, particle acceleration, and hot thermal plasma at the heart of solar flares and hinting at the processes that relate them.▪Resolving in space and time the energization and transport of electrons in a wide range of contexts.▪Mapping the magnetized thermal plasma structure of the solar chromosphere and corona over a substantial range of heights in active and quiet regions of the Sun. This review explains why solar radio imaging spectroscopy is so powerful, describes the body of recent results, and outlines the future work needed to fully realize its potential. The application of radio imaging spectroscopy to stars and planets is also briefly reviewed.

Tree Height and Crown Extraction From UAV-Based Multispectral Imagery

Conventional methods in measuring tree height and crown diameter are time consuming compared to the advanced technology of unmanned aerial vehicle (UAV) multispectral imagery. UAV multispectral imagery is widely used in vegetation analysis such as crop analysis, vegetation monitoring, precise farming and vegetation health assessment. Thus, the purpose of this research is to extract the individual tree height and crown diameter from UAV- based multispectral imagery using the integration of geospatial techniques. Altogether, the total of 395 individual trees were extracted from the study area of Section U11, Shah Alam using the Support Vector Machine (SVM) classifier. Tree height values were extracted from normalized digital surface model (nDSM) using the zonal statistics tool with the tree height range between 1.568m to 27.850m. The range for derived crown diameters is between 0.919m to 24.506m. The final map shows the distribution of tree height and tree crown extraction from the UAV-based multispectral imagery. The spatial distribution data of tree height and crown diameter are beneficial especially in landscaping and identifying the potential of tree hazard in the urban area.

Convoluted Magnetoresistance and Magnetic Reversal Processes in Ni–Fe Segmented Cylindrical Nanodots with Tunable Size and Composition for Technological Applications

AbstractDue to their unique properties, bi‐segmented systems are currently used in several technological applications such as sensing devices, high density magnetic data storage systems, spintronics and microelectromechanical components, among others. In this study, the magnetoresistance and magnetic properties of Ni–Fe bi‐segmented cylindrical nanodots in a broad range of diameters and heights are discussed. The power of the First Principles approach, as considered in the density functional theory formulation, is used to study the structural and magnetic relaxation effects, and atomistic simulations, through the Fast Monte Carlo methodology, are employed to explore the magnetoresistance and magnetic behaviors of these systems. By means of the magnetic hysteresis and magnetoresistance signals, convoluted magnetization reversal schemes are discussed. These effects take place depending on the size of the Ni and Fe components as a result of the interplay among exchange interactions and size and shape effects induced by dipolar interactions. Since size has become an experimental controllable parameter, due to the enriched phenomena, the effects discussed in these bi‐component systems are useful for the design and production of devices for technological applications with relevance beyond the observed in the more restricted single component systems.

The role of driver's eye height in the design of crest curves of roads

AbstractThe driver's eye height from the ground, as what drivers can see on the road, is essential for their safety and for avoiding road hazards. Using the statistical analysis of vehicles sample, the statistical parameters of the measured set of values were determined. A one-sample t-test was done to check whether the measured sample differs from the driver's eye height value specified in the Hungarian design guidelines. A new range of driver's eye height has been found, which is considered an update to the current value and might be applied in the upcoming road design. Parallel with the eye-height analysis, sight distances at vertical crest curves were modeled by AutoCAD Civil 3D. The minimum radiuses of the crest curves were defined for human eye height and for sensors of autonomous vehicles.

Simulation Analysis and Online Monitoring of Suspension Frame of Maglev Train

A maglev train is a new type of high-speed railway transportation. A high-temperature superconducting (HTS) maglev system is one of the typical representatives in the field of maglev trains. In order to research the levitation characteristics of an HTS maglev train, the force characteristics and operation performance of the train were researched. However, at present, there is still no research that simulates the real load situation of a running maglev train while analyzing the suspension frame. Regarding this issue, in this paper, the suspension frame is simulated and analyzed to simulate the real load situation of a maglev train. The results show that the suspension frame of an HTS maglev train can bear corresponding loads under different working conditions, and its strength and stiffness meet the requirements of use, safety, and reliability. Random irregularity in the permanent magnet track of an HTS maglev train route is inevitable, which will make the suspension frame produce a vibration response under different running speeds of the train. Vibration of the suspension frame of the train is inevitable. For the electromagnetic levitation (EMS) train, researchers considered monitoring the train status. However, at present, there is no suspension frame condition monitoring device for an HTS maglev train. In addition, the levitation height of the suspension frame affects the suspension performance and traction performance of the vehicle, and the vibration of the suspension frame during running affects the dynamic performance and safety of the suspension frame and the vehicle. Regarding the issue above, through a suspension frame monitoring system, the lateral and vertical vibration acceleration and levitation height of the suspension frame are monitored at different train speeds. The maximum value of vibration acceleration and the fluctuation range of levitation height are within the safe range. It is verified that the simulation analysis of the suspension frame of an HTS maglev train is correct, the suspension frame is safe, and the train can run safely.

A high-precision multi-dimensional microspectroscopic technique for morphological and properties analysis of cancer cell

Raman and Brillouin scattering are sensitive approaches to detect chemical composition and mechanical elasticity pathology of cells in cancer development and their medical treatment researches. The application is, however, suffering from the lack of ability to synchronously acquire the scattering signals following three-dimensional (3D) cell morphology with reasonable spatial resolution and signal-to-noise ratio. Herein, we propose a divided-aperture laser differential confocal 3D Geometry-Raman-Brillouin microscopic detection technology, by which reflection, Raman, and Brillouin scattering signals are simultaneously in situ collected in real time with an axial focusing accuracy up to 1 nm, in the height range of 200 μm. The divided aperture improves the anti-noise capability of the system, and the noise influence depth of Raman detection reduces by 35.4%, and the Brillouin extinction ratio increases by 22 dB. A high-precision multichannel microspectroscopic system containing these functions is developed, which is utilized to study gastric cancer tissue. As a result, a 25% reduction of collagen concentration, 42% increase of DNA substances, 17% and 9% decrease in viscosity and elasticity are finely resolved from the 3D mappings. These findings indicate that our system can be a powerful tool to study cancer development new therapies at the sub-cell level.

Progress in investigating long-term trends in the mesosphere, thermosphere, and ionosphere

Abstract. This article reviews main progress in investigations of long-term trends in the mesosphere, thermosphere, and ionosphere over the period 2018–2022. Overall this progress may be considered significant. The research was most active in the area of trends in the mesosphere and lower thermosphere (MLT). Contradictions on CO2 concentration trends in the MLT region have been solved; in the mesosphere trends do not differ statistically from trends near the surface. The results of temperature trends in the MLT region are generally consistent with older results but are developed and detailed further. Trends in temperatures might significantly vary with local time and height in the whole height range of 30–110 km. Observational data indicate different wind trends in the MLT region up to the sign of the trend in different geographic regions, which is supported by model simulations. Changes in semidiurnal tide were found to differ according to altitude and latitude. Water vapor concentration was found to be the main driver of positive trends in brightness and occurrence frequency of noctilucent clouds (NLCs), whereas cooling through mesospheric shrinking is responsible for a slight decrease in NLC heights. The research activity in the thermosphere was substantially lower. The negative trend of thermospheric density continues without any evidence of a clear dependence on solar activity, which results in an increasing concentration of dangerous space debris. Significant progress was reached in long-term trends in the E-region ionosphere, namely in foE (critical frequency of E region, corresponding to its maximum electron density). These trends were found to depend principally on local time up to their sign; this dependence is strong at European high midlatitudes but much less pronounced at European low midlatitudes. In the ionospheric F2 region very long data series (starting at 1947) of foF2 (critical frequency of F2 region, corresponding to the maximum electron density in the ionosphere) revealed very weak but statistically significant negative trends. First results of long-term trends were reported for the topside ionosphere electron densities (near 840 km), the equatorial plasma bubbles, and the polar mesospheric summer echoes. The most important driver of trends in the upper atmosphere is the increasing concentration of CO2, but other drivers also play a role. The most studied one was the effect of the secular change in the Earth's magnetic field. The results of extensive modeling reveal the dominance of secular magnetic change in trends in foF2 and its height (hmF2), total electron content, and electron temperature in the sector of about 50∘ S–20∘ N, 60∘ W–20∘ E. However, its effect is locally both positive and negative, so in the global average this effect is negligible. The first global simulation with WACCM-X (Whole Atmosphere Community Climate Model eXtended) for changes in temperature excited by anthropogenic trace gases simultaneously from the surface to the base of the exosphere provides results generally consistent with observational patterns of trends. Simulation of ionospheric trends over the whole Holocene (9455 BCE–2015) was reported for the first time. Various problems of long-term-trend calculations are also discussed. There are still various challenges in the further development of our understanding of long-term trends in the upper atmosphere. The key problem is the long-term trends in dynamics, particularly in activity of atmospheric waves, which affect all layers of the upper atmosphere. At present we only know that these trends might be regionally different, even opposite.

Risk factors associated with football injury among male players from a specific academy in Ghana: a pilot study

There seems to be no information on the incidence of injury and associated risk factors for academy football players in Ghana. We determine the risk factors associated with match and training injuries among male football players at an academy in Ghana. Preseason measurements of players’ height, weight, and ankle dorsiflexion (DF) range of motion (ROM) were measured with a stadiometer (Seca 213), a digital weighing scale (Omron HN-289), and tape measure, respectively. The functional ankle instability (FAI) of players was measured using the Cumberland Ankle Instability Tool (CAIT), and dynamic postural control was measured with the Star Excursion Balance Test. Injury surveillance data for all injuries were collected by resident physiotherapists throughout one season. Selected factors associated with injury incidence were tested using Spearman’s rank correlation at a 5% significance level. Age was negatively associated with overall injury incidence (r = − 0.589, p = 0.000), match (r = − 0.294, p = 0.008), and training incidence (r = − 0.314, p = 0.005). Previous injury of U18s was associated with training injuries (r = 0.436, p = 0.023). Body mass index (BMI) was negatively associated with overall injury incidence (r = − 0.513, p = 0.000), and training incidence (r = − 0.395, p = 0.000). CAIT scores were associated with overall injury incidence (n = 0.263, p = 0.019) and match incidence (r = 0.263, p = 0.029). The goalkeeper position was associated with match incidence (r = 0.241, p = 0.031) while the U16 attacker position was associated with training incidence. Exposure hours was negatively associated with overall injury incidence (r = − 0.599, p = 0.000). Age, BMI, previous injury, goalkeeper and attacker positions, ankle DF ROM, and self-reported FAI were associated with injury incidence among academy football players in Ghana.

Оптимизация конструктивных параметров рекуперативного сцепного устройства, установленного в лесовозном автомобиле с прицепом

This article solves the problem of increasing the efficiency of the functioning of logging road trains in conditions of insufficiently equipped logging roads. Experience in the operation of road trains on such logging roads shows that on these roads the transport and operational qualities of logging road trains are low. The relevance of the scientific direction, aimed at achieving the fuel efficiency of logging road trains and thus increasing the efficiency and competitiveness of logging enterprises, is substantiated. An analysis of the work of foreign scientists is presented, which made it possible to identify significant factors that largely determine the efficiency of the process of hauling timber by timber road trains. A promising design of the coupling device is proposed, which allows converting and usefully using the kinetic energy of the mass of the trailer with timber, which occurs during the movement of a road train along insufficiently equipped logging roads in unsteady and transient traffic modes. The study was based on mathematical and simulation modeling, numerical methods, as well as modern methods for obtaining and processing information with computer support. A mathematical model and a computer program for the movement of a timber road train under changing road conditions have been developed. Computer simulation made it possible to carry out a preliminary assessment of the performance of the proposed pneumohydraulic coupling device with recuperative and damper mechanisms by identifying and analyzing dependencies characterizing the change in the studied performance indicators on the driving conditions of the road train and the design parameters of the device. It has been established that the coupling device during the movement of a logging road train in difficult road conditions at a speed of 30 km/h makes it possible to recuperate up to 7 kW, while the value of the longitudinal acceleration of the trailer link relative to the logging vehicle does not exceed 0.83 m/s2. It is determined that the value of the optimal diameter of the recuperative hydraulic cylinder is 80 ... 100 mm, and the optimal piston stroke is 83 ... 100 mm. In this case, the average power recuperated by the device will be at least 7 kW, and the average longitudinal acceleration of the trailer will be no more than 0.8 m/s2. It was found that the developed recuperation system remains effective in a wide range of roughness heights of 0.2 ... 0.4 m, providing a recuperated power of 2.3 ... 19.7 kW, respectively, with an acceptable average longitudinal acceleration of 0.3 ... 2.2 m/s2. The results obtained will be used as recommendations for designers to refine the proposed coupling device at the design stage.

Photonic THz InISAR for 3D Positioning With High Resolution

Terahertz (THz) radar has been considered as a new solution to the dilemmas in performing ultra-high-resolution imaging and obtaining highly precise target information. In this work, a photonic THz interference inverse synthetic aperture radar (THz InISAR) scheme is proposed and proof-of-concept experimentally demonstrated, targeting high resolution positioning of multiple targets. We employ an optical frequency comb and a uni-traveling carrier photodiode (UTC-PD) to photonically generate a linear frequency-modulation (LFM) signal at 290-310 GHz. By using the anti-electromagnetic-interference THz photonic signal source, broadband THz transceivers and efficient InISAR algorithms, 3D positioning of corner reflectors over a distance of 2.2 m at the 300 GHz band is successfully achieved, reaching a resolution of 8 mm for both range and azimuth dimensions, and a maximum height error of 0.4 mm in a height range of 11 cm. To the best of our knowledge, our proposed system represents the ever-first accurate 3D positioning at the THz band above 300 GHz, revealing the great potential applications of THz radar systems.