Shadow Effect Research Articles

Global Least Squares Algorithm for 3D Elemental Surface Topography Reconstruction Using Quad-Segment Detector in X-ray Spectrometry

Abstract 2D elemental imaging techniques such as micro-X-ray fluorescence (micro-XRF) and micro-particle-induced X-ray emission (micro-PIXE) play a critical role in elemental mapping across diverse fields such as biology, geology, materials science, and engineering. However, surface irregularities often introduce shadow effects, hindering accurate spectrometric analysis. Knowing the topography information is essential for addressing this issue. Here, we propose integrating a global least squares algorithm for reconstructing the 3D surface topography in micro-PIXE analysis which is applicable in other similar techniques based on X-ray microscopy. This algorithm utilizes two independent gradient components, distorted by noise, to calculate the gradient vector from X-ray data acquired by an annular quad-segment spectrometer. We demonstrate the capability of this approach on a real homogeneous sample, yielding 3D elemental surface topography. This noniterative code provides surface reconstructions which in turn could find application to enhance the correction of spatial elemental distributions across heterogeneous sample types.

Software Complex for Documenting Graphical Applications Based on Topological Decomposition

Contemporary software products and services necessitate extensive accompanying information, including user manuals and documentation. The task becomes more complex in the case of graphical applications, as it requires capturing screenshots and highlighting the described elements. Attaining high-quality visual information using conventional means demands considerable effort and time, since, unlike text, raster images do not provide an interface for retrieving metadata about individual elements, necessitating programmatic extraction of such information. This study presents a software complex designed to automate and expedite this process. The primary focus is on a topo­logical decomposition method that segments images based on topological features such as pixel brightness and proximity, enabling the segmentation of screenshots into control elements. This approach demonstrates high accuracy (96-99 %) in identifying graphical components across most tested images. The software product encompasses functions for the automatic capture of application windows, an algorithm for identifying control elements, and the capability to export the entire image or a specified region. Additionally, an algorithm for generating output templates for image insertion has been implemented. The decomposition method has exhibited effectiveness across the majority of test data. In instances with shadow effects, noise levels were recorded at a maximum of 34 %; however, in most cases, this figure did not exceed 3 %. Further research may contribute to enhancing these results. The findings of this study could prove valuable for the continued exploration of graphical user interface decomposition and the assessment of the method's effectiveness on diverse images. The developed software complex significantly simplifies and accelerates the documentation process, thereby opening new avenues in the automation of software development.

Is AI image generation a creative or optimize tool in product design process?—The usage of AI image generation tools for vehicle shape as an example

This study explores the shape thinking processes and decision-making factors of designers when using AI image generation tools for conceptualizing the shapes of two-wheeled vehicles through four design tasks. Eight designers were invited to create hand-drawn sketches based on a specific aesthetic direction (technological geometry), followed by a shape divergence exercise using two AI graphics tools, Stable Diffusion and Vizcom, to generate images from text prompts. After selecting the designs closest to their original concepts and their favorite designs, the designers used an iPad to explore different shape directions (technological biology) for partial shape modifications. Finally, retrospective interviews were conducted to understand whether there were differences in designers’ thinking process regarding the use of various AI tools for shape conceptualization, as well as their focal points regarding design modification and shape thinking at different stages of the process. The research findings indicate that current AI tools are more suitable for shape divergence. If designers wish to achieve shape convergence, they need to be more familiar with the various settings of AI image generation tools and understand which prompts significantly influence specific shape characteristics. Designers’ perceptions of shape modification primarily revolve around: 1. Outline contours, 2. Parting lines, 3. Variations in surface curvature, and 4. The resulting features (light and shadow effects). Furthermore, it is recommended that future AI image generation tools, if developed as professional assistive tools for product design, should provide two modes—shape divergence and convergence—focusing on both the main shape and details. Additionally, it is suggested that developing AI-3D technologies should address the four key aspects of shape manipulation presented in this study, offering adjustments for overall appearance and detailing the contour lines of parts, including the manipulation of surface curvature and shape positioning.

Optimized Airborne Millimeter-Wave InSAR for Complex Mountain Terrain Mapping.

The efficient acquisition and processing of large-scale terrain data has always been a focal point in the field of photogrammetry. Particularly in complex mountainous regions characterized by clouds, terrain, and airspace environments, the window for data collection is extremely limited. This paper investigates the use of airborne millimeter-wave InSAR systems for efficient terrain mapping under such challenging conditions. The system's potential for technical application is significant due to its minimal influence from cloud cover and its ability to acquire data in all-weather and all-day conditions. Focusing on the key factors in airborne InSAR data acquisition, this study explores advanced route planning and ground control measurement techniques. Leveraging radar observation geometry and global SRTM DEM data, we simulate layover and shadow effects to formulate an optimal flight path design. Additionally, the study examines methods to reduce synchronous ground control points in mountainous areas, thereby enhancing the rapid acquisition of terrain data. The results demonstrate that this approach not only significantly reduces field work and aviation costs but also ensures the accuracy of the mountain surface data generated by airborne millimeter-wave InSAR, offering substantial practical application value by reducing field work and aviation costs while maintaining data accuracy.

Catalytic Infrared Promoted the Decontamination of Intense Pulsed Light on Green Sichuan Pepper (Zanthoxylum schinifolium)

ABSTRACTIntense pulsed light (IPL) is an efficient sterilization technology for instantaneous intense UV predominantly, while the decontamination was weakened on green Sichuan pepper (GSP) for “shadow effect.” Catalytic infrared (CIR) has excellent decontamination on uneven surfaces for long‐wave diffraction while was prone to cause flavor decline for “thermal effect.” In this study, a combined method of CIR and IPL was attempted to settle the dispute of decontamination effect and flavor decline on GSP. The inactivation kinetics on the change of bacterial enumeration over sterilization time were determined, and the results showed the sterilization effect of IPL on GSP could be improved significantly after CIR pretreatment, which was promoted from 0.65 ± 0.07 to 2.62 ± 0.07 Lg (p < 0.05), and could realize the active bacteria on commercial GSP was below 100 CFU g−1. Moreover, the flavor of GSP was measured on color and aroma changes, volatile oil content, and total alkaloid content, and the antioxidant function was measured on total reducing power, ABTS+•, and •OH− clearance rates. The results showed CIR could give rise to color change and volatile oil decrease of GSP, which indicated that the treatment time of CIR should be restricted in 5 min based on relevant Chinese national standard. CIR and IPL showed a difference to several oxygen free radicals, and the impact could be weakened by a combined method. In conclusion, under the same sterilization rate, CIR pretreatment could promote the decontamination of IPL on GSP and could weaken the influence of CIR or IPL on the quality of GSP.

Cancellation of cloud shadow effects in the absorbing aerosol index retrieval algorithm of TROPOMI

Abstract. Cloud shadows can be detected in the radiance measurements of the TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel-5P satellite due to its high spatial resolution and could possibly affect its air quality products. The cloud-shadow-induced signatures are, however, not always apparent and may depend on various cloud and scene parameters. Hence, the quantification of the cloud shadow impact requires the analysis of large data sets. Here we use the cloud shadow detection algorithm DARCLOS to detect cloud shadow pixels in the TROPOMI absorbing aerosol index (AAI) product over Europe during 8 months. For every shadow pixel, we automatically select cloud- and shadow-free neighbour pixels in order to estimate the cloud-shadow-induced signature. In addition, we simulate the measured cloud shadow impact on the AAI with our newly developed three-dimensional (3D) radiative transfer algorithm MONKI. Both the measurements and simulations show that the average cloud shadow impact on the AAI is close to zero (0.06 and 0.16, respectively). However, the top-of-atmosphere reflectance ratio between 340 and 380 nm, which is used to compute the AAI, is significantly increased in 95 % of the shadow pixels. So, cloud shadows are bluer than surrounding non-shadow pixels. Our simulations explain that the traditional AAI formula intrinsically already corrects for this cloud shadow effect via the lower retrieved scene albedo. This cancellation of cloud shadow signatures is not always perfect, sometimes yielding second-order low and high biases in the AAI which we also successfully reproduce with our simulations. We show that the magnitude of those second-order cloud shadow effects depends on various cloud parameters which are difficult to determine for the shadows measured with TROPOMI. We conclude that a potential cloud shadow correction strategy for the TROPOMI AAI would therefore be complicated if not unnecessary.

The Effect of Contralateral Routing of Signal Devices on the Quality of Life of Unilateral Cochlear Implant Recipients and Their Frequent Communication Partners.

Unilateral cochlear implant (CI) recipients with limited hearing in the contralateral ear are deprived of the advantages of binaural hearing. To address speech recognition challenges arising from the head shadow effect, a contralateral routing of signal (CROS) device can be used; however, less is known of the broader impact of a CROS device on an individual's quality of life (QoL) or that of their frequent communication partners (FCPs). This preliminary study aimed to evaluate the impact of CROS on speech recognition in noise and its influence on the QoL of unilateral CI recipients and their FCPs. This preliminary study enrolled seven adult unilateral CI recipients and their FCPs. All CI recipients were fitted with CROS devices during their initial appointments. Speech recognition testing was conducted in noise with and without the CROS device in a sound booth before a take-home trial. Participants used the CROS devices for approximately 1 year, with device fitting occurring before and continuing during the COVID-19 pandemic. Participants completed two QoL questionnaires, the Auditory Performance and Satisfaction Scale for Single-Sided Deafness (APS-SSD) and the Nijmegen Cochlear Implant Questionnaire (NCIQ), twice: once prior to CROS device use and once after the take-home trial. Additionally, the FCPs of each CI recipient completed the Significant Other Scale of Hearing Disability (SOS-HEAR) Questionnaire twice, once before and once after extended CROS device use. When noise was directed toward the CI ear and speech toward the non-CI ear, speech recognition improved by 32% with the CROS device (p = .001). CI recipients reported significant median improvement in the "general" domain of the APS-SSD after the take-home trial (Wilcoxon Z = 12.0, p < .05). FCPs reported a significant median reduction in concerns related to their partner's hearing when the CI recipient used the CROS device (Wilcoxon Z = 2.0, p < .05). This preliminary study demonstrates the benefit of CROS devices for unilateral CI recipients in noisy environments. Additionally, it highlights the positive impact of CROS devices on the QoL of both CI recipients and their FCPs. These findings emphasize the importance of considering CROS devices as a valuable solution for unilateral CI recipients to enhance their hearing experience, overall well-being, and that of their FCPs.

Pathophysiological Effects on Coronary Arteries Following Radiofrequency Ablation: A Comprehensive Review.

Radiofrequency ablation (RFA) is a safe and effective treatment for patients experiencing ventricular and atrial tachyarrhythmias. While complications after RFA are generally rare, the occurrence of coronary artery (CA) injury, albeit infrequent, can have significant clinical implications. Given the proximity of CAs to common ablation sites, understanding the interplay between RFA and CA perfusion pathophysiology is paramount. Although previous studies have discussed the presentation and outcomes of CA injury post-ablation, a comprehensive review consolidating the mechanisms of CA injury following RFA remains absent in the cardiology literature. In this review, we conducted an extensive literature search spanning the past three decades to explore the link between the biophysics of RFA and CA perfusion pathophysiology, focusing on injury mechanisms. We delve into RFA lesion pathology, elucidate the mechanisms of CA injury resulting from RFA, and examine factors influencing lesion formation, such as convective cooling and the "shadow effect." Furthermore, we outline methods to mitigate CA injury post-RFA and propose novel research avenues to optimize lesion formation and ensure the safety of arrhythmia treatments, particularly in cases where tissue ablation is performed close to CAs.

Shadow Effect-Triggered Photosensitive Gate of Organic Photoelectrochemical Transistor for Enhanced Biodetection.

The integration of a photosensitive gate into an organic electrochemical transistor has currently emerged as a promising route for biological sensing. However, the modification of the photosensitive gate always involves complex processes, and the degradation of sensitivity of the functional materials under illumination will significantly decrease the stability of the devices. Herein, we designed an organic photoelectrochemical transistor (OPECT) biosensor employing horseradish peroxidase (HRP)@glucose oxidase (GOx)/Pt/n-Si as the photosensitive gate based on the "shadow effect". The glucose-dependent hydrogen peroxide with HRP/GOx was modified on the gate electrode, triggering a biocatalytic precipitation reaction, which induces the illumination contrast, resulting in a biologically gating effect on the corresponding channel current response. Thus, high sensitivity and selectivity in glucose detection of the OPECT devices will be realized. Given the easy fabrication and high stability of the Pt/n-Si electrode, it has great potential to become a superior selectivity as an OPECT gate electrode. This work provides conceptual validation for the study of the interaction between the photosensitive gate based on the "shadow effect" and biomolecular sensing, which can further expand the application of the OPECT biosensors under interior lighting and shadow surroundings.

Numerical Simulation Analysis of an Offshore Multi-Row Arrangement Longline Aquaculture Facility with Lantern Nets Under Environmental Loads

The structural hydrodynamic response of longline aquaculture facilities under the influence of waves and currents is complex. Studying the hydrodynamic characteristics of this aquaculture structure in complex sea environments can contribute to sustainable offshore aquaculture solutions. Thus, we established a numerical model using AquaSim2.18, a proven and effective finite element hydrodynamic software for analyzing the maximum tension in mooring lines and main lines, the displacement of the main lines, and the forces on the lantern nets under waves and currents. The results showed that positioning the system in the direction of incidence of waves and currents minimizes tension in both mooring and main lines, making a downstream arrangement optimal; compared with a single row, the maximum reduction in the tension of the mooring lines is 3.3% and 1.8% for five-row and row-row lines, respectively, and the shadow effects reduced the downstream mooring force. Additionally, line tension increased with wave height and current velocity, whereas wave periods had variable effects due to the period range; the lantern net forces increased with wave height and decreased with wave period. Wave height was also shown to influence the horizontal displacement of main lines. The findings can provide a reference for the hydrodynamic characteristics of different components of the structure.

Design and Prototyping of a Novel Triple Lumen Photo-Angioplasty Device: Lumi-Solve-T.

A triple lumen iteration of the novel photo-angioplasty drug eluting balloon catheter (DEBc) Lumi-Solve may be compromised by guidewire shadow (GWS)-mediated attenuation of balloon surface drug activation. The current study aimed to design and evaluate a novel triple lumen prototype, designated Lumi-Solve-T, to circumvent these issues. Effects of guidewire shadowing (GWS) on vascular smooth muscle cell (VSMC) proliferation was evaluated using the MTT assay. In-silico modelling of GWS in the novel triple lumen design was conducted. Computer-aided design (CAD) and finite element analysis (FEA) contributed to development of a novel triple lumen catheter. 3D printing of rudimentary and refined prototypes of the catheter together with assembly of a novel fibre-optic (FO) complex and ex-vivo evaluation of the triple lumen device, Lumi-Solve T, was also performed. GW insertion in a parallel triple lumen FO: GW port orientation demonstrated significantly reduced inhibition of VSMC proliferation after 7 days confirming the need for an alternative triple lumen design. In-silico analysis identified a multi-fibre FO sleeve design supported uniform, radial and uninterrupted UV365nm light transmission to the angioplasty balloon surface. FEA confirmed a multi-fibre FO ribbon design afforded a practical method of FO sleeve generation and facilitated a novel hub configuration able to afford a FO ribbon to sleeve transition. 3D printed prototypes demonstrated the utility of the novel design. A dedicated third port and lumen for the Lumi-Solve FO is required for optimal balloon surface photo-activation. A novel triple lumen design, Lumi-Solve-T, incorporating a ribbon to sleeve FO transition and novel hub design offers a realistic solution to current device limitations.

Unveiling Nepal’s Hydro-Climatic Diversity: A Comprehensive Study from East to West

This study delves into the comprehensive analysis of temperature, precipitation, and wind patterns across four distinct blocks in Nepal, shedding light on regional climate variations. Examining a 30-year (1990 – 2020) dataset, temperature variations reveal the East: Block 1 consistently experiencing higher average temperatures. Findings align with existing research, emphasizing local geographical features influence on temperature gradients. The precipitation analysis indicates the Block 1 receives the highest rainfall, correlating with established monsoon patterns. Western regions (Block 3) transition to arid climates, influenced by its most area in rain shadow effect of the Himalayas. Regression analysis reveals a warming trend in all blocks, reinforcing global climate change impacts. Precipitation trends exhibit nuances, with the East and Centre (Block 2) experiencing increases, while the Block 4 shows a decreasing trend. Extreme precipitation values highlight spatial variability, crucial for climate adaptation strategies. The study extends to extreme wind analysis, showcasing distinct patterns in each block, providing insights into potential risks. Wind direction analysis reveals unique patterns, contributing to a holistic understanding of regional climate dynamics. These findings contribute to the scientific discourse on climate resilience, emphasizing the need for tailored strategies in diverse geographical contexts.

Simulation model of power generation and the shadow effect of foldable solar panels used in agrivoltaics system

Simulation model of power generation and the shadow effect of foldable solar panels used in agrivoltaics system

Optimal Design of Horizontal Well Cluster Spacing Based on Extended Finite Element and Numerical Simulation

As a crucial component of volumetric fracturing in unconventional oil and gas reservoirs, the design and optimization of cluster spacing significantly impact the morphology and production of fractures. Therefore, this paper establishes a multi-fracture propagation geological model based on the extended finite element method to study the scale and morphology of fracture propagation. Simultaneously, a gas reservoir model is established using CMG software, guided by production goals, and incorporating rock mechanics and physical parameters from region M to optimize cluster spacing design. The results indicate that smaller cluster spacing results in greater stress shadow effects, hindering the propagation of central fractures, and increasing the overlap of pressure drop zones, leading to possible repeated modifications during construction. Conversely, larger cluster spacing reduces stress shadow effects but may leave some areas between clusters unmodified, affecting production. Thus, through combined simulation optimization using both methods, a cluster spacing of 10-15 meters is recommended for region M, which has shown good on-site application results, significantly reducing the rate of repeated modifications.

Semi-Active Vibration Control for Wind Turbines: A Variable Tuned Mass Damper Approach Utilizing 1st Modal and 3P Tuning

Vibration in wind turbine towers poses a significant threat to the service life and structural integrity of wind turbines. Dampers have been identified as a pivotal strategy for alleviating such vibrations. Despite this, the dynamic behavior of large-scale offshore wind turbines is frequently swayed by wind shear, the tower shadow effect, and the Rotor-Nacelle Assembly (RNA) control system, typically manifesting as responses to the blade passing frequency (3P). To mitigate these vibrations, this study introduces a 3P tuning method for tuned mass dampers (TMDs), alongside a sophisticated design approach that targets optimal frequency and damping ratios. The integration of a semi-active variable-tuned mass damper (SA-V-TMD) offers a dual-mode control solution: The “3P tuning mode” adeptly manages vibrations across a spectrum of operating conditions, while the “1st modal frequency tuning mode” stabilizes the structure during parked states. Simulations substantiate the 3P tuning method’s enhanced efficacy over standard methods under operational conditions. Furthermore, the SA-V-TMD demonstrates superior effectiveness and stability in comparison to traditional TMDs, underscoring its potential as a preeminent solution in wind turbine vibration management.

Stress shadow effects in multistage horizontal hydrofracturing of tight reservoirs: a numerical analysis considering perforation cluster spacings and fracturing sequences

AbstractMultistage horizontal fracturing technology of reservoirs has been widely used to enhance tight hydrocarbon resource recovery. Determining the proper perforation cluster spacing is crucial to developing a complex fracture network that connects natural rock fractures and facilitates gas flow in reservoirs. The stress shadow effect that occurs between multiple clusters has a significant effect on the development of the fracture network in reservoirs. The quantification of the stress shadow effect and its influences on the development of fracture networks has not been resolved satisfactorily due to experimental and numerical difficulties with detecting and identifying crack propagation and intersection in deep reservoirs. In this study, we used an adaptive finite element-discrete element method to analyze crack propagation and intersection in tight shale reservoirs by altering perforation spacings and fracture sequences. The effects of five perforation cluster spacings using sequential, simultaneous and parallel fracturing techniques were compared. The non-linear properties of shales, hydromechanical coupling and fluid leak-off effects, proppant transport, dual-rupture criteria of strength and energy, and intersection of hydraulic fractures were taken into account in the simulation. The areas affected by the stress shadow and the optimum perforation cluster spacing in terms of hydraulic fracture propagation lengths, volumes, and microseismic magnitudes were evaluated when adopting different fracturing methods. This study extends the understanding of the impact of the different independent factors that contribute to the stress shadow effect and, therefore, provides new information to help guide wellbore completion design in horizontal fracturing wells.

Biodiversity from the Sky: Testing the Spectral Variation Hypothesis in the Brazilian Atlantic Forest

Tropical forests have high species richness, being considered the most diverse and complex ecosystems in the world. Research on the variation and maintenance of biodiversity in these ecosystems is important for establishing conservation strategies. The main objective of this study was to test the Spectral Variation Hypothesis through associations between species diversity and richness measured in the field and hyperspectral data collected by a Remotely Piloted Aircraft (RPA) in areas with secondary tropical forest in the Brazilian Atlantic Forest biome. Specific objectives were to determine which dispersion measurements, standard deviation (SD) or coefficient of variation (CV), estimated for the n pixels occurring within each sampling unit, better explains species diversity; the effects of pixel size on the direction and intensity of this relationship; and the effects of shaded pixels within each sampling unit. The spectral variability hypothesis was confirmed for the Atlantic Forest biome, with R2 of 0.83 for species richness and 0.76 and 0.69 for the Shannon and Simpson diversity indices, respectively, using 1.0 m illuminated pixels. The dispersion (CV and SD) of hyperspectral bands were most strongly correlated with taxonomic diversity and richness in the red-edge and near-infrared (NIR) regions of the electromagnetic spectrum. Pixel size affected R2 values, which were higher for 1.0 m pixels (0.83) and lower for 10.0 m pixels (0.71). Additionally, illuminated pixels had higher R2 values than those under shadow effects. The main dispersion variables selected as metrics for regression models were mean CV, CV for the 726.7 nm band, and SD for the 742.3 and 933.4 nm bands. Our results suggest that spectral diversity can serve as a proxy for species diversity in the Atlantic Forest. However, factors that can affect this relationship, such as taxonomic and spectral diversity metrics used, pixel size, and shadow effects in images, should be considered.

Stochastic stability analysis method for doubly fed generator sets considering random blade stress

AbstractWith the increasing capacity of doubly fed induction generators (DFIGs), the diameter of the wind turbine is increasing, the blades are getting longer and longer, and in the process of power generation, the tower shadow effect as well as the role of wind shear are more obvious, and the random blade stresses caused by this is also getting bigger. Random blade stresses cause random and cyclic fluctuations in the power generated by the wind turbine, and power fluctuations often cause voltage flicker, which affects the control system and power quality. To address the impact of random blade stresses on the grid‐connected stability of DFIG, the results of the traditional stability analysis methods may be too conservative or lead to too high a dimensionality to be analyzed. To solve the above problems, this paper proposes a grid‐connected stochastic stability analysis method for DFIG sets considering random blade stresses based on the stochastic averaging method under the Hamiltonian system. a stochastic dynamics model of the doubly fed wind farm was established by considering random blade stress. Subsequently, using the proposed generalized Hamiltonian principle, the model and energy functions in the proposed Hamiltonian form H, based on the stochastic averaging method (SAM), were established to obtain the system energy diffusion equation. Probability density function and regional stability probability were obtained from explicit expressions of the mean and regression square root processes. The drift and diffusion coefficients were obtained using the SAM, and the backward Kolmogorov equation was derived from the Ito equation to obtain the conditional reliability function and the probability density of the first crossing time. Finally, the effects of torque fluctuations with different stochastic intensities on the grid‐connected stability of doubly fed wind farms were investigated, and the effectiveness of the proposed generalized Hamiltonian SAM applied to the stochastic stability analysis of DFIG was verified by numerical analysis and Monte Carlo simulation. This provides a theoretical foundation for analyzing the grid‐connected stability of DFIG affected by random blade stresses.

Better Resolved Orography Improves Precipitation Simulation Over the Tibetan Plateau in High‐Resolution Models

AbstractRegarded as the Asian Water Tower, the Tibetan Plateau (TP) collects atmospheric precipitation from a vast area of land and feeds into major rivers that sustain the livelihood of billions of people in East, South and Central Asia. It is critical to reasonably simulate the hydrological cycle over the TP in order to assess future climate risks to agriculture, water resources and ecosystem services. To address the chronic wet biases over the TP in state‐of‐the‐art climate models, we have compared 12 high‐resolution (HR) climate models (25–50 km) to their corresponding low‐resolution versions (100–200 km) with respect to the 1979–2014 climatology. It is found that the HR models consistently reduce about half of the wet biases over the TP, mainly from better resolved orography. The wet biases are reduced by 41% over the northern and western TP, mainly contributed by decreased frequency of light precipitation (0.1–10 mm day−1), which is attributed to reduced evaporation because of weakened surface wind by raised orography. The most significant reduction of biases (53%) rising from decreased frequency of mid‐heavy precipitation (10–50 mm day−1), appears over the southern and eastern TP, on the leeside of elevated orography where steeper orography enhances rain shadow effect by stronger downward motion along the sharper slope, while partly compensated by air column convergence due to vertical stretching of the downward flow for potential vorticity conservation. This study highlights the importance of surface processes and resolving complex orography in simulating precipitation and large‐scale hydrology around the TP which potentially benefits the future hydrological projection.

Vegetative and reproductive morphology of Othniophyton elongatum (MacGinitie) gen. et comb. nov., an extinct angiosperm of possible caryophyllalean affinity from the Eocene of Colorado and Utah, USA.

Eocene foliage formerly attributed to the extant araliaceous genus Oreopanax was found attached to twigs bearing inflorescences and infructescences unlike those of Araliaceae. Using newly observable characters of phyllotaxy, vegetative and floral buds, infructescences and seeds, we sought to reassess the affinities of this strange angiosperm. Fossils were studied from the Parachute Creek Member of the Green River Formation from near Bonanza, Utah and Douglas Pass, Colorado (ca. 47 Ma). Macrofossil impression remains were investigated by low angle reflected light and subtle details of the vegetative and floral buds, stamens, mature fruits, and seeds were revealed by optical shadow effect microscopy documenting previously obscure topographic surface features. Othniophyton elongatum (MacGinitie) Manchester, Judd, Correa-Narvaez gen. et comb. nov. has simple, short-petiolate, elongate, entire-margined leaves with thick midveins, pinnate, brochidodromous secondaries, common intersecondary veins and finely reticulate higher order venation. Inflorescences are small axillary cymes; flower buds are subglobose and pedicellate, in bract axils. The flowers are actinomorphic, bisexual, with ca. five imbricate perianth parts, ca. 24 stamens with elongate anthers and short filaments, arising from a hypanthium. The whorl of stamens persists to fruiting stage. The ovary is superior, with probable basal placentation and five stigmatic arms. Fruits are pedicellate berries with a cup-shaped hypanthium and contain ca. 15 lensoidal reniform seeds, each with a curved embryo and ornamented with concentric ridges. The combined characters refute the prior placement in Araliaceae, and rule out affinities with most extant clades of angiosperms. The distinctive combination of observed features does not coincide with any extant family. Among extant orders of Eudicots, the fossil seems to conform most closely to the order Caryophyllales, but key differences remain. This example indicates that the vegetation of ca. 47 million years ago included some taxa that cannot readily be placed in modern families and genera.