4,916 research outputs found
Problem Frame Analysis of Weapon System of Systems Requirement
AbstractThe requirement of weapon system of systems(WSoS) plays a very important role in the development of WSoS,which is the basis of the design of WSoS and runs through the research of WSoS. Based on the requirement engineering method of problem frame, the problem frame of WSoS requirement(WSoSR) is built which is consisted of requirement, mission domain, task domain, operation domain and system of systems(SoS) domain. The phenomena between the domains is defined and the constraint set is given. The model of the WSoSR problem transformation is put forward including the transformation process and the transformation content. An example of combined firing employment to the enemy ship fleet is shown in the end
Synthesis of novel tetravalent galactosylated DTPA-DSPE and study on hepatocyte-targeting efficiency in vitro and in vivo
HumanSD: A Native Skeleton-Guided Diffusion Model for Human Image Generation
Controllable human image generation (HIG) has numerous real-life
applications. State-of-the-art solutions, such as ControlNet and T2I-Adapter,
introduce an additional learnable branch on top of the frozen pre-trained
stable diffusion (SD) model, which can enforce various conditions, including
skeleton guidance of HIG. While such a plug-and-play approach is appealing, the
inevitable and uncertain conflicts between the original images produced from
the frozen SD branch and the given condition incur significant challenges for
the learnable branch, which essentially conducts image feature editing for
condition enforcement. In this work, we propose a native skeleton-guided
diffusion model for controllable HIG called HumanSD. Instead of performing
image editing with dual-branch diffusion, we fine-tune the original SD model
using a novel heatmap-guided denoising loss. This strategy effectively and
efficiently strengthens the given skeleton condition during model training
while mitigating the catastrophic forgetting effects. HumanSD is fine-tuned on
the assembly of three large-scale human-centric datasets with text-image-pose
information, two of which are established in this work. As shown in Figure 1,
HumanSD outperforms ControlNet in terms of accurate pose control and image
quality, particularly when the given skeleton guidance is sophisticated
Evidence of Carbon Uptake Associated with Vegetation Greening Trends in Eastern China
Persistent and widespread increase of vegetation cover, identified as greening, has been observed in areas of the planet over late 20th century and early 21st century by satellite-derived vegetation indices. It is difficult to verify whether these regions are net carbon sinks or sources by studying vegetation indices alone. In this study, we investigate greening trends in Eastern China (EC) and corresponding trends in atmospheric CO₂ concentrations. We used multiple vegetation indices including NDVI and EVI to characterize changes in vegetation activity over EC from 2003 to 2016. Gap-filled time series of column-averaged CO₂ dry air mole fraction (XCO₂) from January 2003 to May 2016, based on observations from SCIAMACHY, GOSAT, and OCO-2 satellites, were used to calculate XCO₂ changes during growing season for 13 years. We derived a relationship between XCO₂ and surface net CO₂ fluxes from two inversion model simulations, CarbonTracker and Monitoring Atmospheric Composition and Climate (MACC), and used those relationships to estimate the biospheric CO₂ flux enhancement based on satellite observed XCO₂ changes. We observed significant growing period (GP) greening trends in NDVI and EVI related to cropland intensification and forest growth in the region. After removing the influence of large urban center CO₂ emissions, we estimated an enhanced XCO₂ drawdown during the GP of −0.070 to −0.084 ppm yr⁻¹. Increased carbon uptake during the GP was estimated to be 28.41 to 46.04 Tg C, mainly from land management, which could offset about 2–3% of EC’s annual fossil fuel emissions. These results show the potential of using multi-satellite observed XCO₂ to estimate carbon fluxes from the regional biosphere, which could be used to verify natural sinks included as national contributions of greenhouse gas emissions reduction in international climate change agreements like the UNFCC Paris Accord
General framework of quantum complementarity from a measurement-based perspective
One of the most remarkable features of quantum physics is that attributes of
quantum objects, such as the wave-like and particle-like behaviors of single
photons, can be complementary in the sense that they are equally real but
cannot be observed simultaneously. Quantum measurements, serving as windows
providing views into the abstract edifice of quantum theory, are basic tools
for manifesting the intrinsic behaviors of quantum objects. However,
quantitative formulation of complementarity that highlights its manifestations
in sophisticated measurements remains elusive. Here we develop a general
framework for demonstrating quantum complementarity in the form of information
exclusion relations (IERs), which incorporates the wave-particle duality
relations as particular examples. Moreover, we explore the applications of our
theory in entanglement witnessing and elucidate that our IERs lead to an
extended form of entropic uncertainty relations, providing intriguing insights
into the connection between quantum complementarity and the preparation
uncertainty.Comment: 13 pages (including 7 pages in the main text), 6 figure
Long wavelength single photon like driven photolysis via triplet triplet annihilation
Photolysis has enabled the occurrence of numerous discoveries in chemistry, drug discovery and biology. However, there is a dearth of efficient long wavelength light mediated photolysis. Here, we report general and efficient long wavelength single photon method for a wide array of photolytic molecules via triplet-triplet annihilation photolysis. This method is versatile and LEGO -like. The light partners (the photosensitizers and the photolytic molecules) can be energetically matched to adapt to an extensive range of electromagnetic spectrum wavelengths and the diversified chemical structures of photoremovable protecting groups, photolabile linkages, as well as a broad array of targeted molecules. Compared to the existing photolysis methods, our strategy of triplet-triplet annihilation photolysis not only exhibits superior reaction yields, but also resolves the photodamage problem, regardless of whether they are single photon or multiple photon associated. Furthermore, the biological promise of this LEGO system was illustrated via developing ambient air-stable nanoparticles capable of triplet-triplet annihilation photolysis
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