Nonlinear Integral Inequalities in Two Independent Variables and Their Applications

This paper generalizes results of Cheung and Ma (2005) to more general inequalities with more than one distinct nonlinear term. From our results, some results of Cheung and Ma (2005) can be deduced as some special cases. Our results are also applied to show the boundedness of the solutions of a partial differential equation

ScalableMap: Scalable Map Learning for Online Long-Range Vectorized HD Map Construction

We propose a novel end-to-end pipeline for online long-range vectorized high-definition (HD) map construction using on-board camera sensors. The vectorized representation of HD maps, employing polylines and polygons to represent map elements, is widely used by downstream tasks. However, previous schemes designed with reference to dynamic object detection overlook the structural constraints within linear map elements, resulting in performance degradation in long-range scenarios. In this paper, we exploit the properties of map elements to improve the performance of map construction. We extract more accurate bird's eye view (BEV) features guided by their linear structure, and then propose a hierarchical sparse map representation to further leverage the scalability of vectorized map elements and design a progressive decoding mechanism and a supervision strategy based on this representation. Our approach, ScalableMap, demonstrates superior performance on the nuScenes dataset, especially in long-range scenarios, surpassing previous state-of-the-art model by 6.5 mAP while achieving 18.3 FPS. Code is available at https://github.com/jingy1yu/ScalableMap

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Diorganotin dihalide complexes with bidentate nitrogen ligands exhibit some pharmaceutical activities such as antitumour activity, antiviral activity and anti-microbiological activity[1-3], we have synthesized some diorganotin dihalide complexes with bidentate nitrogen ligands, one of which is dibutyldichloro(1,10-phenanthroline-N 1,N 10)tin. A solution of dibutyltin dichloride (1.22 g, 4 mmol) in benzene (20 ml) was added to a solution of 1,10-phenanthroline (0.72 g, 4 mmol) in benzene (20 ml). The mixture was refluxed for 4 h, the solid that appeared upon cooling was filtered and recrystallized from absolute ethanol to give the title compound as white crystal (1.82 g, 94%)

Iron and nickel doped CoSe2 as efficient non precious metal catalysts for oxygen reduction

Iron and nickel doped CoSe2 were prepared by solvothermal method, and they were proved to be ternary chalcogenides by series of physical characterization. The effects of the iron and nickel contents on the oxygen reduction reaction were investigated by electrochemical measurements, and the highest activities were obtained on Co0.7Fe0.3Se2 and Co0.7Ni0.3Se2, respectively. Both Co0.7Fe0.3Se2 and Co0.7Ni0.3Se2 presented four-electron pathway. Furthermore, Co0.7Fe0.3Se2 exhibited more positive cathodic peak potential (0.564 V) and onset potential (0.759 V) than these of Co0.7Ni0.3Se2 (0.558 V and 0.741 V). And Co0.7Fe0.3Se2 displayed even superior stability and better tolerance to methanol, ethanol and ethylene glycol crossover effects than the commercial Pt/C (20 wt% Pt)

Strength degradation mechanism of iron coke prepared by mixed coal and Fe2O3

Iron coke, as a new type of blast furnace burden is helpful for energy saving, emission reduction and green production of iron making. This study aims to investigate the strength degradation mechanism of iron coke prepared by mixed coal and Fe2O3 to provide a theoretical direction to improve its strength. Coking and pyrolysis experiments of mixed coal and Fe2O3 were carried out between 400 and 500 ℃ temperature. Gieseler plastometer and derivative thermogravimetric (DTG) showed that added Fe2O3 inhibited the thermoplasticity and pyrolysis process of mixed coal during coking. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results showed that added Fe2O3 decreased the aromaticity and average stacking height, but increased the interlayer spacing of crystallite, aliphatic chain length and hydrocarbon-generating potential of mixed coal during coking. Further, gas chromatography-mass spectrometer (GCsingle bondMS) analysis suggested that the added Fe2O3 inhibited the cleavage of Calsingle bondO, Calsingle bondS, Calsingle bondN, Calsingle bondCar and Calsingle bondCal bonds, reduced the generation of ethylbenzene, o-xylene and unbranched alkanes with carbon atoms in 24–26, thus decreased the amount of fluid phase generated in coking and ultimately degraded the strength of iron coke

Wavefront shaping: A versatile tool to conquer multiple scattering in multidisciplinary fields

Optical techniques offer a wide variety of applications as light-matter interactions provide extremely sensitive mechanisms to probe or treat target media. Most of these implementations rely on the usage of ballistic or quasi-ballistic photons to achieve high spatial resolution. However, the inherent scattering nature of light in biological tissues or tissue-like scattering media constitutes a critical obstacle that has restricted the penetration depth of non-scattered photons and hence limited the implementation of most optical techniques for wider applications. In addition, the components of an optical system are usually designed and manufactured for a fixed function or performance. Recent advances in wavefront shaping have demonstrated that scattering- or component-induced phase distortions can be compensated by optimizing the wavefront of the input light pattern through iteration or by conjugating the transmission matrix of the scattering medium. This offers unprecedented opportunities in many applications to achieve controllable optical delivery or detection at depths or dynamically configurable functionalities by using scattering media to substitute conventional optical components. In this article, the recent progress of wavefront shaping in multidisciplinary fields is reviewed, from optical focusing and imaging with scattering media, functionalized devices, modulation of mode coupling, and nonlinearity in multimode fiber to multimode fiber-based applications. Apart from insights into the underlying principles and recent advances in wavefront shaping implementations, practical limitations and roadmap for future development are discussed in depth. Looking back and looking forward, it is believed that wavefront shaping holds a bright future that will open new avenues for noninvasive or minimally invasive optical interactions and arbitrary control inside deep tissues. The high degree of freedom with multiple scattering will also provide unprecedented opportunities to develop novel optical devices based on a single scattering medium (generic or customized) that can outperform traditional optical components

Cold-wire assisted arc direct-energy deposition of VC-strengthening 5A06 aluminum alloy: Microstructures and mechanical properties

In this study, vanadium carbide (VC) was initially introduced into the molten pool using the cold wire method to refine the deposit grains and enhance the mechanical properties of arc direct energy deposition (ADED) aluminum alloy. Next, the grain structure's evolutionary behaviors and the second phase in the VC-strengthening ER5A06 aluminum alloy deposits were investigated, and the grain refinement mechanism was determined. The findings demonstrated that the cubic Al10V phase was produced after introducing VC, and the grain structure in the middle stable region of the building wall was transformed from coarse columnar grains (with an average size of 42.3 μm) into equiaxed fine grains (with an average size of 16.4 μm). Both Al10V and VC were coherent to α-Al in terms of orientation: (020)α-Al//(444)Al10V, [101―]α-Al//[112―]Al10V, and (111)α-Al//(111)VC and [011]α-Al//[011]VC. Their interatomic and interplanar spacing misfits were lower than 5 %, facilitating the heterogeneous nucleation of α-Al during molten pool solidification. Moreover, under multiple thermal cycles of ADED, the pinning effect of VC and Al10V effectively restricted the grain growth, thus enabling the building wall to steadily maintain a uniform, equiaxed, and fine-grained structure. Due to grain refinement and homogenization, the horizontal and vertical ultimate tensile strengths of the straight wall were improved by 16.8 % and 50.2 % (351.6 and 348.1 MPa), respectively, thereby eliminating the mechanical anisotropy. This work can provide a theoretical foundation and a novel method for the fine microstructure regulation and reinforcement of ADED aluminum alloy components

Correlation between pulse frequencies, microstructure and mechanical properties of TA15 in wire and arc additive manufacturing

Wire and arc additive manufacturing (WAAM) has been developed to be a highly efficient technique for making large Ti-alloy products. However, the deposition of metal by this method causes coarse texture, which limits its application. To address this, the study utilizes a wire and pulsed arc additive manufacturing (WPAAM) process for making TA15 alloy. Compared with the WAAM method, this WPAAM method inducts several current/voltage-impulse cycles under different pulse frequencies, which makes grains tiny and improves tensile strength. The study then uses a VOF model to discuss the effect of impulse cycles on the solidification process. The findings suggested that the impulse cycles deform the molten pool and influence the vibration in the solid/liquid interface. This makes the coarse columnar grains tiny and forms diminutive α laths. This paper further discusses the correlation between the microstructure and the mechanical properties. The results show that the CBGs and the α laths play a joint contribution to yield strength in the WAAMed TA15 alloy. This study provides a reference for optimizing the microstructure of WAAM titanium alloys by adjusting pulse frequencies and provides a theoretical basis for strengthening WAAMed Ti-alloy