194 research outputs found
Comparative analysis of the physical and mechanical properties of kraft paper and watercolor paper
In order to study the feasibility of kraft paper as watercolor paper, the wetting properties, mechanical properties and friction properties of kraft paper and watercolor paper were compared before and after aging. Aging test was carried out on kraft paper and watercolor paper by aging chamber, the wetting properties of distilled water and three watercolor solutions before and after aging of kraft paper and watercolor paper were compared, tensile tear test of paper on tensile testing machine, the fracture changes of paper were analyzed by scanning electron microscope, the friction tester performs the paper friction test. The results show that both kinds of paper are amorphous, watercolor paper was showed hydrophobicity before and after aging, contact angle was maintained at about 119,09° ± 5° in four different solutions, unaged kraft paper exhibited hydrophilicity, the aged kraft paper showed hydrophobicity with a contact angle of 92,52° ± 1°,the aged kraft paper shows better performance in both tensile and tearing aspects and tensile strength is 20 MPa higher than watercolor paper, surface roughness of kraft paper is higher than watercolor paper. The experiment is helpful for the market to consider whether the cheaper kraft paper replaces the more expensive watercolor paper in some aspects and provides some scientific reference value for the future research
Imbalance Knowledge-Driven Multi-modal Network for Land-Cover Semantic Segmentation Using Images and LiDAR Point Clouds
Despite the good results that have been achieved in unimodal segmentation,
the inherent limitations of individual data increase the difficulty of
achieving breakthroughs in performance. For that reason, multi-modal learning
is increasingly being explored within the field of remote sensing. The present
multi-modal methods usually map high-dimensional features to low-dimensional
spaces as a preprocess before feature extraction to address the nonnegligible
domain gap, which inevitably leads to information loss. To address this issue,
in this paper we present our novel Imbalance Knowledge-Driven Multi-modal
Network (IKD-Net) to extract features from raw multi-modal heterogeneous data
directly. IKD-Net is capable of mining imbalance information across modalities
while utilizing a strong modal to drive the feature map refinement of the
weaker ones in the global and categorical perspectives by way of two
sophisticated plug-and-play modules: the Global Knowledge-Guided (GKG) and
Class Knowledge-Guided (CKG) gated modules. The whole network then is optimized
using a holistic loss function. While we were developing IKD-Net, we also
established a new dataset called the National Agriculture Imagery Program and
3D Elevation Program Combined dataset in California (N3C-California), which
provides a particular benchmark for multi-modal joint segmentation tasks. In
our experiments, IKD-Net outperformed the benchmarks and state-of-the-art
methods both in the N3C-California and the small-scale ISPRS Vaihingen dataset.
IKD-Net has been ranked first on the real-time leaderboard for the GRSS DFC
2018 challenge evaluation until this paper's submission
How to Extend 3D GBSM to Integrated Sensing and Communication Channel with Sharing Feature?
Integrated Sensing and Communication (ISAC) is a promising technology in 6G
systems. The existing 3D Geometry-Based Stochastic Model (GBSM), as
standardized for 5G systems, addresses solely communication channels and lacks
consideration of the integration with sensing channel. Therefore, this letter
extends 3D GBSM to support ISAC research, with a particular focus on capturing
the sharing feature of both channels, including shared scatterers, clusters,
paths, and similar propagation param-eters, which have been experimentally
verified in the literature. The proposed approach can be summarized as follows:
Firstly, an ISAC channel model is proposed, where shared and non-shared
components are superimposed for both communication and sensing. Secondly,
sensing channel is characterized as a cascade of TX-target, radar cross
section, and target-RX, with the introduction of a novel parameter S for shared
target extraction. Finally, an ISAC channel implementation framework is
proposed, allowing flexible configuration of sharing feature and the joint
generation of communication and sensing channels. The proposed ISAC channel
model can be compatible with the 3GPP standards and offers promising support
for ISAC technology evaluation
Dietary L-Tryptophan Modulates the Hematological Immune and Antibacterial Ability of the Chinese Mitten Crab, Eriocheir sinensis, Under Cheliped Autotomy Stress
In pond cultures of juvenile Eriocheir sinensis, limb autotomy stress seriously affects and restricts the quality and economic benefits of aquaculture. This study was designed to evaluate the effects of dietary supplementation of L-tryptophan on E. sinensis under the cheliped autotomy stress. In the present study, 252 crabs were divided into four groups: dietary L-trp supplementation with 0.28, 0.40, 0.53, and 0.70%, and their hematological immunity, antioxidant capacity, anti-stress, and antibacterial ability were evaluated after 14 days of using biochemical analysis, flow cytometry, and molecular biology techniques. First, we counted the mortality after 14 days of feeding and found that compared with other treatments, dietary supplementation of 0.53 and 0.70% L-trp significantly lowered the mortality of E. sinensis. Moreover, the total hemocyte count (THC), hemocyanin, and glutathione (GSH) content, and glutathione peroxidase (GSH-Px) activity significantly increased at 7 and 14 d with dietary supplementation of 0.53 and 0.70% L-trp, in contrast with the significant decrease in malondialdehyde (MDA) content at 14 d in the same dietary groups (P<0.05). Next, the bacterial challenge test after 14 days of feeding showed that the THC levels, phagocytic rate, and acid phosphatase (ACP) and alkaline phosphatase (ALP) activity were significantly higher with dietary supplementation of 0.53 and 0.70% L-trp after 12 and 24 h of Aeromonas hydrophila injection, along with a significant improvement in the antioxidant capacity (P<0.05). Further, we measured the expression of antibacterial-related protein genes (EslecB and HSP 90) and found that they were significant up-regulated in the hepatopancreas, hemocytes, intestine, and gill in the groups with dietary supplementation of 0.53% and 0.70% L-trp after 12 h or 24 h of A. hydrophila injection (P<0.05). Taken together, the observations in this study indicate that dietary supplementation of L-trp can enhance the antioxidant capacity and improve the hematological immune status and antibacterial ability of E. sinensis under the cheliped autotomy stress, thereby increasing the survival rate of E. sinensis under cheliped autotomy stress
Channel Measurement, Modeling, and Simulation for 6G: A Survey and Tutorial
The sixth generation (6G) mobile communications have attracted substantial
attention in the global research community of information and communication
technologies (ICT). 6G systems are expected to support not only extended 5G
usage scenarios, but also new usage scenarios, such as integrated sensing and
communication (ISAC), integrated artificial intelligence (AI) and
communication, and communication and ubiquitous connectivity. To realize this
goal, channel characteristics must be comprehensively studied and properly
exploited, so as to promote the design, standardization, and optimization of 6G
systems. In this paper, we first summarize the requirements and challenges in
6G channel research. Our focus is on channels for five promising technologies
enabling 6G, including terahertz (THz), extreme MIMO (E-MIMO), ISAC,
reconfigurable intelligent surface (RIS), and space-air-ground integrated
network (SAGIN). Then, a survey of the progress of the 6G channel research
regarding the above five promising technologies is presented in terms of the
latest measurement campaigns, new characteristics, modeling methods, and
research prospects. Moreover, a tutorial on the 6G channel simulations is
presented. We introduce the BUPTCMG- 6G, a 6G link-level channel simulator,
developed based on the ITU/3GPP 3D geometry-based stochastic model (GBSM)
methodology. The simulator supports the channel simulation of the
aforementioned 6G potential technologies. To facilitate the use of the
simulator, the tutorial encompasses the design framework, user guidelines, and
application examples. This paper offers in-depth, hands-on insights into the
best practices of channel measurements, modeling, and simulations for the
evaluation of 6G technologies, the development of 6G standards, and the
implementation and optimization of 6G systems.Comment: 41 pages,52 figure
Elevated Monocyte to High-density Lipoprotein Ratio Is a Risk Factor for New-onset Atrial Fibrillation after Off-pump Coronary Revascularization
Atrial fibrillation (AF) is a common complication of coronary revascularization. Currently, the mechanisms of postoperative AF are unclear. This study was aimed at investigating the risk factors for new-onset AF (NOAF) after coronary revascularization and exploring the early warning effects of clinical inflammatory markers. A retrospective analysis was conducted on 293 patients with unstable angina pectoris who underwent coronary artery revascularization in Beijing Chao-Yang Hospital, Capital Medical University, between April 2018 and June 2021, including 224 patients who underwent coronary artery bypass grafting and 69 patients who underwent one-step hybrid coronary revascularization. Baseline data, clinical data, blood indicators and AF episodes within 7 days after the surgery were collected. Participants were divided into two groups according to whether AF occurred, and the data were analyzed between groups. In addition, multivariate logistic regression was used to explore the independent risk factors for developing AF post coronary revascularization. Aging, a larger left atrial inferior-superior diameter, use of an intra-aortic balloon pump, a greater blood volume transfused during perioperative period and a higher monocyte to high-density lipoprotein ratios on postoperative day 1 were independent risk factors for NOAF after coronary artery surgery
A novel active equalization topology for series-connected lithium-ion battery packs
A novel nondissipative two-stage equalization circuit topology based on the traditional buck-boost circuit is proposed to achieve balancing of series-connected lithium-ion battery packs with higher efficiency and less cost, considering the background on international energy issues and the development trend of battery balancing. The proposed topology achieves high efficient balancing of lithium-ion battery packs without adding additional devices. Detailed illustration of the presented topology, the operation principles and control approaches are described with visualized figures in this article. Then, under the condition of accurate modeling of the lithium-ion battery, relying on the experimental data, the simulation block is built based on MATLAB. Furthermore, the prototype of the proposed topology was designed and manufactured. The effectiveness of the proposed topology is verified by both the simulation and experiment
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