223 research outputs found
Effect of irrigation frequency during the growing season of winter wheat on the water use efficiency of summer maize in a double cropping system
Our aim was to investigate the potential effects of irrigation frequency during the growing season of winter wheat on the water use efficiency (WUE) of summer maize in a double cropping system. To this end, we conducted a field experiment with winter wheat cultivated with 1, 2, and 3 irrigation applications with 120 mm water at the time of stem elongation, heading, or milking. The results showed that later irrigation applications increased soil moisture before sowing (SMBS) of summer maize. Summer maize grain yield was enhanced in both the common and excessively rainy years with increased SMBS; however, irrigation during the later growing season of winter wheat in rainy years could increase deep percolation of summer maize. In common and rainy years, the more the SMBS, the higher was the grain yield of summer maize. The highest WUE for summer maize was obtained when it was grown after winter wheat irrigated with 120 mm water at milking or 60 mm water at each, the stem elongation and heading stages. Considering the combined WUE of winter wheat and summer maize, the authors think that winter wheat should be irrigated at the stem elongation and heading stages to achieve reasonable WUE and grain yield for both crops
Correlations between IGF-IR Expression and Clinicopathological Factors and Prognosis in Patients with Lung Adenocarcinoma
Background and objective The incidence of lung adenocarcinoma increases rapidly, and IGF-IR is the key mediator of several growth factors signal transduction, therefore it plays an important role in the proliferation and differentiation of cancer cell. The aim of this study is to detect the expression of IGF-IR in lung adenocarcinoma and to evaluate its implication for the clinicopathological factors and prognosis of patients with this disease. Methods The IGF-IR expression was detected by immunohistochemical staining. Correlations between IGF-IR expression with clinicopathological factors were analyzed using the Chi-squared test. The Kaplan-Meier method was used to calculate the overall patient survival rate, and the difference in survival curves was evaluated using a Log-rank test. Univariate and multivariate analysis was carried out using the Cox proportional-hazard model. Results In 126 cases of tumor sections tested, IGF-IR were detected in 89 cases. Statistical analysis revealed that the IGF-IR expression was related to tumor size and T stage, while there were no relations between IGFIR expression and age, gender, smoking, pathological stages, and differentiation. Cox analysis indicated that metastasis and chemotherapy efficacy were the prognostic factors in these patients, while IGF-IR expression was not the independent prognostic factor. Conclusion The IGF-IR expression is related to tumor size and T stage, while there is no relation between IGF-IR expression and prognosis
Certificateless generalized signcryption
Generalized Signcryption is a fresh cryptographic primitive that not only can obtain encryption and signature in a single operation, but also provives encryption or signature alone when needed. This paper gives a formal definition of certificateless generalized signcryption and its security model is present. A concrete certificateless generalized signcryption scheme is also proposed in this paper
The Application of Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Therapy of Acute Cerebral Infarction
Diffusion- and perfusion-weighted magnetic resonance imaging (DWI and PWI) was applied for stroke
diagnose in 120 acute (< 48 h) ischemic stroke patients. At hyperacute (< 6 h) stage, it is
difficult to find out the infarction zone in conventional T1 or T2 image, but it is easy in DWI,
apparent diffusion coefficient (ADC) map; when at 3–6-hour stage it is also easy in PWI,
cerebral blood flow (CBF) map, cerebral blood volume (CBV) map, and mean transit time (MTT) map;
at acute (6–48 h) stage, DWI or PWI is more sensitive than conventional T1 or T2 image too.
Combining DWI with ADC, acute and chronic infarction can be distinguished. Besides,
penumbra which should be developed in meaning was used as an indication or to evaluate the
therapeutic efficacy. There were two cases (< 1.5 h) that broke the model of penumbra because abnormity was found in DWI but not that in PWI, finally they recovered without any sequela
Collaborative Perception in Autonomous Driving: Methods, Datasets and Challenges
Collaborative perception is essential to address occlusion and sensor failure
issues in autonomous driving. In recent years, theoretical and experimental
investigations of novel works for collaborative perception have increased
tremendously. So far, however, few reviews have focused on systematical
collaboration modules and large-scale collaborative perception datasets. This
work reviews recent achievements in this field to bridge this gap and motivate
future research. We start with a brief overview of collaboration schemes. After
that, we systematically summarize the collaborative perception methods for
ideal scenarios and real-world issues. The former focuses on collaboration
modules and efficiency, and the latter is devoted to addressing the problems in
actual application. Furthermore, we present large-scale public datasets and
summarize quantitative results on these benchmarks. Finally, we highlight gaps
and overlook challenges between current academic research and real-world
applications. The project page is
https://github.com/CatOneTwo/Collaborative-Perception-in-Autonomous-DrivingComment: 18 pages, 6 figures. Accepted by IEEE Intelligent Transportation
Systems Magazine. URL:
https://github.com/CatOneTwo/Collaborative-Perception-in-Autonomous-Drivin
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All-optical active THz metasurfaces for ultrafast polarization switching and dynamic beam splitting.
Miniaturized ultrafast switchable optical components with an extremely compact size and a high-speed response will be the core of next-generation all-optical devices instead of traditional integrated circuits, which are approaching the bottleneck of Moore's Law. Metasurfaces have emerged as fascinating subwavelength flat optical components and devices for light focusing and holography applications. However, these devices exhibit a severe limitation due to their natural passive response. Here we introduce an active hybrid metasurface integrated with patterned semiconductor inclusions for all-optical active control of terahertz waves. Ultrafast modulation of polarization states and the beam splitting ratio are experimentally demonstrated on a time scale of 667 ps. This scheme of hybrid metasurfaces could also be extended to the design of various free-space all-optical active devices, such as varifocal planar lenses, switchable vector beam generators, and components for holography in ultrafast imaging, display, and high-fidelity terahertz wireless communication systems
Neural Gradient Learning and Optimization for Oriented Point Normal Estimation
We propose Neural Gradient Learning (NGL), a deep learning approach to learn
gradient vectors with consistent orientation from 3D point clouds for normal
estimation. It has excellent gradient approximation properties for the
underlying geometry of the data. We utilize a simple neural network to
parameterize the objective function to produce gradients at points using a
global implicit representation. However, the derived gradients usually drift
away from the ground-truth oriented normals due to the lack of local detail
descriptions. Therefore, we introduce Gradient Vector Optimization (GVO) to
learn an angular distance field based on local plane geometry to refine the
coarse gradient vectors. Finally, we formulate our method with a two-phase
pipeline of coarse estimation followed by refinement. Moreover, we integrate
two weighting functions, i.e., anisotropic kernel and inlier score, into the
optimization to improve the robust and detail-preserving performance. Our
method efficiently conducts global gradient approximation while achieving
better accuracy and generalization ability of local feature description. This
leads to a state-of-the-art normal estimator that is robust to noise, outliers
and point density variations. Extensive evaluations show that our method
outperforms previous works in both unoriented and oriented normal estimation on
widely used benchmarks. The source code and pre-trained models are available at
https://github.com/LeoQLi/NGLO.Comment: accepted by SIGGRAPH Asia 202
Recommended from our members
All-optical active THz metasurfaces for ultrafast polarization switching and dynamic beam splitting.
Miniaturized ultrafast switchable optical components with an extremely compact size and a high-speed response will be the core of next-generation all-optical devices instead of traditional integrated circuits, which are approaching the bottleneck of Moore's Law. Metasurfaces have emerged as fascinating subwavelength flat optical components and devices for light focusing and holography applications. However, these devices exhibit a severe limitation due to their natural passive response. Here we introduce an active hybrid metasurface integrated with patterned semiconductor inclusions for all-optical active control of terahertz waves. Ultrafast modulation of polarization states and the beam splitting ratio are experimentally demonstrated on a time scale of 667 ps. This scheme of hybrid metasurfaces could also be extended to the design of various free-space all-optical active devices, such as varifocal planar lenses, switchable vector beam generators, and components for holography in ultrafast imaging, display, and high-fidelity terahertz wireless communication systems
Soil respiration rate in summer maize field under different soil tillage and straw application
Demanding for food security and current situation of global warming give a high and strict request to North China Plain in food production and inhibition of agricultural carbon emission. To explore the effective way to decrease CO2 emission and remain high grain yield, in 2012 summer maize growing season from a long term project in North China Plain, soil organic carbon, soil CO2-C evolution rate, soil temperature, grain yield, and ratio of soil respiration to grain yield in different soil tillage and straw application treatments were invested. The results showed that in 0-20 cm soil layer, the organic carbon in no tillage was significantly higher than that in conventional tillage. Both in no tillage and conventional tillage, straw application could enhance the soil organic carbon concentrations at ma¬turity. The mean soil CO2-C evolution rate in no tillage was significantly lower than that in conventional tillage; how¬ever, straw application could significantly increase soil CO2-C evolution rate, no matter in no tillage or conventional tillage. This result was mainly due to the changes in soil organic carbon, soil total porosity, and soil temperature. No tillage and straw application result in a significantly increase in grain yield and ratio of soil respiration to grain yield of summer maize. The result obtained in field crop conditions support the idea that both no tillage and straw application affect CO2 emissions in North China Plain
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