Construction of Capacity-Achieving Lattice Codes: Polar Lattices

In this paper, we propose a new class of lattices constructed from polar codes, namely polar lattices, to achieve the capacity \frac{1}{2}\log(1+\SNR) of the additive white Gaussian-noise (AWGN) channel. Our construction follows the multilevel approach of Forney \textit{et al.}, where we construct a capacity-achieving polar code on each level. The component polar codes are shown to be naturally nested, thereby fulfilling the requirement of the multilevel lattice construction. We prove that polar lattices are \emph{AWGN-good}. Furthermore, using the technique of source polarization, we propose discrete Gaussian shaping over the polar lattice to satisfy the power constraint. Both the construction and shaping are explicit, and the overall complexity of encoding and decoding is $O(N\log N)$ for any fixed target error probability.Comment: full version of the paper to appear in IEEE Trans. Communication

Surface Electrostatic Properties of Organic Semiconductors

University of Minnesota Ph.D. dissertation. March 2016. Major: Material Science and Engineering. Advisor: C. Frisbie. 1 computer file (PDF); x, 183 pages.Understanding the surface/interface electrostatic properties of organic semiconductors has great implications for the fundamental transport properties of these materials and their performance in devices. Therefore, this thesis aims to correlate electrostatic properties with microstructure and mechanical strain in benchmark organic semiconductors. To this end, a number of scanning probe microscopy (SPM) techniques are employed to examine thin films and single crystals of prototypical organic semiconductors. In particular, strong variations of interfacial polarization at the organic/insulator interfaces are quantified by scanning Kelvin probe microscopy (SKPM). The roles of the dielectric type and deposition condition are identified. Moreover, striking lateral electrostatic heterogeneities are visualized in thermally deposited organic semiconductor bi-layers on various dielectrics, and are directly related to the complex microstructural motifs of the films. The mixed homoepitaxial growth modes, which give rise to the inhomogeneous microstructure, can be conveniently determined by combining two variants of lateral force microscopy (LFM), namely, friction force microscopy (FFM) and transverse shear force microscopy (TSM). Furthermore, a fundamental correlation is established between the surface electrostatic potential and mechanical strain. The effects of tensile and compressive strains in both elastic and plastic regimes are determined for the first time. Overall, organic semiconductors exhibit complex surface/interface electrostatic properties, which can be visualized by SPM and can be correlated with microstructure and mechanical properties

MiR-196a-5p facilitates progression of estrogen-dependent endometrial cancer by regulating FOXO1

Background and Purpose. Estrogen-dependent endometrial cancer mainly occurs in younger pre-menopausal and post-menopausal women and threatens their health. Recently, microRNAs (miRNAs) have been considered as novel targets in endometrial cancer treatment. Therefore, we aimed to explore the effect of miRNA (miR)-196a-5p in estrogen-dependent endometrial cancer. Methods. 17β-estradiol (E2; 2.5, 5, 10 and 20 nM) was used to treat RL95-2, HEC-1B and ECC-1 cells followed by cell viability assessment using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The level of miR-196a-5p was measured by reverse transcription-quantitative PCR (RT-qPCR). We then transfected miR-196a-5p mimic/inhibitor and Forkhead box protein O1 (FOXO1) small interfering RNA (siRNA) into E2-treated cells. Apoptotic cells were measured by flow cytometry. Wound healing and Transwell assays were implemented to assess migration and invasion. Bioinformatics and luciferase reporter assays were applied to confirm the interaction between miR-196a-5p and FOXO1. Immunoblotting determined the levels of FOXO1, Bcl-2, Bax, Caspase 3. Results. E2 promoted cell viability and miR-196a-5p expression in RL95-2 and ECC-1 cells. miR-196a-5p mimic enhanced cell viability, migration and invasion but suppressed apoptosis and FOXO1, whilst miR-196a-5p inhibitor blocked these processes. In addition, miR-196a-5p upregulated Bcl-2, but down regulated Bax and Caspase 3 expression, an effect that was reversed by miR-196a-5p inhibitor. We determined that miR-196a-5p targeted FOXO1, and that si-FOXO1 blocked the effects of miR-196a-5p inhibitor on viability, apoptosis, migration and invasion of E2-treated RL95-2 and ECC-1 cells. Conclusions. Our findings suggested potential diagnostic and therapeutic applications for miR-196a-5p and its FOXO1 target in patients suffering from estrogen-dependent endometrial cancer

Quantitative prediction of palaeo-uplift reservoir control and favorable reservoir formation zones in Lufeng Depression

In this paper, taking the Lufeng Depression as the study object, the distribution characteristics and reservoir-controlling conditions of palaeo-uplift are analyzed from both qualitative and quantitative perspectives. The distribution characteristics of the three-level palaeo-uplift structural pattern are elucidated, which show that the palaeo-uplifts went through three structural evolutionary stages: Eocene, Early-Middle Miocene, and Late Miocene, with long-term inherited development characteristics. Palaeo-uplift controls the distribution of hydrocarbon planes, the direction of dominant hydrocarbon transport, the development of various traps, and the types of hydrocarbon reservoirs. Applying the principle and method of “multi-element matching reservoir formation model”, the corresponding geological and mathematical models are established, which indicate that 86.29% of the number of reservoirs are distributed on the top and slope of the palaeo-uplift, and the reserves and number decrease with the distance to the top of the palaeo-uplift. Based on the palaeo-uplift control model, four high-probability areas for palaeo-uplift control in the Wenchang and Enping Fms are predicted, which are mainly located in the Lufeng middle-low uplift, the Dongsha uplift, and uplifts within the depression.Cited as: Guo, B., Yu, F., Wang, Y., Li, H., Li, H., Wu, Z. Quantitative prediction of palaeo-uplift reservoir control and favorable reservoir formation zones in Lufeng Depression. Advances in Geo-Energy Research, 2022, 6(5): 426-437. https://doi.org/10.46690/ager.2022.05.0

Numerical Analysis and Strength Evaluation of an Exposed River Crossing Pipeline with Casing Under Flood Load

Pipelines in service always experience complicated loadings induced by operational and environmental conditions. Flood is one of the common natural hazard threats for buried steel pipelines. One exposed river crossing X70 gas pipeline induced by flood erosion was used as a prototype for this study. A mechanical model was established considering the field loading conditions. Morison equations were adopted to calculate distributional hydrodynamic loads on spanning pipe caused by flood flow. Nonlinear soil constraint on pipe was considered using discrete nonlinear soil springs. An explicit solution of bending stiffness for pipe segment with casing was derived and applied to the numerical model. The von Mises yield criterion was used as failure criteria of the X70 pipe. Stress behavior of the pipe were analyzed by a rigorous finite element model established by the general-purpose Finite-Element package ABAQUS, with 3D pipe elements and pipe-soil interaction elements simulating pipe and soil constraints on pipe, respectively. Results show that, the pipe is safe at present, as the maximum von Mises stress in pipe with the field parameters is 185.57 MPa. The critical flow velocity of the pipe is 5.8 m/s with the present spanning length. The critical spanning length of the pipe is 467 m with the present flow velocity. The failure pipe sections locate at the connection point of the bare pipe and the pipe with casing or the supporting point of the bare pipe on riverbed