Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell ra...Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs.展开更多
In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safe...In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...展开更多
<b>Introduction:</b> Left-sided acute appendicitis (LSAA) develops in association with two types of congenital anomalies: situs inversus totalis (SIT) and midgut malrotation (MM). A Left sided appendicitis...<b>Introduction:</b> Left-sided acute appendicitis (LSAA) develops in association with two types of congenital anomalies: situs inversus totalis (SIT) and midgut malrotation (MM). A Left sided appendicitis is an ambiguous and difficult diagnosis to make. <b>Aim: </b>To present a proven case of left-sided acute appendicitis (LSAA) associated with situs inversus totalis (SIT). <b>Case</b> <b>Report:</b> A case of Left appendicitis was evaluated in a 28-year-old Asian male, who presented to our hospital in Feb. 2016, with lower abdominal pain more on left side and suspected diverticulitis or acute appendicitis with unusual appendix location. The patient doesn’t recall any history of abdominal surgery or about situs inversus totalis, abdominal and pelvic ultrasound was done, left iliac fossa appendicitis was diagnosed, Erect chest X-ray including upper abdomen revealed dextrocardia and stomach air on right side (situs inversus totalis), the patient underwent diagnostic Laproscop and Endoscopic resection of the appendix, with no incidents, and then discharged without complications, follow visits went unremarkable. <b>Conclusion: </b>The diagnosis of left lower quadrant pain is based on well-established clinical symptoms, physical examination and physician’s experience.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant No.61671145the Key R&D Program of Jiangsu Province of China under Grant BE2018121
文摘Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs.
文摘In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...
文摘<b>Introduction:</b> Left-sided acute appendicitis (LSAA) develops in association with two types of congenital anomalies: situs inversus totalis (SIT) and midgut malrotation (MM). A Left sided appendicitis is an ambiguous and difficult diagnosis to make. <b>Aim: </b>To present a proven case of left-sided acute appendicitis (LSAA) associated with situs inversus totalis (SIT). <b>Case</b> <b>Report:</b> A case of Left appendicitis was evaluated in a 28-year-old Asian male, who presented to our hospital in Feb. 2016, with lower abdominal pain more on left side and suspected diverticulitis or acute appendicitis with unusual appendix location. The patient doesn’t recall any history of abdominal surgery or about situs inversus totalis, abdominal and pelvic ultrasound was done, left iliac fossa appendicitis was diagnosed, Erect chest X-ray including upper abdomen revealed dextrocardia and stomach air on right side (situs inversus totalis), the patient underwent diagnostic Laproscop and Endoscopic resection of the appendix, with no incidents, and then discharged without complications, follow visits went unremarkable. <b>Conclusion: </b>The diagnosis of left lower quadrant pain is based on well-established clinical symptoms, physical examination and physician’s experience.
