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| 1 | Crucial control measures to contain China's first Delta variant outbreak显示文摘The SARS-C oV-2 B.1.617.2(Delta) variant flared up in late May in Guangzhou,China.Transmission characteristics of Delta variant were analysed for 153 confirmed cases and two complete transmission chains with seven generations were fully presented.A rapid transmission occurred in five generations within10 days.The basic reproduction number(R_0) was 3.60(95% confidence interval:2.50-5.30).After redefining the concept of close contact,the proportion of confirmed cases discovered from close contacts increased from 43% to 100%.With the usage of a yellow health code,the potential exposed individuals were self-motivated to take a nucleic acid test and regained public access with a negative testing result.Facing the massive requirement of screening,novel facilities like makeshift inflatable laboratories were promptly set up as a vital supplement and 17 cases were found,with 1 pre-symptomatic.The dynamic adjustment of these three interventions resulted in the decline of Rt from 5.00 to 1.00 within 9 days.By breaking the transmission chain and eliminating the transmission source through extending the scope of the close-contact tracing,health-code usage and mass testing,the Guangzhou D elta epidemic was effectively contained. | Lei Luo Zifeng Yang Jingyi Liang Yu Ma Hui Wang Chitin Hon Mei Jiang Zhengshi Lin Wenda Guan Zhitong Mai Yongming Li Kailin Mai Zhiqi Zeng Chuanmeizi Tu Jian Song Bin Liu Yong Liu Jianfeng He Huiyuan Li Bosheng Li Hang Dong Yutian Miao Shujun Fan Lirui Fan Xingyi Liang Ke Li Chun Chen Huihong Deng Zhicong Yang Nanshan Zhong | 2022 | National Science Review2022,9,4: | 2 |
| 2 | High Robust Broadcasting over DTMB-A with Low-rate LDPC Codes显示文摘As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliability by adopting flexible frame structure and advanced forward error correction coding compared with the 1 st generation DTTB systems.In order to increase the flexibility and robustness of the DTTB network,the frequency reuse scheme of factor one(reuse-1)is proposed,where the same RF channel is used by different stations covering the adjacent service areas.However,it demands a very low carrier-tonoise ratio(C/N)threshold below 0 dB at the DTTB physical layer.In this paper,a robust broadcasting technique is proposed based on DTMB-A with newly designed low-rate low density parity check(LDPC)codes.By adopting quasi-cyclic(QC)Raptor-like structure and progressive lifting method,the high performance low-rate LDPC codes are designed supporting multiple code lengths.Both density-evolution analyses and laboratory measurements demonstrate that DTMB-A with low-rate coding can complete the demodulation reliably with the C/N threshold below0 d B,which is one important necessary condition to support frequency reuse-1 scheme. | Chao Zhang Kewu Peng Zhitong He Yonglin Xue Hui Yang | 2022 | China Communications2022,19,3: | 2 |
| 3 | Kinetics of non-isothermal precipitation process of perovskite phase in oxidized Ti-bearing blast furnace slag 显示文摘 | Wang Minyu He Yuehui Wang Xuewen Lou Taiping Sui Zhitong | 2007 | Transactions of Nonferrous Metals Society of China2007,17,: | 1 |
| 4 | Characteristics of Partial Discharge in Oil-paper Insulated Needle Plate Electrode Model Under Composite AC-DC Voltage显示文摘Converter transformers are the core device in ultrahigh voltage direct current(UHVDC)transmission systems,and the oil-paper insulation at its rectifying valve side deals with the composite AC-DC voltage.A detailed investigation of the partial discharge(PD)mechanism in the oil-paper insulation under the composite AC-DC voltage is,therefore,very important.The oilpaper insulated needle plate electrode simulation model for the electric field and charge distribution can be established using hydrodynamic drift-diffusion theory and bipolar charge carrier theory,and the simulation results can reflect the morphological changes of PD.The development characteristics of PD under composite AC-DC voltage are researched.In addition,the effects of simulation time,the AC-DC component proportion,and model parameters on PD are also explored.Results indicate that differences in applied voltage,interface charge,and geometry structure can cause changes in the electric field strength,which consequently influences the PD process in the simulation model.Oil-immersed paperboard is a type of liquid-immersed dielectric(LID).When the LID is arranged in perpendicular,only the positive streamers have narrow channels oriented toward the LID.When the LID is arranged in parallel,the PDs are in the form of creeping discharges and the negative streamers are more dispersed.The development characteristics of PD and its influencing factors reported here may provide theoretical and simulation support to explain the physical mechanism of PD at the rectifying valve side of the converter transformer. | Hongshun Liu Zhitong Xue Simeng Li Qingquan Li Dongxin He Tian Xia Jian Guo | 2020 | CSEE Journal of Power and Energy Systems2020,6,4: | 1 |
| 5 | Controlling chaos in a chaotic neural network 显示文摘 | Cao Zhitong Zhu Ping Hisakazu Ogura | 2003 | Neural Networks2003,16,: | 1 |
| 6 | A sucrose non-fermenting-1-related protein kinase-1 gene, IbSnRK1, confers salt, drought and cold tolerance in sweet potato显示文摘Sucrose non-fermenting-1-related protein kinase-1(SnRK1)regulates carbon and nitrogen metabolism in plants.However,its roles and their underlying mechanisms in tolerance to abiotic stresses are little known.The present study indicated that the IbSnRK1 gene was strongly induced by Na Cl,polyethylene glycol(PEG)6000,hydrogen peroxide(H2O2),cold(4°C),and abscisic acid(ABA).Its overexpression significantly increased salt,drought,and cold tolerance in transgenic sweet potato plants.ABA,proline,and K+contents were significantly increased,whereas malondialdehyde(MDA),Na+and H2O2 contents and O2-production rate were significantly decreased in the transgenic plants under salt,drought,and cold stresses.Overexpression of the gene up-regulated genes involved in ABA biosynthesis,stress response,and stomatal closure;increased enzyme activities in the reactive oxygen species(ROS)scavenging system;and controlled stomatal closure under salt,drought,and cold stresses.These results show that the IbSnRK1 gene confers salt,drought,and cold tolerance in sweet potato by activating the ROS scavenging system and controlling stomatal closure via the ABA signaling pathway. | Zhitong Ren Shaozhen He Yuanyuan Zhou Ning Zhao Tao Jiang Hong Zhai Qingchang Liu | 2020 | The Crop Journal2020,8,6: | 1 |
| 7 | In-situ encapsulation ofα-Fe_(2)O_(3) nanoparticles into ZnFe_(2)O_(4) micro-sized capsules as high-performance lithium-ion battery anodes显示文摘Transition metal oxides as anode materials for high-performance lithium-ion batteries suffer from severe capacity decay,originating primarily from particle pulverization upon volume expansion/shrinkage and the intrinsically sluggish electron/ion transport.Herein,in-situ encapsulation ofα-Fe_(2)O_(3) nanoparticles into micro-sized ZnFe_(2)O_(4) capsules is facilely fulfilled through a co-precipitation process and followed by heat-treatment at optimal calcination temperature.The porous ZnFe_(2)O_(4) scaffold affords a synergistic confinement effect to suppress the grain growth ofα-Fe2 O3 nanocrystals during the calcination process and to accommodate the stress generated by volume expansion during the charge/discharge process,leading to an enhanced interfacial conductivity and inhibit electrode pulverization and mechanical failure in the active material.With these merits,the preparedα-Fe_(2)O_(3)/Fe_(2)O_(4) composite delivers prolonged cycling stability and improved rate capability with a higher specific capacity than soleα-Fe_(2)O_(3) and Fe_(2)O_(4).The discharge capacity is retained at 700 mAh g-1 after 500 cycles at 200 mA g^(-1) and 940 mAh g^(-1) after 50 cycles at 100 m A g^(-1).This work provides a new perspective in designing transition metal oxides for advanced lithium-ion batteries with superior electrochemical properties. | Wei Wu Yongshan Wei Hongjiang Chen Keyan Wei Zhitong Li Jianhui He Libo Deng Lei Yao Haitao Yang | 2021 | Journal of Materials Science & Technology2021,,16: | 1 |