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| 1 | Effects of key design parameters of tine furrow opener on soil seedbed properties显示文摘The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and yields.In order to analyze the effects of key parameters of tine furrow openers on soil properties(soil bulk density,soil water-stable aggregates(WSA),and soil disturbance)of the surface soil layer of 0-10 cm and surface straw disturbance,the tine furrow openers with different structural parameters,including cutting edge thickness,cutting edge curve,penetration clearance angle and rake angle,were designed and tested under no-till conditions.Orthogonal test and single factor test were performed to analyze the effects of different parameters.Results showed that the rake angle,cutting edge thickness and cutting edge curve had significant effects on cross-sectional area of furrow(Af)and disturbance of surface straw;the rake angle had a significant effect on soil bulk density.Soil types and operating depth had significant effects on soil disturbance caused by tine furrow openers.The concave type tine furrow opener produced the lowest soil disturbance and soil bulk density of seed furrow,the highest surface straw disturbance and the greatest content of WSA(>0.5 mm).With increasing rake angles of tine furrow opener,the width of seedbed(Wsb)and the Af decreased first and then increased,respectively,while the width of soil throw(Wst)and the height of ridge(Hr)increased.The Wsb and Af created by tine furrow opener with 60°rake angle were significantly lower than that with others,respectively.The tine furrow opener with rake angle ranged from 45°to 60°created the lowest soil bulk density.As the penetration clearance angle increased,the content of WSA(>0.5 mm)decreased,but the effect of penetration clearance angle on the content of WSA(<0.5 mm)was not significant.The cutting edge thickness(<2 mm)had no significant effects on soil properties of seedbed.This study could provide a reference for optimal design of the tine furrow opener to create more suitable seedbed environment,and promote the application of the light no-till planters. | Zhang Xiangcai Li Hongwen Du Ruicheng Ma Shaochun He Jin Wang Qingjie Chen Wanzhi Zheng Zhiqi Zhang Zhiqiang | 2016 | International Journal of Agricultural and Biological Engineering2016，9，3： | 7 |
| 2 | Energy-and spectral-efficiency of zero-forcing beamforming in massive MIMO systems with imperfect reciprocity calibration: bound and optimization显示文摘In a time-division duplex(TDD) system with massive multiple input multiple output(MIMO),channel reciprocity calibration(RC) is generally required in order to cope with the reciprocity mismatch between the uplink and downlink channel state information. Currently, evaluating the achievable spectral efficiency(SE) and energy efficiency(EE) of TDD massive MIMO systems with imperfect RC(IRC) mainly relies on exhausting Monte Carlo simulations and it is infeasible to precisely and concisely quantify the achievable SE and EE with IRC. In this study, a novel method is presented for tightly bounding the achievable SE of massive MIMO systems with zero-forcing beamforming under IRC. On the basis of the analytical results, we demonstrate key insights for practical system design with IRC in three aspects: the scaling rule for interference power, saturation region of the SE, and the bound on the SE loss. Finally, the trade-off between spectral and energy efficiencies in the presence of IRC is determined with algorithms developed to optimize SE(EE) under a constrained EE(SE) value. The loss of optimal total SE and EE due to IRC is also quantified, which shows that the loss of optimal EE is more sensitive to IRC in a typical range of transmit power values. | Donglin LIU Fei WU Xin QUAN Wanzhi MA Ying LIU Shihai SHAO | 2018 | Science China(Information Sciences)2018，61，12： | 2 |
| 3 | Positioning taxonomic research for the future显示文摘Why do taxonomists matter? The work of taxonomists is often understated if not completely misunderstood. Without taxonomists, organisms cannot be accurately identified, neither can these organisms be given universally accepted names, and reliably positioned in the phylogenetic tree of life. Thanks to the work of taxonomists over the last 269 years since Carl Linnaeus established the binomial system, we can now measure the health and wealth of our biodiversity in a refined, science-based inventory prescribed by stringent nomenclatural rules. | Deyuan Hong Wenying Zhuang Min Zhu Keping Ma Xiaoquan Wang Dawei Huang Yalin Zhang Guodong Ren Wenjun Bu Wanzhi Cai Dong Ren Ding Yang Aiping Liang Fengyan Bai Runzhi Zhang Fumin Lei Shuqiang Li Hongzhi Kong Lei Cai Yucheng Dai Chaodong Zhu Qisen Yang Jun Chen Zhongli Sha Jianping Jiang Jing Che Donghui Wu Jiatang Li Qiang Wang Xinli Wei Ming Bai Xingyue Liu Xuexin Chen Gexia Qiao | 2022 | Zoological Systematics2022，47，3： | 2 |
| 4 | Performance of an M-QAM full-duplex wireless system with a nonlinear amplifier显示文摘The effect of amplifier nonlinearity is analyzed for M-QAM full-duplex communications in additive white Gaussian noise channels. Two classical memoryless nonlinear amplifier models, i.e., a traveling-wave tube amplifier and a solid-state power amplifier, are considered. An analytical expression for the bit error ratio is derived using a characteristic function and numerical integration. Theoretical results show perfect agreement with those obtained by simulation. The analytical results could be used to evaluate the degradation in performance of an M-QAM full-duplex system caused by amplifier nonlinearity, and will be helpful in finding the optimal static operating point of an amplifier. | Zhaojun HE Wanzhi MA Shihai SHAO Fei WU Chaojin QING Youxi TANG | 2016 | Science China(Information Sciences)2016，59，10： | 2 |
| 5 | A joint call for actions to advance taxonomy in China显示文摘Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China. | Chaodong Zhu Arong Luo Ming Bai Michael COrr Zhonge Hou Siqin Ge Jun Chen Yibo Hu Xuming Zhou Gexia Qiao Hongzhi Kong Limin Lu Xiaohua Jin Lei Cai Xinli Wei Ruilin Zhao Wei Miao Qingfeng Wang Zhongli Sha Qiang Lin Meng Qu Jianping Jiang Jiatang Li Jing Che Xuelong Jiang Xiaoyong Chen Lianming Gao Zongxin Ren Chunlei Xiang Shixiao Luo Donghui Wu Dong Liu Yanqiong Peng Tao Su Chenyang Cai Tianqi Zhu Wanzhi Cai Xingyue Liu Hu Li Huaijun Xue Zhen Ye Xuexin Chen Pu Tang Shujun Wei Hong Pang Qiang Xie Feng Zhang Feng Zhang Xianjin Peng Aibing Zhang Taiping Gao Changfa Zhou Chen Shao Libin Ma Zhaoming Wei Yunxia Luan Ziwei Yin Wu Dai Cong Wei Xiaolei Huang Jingxian Liu Xiangsheng Chen Tianci Yi Zhisheng Zhang Zhulidezi Aishan Qin Li Hongying Hu | 2022 | Zoological Systematics2022，47，3： | 1 |
| 6 | Layeredspace-time codes over Ricean fading channels by reduc- ing the correlation of spatial shaping pulses显示文摘 | SHAO Shihai TANG Youxi MA Wanzhi | 2009 | IEEE Transactions on Wireless Communications2009，8，2： | 1 |
| 7 | Layered space-time codes over Pdcean fading channels by reducing the correlation of spatial shaping pulses显示文摘 | Shihai Shao Tang Youxi and Ma Wanzhi | 2009 | IEEE Transactions on Wireless Communications2009，8，2： | 1 |
| 8 | An enhanced digital predistortion algorithm based on polynomial model identification显示文摘To improve the accuracy of the nonlinear distortion correction for the radio frequency(RF)power amplifier(PA), it is necessary to precisely obtain the reverse function of the PA nonlinear model.However, the direct inversion of the PA nonlinear model involves solving a high-order univariate polynomial,which is difficult to apply in engineering. In this study, based on the envelope memory polynomial(EMP)model, the high-order terms of the nonlinear model are approximated by their previously calculated values through iterations and considered as known constants in the polynomial solution finding process, thereby resulting in a significant reduction in computational complexity. Compared with the direct inversion method,model of a 9 th-order nonlinear, the proposed method reduces the calculation time in the coordinated rotation digital computer(CORDIC) algorithm by at least 80%. The simulation results show that for a long-term evolution(LTE) downlink signal, the results obtained by the proposed simplified method agree well with those obtained by direct inversion method. | Wanzhi MA Xin QUAN Bo ZHAO Ying LIU Wensheng PAN Shihai SHAO Youxi TANG | 2019 | Science China(Information Sciences)2019，62，2： | 0 |
| 9 | Effect of mulching with maize straw on water infiltration and soil loss at different initial soil moistures in a rainfall simulation显示文摘Mulching and soil water content(SWC) have a significant impact on soil erosion,and this study investigated the effect of straw mulching on water infiltration and soil loss under different initial SWC treatments in a rainfall simulation experiment conducted in northern China.Increasing initial SWC can decrease soil infiltration and increase soil loss.During an 80 mm rainfall event(80 mm·h–1for 60 min),8%,12% and 16% initial SWC treatments decreased cumulative infiltration by8.7%,42.5% and 58.1%,and increased total sediment yield by 44,146 and 315 g,respectively,compared to 4%initial SWC.However,in all the straw mulching treatments,there was no significant difference in stable infiltration rate between the different initial SWC treatments.For all initial SWC treatments,straw mulching of30% or more significantly enhanced water infiltration by over 31% and reduced soil loss by over 49%,compared to the unmulched treatment.Taking into consideration the performance of no-till planters,a maize straw mulching rate of 30% to 60%(1400–3100 kg·hm–2) is recommended for the conservation of water and soil in northern China. | Yifu ZHANG Hongwen LI Jin HE Qingjie WANG Ying CHEN Wanzhi CHEN Shaochun MA | 2016 | Frontiers of Agricultural Science and Engineering2016，3，2： | 0 |
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