|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Effects of different tillage and straw retention practices on soil aggregates and carbon and nitrogen sequestration in soils of the northwestern China显示文摘Soil tillage and straw retention in dryland areas may affect the soil aggregates and the distribution of total organic carbon. The aims of this study were to establish how different tillage and straw retention practices affect the soil aggregates and soil organic carbon(SOC) and total nitrogen(TN) contents in the aggregate fractions based on a long-term(approximately 15 years) field experiment in the semi-arid western Loess Plateau, northwestern China. The experiment included four soil treatments, i.e., conventional tillage with straw removed(T), conventional tillage with straw incorporated(TS), no tillage with straw removed(NT) and no tillage with straw retention(NTS), which were arranged in a complete randomized block design. The wet-sieving method was used to separate four size fractions of aggregates, namely, large macroaggregates(LA, >2000 μm), small macroaggregates(SA, 250–2000 μm), microaggregates(MA, 53–250 μm), and silt and clay(SC, <53 μm). Compared to the conventional tillage practices(including T and TS treatments), the percentages of the macroaggregate fractions(LA and SA) under the conservation tillage practices(including NT and NTS treatments) were increased by 41.2%–56.6%, with the NTS treatment having the greatest effect. For soil layers of 0–5, 5–10 and 10–30 cm, values of the mean weight diameter(MWD) under the TS and NTS treatments were 10.68%, 13.83% and 17.65%, respectively. They were 18.45%, 19.15% and 14.12% higher than those under the T treatment, respectively. The maximum contents of the aggregate-associated SOC and TN were detected in the SA fraction, with the greatest effect being observed for the NTS treatment. The SOC and TN contents were significantly higher under the NTS and TS treatments than under the T treatment. Also, the increases in SOC and TN levels were much higher in the straw-retention plots than in the straw-removed plots. The macroaggregates(including LA and SA fractions) were the major pools for SOC and TN, regardless of tillage practices, storing 3.25–6.81 g C/kg soil and 0.34–0.62 g N/kg soil. Based on the above results, we recommend the NTS treatment as the best option to boost soil aggregates and to reinforce carbon and nitrogen sequestration in soils in the semi-arid western Loess Plateau of northwestern China. | WU Jun Yeboah STEPHEN CAI Liqun ZHANG Renzhi QI Peng LUO Zhuzhu LI Lingling XIE Junhong DONG Bo | 2019 | Journal of Arid Land2019，11，4： | 5 |
| 2 | Dual confinement of polysulfides in boron-doped porous carbon sphere/graphene hybrid for advanced Li-S batteries显示文摘由做硼的多孔的碳范围和 graphene (BPCS-G ) 组成的混合结构被设计了并且向解决 polysulfide 梭问题综合了,它是当前的 Li-S 电池的最关键的问题。显示出高表面区域的建议混合结构(870 m 2??????????????? ? €畧湡湩?? 挠瑹獯湩 ?????? ㄠ‰ ????????????? 吠 ?? €?‰ ??????? ‰ ?????????????????????????? ￡桴?? | Wei Ai Jiewei Li Zhuzhu Du Chenji Zou Hongfang Du Xin Xu Yu Chen Hongbo Zhang Jianfeng Zhao Changming Li Wei Huang Ting Yu | 2018 | Nano Research2018，11，9： | 2 |
| 3 | Availability modelling for periodically inspected systems under mixed maintenance policies显示文摘The availability of a periodic inspection system under mixed maintenance policies is studied in this paper.To accommodate the characteristic of multiple failure modes for complex systems,the system failures can be divided into two failure modes:hard failure and soft failure.When hard failure occurs,the corresponding corrective maintenance will be performed,taking a random time under the perfect maintenance policy;in contrast,if the soft failure is found,the corresponding preventive maintenance will be performed,taking a random time under the imperfect maintenance policy.The dynamic age setback model is adopted for imperfect maintenance,which can accurately reflect the fault characteristics of the degraded system.Then an analytical model for system steady state availability and instantaneous availability are derived.Moreover,the optimal method to maximize the system steady-state availability through adjusting the inspection interval is researched.According to the above research,the optimization of system unit time cost,preventive maintenance intervals and availability is researched.Finally,the developed approach is demonstrated by a numerical example. | LI Junliang CHEN Yueliang ZHANG Yong ZHANG Zhuzhu FAN Weijie | 2021 | Journal of Systems Engineering and Electronics2021，32，3： | 2 |
| 4 | Evolution of soil and water conservation in rain-fed areas of China显示文摘Rain-fed(dryland)farming is an ancient agricultural production system in China.It occurs widely across almost the whole country,especially in the Northwest and North China.The semi-arid Loess Plateau is the most important region of rain-fed farming in China,but unfortunately,soil erosion on the Loess Plateau area is the highest in China,and indeed amongst the highest in the world.This highlights the necessity for developing practices that can reduce soil and water erosion,improve soil water use efficiency,improve crop productivity,and reduce rural poverty in the region.Many techniques of soil and water conservation are being used in rain-fed areas of China,including such systems as mulch,ridge and furrow systems.The Appendix describes a unique system of soil and water conservation,called Shatian.Modern research on conservation tillage(No Till),although essential for reducing erosion,increasing crop productivity,and ameliorating poverty,is just beginning in China.Modern conservation tillage research started in the1990s’with support from Australia and other countries.The procedures,however,were modified to be in accord with local conditions and prevailing farmer experiences.With 10 years of experimentation,results show that the most successful conservation practice on the Western Loess Plateau is no till with stubble retention.This technique helps to conserve soil water,increases soil organic carbon,improves soil structure and water infiltration,reduces soil and water erosion,and improves crop productivity and sustainability of rain-fed farming systems.However,its adoption rate remains low due to barriers such as traditional attitude,insufficient rural extension,and so forth. | Li Lingling Zhang Renzhi Luo Zhuzhu Liang Weili Xie Junhong Cai Liqun B.Bellotti | 2014 | International Soil and Water Conservation Research2014，2，1： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员