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Effects of Different Farming Methods and Their Effects on Soil Physicochemical Properties of Guilin Maojian Tea Gardens
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作者 lingyun ZHANG shuyi li +5 位作者 Sisi Qin Changjian JIANG Qifa LONG Min SU Chusheng liU Qianhua WU 《Agricultural Biotechnology》 CAS 2018年第5期186-190,共5页
In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties ... In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties of tea garden soil were studied through the modification of the test sites with the non-farming land as the control. The results showed that human farming, mini-tiller farming and crawler tractor farming could improve the physical and chemical properties of soil. After farming, the soil had good water retention but low moisture content compared to the control group, while the soil bulk density and hardness value were significantly lower than those of the control, and the porosity of soil was significantly higher than that of contrast. With the passage of time, soil bulk density and hardness value gradually increased after farming, while the porosity of soil decreased gradually. There were great differences in the effects, efficiencies and costs of different farming methods. Crawler tractor had the best and most stable farming effect, and the operation efficiency was 10 times that of human farming while the cost was only 0.39 times of human farming. Therefore, it was feasible to adopt mini-tiller or crawler tractor to carry out mechanical farming of Guilin Maojian tea garden, which provided theoretical references for the soil property improvement using mechanical farming and was favorable for promoting the popularization of farming machines and the acceleration of mechanization of tea gardens. But for tea plantations that are intended to be mechanized, apart from the mechanical and technical personnel to be configured in place, the site conditions, planting modes and mechanical way reservation of tea garden should be planned accordingly. It is recommended to select flat or gentle slope for reclamation, and preference is given to non-sexual tea tree varieties with big line spacing over 180 cm long. Moreover, the main road construction should be more than 3.0 m, and trunk road 2.0 m or above. And isolation ditch and drain should be set between the tea garden and the surrounding mountain forests and farmland. 展开更多
关键词 Guilin Maojian tea Tea garden Farming methods SOIL Physical and chemical properties
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Rh/Al_(2)O_(3)催化剂在丙烷脱氢反应中的表面变化
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作者 李书毅 穆长乐 +3 位作者 何念秋 徐杰 郑燕萍 陈明树 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第7期145-155,共11页
丙烯是一种重要的化工原料,需求量较大且逐年增加.丙烷脱氢(PDH)是一种高效的生产丙烯过程,正逐步取代石脑油裂解成为重要的丙烯生产工艺.开发高效且稳定的PDH催化剂将对PDH工业发展起到积极的推动作用.Rh因其较好的C-H键活化能力,展现... 丙烯是一种重要的化工原料,需求量较大且逐年增加.丙烷脱氢(PDH)是一种高效的生产丙烯过程,正逐步取代石脑油裂解成为重要的丙烯生产工艺.开发高效且稳定的PDH催化剂将对PDH工业发展起到积极的推动作用.Rh因其较好的C-H键活化能力,展现出作为PDH催化剂的巨大潜力,但关于Rh应用于PDH的报道较少.明确Rh物种尺寸对PDH产物选择性的影响,对后续设计高效且稳定的Rh基PDH催化剂至关重要.多相催化反应主要发生在催化剂的表面,因此,催化剂的表面状态对其催化性能具有重要的影响.在催化反应过程中,一些催化剂的表面状态会发生显著变化,这些变化会导致活性、产物选择性明显变化.通过采用(准)原位表面研究手段,能够清晰地了解催化剂在反应过程中的表面变化,这对于建立催化剂结构与反应性能之间的构效关系具有非常重要的意义.本文通过沉积-沉淀法制备了不同负载量的Rh/Al_(2)O_(3)催化剂,旨在探究Rh物种尺寸对PDH产物选择性的影响.球差电镜(AC-HAADF-STEM)观察显示,Rh物种以团簇和单原子的形式共存于Al_(2)O_(3)载体上.进一步通过准原位X射线光电子能谱(XPS)证实了不同化学态的Rh物种.通过固定床反应器对Rh/Al_(2)O_(3)催化剂的PDH性能进行测试,结果表明,催化剂在反应初始阶段需要经历诱导期.在此期间,甲烷的选择性显著降低,而丙烯的选择性显著升高,同时,丙烷的转化率显著降低.碳平衡计算表明,诱导期内产生了大量积碳.采用准原位XPS、低能离子散射谱(LEIS)和CO吸附红外光谱(CO-FTIR)研究了Rh/Al_(2)O_(3)催化剂在诱导期的表面变化.结果表明,在反应初始阶段,催化剂表面有大量积碳产生,这些积碳主要聚集在Rh物种表面,覆盖了Rh团簇,而Rh单原子则保持暴露状态,并作为PDH反应的活性中心.AC-HAADF-STEM结果表明,PDH反应4 h后,仍有Rh单原子存在于催化剂表面.结合Rh/Al_(2)O_(3)催化剂的PDH性能和准原位表征结果认为,丙烷在Rh团簇表面发生C-C键断裂反应,生成甲烷和积碳.积碳对Rh团簇的覆盖抑制了丙烷裂解反应,导致甲烷的选择性在诱导期显著降低;而Rh单原子则仍然暴露,具有催化PDH反应活性,并且是高选择性地生成丙烯的位点.该选择性的差异由丙烯在不同尺寸Rh物种上的吸附方式不同引起的,在Rh团簇表面以di-σ键吸附方式为主,吸附强度较强,丙烯不易脱附,并进一步发生裂解产生甲烷和积碳;而在Rh单原子上,丙烯以π键吸附方式存在,吸附强度较弱,不易发生副反应.对反应后的Rh/Al_(2)O_(3)催化剂进行分析,发现积碳主要为碳氢化合物和石墨碳,且随着反应进行,积碳从Rh团簇表面向Al_(2)O_(3)载体上转移.综上所述,本文通过使用准原位XPS,LEIS和CO-FTIR等技术探究了Rh/Al_(2)O_(3)催化剂在PDH反应中的表面变化,揭示了Rh物种尺寸对PDH产物选择性的影响.结果表明,Rh单原子对丙烯选择性有利,而在Rh团簇表面PDH产物主要为甲烷并产生积碳,同时积碳导致了催化剂在反应初始阶段的快速失活.本工作为后续高效Rh基PDH催化剂的设计提供参考. 展开更多
关键词 丙烷脱氢 积碳 单原子 准原位谱学 表面变化
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LDAS&ET-AD:Learnable Distillation Attack Strategies and Evolvable Teachers Adversarial Distillation
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作者 shuyi li Hongchao Hu +3 位作者 Xiaohan Yang Guozhen Cheng Wenyan liu Wei Guo 《Computers, Materials & Continua》 SCIE EI 2024年第5期2331-2359,共29页
Adversarial distillation(AD)has emerged as a potential solution to tackle the challenging optimization problem of loss with hard labels in adversarial training.However,fixed sample-agnostic and student-egocentric atta... Adversarial distillation(AD)has emerged as a potential solution to tackle the challenging optimization problem of loss with hard labels in adversarial training.However,fixed sample-agnostic and student-egocentric attack strategies are unsuitable for distillation.Additionally,the reliability of guidance from static teachers diminishes as target models become more robust.This paper proposes an AD method called Learnable Distillation Attack Strategies and Evolvable Teachers Adversarial Distillation(LDAS&ET-AD).Firstly,a learnable distillation attack strategies generating mechanism is developed to automatically generate sample-dependent attack strategies tailored for distillation.A strategy model is introduced to produce attack strategies that enable adversarial examples(AEs)to be created in areas where the target model significantly diverges from the teachers by competing with the target model in minimizing or maximizing the AD loss.Secondly,a teacher evolution strategy is introduced to enhance the reliability and effectiveness of knowledge in improving the generalization performance of the target model.By calculating the experimentally updated target model’s validation performance on both clean samples and AEs,the impact of distillation from each training sample and AE on the target model’s generalization and robustness abilities is assessed to serve as feedback to fine-tune standard and robust teachers accordingly.Experiments evaluate the performance of LDAS&ET-AD against different adversarial attacks on the CIFAR-10 and CIFAR-100 datasets.The experimental results demonstrate that the proposed method achieves a robust precision of 45.39%and 42.63%against AutoAttack(AA)on the CIFAR-10 dataset for ResNet-18 and MobileNet-V2,respectively,marking an improvement of 2.31%and 3.49%over the baseline method.In comparison to state-of-the-art adversarial defense techniques,our method surpasses Introspective Adversarial Distillation,the top-performing method in terms of robustness under AA attack for the CIFAR-10 dataset,with enhancements of 1.40%and 1.43%for ResNet-18 and MobileNet-V2,respectively.These findings demonstrate the effectiveness of our proposed method in enhancing the robustness of deep learning networks(DNNs)against prevalent adversarial attacks when compared to other competing methods.In conclusion,LDAS&ET-AD provides reliable and informative soft labels to one of the most promising defense methods,AT,alleviating the limitations of untrusted teachers and unsuitable AEs in existing AD techniques.We hope this paper promotes the development of DNNs in real-world trust-sensitive fields and helps ensure a more secure and dependable future for artificial intelligence systems. 展开更多
关键词 Adversarial training adversarial distillation learnable distillation attack strategies teacher evolution strategy
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Fluorine-free,robust and self-healing superhydrophobic surfaces with anticorrosion and antibacterial performances 被引量:2
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作者 Wenliang Zhang shuyi li +3 位作者 Dongsong Wei Zaihang Zheng Zhiwu Han Yan liu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第19期231-243,共13页
Superhydrophobic surfaces with water-repelling ability have important applications, such as self-cleaning, antibacterial and corrosion protection. However, the using of harmful fluorinated materials and its poor mecha... Superhydrophobic surfaces with water-repelling ability have important applications, such as self-cleaning, antibacterial and corrosion protection. However, the using of harmful fluorinated materials and its poor mechanochemical stability limit its practical application. Herein, a fluorine-free, robust and self-healing superhydrophobic surface is prepared through a two-step method of laser processing and spraying coating for anticorrosion and antibacterial applications. Laser processing is used to construct periodic micron-sized pillars for obtaining strong interface bonding between coating and substrate by mechanical interlocking effect, and as an ‘armor’, preventing the removal of the coating. The coating consists of epoxy resin (EP), hexadecyltrimethoxysilane (HDTMS) and γ-aminopropyltriethoxysilane treated Cu2O (KH550-Cu2O). The superhydrophobic surface can withstand various mechanical durability tests, such as multiple sandpaper abrasion and tape peeling cycles. It exhibits excellent corrosion inhibition efficiency (ηp > 99 %) on Mg alloy, Tinplate and Al alloy, which results from superhydrophobicity and organic coating. The superhydrophobicity endows surface with excellent antibacterial adhesion performance in a static liquid environment. The bactericidal activity of KH550-Cu2O can effectively inactivate the bacteria in contact with the surface and the free bacteria, providing excellent antibacterial ability in a dynamic liquid environment. It still exhibits good anticorrosion and antibacterial abilities after multiple mechanical abrasion cycles due to the outstanding mechanical durability. Moreover, it exhibits outstanding self-healing ability to plasma etching and oil contamination, self-cleaning ability under air and oil conditions, and chemical stability against acids and alkalis solution. All the above excellent performances promote its application in a wider range of fields. 展开更多
关键词 SUPERHYDROPHOBICITY SELF-HEALING Durability and stability Antibacterial adhesion and bactericidal activity ANTICORROSION
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Smart Bionic Surfaces with Switchable Wettability and Applications
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作者 shuyi li Yuyan Fan +3 位作者 Yan liu Shichao Niu Zhiwu Han Luquan Ren 《Journal of Bionic Engineering》 SCIE EI CSCD 2021年第3期473-500,共28页
In order to satisfy the needs of different applications and more complex intelligent devices,smart control of surface wettability will be necessary and desirable,which gradually become a hot spot and focus in the fiel... In order to satisfy the needs of different applications and more complex intelligent devices,smart control of surface wettability will be necessary and desirable,which gradually become a hot spot and focus in the field of interface wetting.Herein,we review interfacial wetting states related to switchable wettability on superwettable materials,including several classical wetting models and liquid adhesive behaviors based on the surface of natural creatures with special wettability.This review mainly focuses on the recent developments of the smart surfaces with switchable wettability and the corresponding regulatory mechanisms under external stimuli,which is mainly governed by the transformation of surface chemical composition and geometrical structures.Among that,various external stimuli such as physical stimulation(temperature,light,electric,magnetic,mechanical stress),chemical stimulation(pH,ion,solvent)and dual or multi-triggered stimulation have been sought out to realize the regulation of surface wettability.Moreover,we also summarize the applications of smart surfaces in different fields,such as oil/water separation,programmable transportation,anti-biofouling,detection and delivery,smart soft robotic etc.Furthermore,current limitations and future perspective in the development of smart wetting surfaces are also given.This review aims to offer deep insights into the recent developments and responsive mechanisms in smart biomimetic surfaces with switchable wettability under external various stimuli,so as to provide a guidance for the design of smart surfaces and expand the scope of both fundamental research and practical applications. 展开更多
关键词 bionic surfaces external stimuli switchable wettability responsive mechanisms
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细胞因子与眼科疾病的研究进展 被引量:2
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作者 李坚 陶勇 +2 位作者 郦舒伊 张小花 胡勇平 《中华眼科医学杂志(电子版)》 2022年第2期115-119,共5页
细胞因子有“细胞之间沟通语言”之称,它参与着机体器官组织的生理与病理过程。对细胞因子与眼部疾病的相关研究,不仅可以揭示其发病的分子机制,监测细胞因子的指标还可用于疾病诊断、预判疾病的转归、明确疾病干预的时机并有助于制定... 细胞因子有“细胞之间沟通语言”之称,它参与着机体器官组织的生理与病理过程。对细胞因子与眼部疾病的相关研究,不仅可以揭示其发病的分子机制,监测细胞因子的指标还可用于疾病诊断、预判疾病的转归、明确疾病干预的时机并有助于制定新型靶向治疗的策略。本文中笔者就细胞因子概念与研究的溯源及其在糖尿病性眼病、视网膜静脉阻塞、年龄相关性黄斑变性、自身免疫性葡萄膜炎、青光眼性视神经病变、增殖性玻璃体视网膜病变及早产儿视网膜病变等眼部疾病中的研究进展进行综述。 展开更多
关键词 细胞因子 眼部疾病 分子机制
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地质封存二氧化碳与深地微生物相互作用研究进展 被引量:4
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作者 李术艺 冯旗 董依然 《微生物学报》 CAS CSCD 北大核心 2021年第6期1632-1649,共18页
地质封存将工业和能源相关领域生产活动产生的二氧化碳(CO_(2))进行捕集并注入到深部地下岩石构造中,以实现长期储存的目标,是降低温室气体排放、实现CO_(2)长期封存的重要可行性手段之一。向深部地下地质构造中注入大量CO_(2)会导致深... 地质封存将工业和能源相关领域生产活动产生的二氧化碳(CO_(2))进行捕集并注入到深部地下岩石构造中,以实现长期储存的目标,是降低温室气体排放、实现CO_(2)长期封存的重要可行性手段之一。向深部地下地质构造中注入大量CO_(2)会导致深地环境发生显著变化,进而引起原生微生物活性及群落结构发生明显改变。因此,地质封存CO_(2)能够直接或间接影响深地微生物驱动的生物地球化学过程。同时,微生物在短期和长期的超临界CO_(2)(scCO_(2))胁迫作用下,也会通过不同的适应性进化方式影响CO_(2)在地下环境中的迁移、转化和赋存形态。本文介绍了国内外二氧化碳捕获与封存发展现状以及地质封存CO_(2)影响条件下的scCO_(2)-水-微生物-矿物的相互作用领域的最新科研进展,并展望了利用深地微生物强化CO_(2)固定以及将其转化为高附加值产物的潜力。 展开更多
关键词 二氧化碳地质封存 深地微生物 CO2胁迫 scCO2-水-微生物-矿物的相互作用 生物转化 CO2固定
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Compact and broadband multimode waveguide bend by shape-optimizing with transformation optics 被引量:6
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作者 shuyi li liFENG CAI +5 位作者 DINGSHAN GAO JIANJI DONG JIN HOU CHUNYONG YANG SHAOPING CHEN XINliANG ZHANG 《Photonics Research》 SCIE EI CAS CSCD 2020年第12期1843-1849,共7页
Multimode waveguide bend is one of the key components for realizing high-density mode-division multiplexing systems on chip.However,the reported multimode waveguide bends are either large,bandwidth-limited or fabricat... Multimode waveguide bend is one of the key components for realizing high-density mode-division multiplexing systems on chip.However,the reported multimode waveguide bends are either large,bandwidth-limited or fabrication-complicated,which hinders their applications in future high-density multimode photonic circuits.Here we propose a compact multimode waveguide bend supporting four TE modes simply by shape-optimizing with transformation optics.The shape of the waveguide is optimized in the virtual space with gradient distribution of the refractive index,so that the scattering loss and intermode cross talk are well suppressed.After conformal mapping back into the physical space,a compact(effective radius of 17μm)multimode bending waveguide is obtained.Simulations show that the proposed multimode waveguide bend has little loss(<0.1 dB)and low cross talk(<−20 dB)throughout an ultrabroad wavelength range of 1.16–1.66μm.We also fabricated the shape-optimized multimode bending waveguide on a silicon-on-insulator wafer.At 1550 nm wavelength,the measured excess losses for the four lowest-order TE modes are less than 0.6 dB,and the intermode cross talks are all below−17 dB.Our study paves the way for realizing high-density and large-scale multimode integrated optical circuits for optical interconnect. 展开更多
关键词 WAVEGUIDE MULTIMODE OPTICS
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Recent progress in quantum photonic chips for quantum communication and internet 被引量:6
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作者 Wei Luo lin Cao +12 位作者 Yuzhi Shi lingxiao Wan Hui Zhang shuyi li Guanyu Chen Yuan li Sijin li Yunxiang Wang Shihai Sun Muhammad Faeyz Karim Hong Cai Leong Chuan Kwek Ai Qun liu 《Light(Science & Applications)》 SCIE EI CSCD 2023年第8期1544-1565,共22页
Recent years have witnessed significant progress in quantum communication and quantum internet with the emerging quantum photonic chips,whose characteristics of scalability,stability,and low cost,flourish and open up ... Recent years have witnessed significant progress in quantum communication and quantum internet with the emerging quantum photonic chips,whose characteristics of scalability,stability,and low cost,flourish and open up new possibilities in miniaturized footprints.Here,we provide an overview of the advances in quantum photonic chips for quantum communication,beginning with a summary of the prevalent photonic integrated fabrication platforms and key components for integrated quantum communication systems.We then discuss a range of quantum communication applications,such as quantum key distribution and quantum teleportation.Finally,the review culminates with a perspective on challenges towards high-performance chip-based quantum communication,as well as a glimpse into future opportunities for integrated quantum networks. 展开更多
关键词 QUANTUM STABILITY COMMUNICATION
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The CST bounce universe model——A parametric study
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作者 Yeuk-Kwan Edna Cheung Xue Song +2 位作者 shuyi li YunXuan li YiQing Zhu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2019年第1期9-15,共7页
A bounce universe model with a scale-invariant and stable spectrum of primordial density perturbations was constructed using a consistent truncation of the D-brane dynamics from Type IIB string theory. A coupling was ... A bounce universe model with a scale-invariant and stable spectrum of primordial density perturbations was constructed using a consistent truncation of the D-brane dynamics from Type IIB string theory. A coupling was introduced between the tachyon field and the adjoint Higgs field on the D3-branes to lock the tachyon at the top of its potential hill and to model the bounce process,which is known as the Coupled Scalar and Tachyon Bounce(CSTB) Universe. The CSTB model has been shown to be ghost free,and it fulfils the null energy condition; in addition, it can also solve the Big Bang cosmic singularity problem. In this paper we conduct an extensive follow-up study of the parameter space of the CSTB model. In particular we are interested in the parameter values that can produce a single bounce to arrive at a radiation-dominated universe. We further establish that the CSTB universe is a viable alternative to inflation, as it can naturally produce a sufficient number of e-foldings in the locked inflation epoch and in the post-bounce expansion to overcome the four fundamental limitations of the Big Bang cosmology, which are flatness, horizon,homogeneity and singularity, resulting in a universe of the current size. 展开更多
关键词 BOUNCE UNIVERSE Big Bang singularity TACHYON INFLATION FLATNESS and horizon problems
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Gold nanoparticles cause size-dependent inhibition of embryonic development during murine pregnancy
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作者 Xiaowei Ma Xiaolong Yang +4 位作者 Yufei Wang Juan liu Shubin Jin shuyi li Xing-Jie liang 《Nano Research》 SCIE EI CAS CSCD 2018年第6期3419-3433,共15页
Gold nanoparticles (Au NPs) have been widely utilized in biomedical appli- cations owing to their attractive features and biocompatibility, which greatly increase the risk of humans" being exposed to Au NPs, includ... Gold nanoparticles (Au NPs) have been widely utilized in biomedical appli- cations owing to their attractive features and biocompatibility, which greatly increase the risk of humans" being exposed to Au NPs, including pregnant women. In contrast to mature cells, embryos are more susceptible to outside disruptive stimuli. Nonetheless, a possible inhibitory effect of nanomaterials on embryonic development is usually ignored as long as the NPs do not have significant cytotoxic effects. According to our results, a minimal "nontoxic" concentration of Au NPs during early pregnancy can have lethal inhibitory effects on embryos in vivo and in vitro. We conducted important experiments on the influence of Au NPs on embryonic development and found that Au NPs can disturb embryonic development in a size- and concentration-dependent manner. Au NPs of 15 nm in diameter downregulated the expression pattern of distinct germ layer markers both at mRNA and protein levels; this action prevented differentiation of all three embryonic germ layers. Consequentl~ fetal resorption was observed. Our work reveals the impact of Au NPs on embryonic development and will provide an important guidance and serve as a reference for biomedical applications of Au NPs with minimal side effects. 展开更多
关键词 gold nanoparticles embryonic development fetal resorption DIFFERENTIATION
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Multifunctional fluorine-free superhydrophobic coating with flame-retardant,anti-icing,anti-corrosion,and oil-water separation properties
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作者 shuyi li Chuankun Xie +3 位作者 Wenliang Zhang Dongsong Wei Zaihang Zheng Yan liu 《Biosurface and Biotribology》 EI 2022年第1期23-33,共11页
A fluorine-free and multifunctional superhydrophobic coating(r-MSC)was prepared by the one-step spraying method.The coating had superhydrophobic and low-adhesion properties with the water contact angle of 161.5°�... A fluorine-free and multifunctional superhydrophobic coating(r-MSC)was prepared by the one-step spraying method.The coating had superhydrophobic and low-adhesion properties with the water contact angle of 161.5°�1°and the sliding angle of 3.2°�0.5°.It could be prepared by spraying while maintaining superhydrophobic surface characteristics on any substrates.The coating owed outstanding mechanical durability and chemical stability.Moreover,the coating also possessed the ability of self-cleaning,anti-fouling,anti-icing,and flame retardant ability.Importantly,the presence of multifunc-tional coating endowed the substrate with both water-resistant and fireproof properties.Besides,it also showed excellent oil-water separation ability,which presented the oil-water separation efficiency of over 90%for different types of oils after 10 separation cycles.Furthermore,the coating could improve corrosion inhibition performance and the corrosion current density was reduced by two orders of magnitude from the polarization curve.The r-MSC had the advantages of simple preparation,fluorine-free,environ-mentally friendly and appropriate for large-area fabrication,which could be applied to various fields. 展开更多
关键词 environmentally friendly fluorine-free MULTIFUNCTIONAL spraying SUPERHYDROPHOBIC
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