Ultralow-adhesion icephobic surfaces:Combining superhydrophobic and liquid-like properties in the same surface

As a ubiquitous natural phenomenon,ice/frost formation on solid surfaces have adverse effects on many commercial and residential activities.Icephobic surfaces feature low ice adhesion strengths(<100 kPa)can passively retard ice formation and ease ice removal.Superhydrophobic surfaces and liquid-lubricating surfaces are two prevailing categories of icephobic surfaces.However,their long-term stability is relatively poor,and the ice adhesion strengths are not low enough for passive removal of small ice crystals(e.g.,frosts)from the surfaces.Herein,we combine the superhydrophobic and liquid-like properties in one surface to obtain durable icephobic surfaces with extremely low ice adhesion strengths(about 0.035 kPa).Ices and frosts can be removed from the surface under the action of gravity or gas purge.These surfaces are prepared based on surface nanoconical structure and covalently-grafted liquid-like perfluorinated polyether(PFPE)coating,which show synergy effects on suppressing icing and frosting by promoting expulsion of subcooled condensate droplets from the nanotexture and decreasing ice adhesion strengths.The icephobic surfaces show significantly better durability compared to lubricant-impregnated textured surfaces.Our results provide a new avenue to design passive anti-icing/anti-frosting surfaces for a wide range of applications where surfaces are exposed to humid and low-temperature environments.

Whether and When Superhydrophobic/Superoleophobic Surfaces Are Fingerprint Repellent

Driven by the ever-increasing demand for fingerprint-resistant techniques in modern society,numerous researches have proposed to develop innovative antifingerprint coatings based on superhydrophobic/superoleophobic surface design.However,whether superhydrophobic/superoleophobic surfaces have favorable repellency to the microscopic fingerprint is in fact an open question.Here,we establish a reliable method that enables evaluating the antifingerprint capability of various surfaces in a quantitative way.We show that superhydrophobicity is irrelevant with fingerprint repellency.Regarding superoleophobic surfaces,two distinct wetting states of microscopic fingerprint residues,i.e.,the"repellent"and the“collapsed”states,are revealed.Only in the"repellent"state,in which the fingerprint residues remain atop surface textures upon being pressed,superoleophobic surfaces can bring about favorable antifingerprint repellency,which correlates positively with their receding contact angles.A finger-deformation-dependent intrusion mechanism is proposed to account for the formation of diferent fingerprint wetting states.Our findings offer important insights into the mechanism of fingerprint repellency and will help the design of high-performance antifingerprint surfaces for diverse applications.

Optimal integration of mobile battery energy storage in distribution system with renewables

An optimal sizing method is proposed in this paper for mobile battery energy storage system(MBESS)in the distribution system with renewables.The optimization is formulated as a bi-objective problem,considering the reliability improvement and energy transaction saving,simultaneously.To evaluate the reliability of distribution system with MBESS and intermittent generation sources,a new framework is proposed,which is based on zone partition and identification of circuit minimal tie sets.Both analytic and simulation methods for reliability assessment are presented and compared in the framework.Case studies on a modified IEEE benchmark system have verified the performance of the proposed approach.

NMRCloudQ： a quantum cloud experience on a nuclear magnetic resonance quantum computer

Cloud-based quantum computing is anticipated to be the most useful and reachable form for public users to experience with the power of quantum. As initial attempts, IBM Q has launched influential cloud services on a superconducting quantum processor in 2016, but no other platforms has followed up yet. Here,we report our new cloud quantum computing service – NMRCloud Q(http://nmrcloudq.com/zh-hans/),where nuclear magnetic resonance, one of the pioneer platforms with mature techniques in experimental quantum computing, plays as the role of implementing computing tasks. Our service provides a comprehensive software environment preconfigured with a list of quantum information processing packages,and aims to be freely accessible to either amateurs that look forward to keeping pace with this quantum era or professionals that are interested in carrying out real quantum computing experiments in person. In our current version, four qubits are already usable with in average 99.10% single-qubit gate fidelity and 97.15% two-qubit fidelity via randomized benchmaking tests. Improved control precisions as well as a new seven-qubit processor are also in preparation and will be available later.

Quantum state tomography for generic pure states

We examine the problem of whether a multipartite pure quantum state can be uniquely determined by its reduced density matrices.We show that a generic pure state in three party Hilbert space HA■HB■HC, where dim(HA) = 2 and dim(HB) = dim(HC), can be uniquely determined by its reduced states on subsystems HA■HB and HA■HC. Then, we generalize the conclusion to the case that dim(H_1) > 2. As a corollary, we show that a generic N-qudit pure quantum state is uniquely determined by only two of its[(N+1)/2]-particle reduced density matrices. Furthermore,our results indicate a method to uniquely determine a generic N-qudit pure state of dimension D = d^N with only O(D) local measurements, which is an improvement compared to the previous known approach that uses O(D log^2 D) or O(D log D) local measurements.