Two-dimensional metal-organic frameworks (MOFs) have shown great development po-tential in the field of lithium-sulfur (Li-S) batteries. In this theoretical research work, we propose a novel 3
...transition metals (TM)-embedded rectangular tetracyanoquinodimethane (TM-rTCNQ) as a potential high-performance sulfur host. The calculated results show that all TM-rTCNQ structures have excellent structural stability and metallic properties. Through exploring different adsorption patterns, we discovered that TM-rTCNQ (TM = V, Cr, Mn, Fe and Co) monolayers possess moderate adsorption strength for all polysulfide species, which is mainly due to the existence of the TM-N
active center in these frame systems. Especially for the non-synthesized V-rCTNQ, the theoretical calculation fully predicts that the material has the most suitable adsorption strength for polysul-fides, excellent charging-discharging reaction and Li-ion diffusion performance. Additionally, Mn-rTCNQ, which has been synthesized experimentally, is also suitable for further experimental con-firmation. These findings not only provide novel MOFs for promoting the commercialization of Li-S batteries, but also provide unique insights for fully understanding their catalytic reaction mecha-nism.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The Internet of Things (IoT) now permeates our daily lives, providing important measurement and collection tools to inform our every decision. Millions of sensors and devices are continuously ...producing data and exchanging important messages via complex networks supporting machine-to-machine communications and monitoring and controlling critical smart-world infrastructures. As a strategy to mitigate the escalation in resource congestion, edge computing has emerged as a new paradigm to solve IoT and localized computing needs. Compared with the well-known cloud computing, edge computing will migrate data computation or storage to the network "edge," near the end users. Thus, a number of computation nodes distributed across the network can offload the computational stress away from the centralized data center, and can significantly reduce the latency in message exchange. In addition, the distributed structure can balance network traffic and avoid the traffic peaks in IoT networks, reducing the transmission latency between edge/cloudlet servers and end users, as well as reducing response times for real-time IoT applications in comparison with traditional cloud services. Furthermore, by transferring computation and communication overhead from nodes with limited battery supply to nodes with significant power resources, the system can extend the lifetime of the individual nodes. In this paper, we conduct a comprehensive survey, analyzing how edge computing improves the performance of IoT networks. We categorize edge computing into different groups based on architecture, and study their performance by comparing network latency, bandwidth occupation, energy consumption, and overhead. In addition, we consider security issues in edge computing, evaluating the availability, integrity, and the confidentiality of security strategies of each group, and propose a framework for security evaluation of IoT networks with edge computing. Finally, we compare the performance of various IoT applications (smart city, smart grid, smart transportation, and so on) in edge computing and traditional cloud computing architectures.
The IC industry implements low dielectric constant (low-k) materials in copper/low-k interconnects to reduce the RC delay and crosstalk noises. As low-k dielectrics are weaker than traditional SiO2, ...measuring their mechanical properties is important for numerical simulations to evaluate the structural integrity of a package with low-k materials. In this study, we fabricated freestanding samples of low-k thin film with/without pre-cracks on both sides using lithography and exfoliation for uniaxial tension and coefficient of thermal expansion tests. The tension tests revealed that the average fracture toughness and Young's modulus of the low-k film are 1.41 MPa·m1/2 and ∼2.5 GPa, respectively. Using the measured mechanical properties, we performed a fracture analysis by a 2D finite element model for the low-k material in a wafer-level chip-size package under thermal loading. The computational results showed that the critical microcrack in the low-k layer occurs near the solder balls, where the KI increases rapidly with crack length and exceeds KIC. The results are consistent with the experimental findings in literature. The present methods can help evaluate the integrity of low-k material in a package and improve reliability.
•The low-k testing samples made with lithography patterning and exfoliation to agree with the application scenario.•To obtain the fracture toughness, we conducted tensile tests on low-k thin films with pre-cracks on both sides.•FEA was performed based on the material characterization to identify the risks of the low-k layer in a wafer-level package.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only ...been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at π pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus opens the way to multiphoton experiments with semiconductor quantum dots.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
This paper describes an online short-term voltage stability assessment scheme from an overall view of the load area in the power system. In this scheme, data acquisitions are completed by ...post-contingency phasor measurements and a time series shapelet classification method is employed for classification learning. Combined with decision trees, this novel approach can not only hold a high performance of classification but also offer an acceptable interpretation of classification results. An improved algorithm to speed up shapelet searching is proposed, which makes it more practical. Semi-supervised cluster learning is also adopted in this scheme to mitigate the unreliability of the previous practical criteria. The test results on the Nordic test system demonstrate the effectiveness and reliability of the proposed scheme.
We recently identified a novel plasmid-mediated resistance-nodulation-division (RND)-type efflux pump gene cluster,
, in
that conferred resistance to multiple antimicrobials, including tigecycline. ...While homologs of
were found encoded in many other bacterial species in GenBank, their functions and transfer mechanisms remain unknown. This study identified another mobile gene cluster,
, co-occurring on both a plasmid (pHNNC189-2) and the chromosome of a clinical
isolate, strain NC189, producing KPC-2, NDM-1, and RmtC.
shares high similarity at the nucleotide level with
, with 98.02%, 96.75%, and 99.93% identities to
,
, and
, respectively. Phylogenetic analysis revealed that
may have originated from the chromosome of a
species. The expression of
in an
strain resulted in an 8-fold increase in the tigecycline MIC and decreased susceptibility to other antimicrobials. Genetic context analyses demonstrated that
, together with the adjacent hypothetical site-specific integrase genes, was possibly captured and mobilized by a XerD-like tyrosine recombinase system, forming a putative transposition unit (
-like-
-like-
Δ
-
-like-
-like-
IS
Δ
), which was inserted into
like genes in both the NC189 plasmid pHNNC189-2 and the chromosome. Since
and
could confer multidrug resistance, the spread of these gene clusters, associated with the new recombinase system, calls for more attention.
Building upon the OPLS3 force field we report on an enhanced model, OPLS3e, that further extends its coverage of medicinally relevant chemical space by addressing limitations in chemotype ...transferability. OPLS3e accomplishes this by incorporating new parameter types that recognize moieties with greater chemical specificity and integrating an on-the-fly parametrization approach to the assignment of partial charges. As a consequence, OPLS3e leads to greater accuracy against performance benchmarks that assess small molecule conformational propensities, solvation, and protein–ligand binding.
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IJS, KILJ, NUK, PNG, UL, UM
Inorganic dispersion is of great importance for actual implementation of advanced properties of organic-inorganic composites. Currently, electron microscopy is the most conventional approach for ...observing dispersion of inorganic fillers from ultrathin sections of organic-inorganic composites at the nanoscale by professional technicians. However, direct visualization of macrodispersion of inorganic fillers in organic-inorganic composites using high-contrast fluorescent imaging method is hampered. Here we design and synthesize a unique fluorescent surfactant, which combines the properties of the aggregation-induced emission (AIE) and amphiphilicity, to image macrodispersion of montmorillonite and layered double hydroxide fillers in polymer matrix. The proposed fluorescence imaging provides a number of important advantages over electron microscope imaging, and opens a new avenue in the development of direct three-dimensional observation of inorganic filler macrodispersion in organic-inorganic composites.
Optical performance monitoring (OPM) is the estimation and acquisition of different physical parameters of transmitted signals and various components of an optical network. OPM functionalities are ...indispensable in ensuring robust network operation and plays a key role in enabling flexibility and improve overall network efficiency. We review the development of various OPM techniques for direct-detection systems and digital coherent systems and discuss future OPM challenges in flexible and elastic optical networks.
Lactoferrin (LF) is one of the major functional proteins in maintaining human health due to its antioxidant, antibacterial, antiviral, and anti-inflammatory activities. Abnormal levels of LF in the ...human body are related to some serious diseases, such as inflammatory bowel disease, Alzheimer’s disease and dry eye disease. Recent studies indicate that LF can be used as a biomarker for diagnosis of these diseases. Many methods have been developed to detect the level of LF. In this review, the biofunctions of LF and its potential to work as a biomarker are introduced. In addition, the current methods of detecting lactoferrin have been presented and discussed. We hope that this review will inspire efforts in the development of new sensing systems for LF detection.
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