Tiny Difference Research Articles

A Novel Operation Sequence Similarity-Based Approach for Typical Process Route Knowledge Discovery

A typical process route essentially represents the commonly used process planning-related knowledge and can be modified to generate new process routes easily. Hence, its quality directly affects the performance of newly generated process routes and thereby the goodness of products. To effectively discover typical process route knowledge, a reasonable similarity measure and a clustering method specifically for process routes are required. However, existing operation sequence similarity coefficients often assign coarse-grained similarities, which leads to inaccurate clustering results. For the clustering problem, most researchers have not considered the practical constraints during typical process route discovery. In this paper, an operation sequence similarity-based discovery method is presented. First, the characteristics and information requirements of the operation sequence similarity problem are analysed, and a novel comprehensive similarity coefficient combined with a modified pseudo-longest-common-subsequence (pseudo-LCS) and Jaccard similarity coefficient is proposed based on this analysis. This coefficient considers the precedence relationship, the number of common operations, and the operation similarity simultaneously to handle all the potential similarity situations. Second, two soft constraints, namely, quantity constraint and size constraint, are introduced in the traditional process route clustering problem to ensure the quality and validity of the discovered typical process routes. To solve this more practical problem and achieve a balance between these two conflicting constraints, the K-medoids method is improved with an adjustment mechanism to generate valid results under these two soft constraints. Finally, numerical illustrations are presented to verify the effectiveness of the proposed methods. The results show that compared with existing similarity coefficients, the proposed comprehensive similarity coefficient is more sensitive and much better at distinguishing the tiny difference between the process routes. In addition, the modified K-medoids method can perform much better than existing methods on process route discovery data sets under two conflicting soft constraints.

Time-varying coupling-induced logical stochastic resonance in a periodically driven coupled bistable system* *Project supported by the National Natural Science Foundation of China (Grant No. 31601071).

Coupling-induced logical stochastic resonance (LSR) can be observed in a noise-driven coupled bistable system where the behaviors of system can be interpreted consistently as a specific logic gate in an appropriate noise level. Here constant coupling is extended to time-varying coupling, and then we investigate the effect of time-varying coupling on LSR in a periodically driven coupled bistable system. When coupling intensity oscillates periodically with the same frequency with periodic force or relatively high frequency, the system successfully yields the desired logic output. When coupling intensity oscillates irregularly with phase disturbance, large phase disturbance reduces the area of optimal parameter region of coupling intensity and response speed of logic devices. Although the system behaves as a desired logic gate when the frequency of time-periodic coupling intensity is precisely equal to that of periodic force, the desired logic gate is not robust against tiny frequency difference and phase disturbance. Therefore, periodic coupling intensity with high frequency ratio is an optimal option to obtain a reliable and robust logic operation.

A quantum beat of quantum discord induced by the number of qubits in non-Markovian environments

We investigate the protection of the quantum discord of two qubits, individually originated by two generalized amplitude-damping models. Here, each generalized amplitude-damping model consists of N non-interacting qubits interacting with a common zero-temperature reservoir. First, for initial states with extended Werner-like states, we find that the robust quantum discord of two qubits against decoherence can be obtained by controlling the number of qubits in the reservoir. More interestingly, we find that a quantum beat for quantum discord can occur when both the number of qubits in each reservoir is large and when the number of qubits have a tiny difference, even in the resonant case. Our results shed new light on the protection of quantum discord by means of a quantum-reservoir engineering approach in quantum-information processing.

Magnetohydrodynamics of Lubricant in Recessed Conical Hybrid Journal Bearing With Taper Error

Abstract To improve the performance accuracy of a conical journal bearing system, the surface error needs to be considered in the analysis since a tiny difference in dimensional values can alter the performance; the consideration of surface error may degrade the performance behavior of bearing. However, a better way to overcome such degradation may be to make use of magnetohydrodynamics (MHDs) of fluid. Therefore, the present work is planned to investigate the impact of taper error and MHD lubricant in recessed conical hybrid journal bearing. In this article, the Reynolds equation is derived under stated assumptions along with frictional power loss expression and finally solved using the finite element analysis, Newton–Raphson method, and generalized minimum residual method. The conducted research helped in determination of optimum values of recess width, land width ratio, and restrictor design parameter, and also obtaining the results corresponding to distinct performance indices. The outcome of these results may inspire practicing designers for the development of better tribo components.

Hydrogen Bonding-Derived Healable Polyacrylate Elastomers via On-demand Copolymerization of n-Butyl Acrylate and tert-Butyl Acrylate.

Achieving a desirable combination of good mechanical properties and healing efficiency is a great challenge in the development of self-healing elastomers. Herein, a class of tough and strong self-healing polyacrylate elastomers (denoted as HPs) was developed simply by free-radical copolymerization of n-butyl acrylate (nBA) and tert-butyl acrylate (tBA) and a subsequent hydrolysis reaction rather than direct copolymerization of nBA and acrylic acid (AA). The tiny difference in reactivity between nBA and tBA makes the structural units of the copolymer easy to control. Precise regulation of molecular composition can be realized just by varying the relative monomer content, making its mechanical properties to vary from ductile to robust. Strikingly, when HP samples are cut off within the gauge length, they can heal into coherent and smooth samples and recover at least 79% of the original strength. Hydrogen bond interactions serve as physical cross-linking points, contributing to the high mechanical performance (fracture energy of up to 73.78 MJ·m-3 and tensile strength of up to 17.80 MPa) as well as shape memory function. Moreover, the HP samples emit strong fluorescence when exposed to a 365 nm UV lamp and exhibit an aggregation-enhanced emission effect in the state of dissolution.

A radiative seesaw model linking to XENON1T anomaly

We propose an attractive model that excess of electron recoil events around 1-5 keV reported by the XENON1T collaboration nicely links to the tiny neutrino masses based on a radiative seesaw scenario. Our dark matter (DM) is an isospin singlet inert boson that plays an role in generating non-vanishing neutrino mass at one-loop level, and this DM inelastically interacts with a pair of electrons at one-loop level that is required to explain the XENON1T anomaly. It is also demanded that the mass difference between an excited DM and DM has to be of the order keV. Interestingly, the small mass difference ∼keV is proportional to the neutrino masses. It suggests that we have double suppressions through the tiny mass difference and the one-loop effect. Then, we show some benchmark points to explain the XENON1T anomaly, satisfying all the constraints such as the event ratio of electrons of XENON1T, a long lived particle be longer than the age of Universe, and relic density in addition to the neutrino oscillation data and lepton flavor violations (LFVs).

“EosFit-Pinc: A simple GUI for host-inclusion elastic thermobarometry” by Angel et al. (2017)—Discussion

Abstract In this comment, we show mathematically that the equations of Angel et al. (2017) and Guiraud and Powell (2006) are equivalent. The tiny difference is due to different definitions of strain.

Effect of thermally excited lattice vibrations on the thermodynamic stability of tungsten ditellurides WTe2 under high pressure: A first-principles investigation

The thermodynamic stability as a function of pressure and temperature of three WTe2 polytypes, i.e., Td, 1T′, and 2H phases, is examined using first-principles calculations, where the temperature-dependent contributions, arising particularly from the lattice vibrations, are derived from the quasiharmonic approximation. We find that the critical transition pressure to the 2H phase increases almost linearly with increasing temperature. Through the inspection of the phonon density of states, 2H-WTe2 is dynamically stable not only at high pressure, but also at zero pressure, indicating possible existence of 2H-WTe2 also at ambient conditions. On the other side, our results demonstrate that, at relevant temperature and pressure, the thermodynamic stability of 1T′-WTe2 is comparable to that of Td-WTe2, and further analysis reveals substantial similarities in terms of structural behavior between Td-WTe2 and 1T′-WTe2. These findings suggest not only that the two polytypes are likely to coexist in practical samples of WTe2 due probably to grains/regions either with tiny difference in stress, for example, or with different growth history, but also that the designation of 1T′, having been regularly used to described the compound under pressure in the literature, might actually be a mixture of Td and 1T′ polytypes, whose WTe2 layers laterally slide via low transition barrier induced probably by the applied pressure, resulting in the splitting of (101) and (113) peaks as observed in the diffraction experiments.

Cholesterol and Sitosterol, Two Members of the Steroid Family That Differ in Structure by a Single Ethyl Group Yet Maintain the Right Balance between Plant and Animal Kingdoms

Cholesterol and sitosterol are two members of the steroid family, which molecular structures differ only by the presence of an ethyl substituent at the position 24 of the steroid skeleton. Cholesterol is mainly synthesized in large quantities in the liver of animals and only in small quantities by plants. In contrast sitosterol is only synthesized by plants. This tiny difference of an ethyl group between the two steroids structures have induced profound effects on the climatic changes during evolution, but plant sterols still have important effects on cholesterol metabolism on humans.

Selective Protein Separation Based on Charge Anisotropy by Spherical Polyelectrolyte Brushes.

Protein purification is of vital importance in the food industry, drug discovery, and other related fields. Among many separation methods, polyelectrolyte (PE)-based phase separation was developed and recognized as a low-cost purification technique. In this work, spherical polyelectrolyte brushes (SPBs) with a high specific surface area were utilized to study the protein accessibility and selective protein binding on highly charged nanoparticles (NPs) as well as the selective phase separation of proteins. The correlation between charge anisotropy, protein binding, and phase separation was investigated on various protein systems including those proteins with similar isoelectric points (pI) such as bovine serum albumin (BSA) and β-lactoglobulin (BLG), proteins with similar molecular weights such as BSA and hemoglobin (HB), and even protein variants (BLG-A and -B) with a tiny difference of amino acids. The nonspecific electrostatic interaction studied by turbidimetric titrations and isothermal calorimetry titration (ITC) indicates a specific binding between proteins and SPBs arising from the charge anisotropy of proteins. An optimized output based on selective protein binding on SPBs could be correlated for efficient protein separation through tuning external conditions including pH and ionic strength. These findings, therefore, proved that phase separation based on selective protein adsorption by SPBs was an efficient alternative for protein separation compared with the traditional practice.

3D printed spermathecae as experimental models to understand sperm dynamics in leaf beetles

BackgroundPostcopulatory mate choice occurs ubiquitously in the animal kingdom. However, it is usually a major challenge to visualise the process taking place in a body. This fact makes it difficult to understand the mechanisms of the process. By focusing on the shape of female sperm storage organs (spermathecae), we aimed to elucidate their functional morphology using six representative beetle species and to simulate sperm dynamics in artificial spermathecae with different structural features.ResultsMorphology and material gradients were studied using micro-computed tomography (μCT) and confocal laser scanning microscopy. This study shows a diversity of external and internal structures of the spermathecae among species. Despite the diversity, all species possess a common pumping region, which is composed of a sclerotised chamber, muscles and a resilin-enriched region. By focusing on the species Agelastica alni, whose spermatheca is relatively simple in shape with an internal protuberance, we simulated sperm dynamics by establishing a fabrication method to create enlarged, transparent, flexible and low-cost 3D models of biological structures based on μCT data. This experiment shows that the internal protuberance in the species functions as an efficient mixing device of stored sperm.ConclusionsThe observed spermathecal musculature implies that the sclerotised chamber of the spermatheca with muscles works as a pumping organ. Our fluid dynamics tests based on 3D printed spermathecae show that a tiny structural difference causes entirely different fluid dynamics in the spermatheca models. This result suggests that structural variations of the spermatheca strongly affect sperm dynamics. However, fluid dynamics tests still require essential measurements including sperm viscosity and the velocity of pumping cycles of the spermatheca.

Topological evolution of correlated band structures and heavy-fermion-like behavior in a molybdenum-based metal organic framework C48S36Mo6

Owing to the fascinating properties of two dimensional transition metal dichalcogenides and the stability of ZIF-8 as the subclass of metal organic frameworks (MOFs), we propose a Mo-based MOFs material C48S36Mo6 containing organic ligands connecting to each other by Mo4+ metal ions. We reveal heavy-fermion-like electronic behaviour that results from highly localized impurity-like Mo-d electrons and tiny energy difference (<0.4 meV/atom) between antiferromagnetic and ferromagnetic state, using the generalized gradient approximation and its combination with Coulomb correlation U. Considering thermal fluctuation and weak magnetic exchange energy, C48S36Mo6 is a nonmagnetic metal at room temperature, and magnetic insulator at low temperature with a correlation-driven metal–insulator transition. Our Wannier functions analysis indicates that topological properties of energy bands around the Fermi level can be perturbed by correlation U, leading to moving of close nodal lines in three dimensional momentum space. Further introducing of spin–orbit coupling opens a small inverted energy gap of 3 meV at original nodal line due to bulk inversion symmetry. If a gate voltage of 48 meV is applied, the Fermi level will fall into the small energy gap of band inversion, and the system will realize a phase transition from Kondo metal to topological Kondo insulator.

Polymerization retardation isothermal amplification strategy enables the sensitive and facile investigation of the flanking sequence preference of ten-eleven translocation 2 protein

Active DNA demethylation process critically relies on the intrinsic properties of ten-eleven translocation proteins (Tets), particularly the flanking sequence preference. Challenged by the fact that the proximate bases to the 5-methylcytosine (5mC) are multitudinous and their influence on the Tets/DNA interplay is minute, the current methodologies are very limited in terms of cost, sensitivity and efficiency. Herein, we propose a polymerization retardation isothermal amplification (PRIA) strategy that enables sensitive and fast study of the flanking sequence preference of Tet. By arranging DNA polymerase to repetitively pass DNA strands through an isothermal replication-scission amplification reaction, the tiny difference in the Tet/DNA interplay can be consecutively accumulated and amplified. Low amount sample (80 ng) even multiple samples can be simultaneously analyzed within 10 h on an easily accessible laboratory real-time quantitative PCR instrument. For a proof-of-concept study, the binding preference (PB) of Tet2 for XmCGX, (X = C, G, T, A) was analyzed by PRIA and computational analysis, showing an order of AmCGT > TmCGA ≈ GmCGC > CmCGG. Furthermore, the binding and oxidation preference in Tet/DNA interplay process was individually considered. By comparative evaluation of the total flanking sequence preference (PT) and the PB, for the first time, we revealed that Tet2 has a lower oxidation preference (PO) to proximal flanking bases and the main contributor to PT of Tet2 is PB. The PRIA strategy, due to its reliable, cost-effective, high efficiency and low sample input, would hopefully advance epigenetic researches and other relative studies.

A Product Quality Monitor Model With the Digital Twin Model and the Stacked Auto Encoder

With the development of intelligent manufacturing and computer science, the system of equipment in the workshop has become more and more complex. In the intricate environment, the state of device changes constantly, which could affect the accuracy of methods since they cannot adapt the changing context. Recently, Digital Twin (DT) has received great focus among academic world and industrial world, which provides a new normal form for solving problems. In this paper, the structure of DT is discussed and a DT and Stacked Auto Encoder (SAE) Based Model is proposed to monitor the product quality. Based on the classical structure of DT, the digital model of DT is further divided into two parts, a task-achieved part and a self-update part. The former that comprises an encoder network that is a part of SAE and an Artificial Neural Network (ANN)-based classifier could check whether products are qualified. And a decoder network, another part of SAE, and a parameters-update rule make up the self-update part that could detect the accuracy of the task-achieved part and retrain the neural networks as the accuracy is poor. Furthermore, a new loss function is put forward as a training criterion in order to magnify the tiny difference between input data and result. In order to emulate the changing environment, the experimental data are collected at two different points in time. The data are then input to the proposed model and two other traditional methods to test the ability of accuracy and the adaptability for changing context. The comparisons show that the proposed method has got improvements, especially in where the effect of working environment is significant.

Dual-Mode Upconversion Nanoprobe Enables Broad-Range Thermometry from Cryogenic to Room Temperature.

Noncontact optical thermometers based on the luminescence intensity ratio of two thermally coupled energy levels, exhibiting high sensitivity, excellent accuracy, fast response, and low environment dependence, have attracted great interests in scientific research, life activities, and industrial manufacturing processes. However, the use of optical thermometers in extreme atmospheres (below 150 K) is usually limited by the required large temperature activation because of the relatively big energy difference (200 cm-1 ≤ ΔE ≤ 2000 cm-1). Here, we propose a strategy to alleviate the ultralow temperature-sensing problem by exploiting and utilizing the near-infrared (NIR) thermally coupled Stark sublevels of Tm3+ (3H4|0 → 3H6/3H4|1 → 3H6, ΔE ≈ 300 cm-1) that is much sensitive to minimal temperature variation, especially at ultralow temperatures because of the tiny energy difference. The integration of ultralow temperature-sensitive Tm3+ ions and room-temperature-sensitive Er3+ ions in an ultrasmall α-NaYbF4:Tm3+@CaF2@NaYF4:Yb3+/Er3+@CaF2 core/multishell nanoparticle (∼15 nm) as a dual-mode upconversion luminescent nanoprobe enables the broad-range temperature detection from 10 to 295 K. This structure induces ∼14 times NIR emission and ∼sixfold green upconversion luminescence output in comparison with the α-NaYbF4:Tm3+ core and α-NaYbF4:Tm3+@CaF2@NaYF4:Yb3+/Er3+ core/shell/shell nanoparticles. The maximum absolute and relative sensitivities of this dual-mode temperature sensor reach 0.67% and 3.06% K-1, respectively, showing the advantage of the concurrent utilization of the Tm3+ NIR 801/820 nm band ratio and the typical Er3+ visible 521/538 nm band ratio for a wide-range temperature-sensing purpose. This work provides a promising strategy to develop accurate and effective, contactless broad-range/ultralow temperature sensors.

Energy threshold for chiral symmetry breaking in molecular self-replication.

The homochirality of biological molecules (right-handed sugars and left-handed amino acids) is a signature of life. Extensive research has been devoted to understanding how enrichment of one enantiomer over the other might have emerged from a prebiotic world. Here, we use experimental data from the model Soai autocatalytic reaction system to evaluate the energy required for symmetry breaking and chiral amplification in molecular self-replication. One postulate for the source of the original imbalance is the tiny difference in energy between enantiomers due to parity violation in the weak force. We discuss the plausibility of parity violation energy difference coupled with asymmetric autocatalysis as a rationalization for absolute asymmetric synthesis and the origin of the homochirality of biological molecules. Our results allow us to identify the magnitude of the energy imbalance that gives rise to directed symmetry breaking and asymmetric amplification in this autocatalytic system.

Analogy of Quantum Spin and Matrix Array with Electromagnetic and Gravitational Waves Produced from Pure Mathematics

This short article was inspired by the astronomy/astrophysics course “Greatest Unsolved Mysteries of the Universe”. It was prepared by ANU (the Australian National University), was put on the Internet by edX, and the two presenters in the course’s videos are Dr. Paul Francis and Brian Schmidt (yes, the winner of the Nobel Prize for Physics himself). In the video “V5.8: 21 centimetre radiation and the first stars”, Brian said “(To get emission from the hydrogen atom) we're going to have to resort to a little trick of quantum mechanics that is provided for the hydrogen atom, which is that the proton and electron within quantum mechanics have a spin. It's analogous to a top spinning. It turns out that the hydrogen atom has a different energy if those spins are in opposite directions. It turns out it actually has a lower energy and so you can have an energy transition when that flip occurs and a photon comes out.” Then Paul said, “It's a bit like having two bar magnets. If you have them with north pole to north pole, or north pole to south pole, you'll feel a different amount of force between them; a different energy between these two things. When these things are spinning the same way or the opposite way there's a little tiny energy difference between them.” The following explains analogy of quantum spin to maths’ matrix and how, using that analogy, the statements by Brian and Paul can be converted into a mathematical origin of electromagnetism and gravitation.

The ‘flea on the elephant’ effect

To localise a particle subject to a symmetric double-well potential a symmetry break is needed. If the wells are very distant from one another even a tiny difference between their depths causes a wavefunction concentration in the deeper well. This flea on the elephant (FOTE) effect can be studied in elementary terms by using a couple of unequal delta-like wells. After reviewing the case of equal delta functions, and introducing the Lambert W function, the case of different delta functions is studied. There, an easily solvable asymptotic equation is derived, which allows quantitative evaluations of the FOTE effect to be performed. Finally, the effect of the symmetry breaking on the time evolution of a wave packet is shown.

Bending sensor with parallel fiber Michelson interferometers based on Vernier-like effect

A highly sensitive bending sensor based on two parallel fiber Michelson interferometers (MIs) with a Vernier-like effect is proposed and demonstrated. The interferometric structure consists of a dual-core fiber (DCF) spliced with a short section of dual-side-hole fiber (DSHF). The centric core of the DCF is aligned with one air-hole of the DSHF to form a reflective interface. The centric core of the DCF is connected to the core of the DSHF with a little lateral offset to make the light in the centric core couple to both the core and cladding of the DSHF. The light beams reflected by the end of the DSHF and the DCF interfere with each other, forming two parallel MIs. The free spectral range (FSR) difference between the two MIs is very small due to the tiny difference in refractive index (RI) between the core and cladding of the DSHF, which results in a Vernier-like effect. The most novel feature of the mentioned structure is that both MIs are sensitive to bending with the same sensitive direction. Experimental results indicate that the bending sensitivity of the sensor can reach 38.53 nm/m−1. This kind of sensor has far-reaching significance in the research of structural safety monitoring.

The mechanism of lipopolysaccharide administration-induced cognitive function impairment caused by glucose metabolism disorder in adult rats.

ObjectiveThis essay aims to make investigation on the mechanism of glucose metabolism disorder and Lipopolysaccharide administration-induced cognitive function impairment in adult rats with surgery. Methods: Divide the objects, 40 male Sprague-Dawley rats at the age of 9 months, into 4 groups. Provide unilateral nephrectomy surgery and/or lipopolysaccharide intraperitoneal injection. Postoperative cognitive function evaluation would be tested by the Morris water maze. Rats with Postoperative Cognitive Dysfunction (POCD) were scanned to analyze the brain glucose metabolism by means of 18F-FDG PET/CT. Phosphatidylinositol 3-Kinase (PI3K), Protein Kinase β (AKT), Insulin Substrates Receptor-2 (IRS-2) and Glucose Transporter 4 (GLUT4) were detected as well. Data will be captured through gene expression in POCD rats via Quantitative Real-Time PCR (QRT-PCR). On the other side, Western Blot was used to measure the expression levels of IRS-2, p-IRS-2, p-PI3K, PI3K, p-AKT, AKT, GLUT4, and p-GLUT4. Results: During the Morris water maze test, the staging time (latency) of rats in each group was becoming short gradually as the training progressed. The incubation time of Day 5 of each group was shorter than that of Day 1 (P < 0.05). On the Day 3 after the surgery, the average target quadrant residence time of Group S+L (100 μg/Kg) was shorter, compared with Group C, L and S. Of which, the average number of perforation was reduced greater than that of Group C (P < 0.05). The average swimming speed of the groups is of no distinct difference (P > 0.05). After the operation, there was no great difference shown among the subjects (P > 0.05) in the average residence time of the target quadrant, the mean number of passages, and the mean swimming speed. On Day 3, the average latency of Group S+L (100 μg/Kg) was longer than Group C (P < 0.05) in the working memory test after the operation. The average latency of rats in Group L and S was showed longer than that in Group C, with tiny difference (P > 0.05). In the 7-Day working memory test, the average latency of the rats in Group L, S and S+L (100 μg/Kg) was obviously longer than that in Group C. Comparing to preoperative rats, POCD rats of Group S+L (100 μg/Kg) were scanned by 18F-FDG PET/CT three days later after the operation. Its SUVmax of the frontal and temporal lobe areas were decreased significantly (P < 0.05). However, difference degree was not significantly shown in the SUVmax between Group C and the preoperative rats (P > 0.05). In comparison with the gene expression of of Group C, the PI3K, IRS-2, AKT and GLUT4 mRNA genes are the key genes in the insulin signaling pathways of the hippocampus of the POCD rats. The expression level was reduced. The expression level of all protein of PI3K, IRS-2, GLUT4 and AKT in the POCD rats was of no great contrast with that in Group C. But for IRS-2 protein, the phosphorylation level has increased, and meanwhile decreased for AKT, PI3K and GLUT4 proteins (P < 0.05). Conclusions: Adult SD rats cognitive dysfunction model treated with unilateral nephrectomy combined and 100 μg/kg LPS intraperitoneal injection were led to abnormal both brain glucose metabolism and insulin expression. The proved phenomenal results signal pathway-related proteins PI3K, IRS-2, AKT and GLUT4. It reached the conclusion that surgical trauma, rather than anesthesia, leads to impaired cognitive function. PI3K, IRS-2, AKT, and GLUT4pathway of brain can be partial explanations of the pathogenesis of POCD.