A Fast Model of a 1-D Nonlinear Beam-Wave Interaction for a 225GHz TWT

A code for a fast 1-dimensional model has been developed for the simulation for the beam-wave interaction in the travelling wave tube amplifier (TWTA). the code is based on a Lagrangian algorithm. The input parameters are modified to extend the code validity to structure different from angular symmetric structures. The output power and gain for the double corrugated waveguide (DCW) TWT at 225 GHz is compared with particle in cell (PIC) simulators

Three-Level Supply Chain Coordination under Disruptions Based on Revenue-Sharing Contract with Price Dependent Demand

Considering the market demand is stochastic and dependent on price, this paper shows that the revenue-sharing contract could coordinate a three-level supply chain consisting of one manufacturer, one distributor, and one retailer under normal environment. However, the original revenue-sharing contract cannot coordinate the supply chain under disruptions in circumstances of certain incidents leading to significant changes in market demand and causing additional deviation costs. To solve the problem, this essay introduces two improved forms of revenue-sharing contract: a mixed contract form based on a quantity discount policy and a pure form, which are characterized by antidisruption ability. The model of improved revenue-sharing contract is optimized when the market demand is in the additive form or in the multiplicative form with price dependent demand. Formulas are given to calculate the optimal contract parameters. Finally, this essay demonstrates the accuracy of the model of improved revenue-sharing contract with the help of numerical examples

Study of Multiple Beam Backward Wave Oscillator Based on Corrugated Waveguide TWT

The multiple beam Backward Wave Oscillator (BWO) which based on corrugated waveguide is simulated by Microwave Tube Simulation Suite (MTSS) and CST Particle Studio(PIC). Simulation results show that the saturated output power is about 45W at the expected operating frequency of 220GHz, when the cylindrical electron beam current and Voltage are 20 mA and 44keV

Coordinating Three-Level Supply Chain by Revenue-Sharing Contract with Sales Effort Dependent Demand

Revenue-sharing contract is a kind of mechanism to improve performance or to achieve perfect coordination of supply chain. Considering a three-level supply chain consisting of a manufacturer, a distributor, and a retailer who faces a stochastic and sales effort dependent demand, the paper analyzes the impact of sales effort on supply chain coordination and expounds the reasons why traditional revenue-sharing contract cannot coordinate supply chain in this condition. Given three cases: only the retailer bears the sales effort cost, only the manufacturer bears the sales effort cost, and the retailer bears the sales effort cost with the manufacturer, the paper proposes an improved revenue-sharing contract based on quantity discount policy to coordinate the supply chain. It illustrates that improved revenue sharing contract can coordinate supply chain by implementing it in one transaction or two transactions of three-level supply chain. The model of improved revenue-sharing contract is optimized, respectively, by addition form and multiplication form with sales effort dependent demand. Formulas are given to determine the optimal contract parameters. Finally, numerical experiments are given to test the accuracy of the model of improved revenue-sharing contract

Three-Level Supply Chain Coordination under Disruptions Based on Revenue-Sharing Contract with Price Dependent Demand

Considering the market demand is stochastic and dependent on price, this paper shows that the revenue-sharing contract could coordinate a three-level supply chain consisting of one manufacturer, one distributor, and one retailer under normal environment. However, the original revenue-sharing contract cannot coordinate the supply chain under disruptions in circumstances of certain incidents leading to significant changes in market demand and causing additional deviation costs. To solve the problem, this essay introduces two improved forms of revenue-sharing contract: a mixed contract form based on a quantity discount policy and a pure form, which are characterized by antidisruption ability. The model of improved revenue-sharing contract is optimized when the market demand is in the additive form or in the multiplicative form with price dependent demand. Formulas are given to calculate the optimal contract parameters. Finally, this essay demonstrates the accuracy of the model of improved revenue-sharing contract with the help of numerical examples

Dispersion characteristics of double-corrugated rectangular waveguide for terahertz vacuum devices

An analytical study on the dispersion of the double-corrugated waveguide for THz vacuum devices is presented. The boundary element method (BEM) is introduced to improve the accuracy of the dispersion. The results are compared with the 3D electromagnetic simulations

Elasticity-Controlled Jamming Criticality in Soft Composite Solids

Soft composite solids are made of dispersed inclusions within soft matrices. They are ubiquitous in nature and form the basis of many biological tissues. In the field of materials science, synthetic soft composites are promising candidates for constructing various engineering devices due to their highly programmable features. However, when the volume fraction of inclusions increases, predicting the mechanical properties of these materials poses a significant challenge for the classical theories in composite mechanics. The difficulty arises from the inherently disordered, multi-scale interactions between the inclusions and matrix. To address this challenge, we conducted systematic investigations on the mechanics of densely-filled soft elastomers containing stiff microspheres. We experimentally demonstrated how the strain-stiffening response of the soft composites is governed by the critical scalings in the vicinity of a continuous phase transition, which depend on both the elasticity of the elastomer matrix and the particles. The critical points signify a shear-jamming transition of the included particles in the absence of matrix elasticity. The proposed criticality framework quantitatively predicts diverse mechanical responses observed in experiments across a wide range of material parameters. The findings uncover a novel design paradigm of composite mechanics that relies on engineering the jamming-criticality of the embedded inclusions

Two‐Dimensional Design Strategy to Construct Smart Fluorescent Probes for the Precise Tracking of Senescence

The tracking of cellular senescence usually depends on the detection of senescence‐associated β‐galactosidase (SA‐β‐gal). Previous probes for SA‐β‐gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous β‐gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes. To address this issue, we introduce our fluorescent probes including a second dimension: lysosomal pH, since de‐acidification is a unique feature of the lysosomes in senescent cells. With this novel design, our probes achieved excellent discrimination of SA‐β‐gal from cancer‐associated β‐gal, which enables them to track cellular senescence as well as tissue aging more precisely. Our crystal structures of a model enzyme E. coli β‐gal mutant (E537Q) complexed with each probe further revealed the structural basis for probe recognition.<br/

Insights into the genetic influences of the microbiota on the life span of a host

Escherichia coli (E. coli) mutant strains have been reported to extend the life span of Caenorhabditis elegans (C. elegans). However, the specific mechanisms through which the genes and pathways affect aging are not yet clear. In this study, we fed Drosophila melanogaster (fruit fly) various E. coli single-gene knockout strains to screen mutant strains with an extended lifespan. The results showed that D. melanogaster fed with E. coli purE had the longest mean lifespan, which was verified by C. elegans. We conducted RNA-sequencing and analysis of C. elegans fed with E. coli purE (a single-gene knockout mutant) to further explore the underlying molecular mechanism. We used differential gene expression (DGE) analysis, enrichment analysis, and gene set enrichment analysis (GSEA) to screen vital genes and modules with significant changes in overall expression. Our results suggest that E. coli mutant strains may affect the host lifespan by regulating the protein synthesis rate (cfz-2) and ATP level (catp-4). To conclude, our study could provide new insights into the genetic influences of the microbiota on the life span of a host and a basis for developing anti-aging probiotics and drugs