Productivity analysis for a vertically fractured well under non- Darcy flow condition

This work was supported by the National Natural Science Foundation of China No. 51204148 and the Fundamental Research Funds for the Central UniversitiesPeer reviewedPostprin

Investigating the factors that affect a company’s competitiveness

With the increase of population in New Zealand, the number of houses is increasing. However, for a small flooring business, this trend has not increased its sales of carpet. The purpose of this survey is to understand factors affecting the competitiveness of small carpet enterprises in New Zealand, so as to help them improve their competitiveness. This research adopted a paper questionnaire containing 15 closed questions concentrated on eight aspects of the carpet company: price, quality, installation service, after sales service, product, promotion, brand, and language. The participants were 60 existing or potential customers of the company, chosen by convenience sampling. The results of this research, achieved by manual calculation, indicated the participants' evaluation, preference and expectation of the related aspects of the company. Most of the participants were satisfied with the carpet quality, installation service, and after sale service. However, participants seem not satisfied or expected changes in terms of price, promotion and language

Moir\'e excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices

Highly uniform and ordered nanodot arrays are crucial for high performance quantum optoelectronics including new semiconductor lasers and single photon emitters, and for synthesizing artificial lattices of interacting quasiparticles towards quantum information processing and simulation of many-body physics. Van der Waals heterostructures of 2D semiconductors are naturally endowed with an ordered nanoscale landscape, i.e. the moir\'e pattern that laterally modulates electronic and topographic structures. Here we find these moir\'e effects realize superstructures of nanodot confinements for long-lived interlayer excitons, which can be either electrically or strain tuned from perfect arrays of quantum emitters to excitonic superlattices with giant spin-orbit coupling (SOC). Besides the wide range tuning of emission wavelength, the electric field can also invert the spin optical selection rule of the emitter arrays. This unprecedented control arises from the gauge structure imprinted on exciton wavefunctions by the moir\'e, which underlies the SOC when hopping couples nanodots into superlattices. We show that the moir\'e hosts complex-hopping honeycomb superlattices, where exciton bands feature a Dirac node and two Weyl nodes, connected by spin-momentum locked topological edge modes.Comment: To appear in Science Advance

Buoyancy Regulation in Phaeocystis globosa Scherffel Colonies

Buoyancy of Phaeocystis globosa Scherffel (Prymnesiophyceae) colonies was investigated by measuring the vertical distribution of colonies in quiescent water where convection had been removed. Over 60% of the colonies exhibited negative buoyancy regardless of light condition or growth phase. Positively and neutrally buoyant colonies lost their buoyancy in the dark, but regained buoyancy upon return to the light. Colonies with closer cell packing; i.e., more cells per unit colonial surface area, had greater capability to remain buoyant. Our results suggest that colony buoyancy was not uniform within a P. globosa population, and that biological regulation of colony buoyancy required light energy