LabVIEW Based Whispering Gallery Mode Microtoroid Coupling PID Controller

The aim of this thesis is to test the implementation of PID control algorithm for stabilization of coupling. Efficient and robust coupling is prerequisite in microcavity related applications. But surrounding environments, like temperature and airflow, could easily influence coupling condition. PID algorithm has been used for stabilization and control in industry for several decades. For this reason, the author decided to test further application, with the goal of proving the suitability for Whispering Gallery Mode coupling. The thesis first discusses the Whispering Gallery Mode microtoroid, especially its relative coupling regime. In a second stage, the LabVIEW and Arduino based real time control system structure is introduced. And then, the PID control algorithm is discussed. Finally, experiments results are charted to prove the stability and robust coupling. The results of experiment show that PID algorithm is well suited to stabilize the coupling system. However, due to the nonlinearity of the system, the PID coefficients need to be approximately adjusted in different coupling cases

Towards the Usage of Quarry Blasts as Active Seismic Source

Active seismic sources are often used to obtain subsurface structure via seismic imaging. The geophone’s capability to capture signals at lower frequencies is significantly improved, thus, we are no longer restricted to use the conventional seismic source for imaging. Hence, the choice of the seismic source can shift to an unconventional seismic source, such as the traffic noise, slow-slip events, and quarry blasts, and all these choices are economical and environmental friendlier. For the intention of obtaining the better understanding of subsurface structure in Mills Creek, southern Oklahoma, we designed a receiver line of 72 receivers with spacing of 105m, and the total length of 7,455m, located 120m away from the west side of the quarry exploitation field for 28 days. Here, we use the quarry blasts as an active seismic source and propose a workflow to extract the information that is essential for seismic imaging, such as the source wavelet, wave type identification, origin time and location estimation, we also discuss the observed structure in the study area

How do IT Competence, Organizational Agility and Entrepreneurial Actions Coevolve: The Case of Entrepreneurial Etailers on Ecommerce Platforms

Internet and IT have re-shaped the strategy logic of contemporary organizations. The new logic emphasizes business opportunity leveraging through constantly evolving entrepreneurial actions. The required business capabilities underlying such strategic logic, including organizational agility and IT competence, have also to be built and co-evolved. Based on Sambamurthy et al. [1] conceptual framework and ten case studies of Small and Medium sized etailers on third party platform, this research explains what are entrepreneurial actions, enablers of organizational capabilities and IT competence (including IT capability and digital options) for SME etailers, as well as their evolution path and coevolution mechanisms. This research advances the literature by providing empirical evidence of the new strategic logic of internet firms as suggested by Sambamurthy et al.[1], and systematically addresses the adaptive co-evolutionary mechanisms through real options and adaptive learning perspectives

PM2.5 Concentrations Indoors and Outdoors in Heavy Air Pollution Days in Winter

AbstractThe epidemiological studies have indicated that PM2.5 can increase morbidity and mortality, damage the respiratory system and the cardiovascular system, and affect the immune function. The objectives of this study are to understand PM2.5 pollution status in the households when the heavy air pollution occurs in the winter and the correlation of indoor PM2.5 pollution with outdoor, and to find out the effect of indoor human activities on the changes of indoor PM2.5 concentrations. Indoor PM2.5 concentrations were measured using CLH-2000 portable PM2.5 detector in the four households in December 7-8, 2013. When sampling indoors, the pattern of activity questionnaire was completed. The results showed that the average of indoor PM2.5 concentration is in the range of 112-416μg/m3, and the pollution level is more serious at 4 homes in Beijing in winter. Outdoor pollution, human activities and behaviors are the sources of indoor PM2.5 at homes. Human activities (cooking, smoking and cleaning) have more contribution to indoor PM2.5 than outdoor pollution. In general, the effect of indoor human activities on PM2.5 concentration is stronger than outdoor pollution and air cleaner

Study on Greenway Plant Landscape Based on Bird Habitat Conservation - A Case Study of Wenyu River - North Canal Greenway in Beijing

In recent years, rapid urbanization is leading to a sharp decrease of bird diversity in city. The plant landscape in the greenway plays an important role in habitat conservation. This paper aims to explore the effects of plant landscape planning for the bird habitat conservation in urban greenway, and to study the design methods of greenway plant landscapes based on bird habitats conservation. Wenyu River - North Canal, a river located in the east of Beijing with uninterrupted green spaces along the coast, has the potential to become the migration channel for migratory birds. Dongjiao Wetland Park is an important node. At the macro level, the program investigated the vegetation pattern of Wenyu River-North Canal by using GIS technology and analyzed the distribution and ecological connectivity of different bird habitat types in the greenway. The results show that along the Wenyu River-North Canal, the distribution of habitats for some bird groups is uneven and some habitat types are poorly connected. At the micro level, a field study was conducted in Dongjiao Wetland Park in combination with actual projects, in which the forest form distribution and plant species composition were analyzed and the bird biotope was mapped. The results show that in the Dongjiao Wetland Park, the plant community is dominated by arbor-herb type; evergreen plants, shrubs and food plants are lacking; grasslands habitats and wetlands habitats were small and the area disturbed by human is large. According to the analysis results, aiming at bird habitat conservation, a vegetation landscape optimization plan of Wenyu River-North Canal Greenway and a plant landscape reconstruction design of the Northern Park of Dongjiao Wetland Park were proposed, including protecting important habitat patches, optimizing plant community structure and selecting plant species

α-SNAP regulates dynamic, on-site assembly and calcium selectivity of Orai1 channels

Orai1 forms a highly calcium-selective pore of the calcium release activated channel, and α-SNAP is necessary for its function. Here we show that α-SNAP regulates on-site assembly of Orai1 dimers into calcium-selective multimers. We find that Orai1 is a dimer in resting primary mouse embryonic fibroblasts but displays variable stoichiometry in the plasma membrane of store-depleted cells. Remarkably, α-SNAP depletion induces formation of higher-order Orai1 oligomers, which permeate significant levels of sodium via Orai1 channels. Sodium permeation in α-SNAP–deficient cells cannot be corrected by tethering multiple Stim1 domains to Orai1 C-terminal tail, demonstrating that α-SNAP regulates functional assembly and calcium selectivity of Orai1 multimers independently of Stim1 levels. Fluorescence nanoscopy reveals sustained coassociation of α-SNAP with Stim1 and Orai1, and α-SNAP–depleted cells show faster and less constrained mobility of Orai1 within ER-PM junctions, suggesting Orai1 and Stim1 coentrapment without stable contacts. Furthermore, α-SNAP depletion significantly reduces fluorescence resonance energy transfer between Stim1 and Orai1 N-terminus but not C-terminus. Taken together, these data reveal a unique role of α-SNAP in the on-site functional assembly of Orai1 subunits and suggest that this process may, in part, involve enabling crucial low-affinity interactions between Orai1 N-terminus and Stim1

Peptidergic cell-specific synaptotagmins in Drosophila: Localization to dense-core granules and regulation by the bHLH protein dimmed

Bioactive peptides are packaged in large dense-core secretory vesicles, which mediate regulated secretion by exocytosis. In a variety of tissues, the regulated release of neurotransmitters and hormones is dependent on calcium levels and controlled by vesicle-associated synaptotagmin (SYT) proteins. Drosophila express seven SYT isoforms, of which two (SYT-α and SYT-β) were previously found to be enriched in neuroendocrine cells. Here we show that SYT-α and SYT-β tissue expression patterns are similar, though not identical. Furthermore, both display significant overlap with the bHLH transcription factor DIMM, a known neuroendocrine (NE) regulator. RNAi-mediated knockdown indicates that both SYT-α and SYT-β functions are essential in identified NE cells as these manipulations phenocopy loss-of-function states for the indicated peptide hormones. In Drosophila cell culture, both SYT-α and neuropeptide cargo form DIMM-dependent fluorescent puncta that are coassociated by super-resolution microscopy. DIMM is required to maintain SYT-α and SYT-β protein levels in DIMM-expressing cells in vivo. In neurons normally lacking all three proteins (DIMM(−)/SYT-α(−)/SYT-β(−)), DIMM misexpression conferred accumulation of endogenous SYT-α and SYT-β proteins. Furthermore transgenic SYT-α does not appreciably accumulate in nonpeptidergic neurons in vivo but does so if DIMM is comisexpressed. Among Drosophila syt genes, only syt-α and syt-β RNA levels are upregulated by DIMM overexpression. Together, these data suggest that SYT-α and SYT-β are important for NE cell physiology, that one or both are integral membrane components of the large dense-core vesicles, and that they are closely regulated by DIMM at a post-transcriptional level

A Simple and Efficient Lattice Summation Method for Metallic Electrodes in Constant Potential Molecular Dynamics Simulation

The constant potential molecular dynamics simulation method proposed by Siepmann and Sprik and reformulated later by Reed (SR-CPM) has been widely employed to investigate the metallic electrolyte/electrode interfaces, especially for conducting nanochannels with complex connectivity, *e.g.*, carbide-derived carbon or graphene-assembled membrane. This work makes substantial extensions of this seminal SR-CPM approach. First, we introduce two numerical techniques to determine electrode atom charges with an order of magnitude improvement in computational efficiency compared with those widely employed methods. The first numerical technique dramatically accelerates the to calculation of the Ewald interaction matrix $\mathbf{E}$, which takes advantage of the existing highly optimised electrostatic codes. The second technique introduces a new preconditioning technique in the conjugate gradient method to considerably increase the computational efficiency of a linear equation system that determines electrode atomic charges. Our improved SR-CPM implemented in the LAMMPS package can handle extra-large systems, *e.g.*, over 8.1 million electrode atoms. Second, after demonstrating the importance of the electroneutrality constraint, we propose a two-step method to enforce electroneutrality in the following post-treatment step, applicable for matrix and iterative techniques. Third, we propose a solid theoretical analysis for the adjustable parameter $\alpha_i$ (namely the atomic Hubbard-U $U_i^0$), which is arbitrarily selected in many SR-CPM simulation practices. We proposed that the optimised $\alpha_i$ or $U_i^0$ should compensate for the electrical potential/energy discrepancy between the discrete atomistic model and the continuum limit. The analytical and optimal ${\alpha}_i^0$ values are derived for a series of 2D materials

Equivariant Energy-Guided SDE for Inverse Molecular Design

Inverse molecular design is critical in material science and drug discovery, where the generated molecules should satisfy certain desirable properties. In this paper, we propose equivariant energy-guided stochastic differential equations (EEGSDE), a flexible framework for controllable 3D molecule generation under the guidance of an energy function in diffusion models. Formally, we show that EEGSDE naturally exploits the geometric symmetry in 3D molecular conformation, as long as the energy function is invariant to orthogonal transformations. Empirically, under the guidance of designed energy functions, EEGSDE significantly improves the baseline on QM9, in inverse molecular design targeted to quantum properties and molecular structures. Furthermore, EEGSDE is able to generate molecules with multiple target properties by combining the corresponding energy functions linearly