External Cavity Laser for Chip-Scale Atomic Clock Miao, Jie; Lian, Jiqing; Liu, Tianyu ...
2023 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS),
2023-May-15
Conference Proceeding
In this paper we report a new coherent population trapping (CPT) atomic clock based on external cavity laser. Unlike usual CPT atomic clocks, where used the vertical cavity surface emitting laser ...(VCSEL), we combine the external cavity laser (ECL) with CPT atomic clock to improve the stability. Compared with VCSEL, the ECL has higher laser power of 10 mW and narrower linewidth of 0.8 MHz, meaning that the signal-to-noise ratio of clock can be further improved.
Owing to the complex operating environment of underwater vehicles, many uncertainties of sensors data, big noises of sensors , low precision and high rate of wild points of underwater acoustic ...sensors, data processing of motion sensors data for underwater vehicle navigation system becomes extremely important. The integrated navigation system of autonomous underwater vehicle based on dead-reckoning is introduced. An modified adaptive Kalman filter is adopted for underwater vehicle sensors information data processing. Experimental results show that the modified self-adaptive Kalman filter(SAKF) is effective, and can meet the underwater robots perform a variety of tasks in the navigation and positioning accuracy..
Two novel polyoxometalate derivatives, {l_brace}X{sup IV}W{sup VI}{sub 10}W{sup V}{sub 2}O{sub 40}Cu(en){sub 2}(H{sub 2}O){sub 3}{r_brace} X=V (1), Si (2); en=ethylenediamine, have been ...hydrothermally synthesized and characterized by elemental analyses, IR, UV-Vis, XPS, EPR, TG and single crystal X-ray diffraction analyses. They represent the first classical Keggin polyoxoanion supported by three transition metal complex moieties, which further act as the neutral molecular unit for the construction of the interesting three-dimensional supramolecular frameworks. The magnetic properties of 1 have also been studied in the temperature range of 4-300 K, and its magnetic susceptibility obeys the Curie-Weiss law, showing antiferromagnetic coupling. - Graphical abstract: The first classical Keggin polyoxoanion tri-supported by TMC moieties via bridge oxygen atoms, {l_brace}X{sup IV}W{sup VI}{sub 10}W{sup V}{sub 2}O{sub 40}Cu(en){sub 2}(H{sub 2}O){sub 3}{r_brace}, act as the neutral molecular unit to construct the interesting 3-D supramolecular frameworks.
Effort-Aware Software Defect Prediction (EADP) ranks software modules according to the defect density of software modules, which allows testers to find more defects while reviewing a certain amount ...of code, and allocates testing resources more effectively. However, the recently proposed CBS+ and EASC methods tend to rank the software modules with more LOC (Lines of Code) first. Therefore, there are less inspected modules when inspecting the top 20% LOC via CBS+ and EASC. Although the two methods achieve the high Precision@20% value, the Recall@20% and PofB@20% (Proportion of the found Bugs when inspecting the top 20% LOC) values of the two methods are low. Therefore, we propose a method called EALTR to construct the EADP model by directly maximizing the found bugs when inspecting the top 20% LOC. EALTR uses the linear model to build the EADP model, and then employs the composite differential evolution algorithm to generate a set of coefficient vectors for the linear model. Finally, EALTR selects the coefficient vector that achieves the highest PofB@20% value on the training dataset to construct the EADP model. Our experimental results on eleven project datasets with 41 releases show that the EALTR method performs better than CBS+ and EASC in terms of Recall@20% and PofB@20%.
Abstract Rotenone, a mitochondrial complex-I inhibitor, has been verified to cause dopaminergic neurons degeneration in vivo and in vitro, and the substantia nigra pars compacta (SNc) and the ...striatum are the main target organs of rotenone in the rat brain. However, whether rotenone could cause damage to other regions in the brain has been unclear till now. To address this question, the rotenone-induced neurotoxicity in the hippocampal neurons was investigated in the present study. Rotenone (4 mg/kg) was given to the male Sprague–Dawley rats per day for up to 4 weeks by using the osmotic minipumps. Results showed that neurodegeneration was formed and phosphorylated ERK1/2 (p-ERK1/2) was induced in the hippocampus of rats following rotenone treatment. In additionally, Ras, PKA and PKC were also activated and free Ca2+ i was increased in the cytoplasm of the hippocampus neurons. To determine how ERK cascade was activated, studies in the primary cultured hippocampus neurons were carried out in a further. Cell viability was reduced, and also apoptosis was induced in vitro following rotenone administration. Expressions of p-ERK1/2 were also enhanced evidently in the cultured neurons treated by rotenone. Free Ca2+ i was also increased in the cultured neurons induced by rotenone. However, this influx might not take main effect in ERK1/2 phosphorylation. In conclusion, Ras-Raf-1-MEK-ERK1/2 classic signal pathway, not by PKA/PKC alternative pathway may be the mainly contributor to the ERK1/2 phosphorylation. And also, Ras protein is the dominant activator in the ERK phosphorylation induced by rotenone.
As knowledge discovery in databases, data mining means a process of extraction potentially useful information from data in databases, which can be applied to information management, query processing, ...decision making, process control etc. Those are urgently needed to improve efficient management in water supply industry, since water has been recognized by governments worldwide as a scarce resource. In response to such demand, this paper proposes a software application, which designed to accessing to database, operating the data mining, and output the results and charts. We analyzed the different prediction models and designed the water consumption system, which has two functions of analysis of possible correlations between the water consumption and nature of the industry and prediction on future water consumption. As the system built, the paper provides samples and produces the results and analysis.
Vibration isolation structure of Siemens-Schottel-Propulsor (SSP) is analyzed and the parameters and optimization in vibration isolation structure is computed theoretically in this paper. The choice ...of parameters in vibration isolation structure is an optimization process, and it is subjected to many practical constraints. From the view of the force strength, the vibration isolation materials should be “hard” while from vibration reducing effect it should be “soft”. For the double-layer vibration reducing structure, in addition to meeting the requirement of deformation and strength, the obvious stiff difference should be arranged in structure to reduce vibration. The vibration isolation structure plays the role as a transfer functions, outputs different responses according to different excitation input. The results show that the characteristics of the exciting signals should be considered in the SSP vibration isolation structure’s design, it is important to select the vibration isolation for SSP cushion materials.
The density functional calculation with the generalized gradient approximation is applied to study the structural, electronic and vibrational properties of Pb
n
S
n
clusters up to
n
=
9
. It is found ...that ringlike structures are the lowest-energy configuration for
n
⩽
3
. However, at the beginning of
n
=
4
, three-dimensional spheroid structures are prevailed. The supercluster structures based on Pb
2S
2 and Pb
3S
3 bridges are dominant for the larger Pb
n
S
n
with
n
⩾
3
. In addition, we discussed the size dependence of binding energies, gaps between highest-occupied and lowest-unoccupied molecular orbitals, second-order difference of total energies, and the IR spectra of Pb
n
S
n
clusters.
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