| 1. |
- Alfredsson, Ylfi, et al.
(author)
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Phase and molecular orientation in H2Pc on conducting glass : characterization of two deposition methods
- 2005
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In: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 493:1-2, s. 13-19
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Journal article (peer-reviewed)abstract
- In this study, metal-free phthalocyanine has been deposited on a conducting glass surface by two methods: by spreading the molecular powder directly on the substrate in air and by vapor sublimation under ultra-high vacuum conditions (evaporation). The films have been characterized by means of core level X-ray Photoemission Spectroscopy, X-ray Absorption Spectroscopy (XAS) and Ultra Violet and Visible absorption spectroscopy (UV-Vis). Our results show that the two deposition methods produce molecular overlayers in different polymorphic phases; the UV-Vis measurements indicate that the film obtained by powder deposition is of x-phase type whereas sublimation leads to an α-polymorph structure. The XAS results show that in the powder deposited film the molecules are mainly oriented parallel to the surface. This is opposite to the case of the vapor deposited film, where the molecules mainly are oriented orthogonal to the surface.
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| 2. |
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| 3. |
- Bao, D., et al.
(author)
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A smart catheter system for minimally invasive brain monitoring
- 2015
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In: Proceedings of the International Conference on Biomedical Electronics and Devices. - : SciTePress. - 9789897580710 ; , s. 198-203
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Conference paper (peer-reviewed)abstract
- This paper demonstrates a smart catheter system with intracranial pressure (ICP) and temperature sensing capability which is designed for real-time monitoring in traumatic brain injury (TBI) therapy. It uses a single flexible catheter with a 1 mm (3 Fr) diameter that integrates electrodes and sophisticated silicon chip on flexible substrates, enabling multimodality monitoring of physiological signals. A micro-electromechanical-system (MEMS) catheter pressure sensor is mounted on the distal end. It can be used for detecting both pressure and temperature by different switch configurations, which minimizes the size of catheter and reduces the cost. The interconnects (signalling conductors) are printed on a bio-compatible flexible substrate, and the sensor is interfaced with an embedded electronic system at the far-end. The electronic system consists of analog front end with analog-to-digital converter (ADC), a microcontroller, and data interface to the hospital infrastructure with a graphical user interface (GUI). The overall smart catheter system achieves a pressure sensing root mean square error (RMSE) of ±1.5 mmHg measured from 20 mmHg to 300 mmHg above 1 atm and a temperature sensing RMSE of ±0.08°C measured from 32°C to 42°C. The sampling rate can be up to 10S/s. The in vivo performance is demonstrated in laboratory animals.
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| 4. |
- Bao, Dongxuan, et al.
(author)
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A Wirelessly Powered UWB RFID Sensor Tag With Time-Domain Analog-to-Information Interface
- 2018
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In: IEEE Journal of Solid-State Circuits. - : IEEE. - 0018-9200 .- 1558-173X. ; 53:8, s. 2227-2239
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Journal article (peer-reviewed)abstract
- This paper presents a wirelessly powered radio frequency identification sensor tag with an analog-to-information interface. A time-domain interface, incorporating an ultra-lowpower impulse radio ultra-wideband (IR-UWB) transmitter (TX), is employed. The analog signal from the sensor is compared with a triangular waveform, resulting in a pulse-position modulation signal to trigger UWB pulses. Thanks to the high time-resolution IR-UWB radio, time intervals of the impulses can be used to represent the original input value, which is measured remotely on the reader side by a time-of-arrival estimator. This approach not only eliminates the analog-to-digital converter (ADC) but also significantly reduces the number of bits to be transmitted for power saving. The proposed tag is fabricated in a 0.18-mu m CMOS process with an active area of 2.5 mm(2). The measurement results demonstrate that a 300-kS/s sampling rate with a 6.7-bit effective number of bits (ENOB) is obtained via a UWB receiver with a sensitivity of -93 dBm and an integration window of 10 ns. The ENOB is improved to 7.3 bits when the integration window is reduced to 2 ns. The tag can be powered up by a -18-dBm UHF input signal. The power consumption of the proposed tag is 41.5 mu W yielding a 1.3-pJ/conv.step figure of merit, offering 9x and 67x improvements compared with the state of the art based on an ADC and a backscattering TX, and the tag based on an ADC and a narrowband TX, respectively.
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| 5. |
- Bao, D., et al.
(author)
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A wirelessly-powered UWB sensor tag with time-domain sensor interface
- 2014
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In: Proceedings - IEEE International Symposium on Circuits and Systems. - 9781479934324 ; , s. 2503-2506
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Conference paper (peer-reviewed)abstract
- This paper presents a wirelessly-powered sensor tag with a time-domain sensor interface for wireless sensing applications. The tag is remotely powered by RF wave. Instead of traditional approaches employing conventional ADCs for quantization and transmitter for data communication, in this work, a Pulse Position Modulator incorporating simple impulse radio UWB (IR-UWB) transmitter is proposed to convert and transmit the analog sensing information in time domain. The analog signal is compared with an adjustable triangular wave for analog to time conversion in signal-varying environments. Then a UWB transmitter converts the PPM signal to very short pulses and sends it back to the reader. The time interval of UWB pulses represents the original input signal in time domain which can be measured on the reader side by a time-to-digital conversion. This approach not only simplifies the ADC design but also relaxes the number of bits transmitted on the tag side. The sensor tag is designed in 180nm CMOS process. Simulation results demonstrate that the proposed approach reduce transmission power consumption by nearly 3 orders of magnitude over traditional approaches, while consuming only 85 μW for 1.5 MS/s sampling rate.
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| 6. |
- Bao, Zhuo, et al.
(author)
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Detailed Theoretical and Experimental Description of Normal Auger Decay in O2
- 2008
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In: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 41:12, s. 125101-
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Journal article (peer-reviewed)abstract
- The normal Auger electron spectrum of the O-2 molecule is assigned in detail on the basis of ab initio valence configuration interaction (CI) wavefunctions. Potential energy curves of the ground state, the core-ionized states and the doubly charged final states are calculated and Auger decay rates are obtained with the one-centre approximation. Using the lifetime vibrational interference method, band shapes are obtained for all contributions to the Auger spectrum. The calculated Auger electron spectrum allows us to identify all features observed experimentally. Significant differences to previous assignments are reported. A quantitative simulation of the spectrum is given on the basis of a curve-fitting procedure, in which the energetic positions and intensities of the theoretical bands were optimized. Besides providing a basis for a refined analysis of the spectrum, the fit allows us to assess the accuracy of the calculation. As expected for this level of theory, the absolute accuracy of the valence CI energies is found to be about 0.3 eV. The inherent error of the one-centre transition rates is less than 5% of the most intense transition in the spectrum. The frequently questioned one-centre Auger transition rates are shown to be rather appropriate if applied with reasonable wavefunctions and if the vibrational band structure of the molecular spectrum is properly taken into account.
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| 7. |
- Bao, Zhuo, 1977-
(author)
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Synchrotron Radiation Studies of Free and Adsorbed Molecules
- 2008
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Doctoral thesis (other academic/artistic)abstract
- This thesis contains two parts. The first part concerns the research work on free molecules using synchrotron-radiation-related techniques. Auger electron spectra of two free open-shell molecules, O2 and NO, were studied experimentally and theoretically. Photoionization experimental technique with tunable synchrotron radiation source was used to induce core-level electron ionization and obtain the KVV normal Auger electron spectra. A quantitative assignment of O2 normal Auger spectrum was obtained by applying ab initio CI calculations and LVI Auger line shape simulations including the bond length dependence of Auger transition rates. The photon energy dependence of normal Auger electron spectra was focused on with photon energies in the vicinities of core-ionization threshold energies. Consequently, the MAPCI (Molecular Auger Post Collision Interaction) theory was developed. Taking the near-threshold O2 normal Auger spectrum as an example, the two extreme cases of MAPCI effect, “atomic-like PCI” and “molecular PCI”, were discovered and discussed. The effect of shape resonance on near-threshold molecular normal Auger spectrum was discussed taking NO near threshold normal Auger spectra as example.The second part deals with research work on the chemisorption of small epoxy organic molecules, ethylene oxide, methyl oxirane, on Si (100) surfaces. Synchrotron radiation related techniques, UPS, XPS and NEXAFS, were applied. Based on the valence photoemission spectra, C 1s and Si 2p XPS spectra, the epoxy ring opening reactions of these molecules in chemisorption process were proved. Further tentative search for the surface-adsorbate CDAD effect was performed, and no evident circular dichroism was confirmed.
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| 8. |
- Ceolin, Denis, et al.
(author)
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Effect of the Cl2p core orbital excitation on the nuclear dynamics of the three dichloroethylene isomers
- 2011
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 184:1-2, s. 24-28
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Journal article (peer-reviewed)abstract
- In this article, we present the X-ray absorption spectra of the three isomers of dichloroethylene C2H2Cl2 in the vicinity of the chlorine L-2 and L-3 edges. These isomers were excited along the first Cl2p to lowest unoccupied molecular orbital transition and an analysis of the corresponding resonant Auger spectra shows that the C-Cl bond can break before the electronic decay. An investigation of a possible Auger Doppler-like effect is also presented.
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| 9. |
- Ceolin, Denis, et al.
(author)
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Site-selective resonant Auger spectroscopy of iso-dichloroethylene at the carbon K-edge
- 2012
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 185:8-9, s. 252-258
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Journal article (peer-reviewed)abstract
- This study focuses on the two C1s-to-LUMO (lowest unoccupied molecular orbital) excitations of the iso-dichloroethylene (H2C=CCl2) and the subsequent Auger decay. We investigate the effect of the two different carbon core excitations on the population of the cation produced after electronic relaxation. The resonant Auger spectra are interpreted by comparison to the valence shells photoionization spectrum and with the help of theoretical calculations. Several consequences of the core-hole localization on the electronic decay are observed. In particular, the resonant excitation of the C1s(CH2) to the LUMO leads to a large intensity increase in the region of the first satellite state, whereas no dramatic changes are observed for the C1s(CCl2) excitation.
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| 10. |
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| 11. |
- Feng, Meng-Yao, et al.
(author)
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Work-Related Stress and Occurrence of Cardiovascular Disease A 13-Year Prospective Study
- 2022
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In: Journal of Occupational and Environmental Medicine. - 1076-2752 .- 1536-5948. ; 64:11, s. 927-933
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Journal article (peer-reviewed)abstract
- Objective: The aim of the study is to investigate the influence of work-related psychological and physical stresses on risk of cardiovascular disease (CVD). Methods : A total of 5651 CVD-free participants older than 50 years from the Survey of Health, Ageing and Retirement in Europe were followed up for 13 years to detect incident CVD. Work-related stress was assessed using job strain and job reward questionnaire. Cox regression model was used to estimate the association. Results: High physical demands (hazard ratio [HR], 1.30) and low reward (HR, 1.19) compared with their counterparts, as well as active physical jobs (HR, 1.41) and high physical strain (HR, 1.45) in comparison with low physical strain were associated with higher risk of incident CVD after adjusting for confounders. However, combining physically stressful jobs with low reward did not further increase the CVD risk. Conclusions: Avoiding physically stressful jobs or providing appropriate reward may reduce the occurrence of CVD.
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| 12. |
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| 13. |
- Menkveld, Albert J., et al.
(author)
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Nonstandard Errors
- 2024
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In: JOURNAL OF FINANCE. - : Wiley-Blackwell. - 0022-1082 .- 1540-6261. ; 79:3, s. 2339-2390
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Journal article (peer-reviewed)abstract
- In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty-nonstandard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for more reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants.
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| 14. |
- Piancastelli, Maria Novella, et al.
(author)
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A High-resolution Study of Resonant Auger Decay Processes in N2O After Core Electron Excitation from Terminal Nitrogen, Central Nitrogen and Oxygen Atoms to the 3π LUMO
- 2007
-
In: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 40:17, s. 3357-3365
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Journal article (peer-reviewed)abstract
- Decay spectra of N2O following excitation to the N terminal (Nt) → π*, N central (Nc) → π* and O is → π* intermediate states are reported. The final states reached after participator decay show resonant enhancement consistent with a local-density-of-states analysis based on the Mulliken population of the valence molecular orbitals. In particular, the X-state is resonantly enhanced mostly after excitation from the Nt 1s and the O Is core levels to the π*, while the B-state is mostly enhanced following the excitation of the Nc Is → π* intermediate state. Below the Nt Is threshold, the lowest lying peak related to spectator decay falls at lower binding energy than the highest lying participator peak. This can be attributed to a particularly strong screening effect exerted by the excited electron in the LUMO.
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| 15. |
- Piancastelli, Maria Novella, et al.
(author)
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Electronic and Geometric Structure of Methyl Oxirane Adsorbed on Si (100) 2 × 1
- 2007
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 254:1, s. 108-112
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Journal article (peer-reviewed)abstract
- Electronic and geometric properties of the adsorbate–substrate complex formed upon adsorption of methyl oxirane on Si(1 0 0)2 × 1 at room temperature is reported, obtained with synchrotron radiation-induced valence and core-level photoemission. A ring-opening reaction is demonstrated to occur, followed by a five-membered ring formation involving two of the Si surface atoms bound to a surface dimer. Core-level photoemission spectra support the ring-opening reaction and the SiO and SiC bond formation, while from the valence spectra a more extended molecular fragmentation can be ruled out. We discuss the most likely geometry of the five-membered ring.
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| 16. |
- Piancastelli, Maria Novella, et al.
(author)
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Electronic Structure of Core-excited and Core-ionized Methyl Oxirane
- 2007
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 156, s. 259-264
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Journal article (peer-reviewed)abstract
- We report a detailed analysis of the electronic structure of methyl oxirane, including core-level photoelectron spectroscopy, X-ray absorption at both C and O K-shells, resonant Auger and normal Auger spectroscopy. The X-ray absorption spectra (XAS) around the C K-edge can be easily interpreted on the ground of the chemical shift between the carbon atoms with different chemical environments. The X-ray absorption data around the O K-edge are quite structureless, hinting for a likely fragmentation process (possibly implying a ring-opening reaction). In resonant Auger spectra obtained after excitation below both the C 1s and O 1s ionization thresholds we notice a predominance of spectator decay implying a strong mixing between empty molecular orbitals and Rydberg states.
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| 17. |
- Travnikova, Oksana, et al.
(author)
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A Study of Substituent Effects for Aliphatic CH3-X Compounds by Resonant Auger Spectroscopy
- 2009
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In: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 11:5, s. 826-833
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Journal article (peer-reviewed)abstract
- In this study linear free energy relationships (LFER) are applied to the relaxation of core-excited states in aliphatic CH3X compounds. There are at least two valence orbitals involved in Auger decay following CCH31s →σ*C–X excitation, which may as well be localized on the substituents in this series. Therefore, the observed property cannot be strictly attached to the so-called reaction center. The behavior of substituent constants in the description of core-hole processes in aliphatic compounds is also checked on C1s ionization potentials for the extended series of substituted methanes. The role of the inductive effect for both resonant Auger kinetic energies (Ek) and C1s binding energies (Ecoreb) is very important. CCH31s →σ*C–X excitation energies do not show any significant correlations with inductive substituent constants. On the contrary, Taft’s inductive parameters alone give good correlations for Ek. A simple model with ‘Z + 1’ approximation is developed to describe Ek and explain the observed correlations:Ek = Ecoreb− (Ev(Z)b + Eea(Z+1)+),where Ebv(Z) is the valence ionization potential for CH3X and Eea(Z+1)+ is the electron affinity for [NH3X]+.
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| 18. |
- Travnikova, Oksana, et al.
(author)
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Assignment of the L2,3VV normal Auger decay spectrum of Cl-2 by ab initio calculations
- 2009
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In: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 474:1-3, s. 67-73
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Journal article (peer-reviewed)abstract
- Auger decay processes of the Cl 2p ionized states have been studied in Cl-2 by means of high- resolution electron spectroscopy and ab initio calculations. This led to reassignment of the normal L2,3VV Auger decay spectrum of Cl2. The reliability of this assignment is strongly supported by an independent measurement of the L2; 3VV Auger electron spectrum of Cl2 which has been obtained after selective Cl 2p(3/2)(-1) photoionization of the chlorine molecule. Partial Auger transition rates for the three nongenerate spin-orbit and molecular- field- split 2p(-1) states - 2p(3/2,3/2)(-1) ((2)Pi(3/2)), 2p(3/2,1/2)(-1)((2)Sigma(+)(1/2)) and 2p(1/2,1/2)(-1)((2)Pi(1/2)) - show differences similar to the ones reported in previous works for HCl.
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| 19. |
- Travnikova, Oksana, et al.
(author)
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Disentangling the complex line profiles in the Cl 2p photoelectron spectra of Cl-2
- 2006
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In: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 426:4-6, s. 452-458
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Journal article (peer-reviewed)abstract
- High-resolution Cl (2p) photoelectron spectra Of Cl-2 are reported and their complex structure is analyzed in detail, taking into account molecular field (NIF), spin-orbit (SO) and parity splitting. High-level ab initio calculations were performed to provide reliable values for spectroscopic parameters. Accurate data analysis enabled us to determine the value of molecular-field splitting of 86 7 meV, and values of 92 5, 79 11 and 105 12 meV for the lifetime line widths of the (2)Pi(1/2), (2)Sigma(+)(1/2) and (2)Pi(3/2) states, respectively. The gerade-ungerade splitting of less than 5 meV is obtained from the calculations.
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| 20. |
- Travnikova, Oksana, et al.
(author)
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Selective vibrational excitation in the resonant Auger decay following core-to-pi transitions in N2O
- 2010
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 181:2-3, s. 129-134
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Journal article (peer-reviewed)abstract
- In N2O a detailed study of the vibrational distribution of the (X) over tilde state reached after decay of core-to-pi* excitation of N terminal, N central and 0 1s core levels is reported. We observe a change in the relative intensity of bending versus stretching modes while scanning the photon energy across all three resonances. While this effect is known to be due to the Renner-Teller splitting in the core-excited states, we could derive that the antisymmetric stretching is excited mainly in the decay of the N terminal 1s-to-pi* excitation. An explanation for such selectivity is provided in terms of interplay of vibrational structure on potential energy surfaces of different electronic states involved in the process.
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| 21. |
- Zhang, Wei, et al.
(author)
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Hierarchical Design of a Low Power Standing Wave Oscillator Based Clock Distribution Network
- 2016
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In: 2016 2ND IEEE NORDIC CIRCUITS AND SYSTEMS CONFERENCE (NORCAS). - : IEEE conference proceedings. - 9781509010950
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Conference paper (peer-reviewed)abstract
- This paper introduces a hierarchical clock interconnection network with two-level bufferless standing wave resonant clock distribution to minimize the clock power consumption in a synchronous system. The first level is a serpentine network which consists of many coupled standing wave oscillators to distribute clock signals in the whole chip area. The second level is a group of fishbone architectures connected to the standing wave oscillators to route clock signals in the local areas. A clock synthesis flow for the fishbone architecture is also introduced to enable design automation. This fishbone architecture is studied through a pipelined floating-point fused multiply-add module under 28nm standard CMOS process. Simulation results show that, this architecture can reduce more than 30% clock power consumption compared with a traditional buffered clock network.
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| 22. |
- Zhuo, Lai-Bao, et al.
(author)
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Impact of effort reward imbalance at work on suicidal ideation in ten European countries : The role of depressive symptoms
- 2020
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In: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327 .- 1573-2517. ; 260, s. 214-221
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Journal article (peer-reviewed)abstract
- Background: Evidence of the association between effort reward imbalance (ERI) and suicidal ideation is sparse. This study examined the influence of ERI at work on suicidal ideation and the mediating effect of depressive symptoms. Methods: There were 4963 workers aged 50 + without suicidal ideation at baseline in the Survey of Health, Aging and Retirement in Europe, these workers were followed-up for 8-years to detect incident suicidal ideation. ERI was measured by a short ERI questionnaire. Suicidal ideation was evaluated by one item derived from the 12-item Europe-depression scale, and depressive symptoms were assessed by the remaining 11 items in the scale. Cox models were employed to explore the relationship adjusting for potential confounders. Mediation analysis was used to test the mediating effect of depressive symptoms. Results: A significantly higher incidence of suicidal ideation was related with high effort (HR = 1.51) and low reward (HR = 1.42), respectively. A high effort-low reward imbalance was associated with even higher risk of suicidal ideation (HR = 1.96) as compared to low effort-high reward combination. The association was varied by gender, region, education and household income. Depressive symptoms mediated a modest proportion (natural indirect effect 14.4%) of the total association between ERI and suicidal ideation. Limitation: Suicidal ideation definition based on self-administered questionnaires which could lead to false negatives. And some unmeasured confounders might have biased the results. Conclusions: Efforts in promoting balanced effort-reward at work may reduce suicidal ideation among working population aged 50+. Avoiding depressive symptoms may further enhance such efforts.
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| 23. |
- Zhuo, Lai-Bao, et al.
(author)
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Working life job strain status and cognitive aging in Europe : A 12-year follow-up study
- 2021
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In: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327 .- 1573-2517. ; 295, s. 1177-1183
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Journal article (peer-reviewed)abstract
- Background: To examine the association of job strain with cognitive ability and the influence of life-course job strain on later life cognitive decline.Methods: Data were derived from six waves of the Survey of Health, Aging, and Retirement in Europe. The study sample consists of 13349 participants aged 50 to 98 years at wave 2 and has been followed up for 12-years. Job strain status across working life was assessed using a short demand-control job strain model containing two core dimensions: job demands and job control collected in wave 3. Cognitive abilities concerning episodic memory was assessed by immediate recall and delayed recall tests, executive function was evaluated by verbal fluency test collected in all waves (waves 2–7) except wave 3. Mixed-effects model was used to estimate working life job strain and its cumulative effect on cognitive decline.Results: Both passive and high strain jobs were associated with lower levels of cognitive ability (episodic memory and verbal fluency) in comparison with active job. Long exposure to active- or low strain-job was associated with higher cognitive ability whereas long exposure to passive job or moderate duration of high strain job was associated with lower cognitive ability. The rate of memory decline was positively related to moderate duration of passive job and negatively related to long-term exposure to low strain job.Limitations: Information on working conditions was based on self-reported recollections.Conclusions: Working life variation in job strain status and their duration may explain individual differences in cognitive ability in later life.
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