Transition Intensities Research Articles

Morphological characteristics and flashing mechanism of superheated liquid jets released from rectangular breaches

The leakage of liquefied gases such as liquefied hydrocarbons and liquid chlorine is usually accompanied by an intense phase transition that results in two-phase release. This two-phase release will lead to fire, explosion, toxic diffusion and other major dangerous accidents, seriously endangering the safety of personnel and ecological environment, resulting in inestimable losses. To deepen the understanding of such accidents, a 20L tank was used to simulate the accidental release of superheated liquid and study its accident behavior. This work simulated different breaches by using different shapes of nozzles with equal cross-sectional area and more focused on rectangular nozzles. Besides, the influence of initial temperature (110–130 °C) and pressure (6–16 bar) was also taken into account. A high-speed camera was used to record the external morphological characteristics of the superheated liquid jets released from the nozzles. The jet angle and half-width were extracted as the quantitative characterization of the external morphology by threshold processing algorithm. The results revealed that the rectangular nozzle jet (RNJ) has a different external morphology from the circular nozzle jet (CNJ) due to the presence of vortex and axis-switching phenomena. Aspect ratio plays an important role in the determination of external morphology of the RNJ and there is a critical aspect ratio AR = 3. In addition, this study also demonstrates that the rectangular nozzle has a different flashing mechanism from the circular nozzle, which is the underlying reason for the different external morphologies. In summary, compared to the traditional circular breach, rectangular breach has a significant promotion effect on the jet flashing, and the industrial medium released from the slit breach will have a greater impact range, resulting in more serious consequences of accidents.

Intensity of cooperative vibronic transitions in the Eu(III), Gd(III) and Tb(III) formates spectra.

The luminescence and absorption spectra of the lanthanide ions in solids and coordination compounds are characterized by sharp pure electronic lines, which are accompanied by much weaker lines of vibronic transitions. The vibronic spectroscopy is a good probing tool for investigations of the properties of surrounding ion ligands. The lanthanides formates are efficient luminescent crystals and can be viewed as the elementary type in the whole class of the oxygen-containing lanthanide coordination compounds. The intensity of vibronic transitions in spectra of luminescence and excitation europium (5 D0 →7 F2 , 7 F0 →5 D2 ), terbium (7 F6 →5 D4 ), gadolinium (6 P7/2 →8 S7/2 ) in anhydrous formates of the type Ln(HCOO)3 (Ln = Eu, Tb, Gd) and Y(HCOO)3 .2H2 O doped with Eu3+ and Tb3+ (C ~1 mol%) are reported. Also, the infrared and Raman spectra were obtained for the same compounds. Related integral intensity vibronic sidebands depend on the type of electronic transition of the same ion and varies for the same electronic transitions in different crystals. The obtained experimental data referring to the rate constants of vibronic transitions and intensity distribution in vibronic spectra on normal vibrations of the formate groups are in agreement with the predictions based on the Stavola-Dexter theory of cooperative vibronic transitions.

The 130–360 GHz rotational spectrum of isocyanocyclobutane (C4H7NC) and cyanocyclobutane (C4H7CN)

The 130–360 GHz rotational spectrum of isocyanocyclobutane is reported herein for the first time. Over 2200 transitions were measured, assigned, and least-squares fit to a partial-octic distorted-rotor Hamiltonian with small deviation (σfit < 50 kHz) for the equatorial conformer. The axial conformer has so far remained elusive. For cyanocyclobutane, we measured the rotational spectra of both equatorial and axial conformers in the same frequency region to allow a direct comparison between the isomers. Transition frequencies for each conformational isomer of cyanocyclobutane were similarly fit to partial octic distorted-rotor Hamiltonians with small deviation. The experimental spectroscopic constants are in very good agreement with the predicted values (B3LYP) for all three species and with those reported in an earlier microwave study of cyanocyclobutane. Measurement of the relative transition intensities provides an updated energy difference of 0.69 (7) kcal/mol between the two conformers, with the equatorial conformation being the more stable one. Analysis of the axial conformation of cyanocyclobutane reveals coupling of its ground state to the vibrationally excited states of the equatorial conformation. Our observations of the vibrationally excited states of the equatorial conformer suggest that there are many Coriolis interactions between these states that were not described previously. Combined with literature values of nuclear quadrupole coupling constants, these spectroscopic constants and reported transition frequencies provide the basis for future astronomical searches for isocyanocyclobutane and cyanocyclobutane.

Inference for transition probabilities in non-Markov multi-state models.

Multi-state models are frequently used when data come from subjects observed over time and where focus is on the occurrence of events that the subjects may experience. A convenient modeling assumption is that the multi-state stochastic process is Markovian, in which case a number of methods are available when doing inference for both transition intensities and transition probabilities. The Markov assumption, however, is quite strict and may not fit actual data in a satisfactory way. Therefore, inference methods for non-Markov models are needed. In this paper, we review methods for estimating transition probabilities in such models and suggest ways of doing regression analysis based on pseudo observations. In particular, we will compare methods using land-marking with methods using plug-in. The methods are illustrated using simulations and practical examples from medical research.

Similarity of competing risks models with constant intensities in an application to clinical healthcare pathways involving prostate cancer surgery

The recent availability of routine medical data, especially in a university-clinical context, may enable the discovery of typical healthcare pathways, that is, typical temporal sequences of clinical interventions or hospital readmissions. However, such pathways are heterogeneous in a large provider such as a university hospital, and it is important to identify similar care pathways that can still be considered typical pathways. We understand the pathway as a temporal process with possible transitions from a single initial treatment state to hospital readmission of different types, which constitutes a competing risks setting. In this article, we propose a multi-state model-based approach to uncover pathway similarity between two groups of individuals. We describe a new bootstrap procedure for testing the similarity of constant transition intensities from two competing risk models. In a large simulation study, we investigate the performance of our similarity approach with respect to different sample sizes and different similarity thresholds. The studies are motivated by an application from urological clinical routine and we show how the results can be transferred to the application example.

Theoretical Characterization of Carbonic Acid Clusters in the UV.

Two theoretical structural motifs are proposed to match two experimental solid carbonic acid UV spectra from previous literature ( Astron. Astrophys. 2021, 646, A172): a linear ribbon structure as a single octamer and nonplanar orientations of carbonic acid clusters. The latter have some contribution from approximated amorphous solid carbonic acid in the form of 40 different clusters of 8 carbonic acid molecules ensemble-averaged together, but unoptimized pairs of optimized dimers oriented perpendicular to one another give the strongest intensities of lower energy UV transitions. The linear ribbon structure's predicted spectrum computed with CAM-B3LYP/6-311G(d,p) agrees well with Experimental Solid B─the β-carbonic acid experimental data in the UV region. Meanwhile, the 40 amorphous clusters are built with a randomization script, and the electronically excited states are calculated with both CAM-B3LYP/6-311G(d,p) and ωB97XD/6-311G(d,p). The resulting theoretical spectrum is constructed by employing a Boltzmann distribution of the intensities and artificially broadening the simulated spectra. The nonplanar dimer pairs are computed with CAM-B3LYP and B3LYP with the 6-311G(d,p) basis set. The results of the amorphous simulation weakly correspond with the Experimental Solid A spectrum, but the fully nonplanar motif matches the experiment much more convincingly. As a result, the previous work appears to have observed the traditional crystalline phase of solid carbonic acid in Experimental Solid B, whereas the nonplanar orientations of the carbonic acids in the clusters appear to correlate with Experimental Solid A. This spectral classification will aid in future laboratory work exploring the role that carbonic acid can play in low temperature, low pressure desorbed environments with potential application to astrochemistry.

1193-P: Natural History of Type 2 Diabetes in South Asians: Arrow of Time

Background: People of South Asian ancestry are at high risk for type 2 diabetes, but the time to disease progression in this population is not fully understood. Methods: We analyzed data from 2714 adults aged ≥20 years, enrolled in the Chennai site of the prospective Cardiometabolic risk reduction in South Asia (CARRS) study. Participants had 75g OGTT and HbA1c measurements. We defined normal glucose tolerance (NGT) , isolated impaired fasting glucose (iIFG) , impaired glucose tolerance (IGT) , and diabetes based on ADA criteria. We constructed continuous chain Markov models to estimate the transition through multiple states (NGT -&amp;gt; iIFG -&amp;gt; diabetes; NGT -&amp;gt; IGT -&amp;gt; diabetes) . The annual and five-year transition probability among states was estimated based on transition intensity. Results: Participants were, on average, 38.4 (range 20-89) years old, and 40.1% were male. Prevalence of iIFG and IGT was 16.9% and 7.3%, respectively. Over 5 years of follow up, the progression rates were: NGT to iIFG, 36.3 (95% CI: 32.5, 40.5) per 1,000 person-years (PYR) , NGT to IGT, 27.4 (95% CI: 24.1, 31.1) per 1,000 PYR, iIFG to diabetes 47.3 (95% CI: 40.4, 55.4) per 1,000 PYR, and IGT to diabetes 77.1 (95% CI: 65.1, 91.3) per 1,000 PYR. The estimated annual probability of remaining as NGT, iIFG, and IGT were 95.2% (94.7%, 95.8%) , 87.3% (85.5%, 89.0%) ;%) , and 81.9% (79.6%, 84.3%) %) , respectively. Assuming unidirectional transition, the annual probability of conversion from NGT to iIFG, and iIFG to diabetes were 4.5% (3.9%, 4.9%) , and 12.7% (10.9%, 14.5%) , respectively; and NGT to IGT, and IGT to diabetes were 3.8% (3.3%, 4.2%) and 18.1% (15.7%, 20.3%) . The estimated mean sojourn time (years) in each state were: NGT 20.5 (18.2, 23.2) , iIFG 7.4 (6.4, 8.6) , and IGT 5.0 (4.4, 5.8) , respectively. Conclusion: The course to diabetes in South Asians is rapid once prediabetes sets in, allowing a window of only 5-7.4 years to implement proven prevention. Innovative prevention efforts in normoglycemic people may be needed to prevent prediabetes in the first place. Disclosure K.Narayan: n/a. H.H.Chang: None. N.Tandon: None. V.Mohan: None. D.Kondal: None. L.R.Staimez: None. R.Anjana: None. U.Gujral: None. M.Deepa: None. S.A.Patel: Research Support; Johnson &amp; Johnson. M.K.Ali: Advisory Panel; Bayer AG, Research Support; Merck &amp; Co., Inc. D.Prabhakaran: None. Funding The National Heart, Lung, and Blood Institute (NHLBI) , National Institutes of Health (HHSN268200900026C)

Entropy-Driven Stabilization of Multielement Halide Double-Perovskite Alloys.

Currently, a major obstacle restricting the commercial application of halide perovskites is their low thermodynamic stability. Herein, inspired by the high-stability high-entropy alloys, we theoretically investigated a variety of multielement double-perovskite alloys. First-principles calculations show that the entropy contribution to Gibbs free energy, which offsets the positive enthalpy contribution by up to 35 meV/f.u., can significantly enhance the material stability of double-perovskite alloys. We found that the electronic properties of bandgaps (1.04-2.21 eV) and carrier effective masses (0.34 to greater than 2 m0) of the multielement double-perovskite alloys can be tuned over a wide range. Meanwhile, the parity-forbidden condition of optical transitions in the Cs2AgInCl6 perovskite can be broken because of the lower symmetry of the configurational disorder, leading to enhanced transition intensity. This work demonstrates a promising strategy by utilizing the alloy entropic effect to further improve the material stability and optoelectronic performance of halide perovskites.

Calculation of the singlet-triplet magnetic and electro-quadrupole transitions intensity for Ge2 molecule

Intensity of the parity-forbidden singlet-triplet (S-T) transitions of the Ge2 molecule in the near IR region has been studied by the multi-reference configuration interaction (MRCI) approach with spin-orbit coupling (SOC). Intensity of the sub-band is mainly dominated by the spin angular momentum term in the magnetic-dipole transition moment, which arises from the spin current inside the zero-field split sublevels of the ground state. The Einstein coefficients corresponding to vibronic bands 0–(2∼7), 1–(4∼7), 2–(6∼7), 3–7 of the transition are in the range of 0.304–0.463 s−1; these bands could be detected since they are not overlapped by the allowed rovibronic systems. The magnetic-dipole is only defined by the orbital angular momentum term and the band intensity is not sufficient for observation. The electric-quadrupole and transitions have also been calculated to be negligible. The triply forbidden electro-dipole transitions in the IR spectrum of the Ge2 throws new light on this little known domain of diatomic molecular spectroscopy. Highlights The parity-forbidden singlet–triplet transitions of the Ge2 has been studied. Intensity of the sub-band arises from the spin current inside the zero-field split sublevels of the ground state. Contributions of the a1Δg−1Πg and orbital transitions presented in the magnetic-dipole a 1Δg- transition are negligible.

The energy transition in Europe-a solution for net zero carbon?

Climate change has generated intense concerns from public authorities and international institutions with regard to shaping the behavior of companies, consumers, investors, and other stakeholders so as to manage this challenge as efficiently as possible. In order to address the climate emergency in the post-pandemic era, recovery plans need to trigger decarbonization, and a green transition, including specific investments and providing a more adaptive structure of the sources of energy in different regions, able to meet the need for a systemic shift towards a more sustainable economy that works for both people and the planet. The main measurable effect of energy production and consumption is by far represented by carbon emissions. In the present paper, we aim to identify the statistical significance of several factors influencing the carbon dioxide emission per capita in the European countries-level of economic development, level of globalization, trade openness, and the intensity of energy transition measured by the share of renewable energy in total energy consumption. The results show an increased interest of the experts in energy consumption model shift through green energy increased share, with relatively high differences among the 42 European countries analyzed. The analysis was conducted for the period 1990-2018 and policy differences depending on variables (GDP/capita, globalization index, trade openness, and renewable energy share in total energy consumption) were identified. The results showed that the carbon dioxide emission per capita evaluation designed model is representative of the European countries. The fact that the targets set by European non-EU member states for reducing CO2 emissions are lower than for the EU is influencing the dynamics of the energy transition, with implications for the size and destination of funds to finance the development of renewable energy.

Luminescence and optical properties of sodium germanate glasses doped with Sm3+ ions

Sm3+ doped sodium germanate glasses were synthesized by high temperature melt-quenching technique, suitable glass composition with optimum Sm3+ concentration and good luminescence thermal stability was obtained. The luminescence performance of Sm3+ and its optical transition property in glasses were studied. The optical transition intensity parameters of Sm3+ were calculated according to Judd-Ofelt theory. According to Huang's model and Dexter's model, it was confirmed that the electric dipole-dipole interaction among Sm3+ was responsible for the concentration dependent luminescence quenching of 4G5/2 level of Sm3+. Temperature dependent luminescence characteristics of Sm3+ was also investigated, and the luminescence thermal quenching behavior was found. When the temperature was 423 K, the emission intensity of the sample can still maintain 90% of that at room temperature. The result showed that this kind of red-emitting glass phosphor had an excellent luminescence thermal stability.

Spectral Signatures of Hydrogen Thioperoxide (HOSH) and Hydrogen Persulfide (HSSH): Possible Molecular Sulfur Sinks in the Dense ISM.

For decades, sulfur has remained underdetected in molecular form within the dense interstellar medium (ISM), and somewhere a molecular sulfur sink exists where it may be hiding. With the discovery of hydrogen peroxide (HOOH) in the ISM in 2011, a natural starting point may be found in sulfur-bearing analogs that are chemically similar to HOOH: hydrogen thioperoxide (HOSH) and hydrogen persulfide (HSSH). The present theoretical study couples the accuracy in the anharmonic fundamental vibrational frequencies from the explicitly correlated coupled cluster theory with the accurate rotational constants provided by canonical high-level coupled cluster theory to produce rovibrational spectra for use in the potential observation of HOSH and HSSH. The mode for HSSH at 886.1 cm is within 0.2 cm of the gas-phase experiment, and the rotational constant for HSSH of 6979.5 MHz is within 9.0 MHz of the experimental benchmarks, implying that the unknown spectral features (such as the first overtones and combination bands) provided herein are similarly accurate. Notably, a previous experimentally-attributed 2 mode, at 7041.8 cm, has been reassigned to the combination band based on the present work’s value at 7034.3 cm. The most intense vibrational transitions for each molecule are the torsions, with HOSH having a more intense transition of 72 km/mol compared to HSSH’s intensity of 14 km/mol. Furthermore, HOSH has a larger net dipole moment of 1.60 D compared to HSSH’s 1.15 D. While HOSH may be the more likely candidate of the two for possible astronomical observation via vibrational spectroscopy due to the notable difference in their intensities, both HSSH and HOSH have large enough net dipole moments to be detectable by rotational spectroscopy to discover the role these molecules may have as possible molecular sulfur sinks in the dense ISM.

A multistate model to evaluate COPD progression integrating drugs consumption data and hospital databases

&#x0D; Background&#x0D; The increase in costs related to the diagnosis and treatment of chronic-degenerative diseases requires a better knowledge of the true care pathway of patients. The study objective was to explore, using multi-state modeling, how analyses of drug prescriptions and data obtained from hospital discharge sheets can be used in combination to build a model of patients health care pathway in a non experimental setting. The model was applied to Chronic Obstructive Pulmonary Disease (COPD).&#x0D; Methods&#x0D; Based on the GOLD guidelines, access to hospitalization for COPD and prescription pharmaceuticals were awarded to seven transients states theoretically progressive. The intensity of transition were estimated with the non-parametric method proposed by Aalen and Johansen for multi-state Markov models non-homogeneous in time.&#x0D; Results&#x0D; The COPD patients included in the study are 111190. Patients admitted with a diagnosis of non acute COPD had a growing probability over time of needing prescriptions for inhaled corticosteroids (ICS) or the set combination of long-acting beta-agonists (LABA) and ICS; they also had a rising probability of an exacerbation. The use of ICS alone or in combination with LABA delays a hospital admission for acute respiratory failure by about 6 months, as compared to short-acting beta-agonists or anticholinergics.&#x0D; Conclusion&#x0D; The probabilities of a transition and their distribution in relation to time, sex, age and clinical status can be a helpful tool for those operating in the health care sector, who are called upon to carry out decisions from the standpoints of both efficacious clinical management and an efficient use of resources.

Convergence of jump processes with stochastic intensity to Brownian motion with inert drift

Consider a random walker on the nonnegative lattice, moving in continuous time, whose positive transition intensity is proportional to the time the walker spends at the origin. In this way, the walker is a jump process with a stochastic and adapted jump intensity. We show that, upon Brownian scaling, the sequence of such processes converges to Brownian motion with inert drift (BMID). BMID was introduced by Frank Knight in 2001 and generalized by White in 2007. This confirms a conjecture of Burdzy and White in 2008 in the one-dimensional setting.

Probing the delocalized core-hole via inner-shell excitation in N2

The dispute about whether the 1s core-hole is localized on one atom or delocalized over both in a homonuclear diatomic molecule has continued for decades, which has been extensively studied by the photoelectron and electron–ion coincidence spectroscopies. For N2, if the 1s core-hole is delocalized, the K-shell excitation into the 1π g orbital should split into two components, i.e., the dipole-allowed transition from the ungerade 1σ u state and the dipole-forbidden transition from the gerade 1σ g state. However, only the dipole-allowed transition has been observed up to now. Here, we report the inner-shell electron energy loss spectra of N2 at different scattering angles with an incident electron energy of 1500 eV and an energy resolution of 65 meV. The vibrational structures of both the dipole-allowed and dipole-forbidden states of N2 have been identified at different momentum transfers. The splitting between the and states with the reverse symmetry is determined to be 67 ± 7 meV. Moreover, the momentum transfer dependence behavior of the transition intensity ratio agrees with the theoretical predictions, as increasing to a maximum and then decreasing. The experimental observations clearly show that the inner most electrons can be described by 1σ g and 1σ u , which indicates that the inner-shell 1s core-hole of N2 is delocalized over two N atoms based on the excitation process.

Testing the limitations of harmonic approximation in the determination of Raman intensities

Raman intensities in molecular spectra are usually computed within double harmonic approximation. This procedure relies on treating a vibrating molecule as a collection of harmonic oscillators and on the assumption that polarisability tensor invariants display linear variations around the molecular equilibrium geometry. This methodology, originally formulated by Placzek, constitutes the theoretical foundation for computing Raman intensities in standard quantum chemistry packages. However, the two assumptions underlying double harmonic approximation have not been sufficiently tested. In this work, we employed exact anharmonic ro-vibrational wave functions and distance-dependent polarisability invariants together with their harmonic approximants to investigate the discrepancies in Raman intensities of the fundamental transitions in 12 diatomic molecules, caused by double harmonic approximation. We found that: (i) the errors in total Raman intensities were between −8.2% and +9.5%, (ii) the largest discrepancy was observed for F2, where the polarisability invariants could not be adequately modelled by their linear approximants, and (iii) quantum chemical methods fail to predict reliable polarisability invariants at non-equilibrium molecular geometries; the associated errors in Raman intensities are huge and completely overshadow the shortcomings of double harmonic approximation. We communicate here an urgent need for developing accurate methods capable of computing reliable polarisabilities also at distorted geometries.

Pulseless electrical activity in in-hospital cardiac arrest – A crossroad for decisions

BackgroundPEA is often seen during resuscitation, either as the presenting clinical state in cardiac arrest or as a secondary rhythm following transient return of spontaneous circulation (ROSC), ventricular fibrillation/tachycardia (VF/VT), or asystole (ASY). The aim of this study was to explore and quantify the evolution from primary/secondary PEA to ROSC in adults during in-hospital cardiac arrest (IHCA). MethodsWe analyzed 700 IHCA episodes at one Norwegian hospital and three U.S. hospitals at different time periods between 2002 and 2021. During resuscitation ECG, chest compressions, and ventilations were recorded by defibrillators. Each event was manually annotated using a graphical application. We quantified the transition intensities, i.e., the propensity to change from PEA to another clinical state using time-to-event statistical methods. ResultsMost patients experienced PEA at least once before achieving ROSC or being declared dead. Time average transition intensities to ROSC from primary PEA (n = 230) and secondary PEA after ASY (n = 72) were 0.1 per min, peaking at 4 and 7 minutes, respectively; thus, a patient in these types of PEA showed a 10% chance of achieving ROSC in one minute. Much higher transition intensities to ROSC, average of 0.15 per min, were observed for secondary PEA after VF/VT (n = 83) or after ROSC (n = 134). DiscussionPEA is a crossroad in which the subsequent course is determined. The four distinct presentations of PEA behave differently on important characteristics. A transition to PEA during resuscitation should encourage the resuscitation team to continue resuscitative efforts.

Poly(cyclosilane) Connectivity Tunes Optical Absorbance.

We report herein the influence of skeletal connectivity on the conformation-dependent optical properties of cyclosilane homo- and copolymers. 1,3-Linked cyclosilanes were bathochromically shifted by 20 nm in solution relative to 1,4-linked cyclosilanes, an effect reproduced by quantum chemical calculations on oligomeric model systems. Polysilane optical properties are conformation-dependent, and 1,3-linked cyclosilanes were hypothesized to adopt a favorable conformation unavailable to 1,4-linked cyclosilanes constrained to an endocyclic gauche conformation. Copolymerization of the isomeric cyclosilanes 1,3Si6 and 1,4Si6 afforded linear statistical copolymers, as characterized by 1H and 29Si NMR spectroscopies. The distinct connectivity of each comonomer was found to give rise to tunable absorption spectra, where the position of the absorption band systematically increased with the increased corporation of 1,3Si6. Computational studies pointed to conformation-dependent changes in orbital symmetry in shifting the most intense transition from the low-energy highest occupied molecular orbital (HOMO) → lowest unoccupied molecular orbital (LUMO) transition to a higher-energy HOMO → LUMO + n transition. The results of these studies demonstrate for the first time the role of silicon skeletal connectivity in controlling conformation and optoelectronic properties and provide new insight into the structure-based design of solution-processable silicon-based polymeric materials.

Growth, structure, and polarized spectroscopy of monoclinic Er3+:MgWO4 crystal

We report on the growth, structure, and polarized spectroscopy of a novel promising laser crystal, erbium-doped magnesium monotungstate, Er3+:MgWO4. 1.01 t.% Er3+:MgWO4 was grown by the Top-Seeded Solution Growth method using Na2WO4 as a solvent. The crystal structure was refined by the Rietveld method. Er3+:MgWO4 belongs to the monoclinic class (sp. gr. P2/c, wolframite-type structure, lattice parameters: a = 4.6939(6) Å, b = 5.6747(4) Å, c = 4.9316(6) Å and β = 90.7858(4) Å. The transition intensities for Er3+ ions were determined using the Judd-Ofelt theory accounting for an intermediate configuration interaction (ICI). Er3+ ions in MgWO4 exhibit intense, strongly polarized and broad absorption and emission bands owing to their accommodation in distorted low-symmetry sites (C2). The stimulated-emission cross-section for the 4I13/2 → 4I15/2 transition is 0.31×10−20 cm2 at 1637 nm (light polarization: E || b ). The radiative lifetime of the 4I13/2 state is 4.85 ± 0.05 ms. The multiphonon non-radiative relaxation for Er3+ excited multiplets is quantified. Er3+ ions in MgWO4 feature large Stark splitting of the ground-state, ΔE(4I15/2) = 435 cm-1. Er3+:MgWO4 is attractive for low-threshold lasers at ∼1.64 µm.

The Impact of Economic Growth, Industrial Transition, and Energy Intensity on Carbon Dioxide Emissions in China

Carbon emission reduction has become a worldwide concern on account of global sustainability issues. Many existing studies have focused on the various socioeconomic influencing factors of carbon dioxide (CO2) emissions and the corresponding transmission mechanisms, while very few models have unified the scale effect, structure effect, and technique effect in the context of China. This paper attempted to analyze the impact of economic growth, industrial transition, and energy intensity on CO2 emissions in China by constructing an autoregressive distributed lag (ARDL) model. The results showed that there are long-term cointegration relationships between the three factors mentioned above and CO2 emissions. There is an inverted U-shaped relationship between economic growth and CO2 emissions, which not only verifies the environmental Kuznets curve (EKC) hypothesis, but also upholds the scale effect. In addition, the proportion of added value of secondary industry and energy intensity has significant positive impacts on CO2 emissions. On one hand, this confirms the structure effect and technique effect; on the other hand, it implies that the reduction effect is the dominant effect in the case of China, instead of the rebound effect. This paper is expected to make a valuable contribution to research in the field of sustainable development by providing both theoretical support and implementation of path choice for CO2 reduction in China.