Energy use is often accompanied with air emissions including SOx, NOx, CO2, etc. It is essential to consider both the energy and environmental performance of various sectors to ensure better ...policymaking. This study considered air pollution by calculating energy-environmental efficiency (EEE) at the sectoral level. A few studies have previously applied the slack-based measure (SBM) model to multi-sector EEE assessments. Despite the advantages of SBM model, potential improvements have rarely been proposed. Therefore, a super-efficiency SBM model with undesirable outputs (S-U-SBM) was used to evaluate the EEE of 31 sectors in China. The policy implications of improving EEE, in microcosmic (potential improvement) and macroscopic (influencing factors) terms, were considered. The results indicated that for all sectors there was an overall trend of increasing EEE from 1995 to 2009, except for Rent and Other Business Activities, and Health and Social Work. The average annual potential for energy-saving and emission-reducing measures in all sectors was 1.396 × 1017 J and 7.0780 × 107 tons, respectively. Chemicals and Chemical Materials had the highest potential to save energy and reduce emissions. A panel regression indicated that the relationship between EEE and gross output was U-shaped for all industry, but had an inverted-U shape for heavy industry. Sectoral size, technology, and the proportion of energy demand satisfied by coal significantly influenced EEE.
Background: Open Science seeks to render research outputs visible, accessible and reusable. In this context, Research Data and Research Software sharing and dissemination issues provide real ...challenges to the scientific community, as consequence of recent progress in political, legal and funding requirements.
Methods: We take advantage from the approach we have developed in a precedent publication, in which we have highlighted the similarities between the Research Data and Research Software definitions.
Results: The similarities between Research Data and Research Software definitions can be extended to propose protocols for Research Data dissemination and evaluation derived from those already proposed for Research Software dissemination and evaluation. We also analyze FAIR principles for these outputs.
Conclusions: Our proposals here provide concrete instructions for Research Data and Research Software producers to make them more findable and accessible, as well as arguments to choose suitable dissemination platforms to complete the FAIR framework. Future work could analyze the potential extension of this parallelism to other kinds of research outputs that are disseminated under similar conditions to those of Research Data and Research Software, that is, without widely accepted publication procedures involving editors or other external actors and where the dissemination is usually restricted through the hands of the production team.
The Ce:Nd:YAG is a recent active medium in solar-pumped lasers with great potential. This study focuses on the influence of two secondary concentrators: a fused silica aspherical lens and a ...rectangular fused silica light guide; and consequent pump light distribution on the output performance of a Ce:Nd:YAG side-pumped solar laser. The solar laser head with the aspherical lens concentrated the incident pump light on the central region of the rod, producing the highest continuous-wave 1064 nm solar laser power of 19.6 W from the Ce:Nd:YAG medium. However, the non-uniformity of the absorbed pump profile produced by the aspherical lens led to the rod fracture because of the high thermal load, limiting the maximum laser power. Nevertheless, the solar laser head with the light guide uniformly spread the pump light along the laser rod, minimizing the thermal load issues and producing a maximum laser power of 17.4 W. Despite the slight decrease in laser power, the use of the light guide avoided the laser rod fracture, demonstrating its potential to scale to higher laser power. Therefore, the pumping distribution on the rod may play a fundamental role for Ce:Nd:YAG solar laser systems design.
Varying coefficient models are a flexible extension of generic parametric models whose coefficients are functions of a set of effect-modifying covariates instead of fitted constants. They are capable ...of achieving higher model complexity while preserving the structure of the underlying parametric models, hence generating interpretable predictions. In this paper we study the use of gradient boosted decision trees as those coefficient-deciding functions in varying coefficient models with linearly structured outputs. In contrast to the traditional choices of splines or kernel smoothers, boosted trees are more flexible since they require no structural assumptions in the effect modifier space. We introduce our proposed method from the perspective of a localized version of gradient descent, prove its theoretical consistency under mild assumptions commonly adapted by decision tree research, and empirically demonstrate that the proposed tree boosted varying coefficient models achieve high performance qualified by their training speed, prediction accuracy and intelligibility as compared to several benchmark algorithms.
A tunable multi-wavelength stimulated Brillouin scattering (SBS) Q-switched random fiber laser is proposed and experimentally demonstrated. The random distributed feedback of the random fiber laser ...with a half-open cavity structure is provided by a section of 25 km single mode fiber (SMF). The number of output wavelengths varies from 1 to 18 by adjusting the pump power and the tunable laser source (TLS) power. The wavelength interval of laser output is 0.08 nm, indicating that these multi-wavelengths laser output are produced by SBS in SMF. The repetition rate and peak power of SBS Q-switched pulse change linearly with the pump power and the TLS power, while the average pulse width fluctuates between 0.93 and 1.05 μs. The multi-wavelength output is tunable in 38 nm range by changing the TLS wavelength. And the pulse repetition rate will also change with the change of the TLS wavelength, which is related to the uneven gain spectrum of EDF. It has a broad application prospect in the fields of optical communication, optical measurement, optical fiber sensing and laser imaging.
•An analysis of environmentally sensitive productivity growth of industrial sectors is conducted.•Undesirable outputs are taken into consideration to measure the productivity growth.•Green/yellow ...city and industrial sectors are identified according to the ML/M index.•The contributor to the environmentally sensitive productivity growth is technological progress.
Under the background of new urbanization, urban agglomeration plays an important role in boosting development in surrounding areas. However, while contributing significantly to economic growth, it was accompanied by high levels of energy consumption and emissions of waste gas and water into the surrounding ecological system. Therefore, it is worthwhile measuring the environmentally sensitive productivity changes during the development process. The Malmquist–Luenberger index based on company data for the period 2007–2012 is used to examine both desirable and undesirable outputs for total factor productivity of various industrial sectors in the Pearl River Delta. The trend in productivity growth and indexes in efficiency and technology are analyzed. We find that at the city scale, the industrial productivity levels in Dongguan, Shenzhen, and Zhongshan increased during the study period, while those in other cities decreased. Furthermore, Guangzhou, Dongguan, Foshan, Jiangmen, Shenzhen, and Zhuhai are green development cities. Technological advance was the main contributor to productivity growth. In accordance with the efficiency and technological change indexes, 225 Decision-Making Units (DMUs, refers to industrial sectors in this study) comprising specific industries from nine cities were classified into six categories. It was found that 66.9% of the DMUs developed with improved productivity and 40% developed in a green mode. Conditions and trends of industrial sectors and the key determinants affecting environmentally sensitive productivity growth was specified. Thus, it provides essential information for companies to develop in green way, as well as providing policy makers with an understanding of industrial development at both the city and sector level.
A proliferation of research outputs in recent years that takes into account the erotic subjectivities of the researcher seems to suggest that both research on sexuality and the inclusion of the ...desiring researcher’s body in academic writings have become accepted as valuable and relevant academic research topics and methods. Yet, the often animated and at times uncomfortable discussions these academic interventions generate—also beyond academic settings—attest to the enduring sensitivity that comes with (discussing) the researcher’s sex and sexuality. This special section aims to provide a space to explore the methodological, ethical, and epistemological implications of (i) the researcher’s immersion in or withdrawal from sexual/ized interactions, and (ii) reflexively reporting about the researcher’s erotic subjectivities in scholarly outputs such as journal articles or conference presentations. In doing so, it not only critiques current academic structures and a masculinist politics of science that are at best not equipped to take into account the complexities of (auto-)ethnographic sex research. It also turns a critical eye towards the blind spots we might have as sex researchers towards the differential power relations with different actors involved in (auto-) ethnographic research that explicitly deals with the researcher’s erotic subjectivities. Reducing those blind spots will make us less vulnerable to gratuitous comments by the erotophobic academy as well as the increasing conservative societal forces who are all too eager to delegitimize our academic writings, while exploring the complexities of (auto-) ethnographic sex research aims to increase the rigour of our work. By talking back, we aim to advance conversations on the methodological, ethical and epistemological implications of taking seriously the researcher’s erotic subjectivities in our research endeavours.
•Safety-adjusted transportation efficiency is developed to account for accidents.•Safety-adjusted transportation efficiency reveals distinctive information.•China’s safety-adjusted transportation ...efficiency evolved along a U-shaped path.•China’s safety-adjusted efficiency converges but the regular efficiency diverges.
Traffic accident is a grievous problem that costs more than one million lives worldwide every year, but remains understudied in transportation efficiency literature. This paper develops safety-adjusted transportation efficiency to account for the negative outcomes in transportation including accidents, fatalities, injuries and property loss. We model the transportation efficiency under the data envelopment analysis (DEA) framework by treating the accident-related negative outcomes as undesirable outputs. Two DEA models, based on radial and non-radial structures respectively, are proposed for panel data. We apply the methods to 31 provinces in China over a 20-year horizon 1998–2017. We find that the evolution of China’s overall safety-adjusted transportation efficiency follows a U-shaped path: It deteriorated between 1998 and 2002, steadily improved from 2002 to 2012, and stabilized during 2012–2017. The majority of the provinces improved their safety-adjusted transportation efficiency from 1998 to 2017, except for one province that maintained the status quo and three provinces that experienced a decline in performance. Improvement analysis is carried out to identify gaps in accident-related factors that each province should close to attain best-practice. Further, we find strong evidence of unconditional β-convergence and σ-convergence in safety-adjusted transportation efficiency, indicating that the provinces with low initial efficiency generally grew more rapidly and the dispersion of provincial efficiency levels diminished. The main findings are substantially different from the regular transportation efficiency analysis that does not consider the accident-related undesirable factors. The safety-adjusted transportation efficiency can convey important information that the regular transportation efficiency fails to capture.
In this article, we have proposed and demonstrated a new approach to implementing microwave photonic filter (MPF) with switchable, tunable and reconfigurable passbands based on a multi-wavelength ...fiber laser (MWFL) cooperating with a fiber Mach–Zehnder interferometer (FMZI). An EDFA and an SOA have been employed as a hybrid gain medium in the laser cavity, to suppress the homogeneous broadening of EDF. By inserting the FMZI in the fiber laser cavity, MWFL with tunable and switchable wavelength spacing has been achieved, which can be used as the multi-wavelength optical source to implement switchable, tunable and reconfigurable MPF together with a dispersive medium. By tuning the length of variable optical delay line (VODL), the wavelength spacing of the MWFL can be changed, and thus the passband’s central frequency of the MPF. By adjusting the polarization states, gain of EDFA or SOA of the laser cavity, the shape of the laser output can be adjustable, and as a result, shape-adjustable passbands of the MPF have been realized. By introducing the reflective FMZI structure as the wavelength selective component and carefully adjusting the polarization states, half number of the passband can be suppressed, which means the MPF can be switchable. The proposed MPF exhibits shape-adjustable and switchable passbands and enjoys more flexibility compared to previous methods.
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