bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of China’s energy saving and emission reduction demonstration city policy on urban green technology innovation
Authors: Nie Changfei , Li Ruyi , Feng Yuan , Chen Zhi 
Published: September 2023

AbstractUrban green technology innovation (UGTI) is strongly tied to environmental regulations, which can successfully balance economic and environmental benefits. Selecting the panel data for 280 Chinese cities during 2006–2019, we take the energy saving and emission reduction (ESER) demonstration city policy as a quasi-natural experiment, then employ the difference-in-differences model to examine the effect and its mechanisms of ESER policy on UGTI. Empirical results show that the ESER policy can significantly promote UGTI, especially in the western region, the northern region, and cities with weak government environmental attention. At the same time, China’s ESER policy has a stronger promoting effect on UGTI in cities where environmental targets are more stringent. Mechanism analysis shows that the policy mainly promotes UGTI through two channels: increasing the proportion of science and technology expenditure in fiscal expenditure and upgrading the structure of the industry. In addition, we find that the development of UGTI has positive environmental effects by lowering carbon emissions and air pollution. The findings not only enrich the literature on environmental regulation policies and UGTI at the theoretical level, but also provide references for policymakers to specific implementation methods in further enforcing environmental regulation policies to improve UGTI.
Synthesis of Oxindoles via SmI2-Promoted Reduction of 2-Nitrophenylacetic Acids
Authors: Zhang Songlin , Wang Pengkai 
Published: September 2023

AbstractThe reduction of 2-nitrophenylacetic acids to oxindoles promoted by SmI2 is reported for the first time. This reaction involving the reduction of nitro group proceeds through N–O bond cleavage and direct condensation with the neighboring carboxyl group. From a synthetic point of view, a new method for the synthesis of oxindoles in mild neutral conditions is developed.
Iterative Assembly of Chiral Alcohols Utilizing CMMP-Mediated Mitsunobu Reactions
Authors: Kitamura Kei , Kaku Hiroto , Ise Saki , Tsunoda Tetsuto 
Published: September 2023

AbstractAn iterative assembly of chiral alcohol building blocks is reported utilizing cyanomethylene trimethylphosphorane (CMMP)-mediated Mitsunobu reactions. 1,3-Benzodithiole tetraoxide (BDT) was used as the platform to prepare long-chain saturated compounds with multiple stereocenters en route to polyisoprenoid natural products. Selectively protected chiral 1,3-butanediols played a key role in iterative chain elongation for the construction of 1,5-dimethyl branched arrays with high stereocontrol.
Surveillance after Total Neoadjuvant Therapy: What to do for Near-Complete Responders
Authors: Friedman Garrett 
Published: September 2023

AbstractA proportion of patients who undergo total neoadjuvant therapy for rectal cancer will achieve what is classified as a near-complete response. Significant debate exists as to the optimal management strategy for these patients with large heterogeneity in management. This article will examine the therapeutic and surveillance options for these patients as well as the relevant outcomes data.
A Rare Case Report of Simultaneous Occurrence of Chronic Subdural Hematoma and Acute Extradural Hematoma in a Patient after Multiple Ventriculoperitoneal Shunt Surgeries
Authors: Yadav Vikrant , Prasad Ravi Shankar 
Published: September 2023

AbstractVentriculoperitoneal (VP) shunt surgeries are common neurosurgical procedure for hydrocephalus. Subdural hematoma (SDH) and extradural hematoma (EDH) are rare but potentially life-threatening complications following VP shunt surgeries. We are describing probably the first case in which a 12-year-old boy presented to the emergency room in altered sensorium and gradual onset quadriparesis following multiple shunt revision procedures done in an outside hospital. Computed tomography head showed chronic right-sided frontotemporoparietal chronic SDH and parietal dominant EDH simultaneously with multiple shunt systems in ventricles. Patient was taken for surgery in emergency and emergent evacuation of hematoma was done. Patient improved in the postoperative period. In this case report we will make an attempt to describe a rare complication of VP shunt surgery and possible mechanisms responsible for it.
A cryogenically cooled 200 kV DC photoemission electron gun for ultralow emittance photocathodes
Authors: Gevorkyan Gevork , Sarabia-Cardenas Carlos , Kachwala Alimohammad , Knill Christopher , Hanks Tatum J. , Bhattacharyya Priyadarshini , Li William H. , Cultrera Luca , Galdi Alice , Bazarov Ivan , Maxson Jared , Karkare Siddharth 
Published: September 2023

Novel photocathode materials like ordered surfaces of single crystal metals, epitaxially grown high quantum efficiency thin films, and topologically non-trivial materials with dirac cones show great promise for generating brighter electron beams for various accelerator and ultrafast electron scattering applications. Despite several materials being identified as brighter photocathodes, none of them have been tested in electron guns to extract electron beams due to technical and logistical challenges. In this paper, we present the design and commissioning of a cryocooled 200 kV DC electron gun that is capable of testing a wide variety of novel photocathode materials over a broad range of temperatures from 298 to 35 K for bright electron beam generation. This gun is designed to enable easy transfer of the photocathode to various standard ultra-high-vacuum surface diagnostics and preparation techniques, allowing a full characterization of the dependence of beam brightness on the photocathode material and surface properties. We demonstrate the development of such a high-voltage, high-gradient gun using materials and equipment that are easily available in any standard university lab, making the development of such 200 kV electron guns more accessible.
Dimension of the isometry group in spacetimes with an invariant frame
Authors: Antonio Sáez Juan , Mengual Salvador , Josep Ferrando Joan 
Published: September 2023

Abstract
The necessary and sufficient conditions for a spacetime with an invariant frame to admit a group of isometries of dimension r are given in terms of the connection tensor H associated with this frame. In Petrov–Bel types I, II and III, and in other spacetimes where an invariant frame algebraically defined by the curvature tensor exists, the connection tensor H is given in terms of the Weyl and Ricci tensors without an explicit determination of the frame. Thus, an intrinsic, deductive, explicit and algorithmic characterization of these spacetimes follows. Some examples show that this algorithm can be easily implemented on the xAct Mathematica suite of packages.
FBG displacement sensor with hyperbolic flexible hinge structure
Authors: Shi Yan , Wang Chenxu , Cai Jianxian , Gao Zhitao , Zhang Yuzi 
Published: September 2023

Abstract
This paper proposes a design method for a fiber Bragg grating (FBG) displacement sensor with a hyperbolic flexible hinge structure. A compact FBG displacement sensor with strong micro displacement measurement capability was fabricated. The final assembly testing showed that the sensor achieved good linearity with a linearity of 0.53%F·S at a range of 50 mm. The sensitivity was measured as 24.45 pm mm−1, hysteresis error as 1.1%FS, and repeatability error as 0.659%. The testing results demonstrated that the fabricated FBG displacement sensor exhibited strong practicality and good stability, making it suitable for long-term displacement monitoring of slope safety.
Weight-guided feature fusion and non-local balance model for aluminum surface defect detection
Authors: Liu Guohua , Zhao Wei 
Published: September 2023

Abstract
Aluminum surface defect detection plays a crucial role in the manufacturing industry. Due to the complexity of aluminum surface defects, the existing defect detection methods have false and missed detection problems. To address the characteristics of aluminum surface defects and the problems of existing methods, we propose a weight-guided feature fusion and non-local balance model to improve the detection effect. Firstly, we design the feature extraction network cross-stage partial ConvNeXt, which achieves adequate feature extraction while reducing the model’s size. In addition, we propose a weight-guided feature fusion and non-local balanced feature pyramid (WBFPN). Specifically, we design a weight-guided feature fusion module to replace the simple feature fusion method so that the WBFPN can suppress interference information when fusing feature maps at different scales. The non-local balancing module captures the long-range dependencies of image features and effectively balances small target defects’ detail and semantic information. Finally, the confidence loss was redefined to effectively solve the problem of poor detection effect caused by the imbalance of positive and negative samples. Experimental results show that the average accuracy of the proposed model reaches 91.9%, and the detection speed is high, which meets the requirement of real-time defect detection.
Thermal rectification through the topological states of asymmetrical length armchair graphene nanoribbons heterostructures with vacancies
Authors: Kuo David M T 
Published: September 2023

Abstract
We present a theoretical investigation of electron heat current in asymmetrical length armchair graphene nanoribbon (AGNR) heterostructures with vacancies, focusing on the topological states (TSs). In particular, we examine the 9-7-9 AGNR heterostructures where the TSs are well-isolated from the conduction and valence subbands. This isolation effectively mitigates thermal noise of subbands arising from temperature fluctuations during charge transport. Moreover, when the TSs exhibit an orbital off-set, intriguing electron heat rectification phenomena are observed, primarily attributed to inter-TS electron Coulomb interactions. To enhance the heat rectification ratio (η

Q
), we manipulate the coupling strengths between the heat sources and the TSs by introducing asymmetrical lengths in the 9-AGNRs. This approach offers control over the rectification properties, enabling significant enhancements. Additionally, we introduce vacancies strategically positioned between the heat sources and the TSs to suppress phonon heat current. This arrangement effectively reduces the overall phonon heat current, while leaving the TSs unaffected. Our findings provide valuable insights into the behavior of electron heat current in AGNR heterostructures, highlighting the role of topological states, inter-TS electron Coulomb interactions, and the impact of structural modifications such as asymmetrical lengths and vacancy positioning. These results pave the way for the design and optimization of graphene-based devices with improved thermal management and efficient control of electron heat transport.
Investigation of scan path optimization in improving proton pencil beam scanning continuous delivery
Authors: Liu Chunbo , Beltran Chris J , Shen Jiajian , Lu Bo , Park Chunjoo , Yaddanapudi Sridhar , Tan Jun , Furutani Keith M , Liang Xiaoying 
Published: September 2023

Abstract

Objective. To investigate the impact of scan path optimization on the dose accuracy and beam delivery time (BDT) of proton pencil beam scanning in the dose-driven continuous scanning (DDCS). Approach. A diverse set of six clinical plans, representing various spot patterns and treatment sites, was used to evaluate the effectiveness of scan time optimization and scan length optimization. The DDCS dose discrepancy and BDT with optimized scan paths was compared to the default serpentine scan path. Main results. Both scan time optimization and scan path optimization were able to reduce the DDCS dose discrepancy compared to the default serpentine scan path. All plans, except for the layer repainting lung plan, achieved a 2%/2 mm gamma pass rate of over 99% and less than 1% PTV DVH root mean square error (RMSE) through scan path optimization. In the case of the layer repainting lung plan, when compared to the default serpentine scan path, the 2%/2 mm gamma pass rate showed improvements from 91.3% to 93.1% and 95.8%, while the PTV DVH RMSE decreased from 2.1% to 1.7% and 1.1% for scan time optimization and scan length optimization, respectively. Although scan time optimization resulted in shorter total scan times for all plans compared to the default scan path and scan length optimization tended to have longer total scan times. However, due to the short total scan times and their minimal contribution to the total BDT, the impact of scan path optimization on the total BDT was practically negligible. Significance. Both scan time optimization and scan length optimization proved to be effective in minimizing DDCS dose discrepancy. No definitive winner can be determined between these two optimization approaches. Both scan time and scan length optimization had minimal effect on the total BDT.
Trapped flux in pure and Mn-substituted CaKFe4As4and MgB2superconducting single crystals
Authors: Bud’ko Sergey L , Xu Mingyu , Canfield Paul C 
Published: September 2023

AbstractMeasurements of temperature dependent magnetization associated with trapped magnetic flux in single crystals of CaKFe4As4, CaK(Fe0.983Mn0.017)4As4and MgB2using zero-field-cooled and field-cooled protocols are presented. The results allow for the determination of the values of superconducting transition temperature, lower critical field and self-field critical current density. These are compared with the literature data. Possible experimental concerns are briefly outlined. Our results, on these known superconductors at ambient pressure, are qualitatively similar to those recently measured on superhydrides at megabar pressures (Minkovet al2023Nat. Phys.https://doi.org/10.1038/s41567-023-02089-1) and, as such, hopefully serve as a baseline for the interpretation of high pressure, trapped flux measurements.
Selectable and stable single-frequency fiber laser with flattened power range and sub-kHz linewidth output
Authors: Hsieh Shang-En , Chen Lan-Yin , Hsu Ching-Hsuan , Lai Yu-Ting , Yeh Chien-Hung , Jiang Syu-Yang , Liaw Shien-Kuei , Chow Chi-Wai 
Published: September 2023

Abstract
To achieve stable and tunable single-longitudinal-mode (SLM) wavelength output, an erbium-doped fiber (EDF) laser with two fiber ring architecture and unpumped EDF based saturable absorber (SA) is demonstrated experimentally. The acquired optical signal to noise ratio (OSNR), wavelength linewidth, output stability and power of the fiber laser over an available tuning bandwidth of 1523.0 to 1569.0 nm are also implemented. Furthermore, this EDF laser configuration also can distribute the output power uniformly in the span of 1527.0 to 1569.0 nm within 0.53 dB power difference.
Mechanical resonator cooling to the ground-state by coherent feedback in a double cavity setup including an atomic ensemble
Authors: Mansouri Daryoosh , Rezaie Behrooz , Ranjbar N Abolfazl , Daeichian Abolghasem 
Published: September 2023

Abstract
This study concerns the cooling of a mechanical resonator to the ground-state in the unresolved sideband regime theoretically. To this aim, the optical modes of an optomechanical cavity are coupled with an atomic ensemble and an auxiliary cavity. Then, a coherent feedback loop is applied via a controllable beam splitter, which reflects a fraction of the output field to the input mirror of the optomechanical cavity. Considering the proposed feedback scheme, the optical response of the cavity is analyzed for weak optomechanical coupling to obtain the rate equations. Utilizing the electromagnetically-induced-transparency-like shape of the fluctuation spectrum of the optical force, optimal cooling conditions are calculated to place the peaks and dip of the spectrum at the desired frequencies to maximize the difference between cooling and heating rates. It is shown that the coherent feedback loop enhances the cooling effect while the heating rate is not affected. Moreover, by utilizing two coupled auxiliary systems, the effect of heating transitions is better suppressed compared to the case with one auxiliary system. As a result, not only lower limits for cooling but also larger values of net cooling rate are achieved. The results show that the proposed feedback cooling scheme significantly improves the cooling capability of the hybrid system, and the mechanical resonator can be cooled near the quantum limit. Furthermore, it is shown that the proposed method performs well in a wide range of system parameters.
Computational analysis of hybrid double perovskite materials and their potential in photovoltaic and thermoelectric applications
Authors: Mokhefi Nour elhouda , Sahnoun M , Larbi R , chelil N 
Published: September 2023

Abstract
Hybrid double perovskites are promising for use in next-generation solar cells. The priority is to address their critical problems and gain insight into their operation. The density functional theory is employed to obtain the mechanical, electronic, and optical properties of organic–inorganic double perovskites based on aluminum and gallium. The results revealed that the double perovskite materials are stable, as confirmed by calculating the formation energy and the elastic constant. Moreover, when using the TB-mBJ functional, the electronic properties obtained indicate that the direct band gap values are 1.39 eV and 2.72 eV for (NH4)2AgGaBr6 and (NH4)2AgAlBr6, respectively. Additionally, because of the direct band nature of (NH4)2Ag(Al/Ga)Br6, they exhibit excellent optical properties, including a high order absorption coefficient of 105 cm−1 and low reflectivity, making them useful for multiple optoelectronic applications outside of photovoltaics. Calculations of SLME revealed that (NH4)2AgGaBr6 and (NH4)2AgAlBr6 achieve single-layer efficiency of 32.87% and 8.36% respectively, emphasizing their viability for future applications. The results of the thermoelectric analysis suggest that these compounds have a promising potential for use in transport applications, as they demonstrate a higher figure of merit (ZT) compared to other compounds. Specifically, (NH4)2AgAlBr6 has a ZT value of 0.734, while (NH4)2AgGaBr6 has a ZT value of 0.737.
Charges at the heterogeneous interface of dielectrics
Authors: Gao Xiaoli , Chen Gangjin , Zhang Jianfeng 
Published: September 2023

Abstract
The heterogeneous interface of two different dielectrics is commonly observed in diverse electronic devices. Charge emerging will take place at the heterogeneous interface and may greatly influence the device performance. Typically, charge emerging behavior is attributed to the Maxwell–Wagner effect. The emerged charge by the Maxwell–Wagner effect is unipolar. Nevertheless, bipolar phenomena are also frequently observed. This paper reports the change characteristic of accumulated charge between unipolar and bipolar at the heterogeneous interface composed of two different dielectrics. A theoretical analysis is proposed. As an illustration, the laminated membrane is formed by thermally pressing two non-polar polymers, fluorinated ethylene propylene (FEP) and polypropylene (PP). Its interfacial charge nature is studied by means of electret research. It is found that the bipolar charge derives from contact electrification and is determined by the electronegativity of the atoms at two dielectrics’ interface. The unipolar charge originates from the Maxwell–Wagner effect and is determined by the dielectric constant and conductivity of dielectrics. In the absence of external electric field, the charge nature shows bipolar in the form of dipole electric double-layer. In the presence of external electric field, the change of charge nature from bipolarity to unipolarity will occur depending on the electric field and temperature. Its regulation is closely related to the connection mode of external electric field with the heterogeneous interface of dielectrics. When negative electrode is connected with FEP, the charge nature at the interface evolves from bipolarity to positive polarity. When positive electrode is connected with FEP, the charge nature transforms from bipolarity to negative polarity. A critical point exists for a polarizing voltage to induce the change of charge nature.
The Greenland Telescope—Construction, Commissioning, and Operations in Pituffik
Authors: Chen Ming-Tang , Asada Keiichi , Matsushita Satoki , Raffin Philippe , Inoue Makoto , Ho Paul T. P. , Han Chih-Chiang , Kubo Derek , Norton Timothy , Patel Nimesh A. , Nystrom George , Huang Chih-Wei L. , Martin-Cocher Pierre , Yi Koay Jun , Romero-Cañizales Cristina , Liu Ching-Tang , Huang Teddy , Liu Kuan-Yu , Wei Tashun , Chang Shu-Hao , Chilson Ryan , Oshiro Peter , Jiang Homin , Li Chao-Te , Bower Geoffrey , Shaw Paul , Nishioka Hiroaki , Koch Patrick M. , Chen Chung-Cheng , Srinivasan Ranjani , Rao Ramprasad , Snow William , Jinchi Hao , Han Kuo-Chang , Chang Song-Chu , Lu Li-Ming , Ogawa Hideo , Kimura Kimihiro , Hasegawa Yutaka , Pu Hung-Yi , Koyama Shoko , Nakamura Masanori , Bintley Daniel , Walther Craig , Friberg Per , Dempsey Jessica , Sriharan T. K. , Srikanth Sivasankaran , Doeleman Sheperd S. , Brissenden Roger , Algaba Marcos Juan-Carlos , Jeter Britt , Kuo Cheng-Yu , Park Jongho 
Published: September 2023

Abstract
In 2018, the Greenland Telescope (GLT) started scientific observation in Greenland. Since then, we have completed several significant improvements and added new capabilities to the telescope system. This paper presents a full review of the GLT system, a summary of our observation activities since 2018, the lessons learned from the operations in the Arctic regions, and the prospect of the telescope.
The Study of the Physical Properties and Energy Sources of Five Luminous Type Ibc Supernovae
Authors: Bai 白 Song-Yao 松瑶 , Wang 王 Tao 涛 , Wang 王 Shan-Qin 善钦 , Gan 甘 Wen-Pei 文沛 , Wang 王 Liu-Yi 浏毅 , Liang 梁 En-Wei 恩维 
Published: September 2023

Abstract
In this paper, we study five luminous supernovae (LSNe) Ibc (SN 2009ca, ASASSN-15mj, SN 2019omd, SN 2002ued, and SN 2021bmf) whose peak absolute magnitudes M
peak are ≈ −19.5 to −21 mag by fitting their multi-band light curves (LCs) with different energy source models. We find that SN 2009ca might be powered by the 56Ni model since the required 56Ni mass (0.56 M
⊙) is comparable to those of energetic SNe Ic, while the rest four SNe cannot be accounted for the 56Ni model since their derived 56Ni masses are ≳1 M
⊙ or the ratios of the 56Ni mass to the ejecta mass are larger than 0.2. This indicates that some LSNe might be powered by 56Ni decay, while most of them need additional energy sources. We then use the magnetar plus 56Ni model and the fallback plus 56Ni model to fit the LCs of the four LSNe that cannot be explained by the 56Ni model, finding that the two models can account for the four SNe, and the derived parameters are comparable to those of LSNe or superluminous SNe in the literature, if they were (mainly) powered by magnetars or fallback. We suggest that the magnetar plus 56Ni model is more reasonable than the fallback plus 56Ni model, since the validity of the fallback plus 56Ni model depends on the value of accretion efficiency (η) and favors a large η value, and the magnetar plus 56Ni model yields smaller χ
2/dof values. It should be pointed out that, however, the fallback plus 56Ni model is still a promising model that can account for the four SNe in our sample as well as other LSNe.