nils-herrmann/clean_scirepeval huggingface dataset:
Random unitaries, amenable linear groups and Jordan's theorem

It is well known that a dense subgroup $G$ of the complex unitary group $U(d)$ cannot be amenable as a discrete group when $d>1$. When $d$ is large enough we give quantitative versions of this phenomenon in connection with certain estimates of random Fourier series on the compact group $\bar G$ that is the closure of $G$. Roughly, we show that if $\bar G$ covers a large enough part of $U(d)$ in the sense of metric entropy then $G$ cannot be amenable. The results are all based on a version of a classical theorem of Jordan that says that if $G$ is finite, or amenable as a discrete group, then $G$ contains an Abelian subgroup with index $e^{o(d^2)}$.

Field of study: Mathematics
Comparing bird assemblages in large and small fragments of the Atlantic Forest hotspots

The Atlantic Forest (AF) is one of the five most threatened and megadiverse world hotspots. It is arguably the most devastated and highly threatened ecosystem on the planet. The vast scope of habitat loss and extreme fragmentation in the AF hotspots has left intact very few extensive and continuous forested fragments. We compared bird assemblages between small (<100 ha) and large (>6,000 ha) forest remnants, in one of the largest AF remnants in Argentina. We performed 84 point-counts of birds in four large fragments (LF) and 67 points in 25 small fragments (SF). We recorded 4,527 bird individuals belonging to 173 species; 2,632 belonging to 153 species in LF and 1,897 in 124 species in SF. Small fragments suffered a significant loss of bird richness, mainly forest dependent species, but the birds abundance did not decrease, due to an increase in abundance of forest independent and semi-dependent bird species (edge and non forest species) that benefit from forest fragmentation. The bird guilds of frugivores, undestory, terrestrial and midstory insectivores, nectarivores and raptors, and the endemic species of AF were area sensitive, decreasing significantly in richness and abundance in the SF. Terrestrial granivores were the only guild positively affected by forest fragmentation, containing mainly edge species, which forage in open areas or borders including crops. Our first observations on fragmentation effects on bird assemblages in the southernmost Argentinean Atlantic Forests did not validate the hypothesis on pre-adaptation to human disturbances in the bird communities of AF. On the contrary, we observed that forest dependent, endemic and several sensitive bird guilds were strongly affected by fragmentation, putting in evidence the vulnerability to the fragmentation process and the necessity to conserve large remnants to avoid reduction of the high biodiversity of AF birds.

Field of study: Environmental science
Measuring the New World: Enlightenment Science and South America (review)

conquest of Mexico to a discourse on imperial power. He agrees with recent interpretations of these images that emphasize the importance of the idea of succession and of the translatio imperii by which Moctezuma voluntarily relinquished his empire to Charles V via Cortes as the king's representative. He posits, however, that these images may also be read as glorification of the Spanish monarchy's authority rather than as expressions of local or proto-national history. Finally, in chapter five, the author examines constructions of Spain's "Universal Monarchy" through an analysis of a group of cartographic and allegorical representations of the world produced in New Spain. Such imagery, he argues, points to the development and circulation of different conceptualizations of global space in seventeenth-century New Spain.

Field of study: History
Synthesis of N-Substituted-2-Aminobenzothiazoles by Ligand-Free Copper(I)-Catalyzed Cross-Coupling Reaction of 2-Haloanilines with Isothiocyanates

A novel and efficient formation of N-substituted-2-aminobenzothiazoles by a ligand-free copper(I)-catalyzed one-pot cascade process was developed. A variety of isothiocyanates coupled with 2-iodoanilines to give N-substituted-2-aminobenzothiazoles in moderate to excellent yields under mild conditions.

Field of study: Chemistry
Process Dependent Build-Up of Interface States in Irradiated N-Channel MOSFETs

The build-up of fast-states (¿Dit) continues to occur in the Si/SiO2 interface region even after the irradiation has stopped. For the devices described in this paper, the process of conversion of trapped positive charges (¿Qot) into ¿Dit appears to be responsible for the build-up. The presence of ambient hydrogen is necessary for the conversion to occur in well annealed MOS devices without SiN-Caps. The decrease in the highest temperature after the source/drain implant, dictated by the demand for shallow junctions, leaves residual neutral traps in the interface region which cause increase in the rate of conversion of ¿Qot into ¿Dit. The low-field effective mobility (¿eff) of the inversion layer electrons has been characterized as a function of the gamma-radiation dose. The reduction of ¿eff due to gamma rays is predominantly attributed to the decrease in the number of carriers available for conduction because of the fast-states. A universal model of ¿eff is presented; it is a very powerful tool in studying the Si/SiO2 interface properties.

Field of study: Physics
Impacts on the Ratio of Peak to Total and Peak to Source for Si-PIN Detector Through the Monte Carlo Method in XRF Analysis

This basic study investigates the ratio of peak to total ( ) and peak to source ( ) for Si-PIN detectors in X-ray fluorescence (XRF) analysis, with emphasis on analysis the parameters for and using the Monte Carlo method. Many XRF system models have been simulated using the Monte Carlo Neutron-Particle Transport Code MCNP5. Various parameters are set to calculate the detection efficiency in those models, such as the desired X-ray collection angle, thickness, density, moisture content, X-ray angles, geometric distance, and so on. These parameters can impact and in the exponential form to some extent. This study provides a convenient and reliable method for the passive calibration of XRF measurements.  The X-ray fluorescence (XRF) analysis technique has been widely applied, such as in the field of biology, petrochemical, materials, food and so on 1-11 . Detection efficiency is obtained through efficiency calibration curves in general cases, which is drawn by standard samples. In practice, this efficiency calibration curves are applied in samples similar to standard samples, or similar ingredients. However, the sample’s ingredients remain uncertain. The composition and material structure in unknown samples is different with standard samples. If the same efficiency calibration curves are used for every unknown sample, large errors would be produced in XRF measurements. In order to improve the accuracy of detection efficiency, Sharshar T. prepared a number of standard samples 12 , which had different compositions and material structures, in order to meet the actual needs of the XRF analysis. Obviously, this approach was a huge workload. This study calculates the detection efficiency for Si-PIN detector using the Monte Carlo method. Many XRF system models have been simulated using the Monte Carlo Neutron-Particle Transport Code MCNP5. Various parameters have been set to calculate the detection efficiency in those models, such as the desired X-ray collection angle, thickness, density, moisture content, incident angles, geometric distance, and so on. This study provides a convenient and reliable method for the passive calibration of XRF measurements. First author, Hefan-LIU, Chengdu Research Academy of Environmental Sciences, 8th, Fanglin Road, Qingyang District, Chengdu, China

Field of study: Engineering
Design and measurements of the optical klystron for FEL

An optical klystron (OK), which means for harmonic generation FEL, is designed and constructed with NdFeB magnets. The analysis equations for designing the OK are listed. The design result was checked by 3 dimensional electromagnetic computation software, the Opera3d. The buncher of the OK and its induction field in the middle plane of the OK, computed with Opera3d are respectively shown. The measured B H curve of the magnets used in the computation is given. The computed induction field in the beam axis by Opera3d matches well with the field measured by 0.1mm×0.1mm hall probe. The typical parameters of the optical klystron are listed. The magnet gaps of the three OK undulator sections can be independently adjusted from 40mm to 140mm. After the OK spontaneous emission is got at the beam energy of 163MeV and 200MeV, it is now being upgraded to coherent harmonic generator.

Field of study: Physics
ENGINE HEAT RELEASE VIA SPREAD SHEET

Calculation of rates of heat release from engine fuels provides a useful diagnostic tool. As one example, the 
technique was useful in discovering that retarding injection timing will reduce the proportion of premixed combustion and 
thereby reduce NOx emissions from a diesel engine. The technique for calculating heat release rates was proposed more 
than 30 years ago. Initially a cumbersome technique, it has been simplified over the years. In the present work, the author 
presents equations which allow calculation of heat release rates within a spread sheet.

Field of study: Agricultural and Food sciences
Depositional environments, sea-level history and palaeobiogeography of the late Campanian-Maastrichtian on the Calabar flank, SE Nigeria

Campanian-Maastrichtian palaeoenvironments and seal-level history on the Calabar Flank are interpreted by recognising palynofacies based on statistical and morphological variations in organic-walled microplankton, mainly dinoflagellates and miospores. A holomarine palynofacies defining an inner-neritic depositional environment is characterized by > 80% dinoflagellates, mainly spiniferate cysts with short, simple to complexly hooked or barbed processes. Fluvio-marine palynofacies corresponding to a littoral setting shows close abundance percentages of dinoflagellates and miospore elements. Both spiniferate and peridinioid cysts with short, long and simple processes occur abundantly and the miospore elements are dominated by mangrove-type species. A non-marine palynofacies representing a fresh-water environment is dominated by miospores of hinterland affinities. Few peridinioid cysts with long processes are present. Sedimentation and palynofacies disposition was mainly controlled by eustatic sea level fluctuations. Resolution of palynofacies, in relation to outcrop data, presents two depositional cycles, each exhibiting trangressive, highstand and lowstand systems tract deposits. The boundary between the two cycles is marked by an abrupt change from non-marine to holomarine palynofacies. These cycles, dated as late Campanian-mid Maastrichtian and late Maastrichtian, relate favourably with the 75 Ma and 71 Ma depositional sequences recorded on the Global Cycle Chart.

Field of study: Environmental science, Geography
Fly, you fool! Faster Frodo for the ARM Cortex-M4

We present an efficient implementation of FrodoKEM-640 on an ARM Cortex-M4 core. We leverage the single instruction, multiple data paradigm, available in the instruction set of the ARM Cortex-M4, together with a careful analysis of the memory layout of matrices to considerably speed up matrix multiplications. Our implementations take up to 79.4% less cycles than the reference. Moreover, we challenge the usage of a cryptographically secure pseudorandom number generator for the generation of the large public matrix involved. We argue that statistically good pseudorandomness is enough to achieve the same security goal. Therefore, we propose to use xoshiro128∗∗ as a PRNG instead: its structure can be easily integrated in FrodoKEM-640, it passes all known statistical tests and greatly outperforms previous choices. By using xoshiro128∗∗ we improve the generation of the large public matrix, which is a considerable bottleneck for embedded devices, by up to 96%.

Field of study: Computer science, Mathematics
MgB2 tunnel junctions and 19 K low-noise dc superconducting quantum interference devices

Point contact junctions made from two pieces of MgB2 can be adjusted to exhibit either superconductor-insulator-superconductor (SIS) or superconductor-normal metal–superconductor (SNS) current–voltage characteristics. The SIS characteristics are in good agreement with the standard tunneling model for s-wave superconductors, and yield an energy gap of (2.02±0.08) meV. The SNS characteristics are in good agreement with the predictions of the resistively-shunted junction model. DC superconducting quantum interference devices made from two SNS junctions yield magnetic flux and field noise as low as 4 μΦ0 Hz−1/2 and 35 fT Hz−1/2 at 19 K; Φ0 is the flux quantum.

Field of study: Physics
A generalized Conway-Maxwell-Poisson distribution which includes the negative binomial distribution

The Conway-Maxwell-Poisson (COM-Poisson) distribution with two parameters was originally developed as a solution to handling queueing systems with state-dependent arrival or service rates. This distribution generalizes the Poisson distribution by adding a parameter to model over-dispersion and under-dispersion and includes the geometric distribution as a special case and the Bernoulli distribution as a limiting case. In this paper, we propose a generalized COM-Poisson (GCOM-Poisson) distribution with three parameters, which includes the negative binomial distribution as a special case, and can become a longer-tailed model than the COM-Poisson distribution. The new parameter plays the role of controlling length of tail. The GCOM-Poisson distribution can become a bimodal distribution where one of the modes is at zero and is applicable to count data with excess zeros. Estimation methods are also discussed for the GCOM-Poisson distribution.

Field of study: Mathematics
An Investigation Report on the Integration of Information Technology into English Leaning

English language teaching and CALL, particularly as they are implemented through the Internet,are likely to shape the future of our English language education in China. But the implementation of educational changes is not going to be an easy job. Our knowledge about classroom English teaching probably does not apply directly to the integration of technology into the English curriculum because of the different configuration of variables such as learners' and teachers' roles, effective use of basic technology tools and applications and equitable access to technology for all students and teachers. This paper investigates some basic factors in creating new technology supported English learning and teaching environments and concerns the promotion of an independent learning ethos and professional development. In order to use technology effectively to ensure the best possible English teaching and learning, schools have to make further progress in acquiring hardware, establishing connectivity, ensuring English teachers receive technology training and integrating digital content into the English curriculum.

Field of study: Economics
Concentration in the Greek private hospital sector: a descriptive analysis.

Over the last 20 years, governments all around the world have attempted to boost the role of market and competition in health care industries in order to increase efficiency and reduce costs. The increased competition and the significant implications on costs and prices of health care services resulted in health care industries being transformed. Large firms are merging and acquiring other firms. If this trend continues, few firms will dominate the health care markets. In this study, I use the simple concentration ratio (CR) for the largest 4, 8 and 20 companies to measure the concentration of Greek private hospitals during the period 1997-2004. Also, the Gini coefficient for inequality is used. For the two different categories of hospitals used (a) general and neuropsychiatric and (b) obstetric/gynaecological it is evident that the top four firms of the first category accounted for 43% of sales in 1997, and 52% in 2004, while the four largest firms of the second category accounted for almost 83% in 1997, and 81% in 2004. Also, the Gini coefficient increases over the 8-year period examined from 0.69 in 1997 to 0.82 in 2004. It explains that the market of the private health care services becomes less equal in the sense that fewer private hospitals and clinics hold more and more of the share of the total sales. From a cross-industry analysis it is clear that the private hospital sector has the highest concentration rate. Finally, it appears that the market structure of the private hospitals in Greece resembles more closely to an oligopoly rather than a monopolistic competition, since very few firms dominate the market.

Field of study: Medicine, Political science
Real-Time Diagrammatic Theory of Electron Waiting Time Distributions: Interaction Effects and Higher-Order Tunneling Processes

We develop a real-time diagrammatic theory of electron waiting time distributions for quantum transport in strongly interacting nanostructures. While existing methods address either weakly coupled systems with strong Coulomb interactions or coherent transport in mesoscopic conductors without interactions, our approach makes it possible to treat the interesting intermediate regime where both interaction effects and higher-order tunneling processes are important. As an illustration of experimental relevance, we consider a quantum dot coupled to electronic reservoirs and find that the distribution of waiting times between transferred electrons is drastically affected by virtual charge fluctuations and higher-order tunneling processes such as cotunneling that lead to non-Markovian dynamics on the quantum dot, and which can now be accounted for by our theoretical framework.

Field of study: Physics
On the Cachazo-Douglas-Seiberg-Witten conjecture for simple Lie algebras

Recently, motivated by supersymmetric gauge theory, Cachazo, Douglas, Seiberg, and Witten proposed a conjecture about finite dimensional simple Lie algebras, and checked it in the classical cases. We prove the conjecture for type G_2, and also verify a consequence of the conjecture in the general case.

Field of study: Mathematics
Thermoelectric Properties of Scandium Sesquitelluride

Rare-earth (RE) tellurides have been studied extensively for use in high-temperature thermoelectric applications. Specifically, lanthanum and praseodymium-based compounds with the Th3P4 structure type have demonstrated dimensionless thermoelectric figures of merit (zT) up to 1.7 at 1200 K. Scandium, while not part of the lanthanide series, is considered a RE element due to its chemical similarity. However, little is known about the thermoelectric properties of the tellurides of scandium. Here, we synthesized scandium sesquitelluride (Sc2Te3) using a mechanochemical approach and formed sintered compacts through spark plasma sintering (SPS). Temperature-dependent thermoelectric properties were measured from 300–1100 K. Sc2Te3 exhibited a peak zT = 0.3 over the broad range of 500–750 K due to an appreciable power factor and low-lattice thermal conductivity in the mid-temperature range.

Field of study: Materials science
Inf lammatory Mass with Fibrinoid Necrosis of Vessels Caused by Methylene Blue Marking of a Colonic Polyp.

Methylene blue is a relatively non-toxic dye that is used in a variety of procedures including the marking of margins and skin flaps, identifying sinus and fistulous tracts, localizing islet cell tumors, and marking colonic polyps. It has been used intravascularly for the labeling of arteriovenous malformations or to find small bleeding sites. Few adverse effects have been reported with its use. We report an unusual case of an inflammatory mass secondary to transmural injection of methylene blue that resulted in fibrinoid necrosis of arterial media mimicking a necrotizing vasculitis.

Field of study: Biology, Medicine
Morphologic studies of cell endogenous repopulation in decellularized aortic and pulmonary homografts implanted in sheep.

PURPOSES
The rationale of this study was to assess morphologically the effects of implantation of decellularized aortic and pulmonary homografts into growing sheep, with the objective to establish type and extent of cell repopulation and propensity to dystrophic calcification over a prolonged period of time.



Pulmonary and aortic homografts were obtained from healthy euthanized juvenile sheep (35-45kg). Complete decellularization was accomplished in 0.5% sodium deoxycholate and 0.5% sodium dodecylsulfate for 24h. Twelve homografts from 11 animals were studied as follows: Gross, X-ray, histology, immunohistochemistry, morphometry, transmission electron microscopy and calcium content spectroscopy investigations were carried out.



Decellularization appeared complete in unimplanted homografts. The extracellular matrix was intact. Explanted homografts showed soft, pliable cusps without gross calcium deposits and tears; calcium content showed slight difference between aortic and pulmonary cusps (5.505±2.04 vs. 2.77±1.06mg/g dry weight, P=.04). Microscopic calcifications were observed in two aortic homografts on smooth muscle cells of repopulated homograft wall and on valvular interstitial cells, respectively. Inflammatory infiltrates were never seen. Cell repopulation occurred in homograft wall with actin smooth muscle and vimentin positive cells in media lamellar units (cell density per millimeter squared, 885.4±424.38 in native vs. 172.64±160.33 in implanted homograft, P<.01) as well as in cusps (cell density per millimeter squared, 495.96±63.92 in native vs. 184.66±140.74 in implanted homograft, P<.01). The percentage area of recellularization was 71.27±3.03 in the homograft wall and 22.16±3.06 in the cusps. Thickness of pulmonary explanted homograft wall and cusps was 900.68±321.52μm vs. 994.36±135.92μm and 204.75±66.64μm vs. 231.04±105.94, respectively (P=NS), whereas in aortic homograft wall and cusps it was 1358.604±423.79μm vs. 2065.32±431.46μm, P=.016, and 248.01±93.95μm vs. 390.30±104.81μm, P=.03, respectively. The endothelial lining was restored.



Endogenous cell repopulation in decellularized homografts occurs and persists following implantation, at both wall and cusp level, without evidence of immune reaction. Even in the long term, the cusps exhibit no structural deterioration and negligible calcification.

Field of study: Biology, Medicine
Bioaugmented Treatment of Erythromycin by Engineered Microorganism in Surface Water

Erythromycin-degrading strains were isolated from activated sludge collected from a sewage treatment plant,which were identified as Pseudomonas putida. It was found that the removal rate as high as 76.6% of erythromycin within 5d could be achieved at temperature of 30 ℃,pH of 7.0 ~7.5,initial erythromycin concentration of 30 mg/L. Removal of erythromycin was investigated as isolated degrading-strains were inoculated into biological aeration filters(BAF),using bioceramic media and volcanic rock as the filters. Results showed that the effect with erythromycin-degrading bacteria addition on start-up of BAF was negligible. However,the erythromycin removal increased at the beginning and then decreased as the aeration intensity increased. The erythromycin removal decreased when the hydraulic residence time decreased. The performance during the stable operation indicated that the erythromycin removal efficiencies by bioaugmented bio-ceramic media and bioaugmented volcanic rock filters increased by 33.9% and 40.1% respectively, demonstrating that the improvement of erythromycin removal via bioaugmentation was feasible and effective.

Field of study: Environmental science