nils-herrmann/clean_scirepeval huggingface dataset:
Study on Phase and Microstructure of B_4C/Al Composite

B4C/Al composite was fabricated by pressureless infiltration.The phase and microstructure of the composite were studied by XRD,EDS,SEM,TEM and optical microscopy.The results show that,Al3BC forms on the interface of B4C and Al,connecting aluminum with ceramic toughly.AlB2 as strip crystal forms between B4C and Al,which has higher fracture toughness.The boron carbide exists in the form of continuous skeleton structure,and the infiltrated aluminum exists in the form of continuous matrix.The fracture ways of B4C/Al composite are transcrystalline rupture of ceramics skeleton and crack bridging of Al.

Field of study: Materials science
Some facts from descriptive set theory concerning essential spectra and applications

Let X be a separable Banach space and denote by L(X) (resp. K(C)) the set of all bounded linear operators on X (resp. the set of all compact subsets of C). We show that the maps from L(X) into K(C) which assign to each element of L(X) its spectrum, approximate point spectrum, essential spectrum, Weyl essential spectrum, Browder essential spectrum, respectively, are Borel maps, where L(X) (resp. K(C)) is endowed with the strong operator topology (resp. Hausdorff topology). This enables us to derive the topological complexity of some subsets of L(X) and to discuss the properties of a class of strongly continuous semigroups. We close the paper by giving a characterization of strongly continuous semigroups on hereditarily indecomposable Banach spaces.

Field of study: Mathematics
Nutritional management of acute renal failure.

The principles of nutritional therapy (ie, maintain lean body mass, stimulate immunocompetence, and repair functions, such as wound healing) are similar for patients with acute renal failure (ARF) and with other catabolic clinical conditions. However, if a patient with ARF requires nutritional support, the multiple metabolic consequences of acute uremia must be taken into account. These do not only affect fluid, electrolyte, and acid-base balance but also the metabolism of amino acids, proteins, carbohydrates, and lipids. In addition, these metabolic alterations are modified by the acute disease process per se, by associated complications (such as severe infections), and last but not least, by the type and intensity of renal replacement therapy. Whenever possible, enteral nutrition should be provided in patients with ARF because even small amounts of luminal nutrients will help to maintain intestinal functions. Nevertheless, in many patients a parenteral nutrition, at least supplementary and/or temporarily, will become necessary. Metabolic complications of nutritional support frequently occur in patients with ARF because tolerance to volume load and electrolytes is limited and the use of various nutrients is impaired. Despite the notorious difficulty to demonstrate clear-cut benefits of nutritional interventions and especially, of parenteral nutrition on prognosis in critically ill patients, there can be no doubt that nutritional therapy presents a cornerstone in the treatment of patients with ARF. Preexisting and/or hospital-acquired malnutrition have been identified as important factors contributing to the persisting high mortality in acutely ill patients with ARF.

Field of study: Medicine
Influence of Changes in Adrenergic and Cholinergic Activity upon Acquisition of Operant Discrimination in Albino Rats

The effect of adrenergic and cholinergic drugs upon two discrete-trial fixed-interval reinforcement schedules that generate either high or low rates of unreinforced (SΔ) responding was investigated. Amphetamine and scopolamine decreased high SΔ rates while having no effect on low SΔ rates. Withdrawal of amphetamine after acquisition under the drug led to a dramatic increase in SΔ rates under both reinforcement schedules. Alpha methyl-p-tyrosine reduced high SΔ rates, while pilocarpine had no effect on behavior. These results suggest that the similarities between the behavioral effects of amphetamine and scopolamine on appetitive schedules may primarily reflect their motivational properties. Furthermore, these data indicate that withdrawal from chronic amphetamine administration can produce dramatic alterations in response rate even in cases where the acquisition of behavior is unaltered by chronic drug treatment.

Field of study: Psychology
DETERMINATION OF SIGNIFICANT WAVELENGTHS AND PREDICTION OF NITROGEN CONTENT FOR CITRUS

This research was conducted as a preliminary step toward developing a real-time spectral-based nitrogen sensor 
for citrus trees. Diffuse reflectance of leaf samples, with five nitrogen application rates (0, 112, 168, 224, and 280 kg ha-1), 
was measured from 400 to 2500 nm using a spectrophotometer in a laboratory environment. A correlation coefficient 
spectrum, a stepwise multiple linear regression (SMLR) procedure, and the B-matrix in partial least squares (PLS) regression 
were used to determine important wavelengths. Some wavelengths (448, 669, 719, 1377, 1773, and 2231 nm) were identified 
by both SMLR and PLS as significant wavelengths for nitrogen detection. The results from the calibration models built by 
SMLR and PLS showed strong relationships between predicted and actual nitrogen concentration. SMLR performed better 
on a 20 nm averaged dataset with lower collinearity. With the best calibration model built on wavelengths selected by SMLR 
from this averaged data set, R2 for the validation data set was 0.839, and the root mean square difference (RMSD) was 0.122%. 
PLS was more suitable for full spectrum analysis due to its ability to reduce collinearity in the dataset. The calibration model 
built by PLS on the full spectral region had an R2 of 0.828 and an RMSD of 0.122% for the validation data set.

Field of study: Agricultural and Food sciences
"Transitive inference" in multiple conditional discriminations.

We used multiple conditional discriminations to study the inferential abilities of pigeons. Using a five-term stimulus series, pigeons were trained to respond differentially to four overlapping pairs of concurrently presented stimuli: A+ B-, B+ C-, C+ D-, and D+ E-, where plus and minus indicate the stimulus associated with reinforcement and extinction, respectively. Transitive inference in such situations has been defined as a preference for Stimulus B over Stimulus D in a transfer test. We measured this and other untrained preferences (A vs. C, A vs. D, B vs. E, etc.) during nonreinforced test trials. In three experiments using a novel, rapid training procedure (termed autorun), we attempted to identify the necessary and sufficient conditions for transitive inference. We used two versions of autorun: response-based, in which the subject was repeatedly presented with the least well-discriminated stimulus pair; and time-based, in which the subject was repeatedly presented with the least-experienced stimulus pair. In Experiment 1, using response-based autorun, we showed that subjects learned the four stimulus pairs faster than, but at a level comparable to, a previous study on transitive inference in pigeons (Fersen, Wynne, Delius, & Staddon, 1991), but our animals failed to show transitive inference. Experiments 2 and 3 compared time- and response-based autorun. Discrimination performance was maintained, but transitive inference was observed only on the second exposure to the response-based procedure. These results show that inferential behavior in pigeons is not a reliable concomitant of good performance on a series of overlapping discriminations. The necessary and sufficient conditions for transitive inference in pigeons remain to be fully defined.

Field of study: Biology, Psychology
Toxicity assessment of simulated urban runoff containing polycyclic musks and cadmium in Carassius auratus using oxidative stress biomarkers.

The objective of this study was to assess potential toxic effects of simulated urban runoff on Carassius auratus using oxidative stress biomarkers. The activity of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the content of malondialdehyde (MDA) in the liver of C. auratus were analyzed after a 7-, 14- and 21-day exposure to simulated urban runoff containing galaxolide (HHCB) and cadmium (Cd). The results showed that the activity of antioxidant enzymes and the content of MDA increased significantly exposed to the simulated urban runoff containing HHCB alone or mixture of HHCB and Cd. The activity of the investigated enzymes and the content of MDA then returned to the blank level over a longer period of exposure. The oxidative stress could be obviously caused in the liver of C. auratus under the experimental conditions. This could provide useful information for toxic risk assessment of urban runoff.

Field of study: Environmental science
Diffusionskonstante und charakteristische Absorption vor der Bandkante von Mn in ZnO-Kristallen

ZnO single crystals were doped with Mn and Co by diffusion. In the temperature range from 1400–1600 K the Mn and Co-diffusion-constants were determined:DMn=3.2 · 10−3 exp (−2.87 eV/kT) cm2 sec−1 andDCo=1·10exp(−3.98 eV/kT) cm2 sec−1.The Mn doped ZnO crystals show a characteristic colour due to an absorption near the intrinsic absorption edge. The corresponding absorption spectra were measured forE⊥c andE∥c. A discussion of different absorption mechanism shows that a charge-transfer transition is responsible for this absorption.

Field of study: Physics
Untersuchungen über Polyfructosane, LXII. Der Aufbau der Polyfructosane in der Gerste

Wie im Roggen2) und Weizen3) konnten in junger Gerste Isokestose, Kestose, Bifurcose und ein Pentasaccharid als erste Stufen der Transfructosidierung auf Saccharose nachgewiesen werden. Der Aufbau der aus Gerstenhalmen isolierten und in ihrer Konstitution bereits bestimmten4) hochstmolekularen, verzweigten Polyfructosane, des Kritesins vom Inulintyp und des Hordeacins vom Phleintyp, vollzieht sich also analog wie im Roggen und Weizen: er geht aus von der Bifurcose, dem ersten verzweigten Oligosaccharid, und wird durch weitere Transfructosidierung entweder auf die erste oder sechste Hydroxylgruppe ihrer beiden endstandigen Fructosereste in zwei parallelen Reihen bis zum Kritesin und Hordeacin fortgesetzt.

Field of study: Chemistry
Differential modulation of bradykinin-induced relaxation of endothelin-1 and phenylephrine contractions of rat aorta by antioxidants

We tested the hypothesis that bradykinin (BK)-induced relaxation of phe-nylephrine (PE) and endothelin-1 (ET-1) contractions can be differentially modulated by reactive oxygen species (Aortic rings isolated from Sprague-Dawley rats were used for the study. The contribution of ROS to PE (1×10−9−1×10−5 mol/L)- and ET-1 (1×10−10−1×10−8 mol/L)-induced contractions and the influence of ROS in BK (1×10−9−1×10−5 mol/L) relaxation of PE (1×10−7 mol/L) or ET-1 (1×10−9 mol/L)-induced tension was evaluated in the aorta in the presence or absence of the following antioxidants: catalase (CAT, 300 U/mL), superoxide dismutase (SOD, 300 U/mL), and vitamin C (1×10−4 mol/L).Results:Tension generated by ET-1 (1 ×10−9 mol/L) or PE (1×10−7 mol/L) was differentially relaxed by BK (1×10−5 mol/L), producing a maximal relaxation of 75%±5% and 35±4%, respectively. The BK (1×10−5 mol/L)-induced relaxation of PE (1×10−7 mol/L) tension was significantly enhanced from 35%±4% (control) to 56%±9%, 60%±5%, and 49%±6% by SOD, CAT, and vitamin C, respectively (P < 0.05, n =8). However, the relaxation of ET-1 (1×10−9 mol/L) tension was significantly attenuated from 75%±5% (control) to 37%±9%, 63%±4%, and 39%±7% by SOD, CAT, and vitamin C, respectively (P < 0.05, n =8). On the other hand, CAT had no effect on PE-induced tension, while SOD enhanced PE-induced tension (36%, P < 0.05, n =10) and vitamin C attenuated (66%, P < 0.05, n = 8) the tension induced by PE. By contrast, SOD or vitamin C had no effect, but CAT attenuated (44%, P < 0.05, n = 9) the tension induced by We have demonstrated that O2− and H2O2 differentially modulate BK relaxation in an agonist-specific manner. O2− attenuates BK-induced relaxation of PE contraction, but contributes to the relaxation of ET-1 contraction. O2− seems to inhibit PE contraction, while H2O2 contributes to ET-1-induced contraction. Thus, ROS differentially modulate vascular tone depending on the vasoactive agent that is used to generate the tone.

Field of study: Biology, Chemistry, Medicine
Hall helps Ohm: some corrections to negative-U centers approach to transport properties of YBa$_2$Cu$_3$O$_x$ and La$_{2-x}$Sr$_x$CuO$_4$

For broad oxygen and strontium doping ranges, temperature dependences (T-dependences) of the normal state resistivity \rho(T) of YBa_2Cu_3O_x (YBCO) and La_(2-x)Sr_xCuO_4 (LSCO) are calculated and compared to experiments. Holes transport was taken in the \tau-approximation, where \tau(T,\epsilon) is due to acoustic phonons. Besides, T-dependence of the chemical potential \mu(T) and effective carrier mass m* ~10-100 free electron masses, obtained by negative-U centers modelling the T-dependence of the Hall coefficient, were used to calculate \rho(T). In addition, it is demonstrated that anisotropy of the cuprates does not affect the calculated T-variation of neither Hall coefficient nor \rho, but only rescale their magnitudes by factors depending on combinations of m_ab and m_c.

Field of study: Physics
Comments on CHEN Jia-gen's patriotic sports ideology and its feature

CHEN Jia-gen' patriotic spots ideology is under the guidance of "honesty and perverence",puts the same stress on moral,intelligent and physical education and regards it as the education goal of Jimei University.It makes use of the western advanced things and proposed that massive sports should be popularized,exercises should be persisted.In an era of overall construction for a prosperous society,Chen Jiagen's patriotic ideology is of great use for us to make sights and put into practice.

Field of study: Education
LASER PARAMETER CONTROL: Oscillation spectra of Ar-Xe and He-Ar-Xe mixtures pumpbed by a radially converging electron beam with a pulse length ~ 0.1 ms

We have investigated lasers oscillating on atomic transitions of xenon and pumped by a radially converging electron beam with pulse lengths between 0.07 and 0.1 ms. We have determined experimentally the dependence of the threshold beam current density and the output spectrum on the Q-factor of the laser resonator. We have shown that for beam current densities smaller than 16 mA/cm2 and for a pulse length ~ 0.1 ms there is a quasisteady lasing at wavelengths λ = 1.73, 2.65, 2.03, and 2.63 μm if the resonator output mirror and the mixture composition are chosen appropriately. We have also observed simulatenous oscillation on the following pairs of lines: λ = 1.73 and 2.03 μm, 2.03 and 2.65 μm, and 2.65 and 2.63 μm. When the lattice supporting the foil covering the beam window was cooled with water, periodic-pulse operation at a repetition rate of 5 Hz was achieved in a laser with a pumped volume ~ 18 liters.

Field of study: Engineering, Physics
LightLDA: Big Topic Models on Modest Computer Clusters

When building large-scale machine learning (ML) programs, such as massive topic models or deep neural networks with up to trillions of parameters and training examples, one usually assumes that such massive tasks can only be attempted with industrial-sized clusters with thousands of nodes, which are out of reach for most practitioners and academic researchers. We consider this challenge in the context of topic modeling on web-scale corpora, and show that with a modest cluster of as few as 8 machines, we can train a topic model with 1 million topics and a 1-million-word vocabulary (for a total of 1 trillion parameters), on a document collection with 200 billion tokens --- a scale not yet reported even with thousands of machines. Our major contributions include: 1) a new, highly-efficient O(1) Metropolis-Hastings sampling algorithm, whose running cost is (surprisingly) agnostic of model size, and empirically converges nearly an order of magnitude more quickly than current state-of-the-art Gibbs samplers; 2) a model-scheduling scheme to handle the big model challenge, where each worker machine schedules the fetch/use of sub-models as needed, resulting in a frugal use of limited memory capacity and network bandwidth; 3) a differential data-structure for model storage, which uses separate data structures for high- and low-frequency words to allow extremely large models to fit in memory, while maintaining high inference speed. These contributions are built on top of the Petuum open-source distributed ML framework, and we provide experimental evidence showing how this development puts massive data and models within reach on a small cluster, while still enjoying proportional time cost reductions with increasing cluster size.

Field of study: Computer science
Stripping Analysis Using Ion-Transfer Voltammetry at Liquid/Liquid Interface

Principles and theory of stripping ion-transfer voltammetry at the organic solvent (O)/water (W) interface are described, in which a thin O-film is used to preconcentrate an ionic substance by electroextraction followed by stripping analysis using linear sweep voltammetry or normal pulse voltammetry. For ease of handling, the thin O-film was gelled by adding poly(vinyl chloride) to make an O-gel electrode. Lead(II), cadmium(II) and zinc(II) ions behave reversibly or quasi-reversibly in voltammetric transfer at the O/W interface assisted by 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine (DPT) present in the O-phase. Thus, these ions at trace levels can be determined using stripping ion-transfer voltammetry with the O(DPT)-gel electrode. The detection limit was as low as a few tens of nmol/l of these ions. Simultaneous determination of two or more ions is possible when their half-wave potentials of ion transfer are reasonably separated.

Field of study: Chemistry
Plant hydraulics and photosynthesis of 34 woody species from different successional stages of subtropical forests.

It is important to understand the ecophysiological characters of plants when exploring mechanisms underlying species substitution in the process of plant succession. In the present study, we selected 34 woody species from different stages of secondary succession in subtropical forests of southern China, and measured their hydraulic conductivity, gas exchange rates, leaf nutrients and drought-tolerance traits such as xylem resistance to cavitation, turgor loss point and carbon isotope ratio. Principal component analysis revealed that early-, mid- and late-successional species were significantly separated along axis 1, which was strongly associated with hydraulic-photosynthetic coordination. In contrast to species distributed in late-successional forest, early-successional species had the highest hydraulic conductivity, net photosynthetic rates, photosynthetic nitrogen and phosphorus use efficiencies, but had the lowest photosynthetic water-use efficiency. However, changes of the measured drought-tolerance traits of the 34 species along the succession did not demonstrate a clear trend - no significant correlations between these traits and plant successional stages were found. Moreover, the trade-off between hydraulic efficiency and safety was not identified. Taken together, our results suggested that hydraulic efficiency and photosynthetic function, rather than drought tolerance, play an important role in species distributions along plant succession in subtropical forests.

Field of study: Environmental science
Nonlinear impacts of future anthropogenic aerosol emissions on Arctic warming

Past reductions of anthropogenic aerosol concentrations in Europe and North America could have amplified Arctic warming. In the future the impact of air pollution policies may differ, because the major anthropogenic sources of atmospheric aerosols are increasingly located in Asia. In this study numerical experiments evaluating only direct aerosol effects on atmospheric temperatures indicate that, while reduced carbon dioxide (CO2) emissions weaken Arctic warming, direct radiative forcing effects by reductions of anthropogenic aerosol concentrations, additional to those obtained by lower CO2 emissions, can either amplify or diminish it. Interactions between regionally modified radiation in Asia and internal climate variability may differently initiate and sustain atmospheric planetary waves propagating into the Arctic. In a nonlinear manner planetary waves may redistribute atmospheric and oceanic meridional heat fluxes at the high latitudes and either amplify or diminish Arctic warming in 2050. Lower CO2 concentrations might apparently contribute to reduce the interactions between the Arctic system and the lower latitudes, thus reducing the influence of strong air quality measures in Asia on the Arctic amplification of global warming. While past and present air pollution policies could have amplified Arctic warming, in the future the effects from atmospheric pollution reductions are less certain, depending on the future CO2 concentrations, and requiring improved simulations of changing aerosol concentrations and their interactions with clouds in Asia and the Arctic.

Field of study: Environmental science
A Randomized, Controlled Trial Comparing Autologous Matrix-Induced Chondrogenesis (AMIC®) to Microfracture: Analysis of 1- and 2-Year Follow-Up Data of 2 Centers

Microfracture (MFx) is currently the recommended option for the treatment of small cartilage defects but is not regarded as suitable for the treatment of defects larger than 2.5 cm2. To extent its applicability to medium-sized defects MFx has been combined with a collagen type I/III matrix (Chondro-Gide®). This technique is called Autologous Matrix-Induced Chondrogenesis (AMIC®) and meanwhile a clinically established treatment option for localized full-thickness small- to medium-sized cartilage defects. Despite its more spreading clinical use, clinical data published so far are limited to mainly case report series. In this study, we report the first results of a randomized, controlled trial assessing the efficacy and safety of AMIC® versus MFx. Patients enrolled in 2 centers were included in this analysis. 38 patients (aged 21-50 years, mean defect size 3.4 cm2) were randomized and treated either with MFx, with sutured AMIC® or glued AMIC®. Clinical outcomes (modified Cincinnati and ICRS score) could be assessed in 30 patients at 1-year and 27 patients at 2-years post-operation. Improvements in both scores were seen at 1-and 2-years post-operation, irrespective of the technique used. MRI assessment revealed a satisfactory and homogenous defect filling in the majority of patients. No treatment-related adverse events were reported. This interim analysis confirms the mid-term results for AMIC® reported in literature. It demonstrates clearly that clinical outcomes at 1-year post-operation are maintained at 2-years. Therefore we consider enhancing MFx with Chondro-Gide® is a valid and safe cartilage repair option for small- to medium-sized cartilage defects of the knee.

Field of study: Medicine