Methods for a blind analysis of isobar data collected by the STAR collaboration

In 2018,the STAR collaboration collected data from^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zr at√^(S)NN=200 Ge V to search for the presence of the chiral magnetic effect in collisions of nuclei.The isobar collision species alternated frequently between 9644 Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zr.In order to conduct blind analyses of studies related to the chiral magnetic effect in these isobar data,STAR developed a three-step blind analysis procedure.Analysts are initially provided a"reference sample"of data,comprised of a mix of events from the two species,the order of which respects time-dependent changes in run conditions.After tuning analysis codes and performing time-dependent quality assurance on the reference sample,analysts are provided a species-blind sample suitable for calculating efficiencies and corrections for individual≈30-min data-taking runs.For this sample,species-specific information is disguised,but individual output files contain data from a single isobar species.Only run-by-run corrections and code alteration subsequent to these corrections are allowed at this stage.Following these modifications,the"frozen"code is passed over the fully un-blind data,completing the blind analysis.As a check of the feasibility of the blind analysis procedure,analysts completed a"mock data challenge,"analyzing data from Au+Au collisions at√^(S)NN=27 Ge V,collected in 2018.The Au+Au data were prepared in the same manner intended for the isobar blind data.The details of the blind analysis procedure and results from the mock data challenge are presented.

新一代天然纤维——牛角瓜绒

近年来,天然纤维凭借其良好的生物相容性、可生物降解性、生产加工无毒无害,以及产量丰富等优点,在各技术和商业领域得到了广泛的应用。棉纤维从一开始就是制造服装的首选原料。虽然现在人们发明了各种合成纤维、人造纤维,但仍没有找到合适的原料替代棉纤维。牛角瓜绒是一种植物的种子纤维,其具有与木棉纤维相似的外观,以及很多优良的性能,可作为棉纤维的替代品。对牛角瓜绒的植物来源、特点、可纺性、机械性能及吸湿性进行了介绍。

Comparisons of carbon pools and economic profitability for managed ponderosa pine stands in Wyoming,USA

A forest carbon （C） sequestration project was conducted to evaluate the economic incentives that would be required by landowners to engage in C trading under different management regimes. Costs associated with joint management for C sequestration and timber would be valuable for establishing sound forest C trading systems. In this study, we calculated the C yield and amortized value of three Wyoming, ponderosa pine stands. The management practices examined were, unmanaged, even-aged （regeneration after clear-cut） and uneven-aged （selectively harvested）. Costs and revenues associated with three stands were converted into 2006 real dollars using the all commodity producer price index to facilitate a comparison among the net revenues of three stands. Net revenues were annualized using a conservative annual interest rate of 4.5%. Our even-aged stand bad the highest annual average C yield of 2.48 Mg·ha^-1·a^-1, whereas, the uneven-aged stand had the lowest C accumulation （1.98Mg·ha^-1·a^-1）. Alternatively, the even-aged stand had the highest amortized net return of S276·ha^-1·a^-1 and the unmanaged stand had the lowest net return of S64·ha^-1·a^-1. On the plots examined, an annual payment of S22 for each additional Mg of C sequestered would encourage a change from uneven aged management to an unmanaged stand that sequesters additional C, in the absence of transactions costs.

印度的钢铁工业

早在1900年,印度就开始了钢铁生产,在Jamshe-dpur建设了Tata钢铁厂,这是印度第一家钢铁联合企业。1947年独立以前,在Burnpur建设了另一座私营联合企业——印度钢铁股份有限公司。1947年独立后不久,印度的钢铁工业发展很快。50年代末和60年代初,在Rourkela,Bhilai和Durgapur建设了三座国营钢铁厂。其后,在70年代初建成了Bokaro钢铁厂和目前的Vizg钢铁厂已接近完工。这些厂都是国营的。

Investigating the fission dynamics of the following neutron shell closed nuclei within a stochastic dynamical approach:^(210)Po,^(212)Rn,and ^(213)Fr

The dissipative dynamics of nuclear fission is a well confirmed phenomenon that can be either described by a Kramers-modified statistical model or by a dynamical model employing the Langevin equation.Although dynamical models as well as statistical models incorporating fission delays have been found to explain the measured fission observables in several studies,they present conflicting results for shell closed nuclei in the mass region of 200.Notably,an analysis of the recent data on neutron shell closed nuclei in the excitation energy range of 40-80 MeV failed to provide a satisfactory description of the data,which was attributed to a mismatch with shell effects and/or entrance channel effects,without reaching a definite conclusion.In the present study,we demonstrate that a well established stochastic dynamical code can simultaneously reproduce the available data for pre-scission neutron multiplicities and fission and evaporation residue excitation functions for the following neutron shell closed nuclei^(210)Po and^(212)Rn and their isotopes^(206)Po and^(214,216)Rn without the need for including any extra shell or entrance channel effects.The relevant calculations are performed by using a phenomenological universal friction form factor with no ad-hoc adjustment of the model parameters.However,we note a significant deviation,beyond experimental errors,for some Frisotopes.

Measurement of away-side broadening with self-subtraction of flow in Au+Au collisions at √sNN=200 GeV

High transverse momentum(pT)particle production is suppressed owing to the parton(jet)energy loss in the hot dense medium created in relativistic heavy-ion collisions.Redistribution of energy at low-to-modest pT has been difficult to measure,owing to large anisotropic backgrounds.We report a data-driven method for background evaluation and subtraction,exploiting the away-side pseudorapidity gaps,to measure the jetlike correlation shape in Au+Au collisions at √sNN=200 GeV in the STAR experiment.The correlation shapes,for trigger particles pT>3GeV/c and various associated particle pT ranges within 0.5<pT<10GeV/c,are consistent with Gaussians,and their widths increase with centrality.The results indicate jet broadening in the medium created in central heavy-ion collisions.