科研成果

We propose a simple iterative (SI) algorithm for the maxcut problem through fully using an equivalent continuous formulation. It does not need rounding at all and has advantages that all subproblems have explicit analytic solutions, the cut values are monotonically up- dated and the iteration points converge to a local optima in finite steps via an appropriate subgradient selection. Numerical experiments on G-set demonstrate the performance. In particular, the ratios between the best cut values achieved by SI and those by some ad- vanced combinatorial algorithms in [Ann. Oper. Res., 248 (2017), 365–403] are at least 0.986 and can be further improved to at least 0.997 by a preliminary attempt to break out of local optima.

Harmful algal blooms pose tremendous threats to ecological safety and human health. In this study, simulated solar light (SSL) irradiation was used to activate periodate (PI) for the inactivation of Microcystis aeruginosa and degradation of microcystin-LR (MC-LR). We found that PI-SSL system could effectively inactivate 5 × 106 cells·mL−1 algal cells below the limit of detection within 180 min. ·OH and iodine (IO3· and IO4·) radicals generated in PI-SSL system could rupture cell membranes, releasing intracellular substances including MC-LR into the reaction system. However, the released MC-LR could be degraded into non-toxic small molecules via hydroxylation and ring cleavage processes in PI-SSL system, reducing their environmental risks. High algae inactivation performance of PI-SSL system in solution with a wide pH range (3–9), with the coexisting anions (Cl−, NO3− and SO42−) and the copresence of natural organic matters (humic acid and fulvic acid), real water (lake water and river water), as well as in continuous-flow reactor (14 h) were also achieved. In addition, under natural sunlight irradiation, effective algae inactivation could also be achieved in an enlarged reactor (1 L). Overall, our study showed that PI-SSL system could avoid the inference by the background substances and could be employed as a feasible technique to treat algal bloom water.

Direction of arrival (DoA) estimation in complex environments is a challenging task. The traditional methods suffer from invalidity under low signal-to-noise ratio (SNR) and reverberation conditions, and the data-driven methods lack of generalization to unseen data types. In this paper we propose a robust DoA estimation approach by combining the two methods above. To focus on spatial information modeling, the proposed method directly uses the compressed covariance matrix of the first-order ambisonics (FOA) signal as input, while only white noise is used during training. To adapt to different characteristics of FOA signals in different frequency bands, our method estimates DoA in different frequency bands by particular models, and the subband results are finally integrated together. Experiments are carried out on both simulated and measured datasets, and the results show the superiority of the proposed method than existing baselines under complex conditions and the scalability for unseen data types.

Linguistic communication requires interlocutors to consider differences in each other’s knowledge (perspective-taking). However, perspective-taking might either be spontaneous or strategic. We monitored listeners’ eye movements in a referential communication task. A virtual speaker gave temporally ambiguous instructions with scalar adjectives (“big” in “big cubic block”). Scalar adjectives assume a contrasting object (a small cubic block). We manipulated whether the contrasting object (a small triangle) for a competitor object (a big triangle) was in common ground (visible to both speaker and listener) or was occluded so it was in the listener’s privileged ground, in which case perspective-taking would allow earlier reference-resolution. We used a complex visual context with multiple objects, making strategic perspective-taking unlikely when all objects are in the listener’s referential domain. A turn-taking, puzzle-solving task manipulated whether participants could anticipate a more restricted referential domain. Pieces were either confined to a small area (requiring fine-grained coordination) or distributed across spatially distinct regions (requiring only coarse-grained coordination). Results strongly supported spontaneous perspective-taking: Although comprehension was less time-locked in the coarse-grained condition, participants in both conditions used perspective information to identify the target referent earlier when the competitor contrast was in privileged ground, even when participants believed instructions were computer-generated.

The influence and mechanisms of starvation on the bacterial mobile performance in porous media with different nutrition conditions are not well understood. The present study systematically investigated the impacts of starvation on the mobility and attachment of both Gram-negative and Gram-positive strains in porous media without and with nutrients on surfaces in both simulated and real water samples. We found that regardless of strain types and water chemistries, starvation would greatly inhibit bacterial attachment onto bare porous media without nutrients yet could significantly enhance cell attachment onto porous media with nutrients on their surfaces. The mechanisms driving the opposite transport behaviors induced by starvation in porous media without and with nutrients were totally different. We found that the starvation process decreased cell motility and increased repulsive force between bacteria and porous media via decreasing cell sizes and zeta potentials, reducing EPS secretion and cell hydrophobicity, thus increasing transport/inhibiting attachment of bacteria in porous media without nutrients on sand surfaces. In contrast, through strengthening the positive chemotactic response of bacteria to nutrients, the starvation process greatly enhanced bacterial attachment onto porous media with nutrients on sand surfaces. Clearly, via modification of the nutrient conditions in porous media, the mobility/attachment performance of bacteria could be regulated.

This study reassesses an inscribed victory catalogue from Sinope (IK Sinope 105) that is often discussed in scholarship concerning agonistic culture in the Roman world. One particularly curious element of this inscription is the empty nature of the penultimate line, which bears only the numerals rho-nu. In the existing scholarship, this is usually interpreted as the sum of all the athlete’s victories. This paper challenges the orthodox interpretation, using a combination of David French’s squeezes housed at the British Institute at Ankara, supported by autopsy and recent photographs of the stone itself. It goes on to reconsider the practice of summing athletic victories in honorific inscriptions more generally, examining a specially compiled dossier of 207 inscriptions of comparable date to IK Sinope 105, and concluding that the practice was relatively rare. Finally, this paper considers other possible interpretations of the rho-nu in IK Sinope 105, among which is the suggestion that rho-nu could be a chronographic feature. While the interpretation of the rho-nu in IK Sinope 105 remains open, the combination of a close analysis of the stone with a wider contextual consideration of the genre demonstrates how much more remains to be said about even a well-known and often cited inscription. Özet Bu çalışma, Roma dünyasındaki agonistik kültürle ilgili araştırmalarda sıklıkla tartışılan, Sinop’dan ele geçen bir zafer kataloğu yazıtını (IK Sinope 105) yeniden değerlendirmektedir. Bu yazıtın özellikle merak uyandıran unsurlarından biri, sadece rho-nu rakamlarını taşıyan, sondan bir önceki satırın boş olmasıdır. Mevcut akademik çalışmalarda bu rakamlar genellikle atletin tüm zaferlerinin toplam sayısı olarak yorumlanmaktadır. Bu makale, taşın yakından incelenmesi ile son zamanda çekilmiş fotoğraflarıyla desteklenen, British Institute at Ankara’da bulunan French’in yazıt mülajlarını birlikte değerlendirerek bu geleneksel yorumu sorgulamaktadır. Daha genel olarak, onurlandırma yazıtlarında atletik zafer sayılarının toplanması uygulamasını yeniden gözden geçirerek, IK Sinope 105 ile karşılaştırılabilir tarihe sahip 207 yazıttan oluşan özel olarak derlenmiş bir dosyayı incelemekte ve uygulamanın nispeten nadir olduğu sonucuna varmaktadır. Son olarak, bu makale IK Sinope 105’teki rho-nu hakkındaki diğer olası yorumları da ele almaktadır; bunların arasında rho-nu’nun kronografik bir özellik olabileceği önerisi de bulunmaktadır. IK Sinope 105’teki rho-nu’nun yorumu açık kalmaya devam ederken, taşın yakından bir analizi ile bu çeşit yazıtların daha geniş bir bağlamsal değer- lendirmesinin birleşimi, iyi bilinen ve sıklıkla atıfta bulunulan bir yazıt hakkında bile söylenecek daha ne kadar çok şey olduğunu göstermektedir.

During the 1960 campaign of the Corinth Excavations, a Tang Dynasty coin was found in an ash and charcoal layer with deposits from the mid- to late 13th century ce and earlier. Considering similar coin finds from the Xinjiang Uygur Autonomous Region, China, and the Chui Region, Kyrgyzstan, this article argues that the Corinth Tang coin is likely an Anxi Protectorate issue, though a Chui valley origin cannot be ruled out. This article discusses the origins, survival, and mobility of this minimal-value cash coin in a web of Eurasian connections, with particular focus on the connectivity of the Church of the East and the Jewish merchant network from the 8th to the 13th century ce.