The Jesuits and the Chinese literati: lessons from the first intellectual contact between China and Europe

The conventional view that attributes China’s scientific stagnation to Confucian literati’s lack of interest couldn’t be farther from the truth. In a quantitative historical study, Chicheng Ma reveals a different picture. In 1582 the Jesuits arrived in China and won over the Confucian elites with astronomy and mathematics. Chinese scientific publications exploded. The problem came later, when the Jesuits were not welcome in China anymore. The stagnation may be related to the autarkic principle of Ming-Qing China

Nonlinear parity-time-symmetric transition in finite-size optical couplers

Parity-time-symmetric ($\mathcal{PT}$-symmetric) optical waveguide couplers offer a great potential for future applications in integrated optics. Studies of nonlinear $\mathcal{PT}$-symmetric couplers present new possibilities for ultracompact configurable all-optical signal processing. Here, we predict nonlinearly triggered transition from a full to a broken $\mathcal{PT}$-symmetric regime in finite-size systems described by smooth permittivity profiles and, in particular, in a conventional discrete waveguide directional coupler configuration with a rectangular permittivity profile. These results suggest a practical route for experimental realization of such systems

Dynamic behavior of flexible rectangular fluid containers with time varying fluid

With fuel consumption, the fuel container system vibrates with decreasing mass, which is a typical variable mass system. This paper investigates the dynamic characteristics of flexible rectangular fluid containers with decreasing liquid. The dynamic equations of the container with time varying liquid are derived by combining finite element method (FEM) and virtual mass method (VMM). Free vibration states of the variable mass system are mainly investigated. The vibration signals are decomposed using Choi-Walliam Distribution, and the energy density spectrum is given by time frequency analysis. Results show that decrease of the liquid of the system induces increase of the vibration frequencies of the system, and generates an additional negative damping causing the vibration decay slowly. It is found that the additional damping is proportional to rate of mass change. The additional negative damping can cause the system vibrate with increasing amplitudes while the negative damping plays the dominant role rather than the structural damping

Photochemical Cleavage and Release of Carboxylic Acids and Substituted Phenols from [alpha]-Keto Amides

α-Keto amides with various leaving groups at the position α to the keto group were synthesized. Leaving groups such as carboxylates were photochemically cleaved under aqueous conditions to give carboxylic acids in 70-90% yields with quantum yields of 0.3. Based on mechanistic studies, the elimination of the carboxylate leaving groups was proposed to occur in photogenerated zwitterionic intermediates produced upon hydrogen transfer from an N -alkyl group to the keto group. The major cleavage coproduct was an oxazolidinone hemiacetal, which was accompanied by minor amounts of an α-methyleneoxazolidinone. This latter photoproduct was exclusively formed in the case of N,N -diisopropyl amides. In pure CH3 CN an aminal photoproduct is observed via ion pair return. In water the aminal converts to the aforementioned hemiacetal. γ-Aminobutyrate (GABA) was released within 30 ms according to time-resolved FT-IR spectroscopic studies. Time-resolved pH jump studies with N,N -diethyl α-keto amides gave time constants for carboxylate release ranging from 18-136 μs, depending on leaving group ability of a series of carboxylate groups, and an inverse solvent isotope effect was observed. N,N -Diisopropyl α-keto amides, in contrast, showed only a weak leaving group effect and a small normal solvent isotope effect which means that proton release in a subsequent step is rate determining. Cleavage and release of para -substituted phenols is observed for Y = CN, CF3 , or H and the cleavage coproduct is an α-methyleneoxazolidinone; a hemiacetal coproduct is only observed for Y = CN, CF3 in the case of N,N -diethylamides. 1,3-Photorearrangement of the phenolic group becomes increasingly important for Y = CH3 , OCH 3 . The 1,3-photorearrangements involve radical pair intermediates produced upon excited state homolysis of the ArO-C bond, according to laser flash photolysis studies. Total quantum yields are essentially constant, ca. 0.2-0.3, as the substituent Y is varied. Carboxylate groups are not released in photolyses of N,N -diisopropyl 3-phenyl-2-oxoamide in aqueous CH3 CN. The major photoproduct is a β-lactam, which is likely produced via a nonplanar 1,4-diradical formed upon hydrogen transfer from an N -isopropyl group. Laser flash photolyses show a transient intermediate ascribable to the biradical, which decays on the nanosecond timescale

Photochemical Cleavage and Release of Carboxylic Acids and Substituted Phenols from [alpha]-Keto Amides

α-Keto amides with various leaving groups at the position α to the keto group were synthesized. Leaving groups such as carboxylates were photochemically cleaved under aqueous conditions to give carboxylic acids in 70-90% yields with quantum yields of 0.3. Based on mechanistic studies, the elimination of the carboxylate leaving groups was proposed to occur in photogenerated zwitterionic intermediates produced upon hydrogen transfer from an N -alkyl group to the keto group. The major cleavage coproduct was an oxazolidinone hemiacetal, which was accompanied by minor amounts of an α-methyleneoxazolidinone. This latter photoproduct was exclusively formed in the case of N,N -diisopropyl amides. In pure CH3 CN an aminal photoproduct is observed via ion pair return. In water the aminal converts to the aforementioned hemiacetal. γ-Aminobutyrate (GABA) was released within 30 ms according to time-resolved FT-IR spectroscopic studies. Time-resolved pH jump studies with N,N -diethyl α-keto amides gave time constants for carboxylate release ranging from 18-136 μs, depending on leaving group ability of a series of carboxylate groups, and an inverse solvent isotope effect was observed. N,N -Diisopropyl α-keto amides, in contrast, showed only a weak leaving group effect and a small normal solvent isotope effect which means that proton release in a subsequent step is rate determining. Cleavage and release of para -substituted phenols is observed for Y = CN, CF3 , or H and the cleavage coproduct is an α-methyleneoxazolidinone; a hemiacetal coproduct is only observed for Y = CN, CF3 in the case of N,N -diethylamides. 1,3-Photorearrangement of the phenolic group becomes increasingly important for Y = CH3 , OCH 3 . The 1,3-photorearrangements involve radical pair intermediates produced upon excited state homolysis of the ArO-C bond, according to laser flash photolysis studies. Total quantum yields are essentially constant, ca. 0.2-0.3, as the substituent Y is varied. Carboxylate groups are not released in photolyses of N,N -diisopropyl 3-phenyl-2-oxoamide in aqueous CH3 CN. The major photoproduct is a β-lactam, which is likely produced via a nonplanar 1,4-diradical formed upon hydrogen transfer from an N -isopropyl group. Laser flash photolyses show a transient intermediate ascribable to the biradical, which decays on the nanosecond timescale

Essays on economics of conflicts : piracy and peasant rebellions in historical China

Essay One The Economic Origins of Piracy: “Experiments” by Chinese Emperors and European Explorers The most powerful episode of piracy to have occurred in the history of the world took place in the coastal waters of Ming China around 1550, but quickly receded after only two decades. In this essay, I document that the occurrence of this great wave of piracy was primarily due to the unprecedented growth of European trade with China around 1550 being impeded by Ming China’s prohibition on private foreign trade (the sea ban). After the sea ban was lifted in 1567, piracy plummeted and was replaced by the rapid development of private foreign trade. My findings indicate that piracy was promoted mainly by economic incentives resulting from disequilibrium between supply and demand in the maritime market, and highlight the importance of trade liberalization in reducing maritime crime. Essay Two Can State Ideology Reduce Civil Conflict? Confucianism and Peasant Rebellion in Qing China This essay examines the role of Confucianism—the state orthodoxy that has inculcated morality and social harmony for several millennia in imperial China—in mitigating the impact of crop failure on the incidence of peasant rebellions. Drawing upon county-level data from the Qing dynasty (1644-1911), and exploiting exogenous variations in the distance to Confucius’ birthplace as the instrumental variable for the strength of Confucianism, my findings indicate that the positive link between crop failure and peasant rebellions could not be alleviated by the Confucian ethos. This conclusion indicates that economic shocks, rather than cultural norms, play a fundamental role in conflict determination

Institutional environment and private entrepreneurs' political connections

This paper examines the impact of government discrimination, a prevalent institutional obstacle faced by private enterprises in China, on private entrepreneurs’ political connections in the industrial sector. Since government discrimination is endogenous due to reverse causality, omitted variables bias and measurement errors, we use regional differences in mineral abundance as the instrumental variable, reasoning that mineral abundance affects regional differences in the dominance of state-owned industries, which further affects government discrimination against industrial private enterprises. The IV regressions indicate that government discrimination has a substantial impact on private entrepreneurs’ political connections. This impact is proved to be not driven by other underlying factors. Through this study we provide a new micro level example to examine the role of institution but linking it to the exogenous factor endowments

Friends with Benefits: How Political Connections Help to Sustain Private Enterprise Growth in China

© 2016 The London School of Economics and Political Science. By analysing data from a survey of 511 Chinese private enterprises, we find that their owners respond to government discrimination by developing political connections with government officials. A one-standard-deviation increase in the insecurity of property rights has the effect of increasing the number of 'friends' in the government by a substantial 22%. These 'friends' significantly help to mitigate by half the negative effect arising from the difficulties of obtaining land and excessive regulations on enterprise growth. This explains why an institutional environment of weak property rights has not stopped private enterprises in China from developing rapidly. EconomicaLink_to_subscribed_fulltex