社会目的于董事义务标准的形塑--以公司型社会企业为视角

从社会企业兴起现状来看,其社会目的的存在对传统董事义务标准及其影响要素产生冲击,学理上不仅对利润最大化的传统商法宗旨提出质疑,也对多重目的企业本质发出疑问。我国社会企业日渐发展的趋势和不成一体的制度化规定使对此问题的研究迫在眉睫。英美法是社会企业和董事义务标准发展之本源,其较为完善的社会企业发展路径对我国具有重要的参考价值。对此,我们应当强调社会目的与董事义务标准之间的必然联系,董事决策中信义义务的履行应当跟随公司型社会企业目标宗旨调整匹配,以此区分与其他组织体之间的差异,并为我国社会企业进一步立法和责任规制提供重要路径。

The impacts of climate change on hydrology in a typical glacier region A case study in Hailuo Creek watershed of Mt.Gongga in China

The glaciers of the Hengduan Mountains play an important role in the hydrology processes of this region. In this study, the HBV Light model, which relies on a degree-day model to simulate glacier melting, was employed to simulate both glacier runoffand total runoff. The daily temperature and precipitation at the Hailuo Creek No. 1 Glacier from 1952 to 2009 were obtained from daily meteorological observed data at the glacier and from six national meteorological stations near the Hailuo Creek Basin. The daily air temperature, precipitation, runoff depth, and monthly potential evaporation in 1995, 1996, and 2002 were used to obtain a set of optimal parameters, and the annual total runoff and glacier runoff of the Hailuo Creek Glacier （1952--2009） were calculated using the HBV Light model. Results showed the average annual runoff in the Hailuo Creek Basin was 2,114 mm from 1952 to 2009, of which glacial melting accounted for about 1,078 mm. The river runoff in the Hailuo Creek catchment increased as a result of increased glacier runoff. Glacier runoff accounted for 51.1% of the Hailuo Creek stream flow in 1994 and increased to 72.6% in 2006. About 95% of the increased stream flow derived from the increased ~lacier runoff.

Simple,stable and efficient nonlinear pulse compression through cascaded filamentation in air

Nonlinear compression has become an obligatory technique along with the development of ultrafast lasers in generating ultrashort pulses with narrow pulse widths and high peak power.In particular,techniques of nonlinear compression have experienced a rapid progress as ytterbium(Yb)-doped lasers with pulse widths in the range from hundreds of femtoseconds to a few picoseconds have become mainstream laser tools for both scientific and industrial applications.Here,we report a simple and stable nonlinear pulse compression technique with high efficiency through cascaded filamentation in air followed by dispersion compensation.Pulses at a center wavelength of 1040 nm with millijoule pulse energy and 160 fs pulse width from a high-power Yb:CaAlGdO_(4) regenerative amplifier are compressed to 32 fs,with only 2.4% loss from the filamentation process.The compressed pulse has a stable output power with a root-meansquare variation of 0.2% over 1 hour.

Carbonaceous aerosol transport from the Indo-Gangetic Plain to the Himalayas:Carbon isotope evidence and light absorption characteristics

The Indo-Gangetic Plain(IGP)is a major regional and global emitter of atmospheric pollutants,which adversely affect surrounding areas such as the Himalayas.We present a comprehensive dataset on carbonaceous aerosol(CA)composition,radiocarbon(D14C)-based source apportionment,and light absorption of total suspended particle(TSP)samples collected over a 3-year period from high-altitude Jomsom in the central Himalayas.The 3-year mean TSP,organic carbon(OC),and elemental carbon(EC)concentrations were 92.0±28.6,9.74±6.31,and 2.02±1.35 lg m^(3),respectively,with the highest concentrations observed during the pre-monsoon season,followed by the post-monsoon,winter,and monsoon seasons.The △^(14)C analysis revealed that the contribution of fossil fuel combustion(ffossil)to EC was 47.9%±11.5%,which is consistent with observations in urban and remote regions in South Asia and attests that EC likely arrives in Jomsom from upwind IGP sources via long-range transport.In addition,the lowest f_(fossil)(38.7%±13.3%)was observed in winter,indicating large contributions in this season from local biomass burning.The mass absorption cross-section of EC(MACEC:8.27±1.76 m^(2)/g)and watersoluble organic carbon(MACWSOC:0.98±0.45 m^(2)/g)were slightly higher and lower than those reported in urban regions,respectively,indicating that CA undergo an aging process.Organic aerosol coating during transport and variation of biomass burning probably led to the seasonal variation in MAC of two components.Overall,WSOC contributed considerably to the light absorption(11.1%±4.23%)of EC.The findings suggest that to protect glaciers of the Himalayas from pollution-related melting,it is essential to mitigate emissions from the IGP.

Seasonality of carbonaceous aerosol composition and light absorption properties in Karachi,Pakistan

Characteristics of carbonaceous aerosol(CA)and its light absorption properties are limited in Karachi,which is one of the most polluted metropolitan cities in South Asia.This study presents a comprehensive measurement of seasonality of CA compositions and mass absorption cross-section(MAC)of elemental carbon(EC)and water-soluble organic carbon(WSOC)in total suspended particles(TSP)collected from February 2015 to March 2017 in the southwest part of Karachi.The average TSP,organic carbon(OC),and EC concentrations were extremely high with values as 391.0±217.0,37.2±28.0,and 8.53±6.97μg/m3,respectively.These components showed clear seasonal variations with high concentrations occurring during fall and winter followed by spring and summer.SO42-,NO3-,K+,and NH4+showed similar variations with CA,implying the significant influence on atmospheric pollutants from anthropogenic activities.Relatively lower OC/EG ratio(4.20±2.50)compared with remote regions further indicates fossil fuel combustion as a primary source of CA.Meanwhile,sea salt and soil dust are important contribution sources for TSP.The average MAC of EC(632 nm)and WSOC(365 nm)were 6.56±2.70 and 0.97±0.37 m2/g,respectively.MACEC is comparable to that in urban areas but lower than that in remote regions,indicating the significant influence of local emissions.MACwsoc showed opposite distribution with EC,further suggesting that OC was significantly affected by local fossil fuel combustion.In addition,dust might be an important factor increasing MACwsoc particularly during spring and summer.

Weak RF signal detection with high resolution and no blind zone based on ultra-simple multi-mode optoelectronic oscillation

Weak RF signal detection with high resolution and no blind zone based on directly modulated multi-mode optoelectronic oscillation has been proposed.The high-sensitivity optical modulators and optical filters are avoided because multi-mode oscillation is obtained based on directly modulating the semiconductor laser at the relaxation oscillation frequency.For the directly modulated optoelectronic oscillator,the detection characteristics such as gain for the RF signal,resolution,noise floor,and sensitivity are firstly analyzed.The experimental results are consistent with the simulated results.For the RF signal of unknown frequency,it can be detected out and amplified by tuning the bias current and delay time of the loop.There is no blind zone within 1–4.5 GHz.The system provides a maximum gain of 17.88 dB for the low-power RF signal.The sensitivity of the system can reach as high as-95 dBm.The properties such as gain dynamic range and power stability are also investigated.The system has potential for weak RF signal detection,especially for the RF signal with unknown frequency.

Enhanced piezoelectric properties in low-temperature sintering PZN-PZT ceramics by adjusting Zr/Ti ratio

Pb_(0.96)Sr_(0.04)(Zr,Ti)_(0.7)(Zn_(1/3)Nb_(2/3))_(0.3)O_(3)(PZN-PZT)piezoceramics with various Zr/Ti ratios and Li_(2)CO_(3)sintering aid were sintered at 900°C by the solid-state reaction route.The samples with different Zr/Ti ratios were compared according to microstructure,phase structure,piezoelectricity,ferroelectricity,and dielectric relaxation.The Zr/Ti ratio in the PZN-PZT ceramics greatly affects the electrical properties.The Zr/Ti ratio affects the proportion between the rhombohedral and tetragonal phases and also affects the grain size.The PZN-PZT ceramics with the Zr/Ti ratio of 53:47 have the largest grain size and have optimized piezoelectric prop-erties(k_(p)=0.58,d_(33)=540 pC/N,and T_(C)=250°C).The larger the grain size,the lesser the grain boundary,the easier the domain wall motion,and the better the piezoelectric properties.The PZT ceramic with Zr/Ti ratio of 53:47 locates the morphotropic phase boundary(MPB)region which is one of the key factors for the high piezoelectric properties of the PZT.

Use of Different Murder Weapons by a Single Murderer:Two Case Reports

Homicide is an extremely serious crime,and although the offender usually uses the same weapon to initially injure and complete the killing,there are exceptions.We report two cases in which a single murderer killed a victim using different weapons and summarize several situations in which a murderer might use different weapons to kill.The number of murders should be determined and estimated after a comprehensive complicated investigation of the scene,careful examination of the victim’s injuries,and evaluation of evidence reported by eyewitnesses.

High-efficiency and flexible photonic microwave harmonic down-converter based on self-oscillation optical frequency combs

Photonic microwave harmonic down-converters (PMHDCs) based on self-oscillation optical frequency combs (OFCs) are interesting because of their broad bandwidth compared with plain optoelectronic oscillators. In this paper, a high-efficiency and flexible PMHDC is proposed and demonstrated. The properties of the OFC, such as the carrier-to-noise ratio (CNR),bandwidth and free spectral range (FSR), and the influence of optical injection, are investigated. The broadband OFC provides a frequency tunable and high-quality local oscillation (LO), which guarantees flexible down-conversion for the radio frequency (RF) signal. The sideband selective amplification (SSA) effect not only improves the conversion efficiency but also promotes single-sideband modulation. The conversion range can reach 100 GHz. The 12–40 GHz RF signal can be downconverted to intermediate frequency (IF) signals with a high conversion efficiency of 14.9 dB. The fixed 40-GHz RF signal is flexibly down-converted to an IF signal with the frequency from 55.4 to 2129.4 MHz. The phase noise of an IF signal at a frequency offset of 10 kHz is the same as that of the input RF signal. The PMHDC shows great performance and will find applications in radio-over-fiber (RoF) networks, electronic warfare receivers, avionics, and wireless communication systems.