A Single-Frequency Linearly Polarized Fiber Laser Using a Newly Developed Heavily Tm3+-Doped Germanate Glass Fiber at 1.95 μm

A compact linearly polarized, low-noise, narrow-linewidth, single-frequency fiber laser at 1950nm is demonstrated. This compact fiber laser is based on a 21-mm-long homemade Tm3＋-doped germanate glass fiber. Over 100-mW stable continuous-wave single transverse and longitudinal mode lasing at 195Ohm are achieved. The measured relative intensity noise is less than -135dB/Hz at frequencies over 5 MHz. The signal-to-noise ratio of the laser is larger than 72dB, and the laser linewidth is less than 6kHz, while the obtained linear polarization extinction ratio is higher than 22 dB.

Heavily doped silicon:A potential replacement of conventional plasmonic metals

The plasmonic property of heavily doped p-type silicon is studied here.Although most of the plasmonic devices use metal-insulator-metal(MIM)waveguide in order to support the propagation of surface plasmon polaritons(SPPs),metals that possess a number of challenges in loss management,polarization response,nanofabrication etc.On the other hand,heavily doped p-type silicon shows similar plasmonic properties like metals and also enables us to overcome the challenges possessed by metals.For numerical simulation,heavily doped p-silicon is mathematically modeled and the theoretically obtained relative permittivity is compared with the experimental value.A waveguide is formed with the p-silicon-air interface instead of the metal-air interface.Formation and propagation of SPPs similar to MIM waveguides are observed.

Short-term Effects of Air Pollution on Mortality in a Heavily Polluted Chinese City

Since the London fog in 1952, numerous epidemioLogical studies have revealed that both short-term and long-term exposure to air pollutants is associated with the development of diseases[1]. Up to date, the assessment of air quality on health and air quality standard establishment in developing countries were mainly relied on extrapolation based on the results from long-term cohort studies conducted in Europe and North America.

Effect of Rapid Thermal Process on Oxygen Precipitates in Heavily Sb-Doped Silicon Wafer

Oxygen precipitates in heavily Sb-doped silicon after rapid thermal process (RTP) in Ar ambient were investigated by RTP at high temperature following annealing at 800 ℃ for 4 h and 1000 ℃ for 16 h. RTP temperature and cooling rates were changed from 1200 to 1260 ℃ and from 10 to 100 ℃·s-1, respectively. The experiment results show that high density of oxygen precipitates is observed in heavily Sb-doped wafer. It is found that the oxygen precipitates in heavily Sb-doped silicon are enhanced at high cooling rate.

Interstitial Oxygen Determination in Heavily Doped Silicon with "Peak-height" Method by FT-IR Spectra

Due to ineffectiveness of routine IR-absorption method for determinahon of intershtial oxygen in heavily doped silicon, a 'peak-height' method has been dcveloped. The phosphorus-doped CZ-Si with n=(7.l～l2)× 10~17cm^(-3) was taken as sample for characterization. The calculation results at 300 K and 10 K were ptesented in detail. The'peak-height' method is much simpler than 'short-baseline' and 'curved-baseline' methods.

Effect of Growth Parameters on Core Length of Φ76．2mm Heavily Sb－doped Si Crystals

An M-shaped interface was observed in the top part of Φ76. 2 mm , (111) , dislocation-free, heavily Sb-doped Si single crystals, which is beneficial for crystals to keep dislocation-free condition at the beginning ofbody growth. Effects of seed rotation, crucible rotation , crown shape and growth rate on M-shaed interfacewere studied. Under proper conditions, impurity core length can be shortened from 6 cm to 1 cm , the yield israised by more than 5 %.

FORMATION AND PROPERTIES 0F POROUS SILICON LAYER ON HEAVILY DOPED n-Si

The anodic voltammetric curves of heavily doped n-Si in HF solution, on which three different regions have emerged, and were plotted, A porous silicon layer with fine morphology was formed in linear region.

Doping Evolution of the Superconducting Gap Structure in Heavily Hole-Doped Ba1-xKxFe2As2:a Heat Transport Study

We perform systematic thermal conductivity measurements on heavily hole-doped Ba1-xKxFe2As2 single crystals with 0.747 ≤ x ≤ 0.974. At x=0.747, the K0/T is negligible, indicating a nodeless superconducting gap. A small residual linear term K0/T （=0.035 m W.K-2 cm-1） appears at xz0.826, and it increases slowly up to x=0.974, followed by a substantial increase of more than 20 times to of K0/T clearly shows that the nodal gap appears near x surface topology. The small values of K0/T from x=0.826 the pure KFe2As2 （x=1.0）. This doping dependence = 0.8, possibly associated with the change of Fermi to 0.974 are consistent with the Y-shaped nodal s- wave gap recently revealed by angle-resolved photoemission spectroscopy experiments at x=0.9. Furthermore, the substantial increase of K0/T from x=0.974 to 1.0 is inconsistent with a symmetry-imposed d-wave gap in KFe2 As2, and a possible nodal gap structure in KFe2As2 is discussed.

Extraction Timing of Heavily Destructed Upper First Permanent Molars

The first permanent molar as the first permanent tooth in the mouth and with a general insufficient oral hygiene of the children, is commonly subject to significant compromise which may arise due to caries or endodontic complication, or from developmental anomalies such as hypoplasia. Compromised teeth with questionable prognosis may result in short- and long-term clinical dilemmas. The aim of this research is to highlight the factors that require careful consideration when a compromised UFPM is detected and the importance of timely UFPM extraction to ensure the mesial drift of the upper second permanent molar (USPM) to fulfill the space of the extracted UFPM without any orthodontic intervention. For this purpose 52 heavily destructed UFPMs were extracted at age of 10.5 years old, 44 (84.6%) USPMs erupted exactly distal to the second premolar while only 7 (13.4%) USPMs erupted 1 mm distal to the second premolar. Clinically it is recommended to extract the heavily destructed upper first molars at age of 10.5 years old to ensure the complete closure of the extraction space by the passive mesial drift of upper second permanent molar.

Rapid control of black and odorous substances from heavilypolluted sediment by oxidation:Efficiency and effects

The control ofblack and odorous substances in sediments is of crucial importance to improve the urban ecological landscape and to restore water environments accordingly.In this study,chemical oxidation by the oxidants NaClO,H2O2,and KMnO4 was proposed to achieve rapid control of black and odorous substances in heavily-polluted sediments.Results indicate that NaClO and KMnO4 are effective at removing Fe(II)and acid volatile sulfides.The removal efficiencies of Fe(II)and AVS were determined to be 45.2%,94.1%,and 93.7%,89.5%after 24-h exposure to NaClO and KMnO4 at 0.2 mmol/g,respectively.Additionally,rapid oxidation might accelerate the release of pollutants from sediment.The release of organic matters and phosphorus with the maximum ratios of 22.1%and 51.2%was observed upon NaClO oxidation at 0.4 mmol/g.Moreover,the introduction of oxidants contributed to changes in the microbial community composition in sediment.After oxidation by NaClO and KMnO4 at 0.4 mmol/g,the Shannon index decreased from 6.72 to 5.19 and 4.95,whereas the OTU numbers decreased from 2904 to 1677 and 1553,respectively.Comparatively,H2O2 showed a lower effect on the removal of black and odorous substances,pollutant release,and changes in sediment microorganisms.This study illustrates the effects of oxidant addition on the characteristics of heavily polluted sediments and shows that chemical oxidants may be an option to achieve rapid control of black and odorous substances prior to remediation of water environments.

Spatial correlations between urbanization and river water pollution in the heavily polluted area of Taihu Lake Basin, China

Water pollution in the Taihu Lake Basin has been the focus of attention in China and abroad for a long time, due to its position in the forefront of urban development in China. Based on data gathering and processing from 84 monitoring sections in this heavily polluted area, this study first analyzes spatial patterns of urbanization and the distribution of river water pollution, and then uses the GeoDa bivariate spatial autocorrelation model to investigate the spatial correlation between urbanization and river water pollution at the scale of township units. The results show that urbanization has adverse impacts on water pollution, and the influence varies in different levels of development areas. The urban township units have the highest level of urbanization and highest pollution, but the best water quality; the suburban units have lower level of urbanization, but higher pollution and worse water quality; however the rural units have the lowest level of urbanization and lowest pollution, mainly affected by upstream pollution, but worst water quality. Lastly, urban and rural planning committees, while actively promoting the process of development in the region, should gradually resolve the issue of pollution control lagging behind urban life and urban develop- ment, giving priority to construction of centralized sewage treatment facilities and associated pipeline network coverage in the rural areas and suburban areas.

Special magnetic phenomena in heavily doped La_(0.7-x)Dy_xSr_(0.3)MnO_3 system

The magnetism in heavily Dy doped La0.7-xDyxSr0.3MnO3(0.40≤x≤0.70)system is studied in this paper.The M-T relation seems to be complicated with the increase of x.For sample with x=0.40,AFM behavior exists at T≤TN and M-T curves under zero field cooling(ZFC)and field cooling(FC)exhibit typical behavior of spincluster glass state above TN.For the sample with x=0.50,the M-T curve under ZFC exhibits a valley at a low temperature while the M-T curve under FC exhibits the negative magnetization below TN.For samples with x=0.60,0.70,their ZFC M-T curves are similar to that of x=0.50,but the FC M-T curves do not exhibit negative values any more.All the peculiar phenomena above are well explained by Néel double-lattice model combined with M-H relation at typical temperatures.The molecular field theory fits well the negative magnetization for x=0.50.

Almost Sure Central Limit Theorems for Heavily Trimmed Sums

We obtain an ahnost sure central limit theorem(ASCLT)for heavily trimmed sums.We also prove a function-typed ASCLT under the same conditions that assure measurable functions to satisfy the ASCLT for the partial sums of i.i.d,random variables with EX_1=0,EX_1~2=1.

Does green governance affect financing constraints?Evidence from China's heavily polluting enterprises

Given the increasing focus on global sustainable development, many enterprises in developing countries such as China participate in green governance and scale up their green investment;however, many enterprises still experience financing difficulties. Our study investigates whether green governance can mitigate corporate financing constraints. Using a sample of Chinese, A-share listed, high-pollution enterprises from 2013 to 2018, we find that corporate green governance practices, including environmental performance and information disclosure, ease corporate financing constraints. This effect is pronounced in areas with high levels of financial development and for stateowned enterprises. This paper not only proposes a channel for alleviating enterprises’ financing constraints but also reveals the importance of industrial transformation and emissions reduction for energy-intensive industries in emerging markets.

HAZARD FUNCTION AND CHARACTERIZATIONS ON DISTRIBUTION TAILS OF NONNEGATIVE RANDOM VARIABLES

Some equivalent conditions on the classes of lighted-tailed and heavily heavy-tailed and lightly heavy-tailed d.f.s are introduced.The limit behavior of xα(x) and e λx(x) are discussed.Some properties of the subclass DKc and subclass DK 1 are obtained.

MULTI-NATIONAL CO-ORDINATION: FEASIBILITY IN ASIA-PACIFIC

There have taken place in recent years the most profound changes in the inter-national situation since the Second World War. After the Gulf War and thedisintegration of the former Soviet Union, there is no longer the bipolar structuresymbolizing the Cold War. Various political forces are now in a process of align-ment and realignment and the world is speeding up its pace to go toward multi-po-

Research of Crystallization of Aluminums Cast Iron

In work was researched the composition and structure of high-alloyed aluminum cast iron ЧЮ22Ш. Crystalization of cast iron ЧЮ22Ш (ЧЮ22Ш standard cast iron) was researched by phase transformation, leaking upon its harden and cooling –down. High-alloyed materials are widely applied as the heat-resistant materials. Overall content of that reaches 30-50% and more. Previous performed researches allowed to optimize the content high-alloyed aluminum cast iron ЧЮ22Ш, to research its structure, casting and operational characteristics, to develop technological mode of melting, casting and thermal / heat treatment casts, to held its industrial examination and to determine perspective direction of its application. However, in present time ability of the aluminum cast iron ЧЮ22Ш is being used not sufficiently.

IMW——combustion research facility

Xi’an Thermal Power Research Institute (TPRI) isone of the research organizations directly under theMinistry of Energy.Its responsibility is to solve key technicalproblems occurred in thermal power plants,and to undertake therelated research and development projects.China relies heavily on coat for energy generation.The to-