Ammonia and salinity tolerance of Penaeus monodon across eight breeding families

© 2016 Chen et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Ammonia nitrogen and salinity tolerance of Penaeus monodon from eight selected breeding families were evaluated at the concentration of 67.65 mg L−1 ammonia-N and reducing salinity from 15 to 0 ‰. The final survival of family A (88.67 ± 9.81 %) was highest, and the final survival of family B was lowest (24.33 ± 14.01 %) after the ammonia tolerance test. Upon completing the sudden drop salinity test from 15 to 0 ‰, the highest survival was observed in family B (98.00 ± 1.73 %), and the lowest survival was found in family H (18.00 ± 1.73 %). Family A showed the strongest ability to tolerate ammonia stress, and family B showed the strongest tolerance to low salinity. This study suggests that the tolerance of salinity and ammonia nitrogen varied between breeding families. Results from the present study provide useful information towards selective breeding in shrimp in aquaculture for environmental tolerance

Raman signature and phonon dispersion of atomically thin boron nitride

Raman spectroscopy has become an essential technique to characterize and investigate graphene and many other two-dimensional materials. However, there is still a lack of consensus on the Raman signature and phonon dispersion of atomically thin boron nitride (BN), which has many unique properties distinct from graphene. Such a knowledge gap greatly affects the understanding of the basic physical and chemical properties of atomically thin BN as well as the use of Raman spectroscopy to study these nanomaterials. Here, we use both experiment and simulation to reveal the intrinsic Raman signature of monolayer and few-layer BN. We find experimentally that atomically thin BN without interaction with a substrate has a G band frequency similar to that of bulk hexagonal BN (hBN), but strain induced by the substrate can cause a pronounced Raman shift. This is in excellent agreement with our first-principles density functional theory (DFT) calculations at two levels of theory, including van der Waals dispersion forces (opt-vdW) and a fraction of the exact exchange from Hartree–Fock (HF) theory through the hybrid HSE06 functional. Both calculations demonstrate that the intrinsic E2g mode of BN does not depend sensibly on the number of layers. Our simulations also suggest the importance of the exact exchange mixing parameter in calculating the vibrational modes in BN, as it determines the fraction of HF exchange included in the DFT calculations

Mechanical properties of atomically thin boron nitride and the role of interlayer interactions

Atomically thin boron nitride (BN) nanosheets are important two-dimensional nanomaterials with many unique properties distinct from those of graphene, but investigation into their mechanical properties remains incomplete. Here we report that high-quality single-crystalline mono-and few-layer BN nanosheets are one of the strongest electrically insulating materials. More intriguingly, few-layer BN shows mechanical behaviours quite different from those of few-layer graphene under indentation. In striking contrast to graphene, whose strength decreases by more than 30% when the number of layers increases from 1 to 8, the mechanical strength of BN nanosheets is not sensitive to increasing thickness. We attribute this difference to the distinct interlayer interactions and hence sliding tendencies in these two materials under indentation. The significantly better interlayer integrity of BN nanosheets makes them a more attractive candidate than graphene for several applications, for example, as mechanical reinforcements

The removal of phosphorus and boron by slag and acid leaching treatment

The rapid development of photovoltaic industry is causing many researches on the refining of silicon, especially the purification of silicon by metallurgical method from the metallurgical-grade silicon (MG-Si). The removal of phosphorus and boron is one of the major problems on the refining of MG-Si to Solar-grade silicon (SoG-Si). At present, the removal method of phosphorous and boron by slagging of CaO-SiO2-CaF2 and acid leaching treatment is being researched. It was found that the best removal ratio of phosphorous and boron could reach up to 81% and 92%. Meanwhile, the principle of removal of phosphorous and boron has been studied

Association analysis of alpha-amylase (AMY) and cathepsin L (CTSL) SNPs with growth traits in giant tiger shrimp Penaeus monodon

Alpha-amylase (AMY) and cathepsin-L (CTSL) were selected as candidate genes for SNP discovery for growth traits of P. monodon. Six SNPs were found in AMY and three in CTSL in P. monodon. Association analyses for the candidate SNPs with important economic traits were performed in populations. That allele A at CTLS-213 SNP, AA, and GA, tended to be associated with increased body weight. Shrimps with genotype GG had significantly smaller CL, CW, and CH values than those with GT and TT genotypes (P < 0.05). While CTLS-820 SNP was found to be significantly associated with CH and FSL (P <0.05). These SNPs will be valid for marker-assisted selection breeding programs in P. monodon

Haematology specimen acceptability: a national survey in Chinese laboratories

Introduction: Specimen adequacy is a crucial preanalytical factor affecting accuracy and usefulness of test result. The aim of this study was to determine the frequency and reasons for rejected haematology specimens, preanalytical variables which may affect specimen quality, and consequences of rejection, and provide suggestions on monitoring quality indicators as to obtain a quality improvement. Materials and methods: A cross-sectional survey was conducted and a questionnaire was sent to 1586 laboratories. Participants were asked to provide general information about institution and practices on specimen management and record rejections and reasons for rejection from 1st to 31st July. Results: A total survey response rate was 56% (890/1586). Of 10,181,036 tubes received during the data collection period, 11,447 (0.11%) were rejected, and the sigma (σ) was 4.6. The main reason for unacceptable specimens was clotted specimen (57%). Rejected specimens were related to source department, container type, container material type, transportation method and phlebotomy personnel. The recollection of 84% of the rejected specimens was required. The median specimen processing delay in inpatient, outpatient and emergency department were 81.0 minutes, 57.0 minutes and 43.3 minutes, respectively. Conclusions: Overall, rejection rate was a slightly lower than previously published data. In order to achieve a better quality in the preanalytical phase, haematology laboratories in China should pay more attention on training for phlebotomy and sample transportation, identify main reasons for clotted specimen and take effective measures. The platform in the study will be helpful for long-term monitoring, but simplification and modification should be introduced in the following investigation

NOx formation of biomass co-firing with coal in two-stage drop-tube furnace

The co-firing of biomass with coal is one of the technologies to reduce the carbon emission from the coal-fired power plant. The position of biomass co-firing has a significant impact on NOx emission during the co-firing process. Therefore, in order to study the effect of the biomass co-firing position and the temperature on the NOx emission, a two-stage drop-tube furnace was used to study the NOx emission of biomass co-firing with coal from the primary combustion zone and the burnout zone as well as the migration of fuel N. The results show that NOx emission behaviors are significantly different when biomass is mixed from the primary combustion zone and the burnout zone. When biomass is mixed from the primary combustion zone, NOx emission at studied temperature shows a decreasing trend with the increase of the biomass co-firing ratio from 0 to 40%, with the increase of the over-fire air ratio, the lowest NOx emission occurs when the ratio is 0.33. When biomass is mixed from the burnout zone, the NOx emission decreases continuously with the increase of the biomass co-firing ratio from 0 to 40% at the burnout temperature of 1 000 ℃. At the burnout temperatures of 1200 and 1400 ℃, the NOx emission is lowest when the biomass co-firing ratio is 10%. There is a significant difference in the conversion of fuel N to intermediate products of HCN and NH3 during biomass co-firing in the burnout zone. At the studied burnout temperature, when biomass is mixed in the burnout zone, the conversion rate of fuel N to HCN always increases with the increase of biomass co-firing ratio. The conversion of fuel N to NH3 increases with the increase of biomass co-firing ratio at the burnout temperature of 1 000 ℃; when the burnout temperatures is 1200 and 1 400 ℃, the conversion rate of NH3 is the highest at biomass co-firing ratio of 10%. When the primary zone temperature is 1 200 ℃ and the burnout temperature is 1 400 ℃, about 94% of the fuel N is converted to N2 and ash N, about 5% is converted to NOx, and less than 1% is converted to HCN and NH3. The co-firing of biomass can reduce the conversion of fuel N to NOx compared to pure coal combustion. However, as the biomass co-firing ratio increases, the conversion rate of fuel N to NOx and ash N increases, and the conversion rate of fuel N to N2 decreases