Topological Magnetoresistance of Magnetic Skyrmionic Bubbles

Magnetic skyrmions offer promising prospects for constructing future energy-efficient and high-density information technology, leading to extensive explorations of new skyrmionic materials recently. The topological Hall effect has been widely adopted as a distinctive marker of skyrmion emergence. Alternately, here we propose a novel signature of skyrmion state by quantitatively investigating the magnetoresistance (MR) induced by skyrmionic bubbles in CeMn2Ge2. An intriguing finding was revealed: the anomalous MR measured at different temperatures can be normalized into a single curve, regardless of sample thickness. This behavior can be accurately reproduced by the recent chiral spin textures MR model. Further analysis of the MR anomaly allowed us to quantitatively examine the effective magnetic fields of various scattering channels. Remarkably, the analyses, combined with the Lorentz transmission electronic microscopy results, indicate that the in-plane scattering channel with triplet exchange interactions predominantly governs the magnetotransport in the Bloch-type skyrmionic bubble state. Our results not only provide insights into the quantum correction on MR induced by skyrmionic bubble phase, but also present an electrical probing method for studying chiral spin texture formation, evolution and their topological properties, which opens up exciting possibilities for identifying new skyrmionic materials and advancing the methodology for studying chiral spin textures.Comment: 17 pages,5 figures,submitte

Ensuring water resource security in China; the need for advances in evidence based policy to support sustainable management.

China currently faces a water resource sustainability problem which is likely to worsen into the future. The Chinese government is attempting to address this problem through legislative action, but faces severe challenges in delivering its high ambitions. The key challenges revolve around the need to balance water availability with the need to feed a growing population under a changing climate and its ambitions for increased economic development. This is further complicated by the complex and multi-layered government departments, often with overlapping jurisdictions, which are not always aligned in their policy implementation and delivery mechanisms. There remain opportunities for China to make further progress and this paper reports on the outcomes of a science-to-policy roundtable meeting involving scientists and policy-makers in China. It identifies, in an holistic manner, new opportunities for additional considerations for policy implementation, continued and new research requirements to ensure evidence-based policies are designed and implemented and identifies the needs and opportunities to effectively monitor their effectiveness. Other countries around the world can benefit from assessing this case study in China

Canonical Correspondence Analysis of Phytoplankton Community and Environmental Factors in Genhe River

To understand the status of phytoplankton community of the Genhe River in the summer of 2015, we investigated the phytoplankton in Genhe River. We identified 5 phyla and 36 species, among which Bacillariophyta (23) were the most, followed by Chlorophyta (10), Cyanophyta (1), Chrysophyta (1), Pyrrophyta (1). The phytoplankton abundance was (15.6-810)×104 ind·L－1; the biomass was (0.07-2.876) mg·L－1; Shannon-wiener index was 1.05-3.24; Pielou evenness index was 0.27-0.96. Using Shannon-wiener index and Pielou index, the water quality of Genhe River was assessed, and the results showed that the water quality was the best at 5# sampling point, the water quality was good in 3#, 4#, 7#, 8#, 9# sampling points, and there was a state of pollution at other sampling points. Canonical correspondence analysis and Pearson correlation analysis showed that iron ion, transparency, pH value, water depth and water temperature were important environmental factors that affect the distribution of phytoplankton, and copper ion, nitrite ion and COD also significantly affected the distribution of phytoplankton

A Study on the Fish Diversity of Sanhuanpao Wetland in Heilongjiang Province

The current situation of fish in Sanhuanpao Wetland was investigated for the first time in this paper. In May (Spring), July (summer), September (autumn) 2016, it was sampled three times for investigation, and based on the investigation data about the fish caught by net 45 times in 9 sampling points, the species composition of fish community in the water was analyzed. The results showed that a total of 12 fish species were caught in this investigation, belonging to 4 orders, 6 families and 12 genera. There were 5 fish species for Cyprinidae, accounting for 41.7% of total species, followed by Cobitidae with 3 species, accounting for 25% of total species; Siluridae, Esocidae, Eleotridae and Channidae each had 1 species, accounting for 8.3% of total species. The fish with index of relative importance (IRI) greater than 1000 is the dominant species, and it was calculated that the dominant species were Carassius auratus gibelio, Rhynchocypris percnurus, Misgurnus mohoity, Cobitis taenia Linnaeus, and Perccottus glenii. In this paper, based on the number of individuals, by calculating Margalcf abundance index (D), Shannon-Wiener diversity index (H') and Pielou evenness index (J') for the fish in the water, the current situation of fish resources in Sanhuanpao Wetland was analyzed and the corresponding protection recommendations were put forward

Seasonal dynamics of Zooplankton functional groups in relation to environmental variables in Xiquanyan Reservoir, Northeast China

In this study, the concept of functional feeding groups was used to classify and model the seasonal variation of zooplankton functional groups in relation to environmental variables. A total of 48 zooplankton species were observed in the reservoir and grouped into 8 functional groups. Both environmental variable and the biomass of zooplankton functional groups vary spatially and seasonally. Water temperature, water transparency, total nitrogen and nitrates were significantly higher in summer, while chlorophyll-a and ammonium were higher in autumn and spring, respectively. Biomass of zooplankton was significantly higher in summer (245.81 μg/L), followed by autumn (196.54 μg/L) and spring (54.25 μg/L). Group RF (rotifer filter feeders) dominated in spring, accounting for 80% of the total biomass. In summer and autumn, group RC (rotifer carnivore) and SCF (small copepods and cladocerans filter feeders) were the dominant, respectively. Total nitrogen, total phosphorus, ammonium, chlorophyll-a and water transparency were the major factor influencing zooplankton community. Group RF was positively influenced by ammonium and total phosphorus, while RC, SCF and MCF (middle copepods and cladocerans filter feeders) were positively correlated with chlorophyll-a. Top-down control of phytoplankton by groups RC, SCF and MCF in Xiquanyan reservoir is not strong enough to produce negative effect. Increase in predator size biomass did not strengthen top-down control on prey. It is quite clear that the zooplankton function groups of Xiquanyan reservoir followed a predictable seasonal pattern. This therefore highlights the significance of environmental variables in structuring plankton composition in the reservoir.The concept of functional feeding groups was used to classify and model the seasonal variation of zooplankton functional groups in relation to environmental variables. Zooplankton species were grouped into 8 functional groups that vary spatially and followed a predictable seasonal pattern. Total nitrogen, total phosphorus, ammonium, chlorophyll-a and water transparency were the major factor influencing zooplankton community. Top-down control of phytoplankton by zooplankton in Xiquanyan reservoir is not strong enough to produce negative effect

Current Development and Prospects of Pond Smelt (Hypomesus olidus) Farming Industry in China

The pond smelt (Hypomesus olidus), originally transplanted from North Korea, was introduced to China in 1938 and gradually distributed to various areas of China. The pond smelt was the first fish species introduced to the water of China. It not only has the function of protecting water quality, and also has high economic and nutritional values which are helpful for diversifying the fishery productive activities of China. The present review analyzed the transplantation and production status of pond smelt in China, described the key situations and factors influencing the establishment and current level of aquaculture development. Since its introduction, the pond smelt transplantation in China was distributed in Northeast of China. From the 1980s, reservoirs and lakes all over China began to transplant pond smelt, and the transplantation of pond smelt went into the outbreak period. In order to improve the efficiency of transplantation, scientific and technical personnel studied the simple and practical technology of artificial breeding and transplantation, the medicine for preventing and controlling saprolegniasis which often leads to death of fertilized eggs. To meet the demand of market, more and more pond smelt processing products have been studied and developed, such as grilled, milk flavor, fish sauce, ham-sausage, and brew vinegar of pond smelt. The pond smelt farming in China has broad prospects development, yet there are also challenges to overcome. It is recommended to take proper policies for pond smelt development, strengthen pond smelt scientific research, transplantation technology training, establish pond smelt fisheries association, support dominant enterprises, and implement brand strategy

On-Balance-Sheet Duration Hedging and Firm Value

In this study we consider the determinants and effects of on-balance-sheet duration hedging for non-financial US firms. The difference between the duration of assets and liabilities, or duration gap, is negatively related to growth opportunities, and positively related to profitability, corporate cash holdings, and managerial ownership. We find that both a lower duration gap and a lower absolute value of duration gap are associated with higher firm values. Moreover, we find some evidence that firms with larger duration gaps performed worse during the market-wide liquidity shock accompanying the Lehman Brothers bankruptcy

Effects of Habitat Types on Macroinvertebrates Assemblages Structure: Case Study of Sun Island Bund Wetland

Sun Island Bund Wetland (SIBW) is a river floodplain wetland located at the south part of Heilongjiang Province in Northeast China. An investigation of the influence of habitat type on macroinvertebrates assemblages structure was conducted in July 2016. Nine (9) sampling sites were selected based on sediment type, water condition, and aquatic vegetation type. Macroinvertebrates attributes including density, biomass, and four diversity indices (Simpson diversity index, Margalef richness index, Shannon-Weiner index, and Pielou evenness index) were assessed. A total of 53 taxa were collected during the study period, with the highest density dominated being from aquatic insects and gastropods. Bellamya purificata and Exopalaemon annandalei were the most dominant among all the species. The results showed that the assemblages structure of macroinvertebrates in different habitats was significantly different. Also, the results with PCA showed that the higher values of invertebrates density, biomass, diversity indices, and species richness had a greater association with the habitat types of silt-humus sediment, closed lentic area, and submerged-flouting-emergent vegetation