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Functionalized N-doped porous carbon nanofiber webs/sulfur (N-PCNF/S) composites are first proposed as the cathode materials for an advanced lithium−sulfur battery. The functionalized N-doped porous carbon nanofiber webs (N-PCNF) with an appropriate N doping (4.32 wt %) are synthesized by a facile approach, which consists of pyrolyzation of polypyrrole nanofiber and a subsequent KOH activation. Instrumental analysis shows that N-PCNF possesses a large specific surface area (2642 m 2 g −1 ) and a high inner pore volume (1.31 cm 3 g −1 ). When evaluating its electrochemical properties in a lithium−sulfur battery, the N-PCNF/S composite with 77.01 wt % sulfur content displays an excellent electrochemical performance. The specific discharge capacity still reaches 749.8 mAh g −1 after 180 cycles at 0.2 C. At a higher rate of 1 C, the capacity stabilizes at 666.0 mAh g −1 after 200 cycles. This work demonstrates that combining the favorable aspects of N doping modification and one-dimensional nanostructure in the carbon matrix design is an effective way to improve the electrochemical performance of the carbon/sulfur cathodes.

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Summary The authors examined the current status of sturgeon aquaculture in China, including its geographic distribution, an account on farmed species, overall production trends, state of controlled reproduction, seedling output and export. The study is based on a nationwide survey of 125 farms undertaken July and August 2009 together with data from previous studies. The census shows that: (i) the main provinces in increasing order of production are Sichuan (including Chongqing), Beijing, Hubei, Shandong and Hunan, (ii) Acipenser baerii, (and its hybrids) and A. schrenckii are the dominant cultured species, accounting for 95% of the total production, (iii) the production of farmed sturgeon has experienced a steady increase, from 17 424 t in 2006 to 21 000 t in 2009, (iv) the total reserves of captive stocks have continuously increased, reaching at present an estimated 1.22 million individuals, (v) the total supply of fertilized eggs or larvae from farmed broodstocks in China has gone up during the past 3 years, and can now basically meet the domestic demand for farming, while the number of seedlings obtained from the wild and imported from other countries gradually declined, and (vi) since 2006, China has started to export farmed caviar and the exports have been increasing year by year, meanwhile, the number of caviar processing factories has also increased. Moreover, other value‐added products derived from farmed sturgeon (e.g. medical and health products, cosmetics, leather etc.) appeared in recent years on China markets. Corresponding to the sturgeon aquaculture development in China, some additional future aquaculture strategies are discussed: (i) make full use of the resources, (ii) strengthen management strategies and upgrade the culture techniques, (iii) develop and implement labeling systems for good quality control, (iv) foster deep‐processing (value added products) in sturgeon farming to widen market options, (v) enhance extensive genetic studies and research on gynogenesis and cryopreservation of gametes for better resource management, (vi) improve the knowledge on early sex‐differentiation in sturgeon, and (vii) prepare standards for management of sustainable sturgeon aquaculture. Considering the current progress of sturgeon aquaculture, the prospects of future sturgeon farming are assessed: (i) there will be a potential for considerable aquaculture to serve the caviar market, and farmed caviar may replace wild products, (ii) product diversification will increase and target for export markets, (iii) hatchery operations to produce juveniles from controlled reproduction will completely replace supply from wild and imported resources, and (iv) an industry chain will be gradually established to ensure sustainable sturgeon aquaculture production in China.