Electrochemical reduction of carbon dioxide to valuable chemicals is a promising way of storing renewable energy through electric-to-chemical energy conversion, while its large-scale application is in urgent need of cheap and high-performance catalysts. Herein, we invent a convenient method to synthesize N-doped porous carbon by ammonia etching the pyrolysis carbon of petroleum pitch. We found the ammonia etching treatment not only increase the pyridinic-N content, but also enlarge the specific surface area of the petroleum pitch-based porous carbon. As a cheap and easily available catalyst for carbon dioxide electroreduction, up to 82% of Faradaic efficiency towards carbon monoxide was obtained at − 0.9 V vs the reversible hydrogen electrode in 0.1 M KHCO3. After a long time electrocatalysis of more than 20 h, the Faradaic efficiency of carbon monoxide remains 80%, indicating the porous carbon as made have an ultra-high stability as catalyst for carbon dioxide reduction. Our work provides a new technology to economically prepare efficient electrocatalysts for carbon dioxide reduction.

본 연구는 겨울철 제설제 (CaCl2) 농도처리에 따른 맥문동(Liriope platyphylla)과 수호초(Pachysandra terminalis)의 내염성을 평가하고자 수행하였다. 국내에서 제설제로 가장 많이 사용하는 염화칼슘을 각각 0%(Control), 0.5%, 1.0%, 3.0%, 5.0%로 처리한 실험구에 2015년 11월에 맥문동과 수호초를 정식한 후, 이듬해 이른 봄인 2016년 3월에 내염성을 평가하기 위해 초장, 엽장, 엽폭, 엽형지수, 생체중, 건물중, 엽록소함량, 광합성률, 기공전도도, 증산율 등을 측정하였다. 초장, 엽장, 엽폭, 엽형지수, 생체중, 건물중, 엽록소함량, 광합성률, 기공전도도, 증산율 등은 제설제 처리농도가 높을수 록 감소되는 것은 두 식물이 동일하였으나, 맥문동이 수호초보다 좀 더 안정된 생육 및 생리적 특징을 보였다. 무엇보다, 맥문동은 3.0% 이상에서, 수호초는 1.0% 이상의 농도처리에서 생존이 불가능해 맥문동이 수호초보다 내염성이 높은 것으로 판단되었으며, 도시 내 제설제 피해지역에 활용이 가능할 것으로 기대된다.

We investigated genetic diversity among and within the populations of cultivated ginseng (Panax ginseng C. A. Meyer ) using SRAP profiles. A total of 24 ginseng plants were sampled from the three populations (two from China, one from Korea). Since all these populations are previously shown closely related to each other assister groups, we used Panax quinquefolium L. and wild ginseng as a reference species, which is not "within the sister group". All individuals from the three populations were screened with a total of 36 primer pairs with 26 primers generated from 328 SRAP bands of DNA gels. The mean gene diversity (HE) was estimated to be 0.057 within populations (range 0.032-0.067), and 0.086 at the species level. The genetic differentiation (Gst=0.31) indicates that genetic variation apportioned 30% among populations and 70% within populations. Generally, the result of this study indicates that ginseng contains high molecular variation in its populations.