正规网投 - 正规网投
正规网投2024-03-17

中国科学家构建出新型人工碳晶体******

  中新社合肥1月12日电 (记者 吴兰)中国科学家在新型碳基晶体研究方面取得重要进展——构建出新型人工碳晶体,并实现了其克量级制备。1月12日,国际学术期刊《自然》(Nature)刊发了这一研究成果。

  中国科学技术大学朱彦武教授研究团队通过对富勒烯碳60分子晶体进行电荷注入,在常压条件下构建了碳60聚合物晶体以及长程有序多孔碳晶体。

  朱彦武介绍:“这里的长程有序多孔碳晶体,微观上具有多孔特征但完整保留了晶体的宏观周期性,是一类新的人工碳晶体,未来可能在能量存储、离子筛分、负载催化等领域具有潜在应用。电荷注入技术为构建这类碳基晶体材料提供了一种拼‘乐高’式的制备技术,有望成为在原子级精度上调控晶体结构的新手段。”

  碳是自然界最常见的元素之一,碳原子之间通过不同排列方式,能够形成多种结构,比如石墨、金刚石和无定型碳,已经广泛应用于各领域。近年来,富勒烯、纳米碳管、石墨烯和石墨炔等新型碳材料的发现和发展,引起了广泛关注与研究热潮。

  “如果我们可以在一个晶体结构中引入纳米单元,例如用富勒烯、石墨烯等作为基本结构单元代替普通晶体中的原子,像搭积木一样‘搭建’出新型碳材料,可能会发掘更多新奇性质,发挥更大应用潜力。”朱彦武说。

  此前,对于制备这类新型碳材料,研究人员要么是利用高温高压等极限条件,要么是采用紫外光、电子束辐照等微观处理技术,但其产率较低、产物不纯,阻碍了人们对该类材料的性质与应用进行更深入探索。

  朱彦武团队长期致力于发展新型碳材料的规模化制备技术,早在2011年,就找到了一种化学“活化”的方式“激活”石墨烯。此后,团队进一步探索了“活化”方法的普适性。

  在此次研究中,朱彦武团队创造性地使用氮化锂对富勒烯碳60分子晶体进行电荷注入,并在温和温度下进行热处理,最终得到大量的碳60聚合物晶体以及长程有序多孔碳晶体。

  朱彦武表示:“接下来,我们将系统地研究长程有序多孔碳基晶体的性质,期望通过精细调节实验参数进一步调控晶体的原子级结构特征,探索更多的性质和应用。”(完)

正规网投

中新网评:处理核污水绝不是日本自家私事******

  中新网北京1月19日电(蒋鲤)日本政府近日称,将于2023年春夏期间开始向海洋排放经过处理的福岛第一核电站核污水。日本罔顾国内民众及周边国家的屡屡反对,企图将核污水“一倒了之”,把一件关乎全球海洋生态环境和公众健康的事当成了自家私事。

资料图:日本福岛第一核电站。

  2011年,福岛核电站事故发生后,大量放射性物质泄漏到大气层和太平洋,对周围环境造成了难以逆转的伤害,数十万人被迫撤离该地区。时至今日,作为日本邻国之一的韩国仍未解除福岛海鲜禁令。

  日本以核污水存储能力即将达到上限为由,在2021年4月13日,正式决定将福岛第一核电站核污水排入太平洋。过去一年多,日本政府和东京电力公司一直在持续推进核污水排海计划。

  日本政府辩称,这些核污水经多核素处理系统(ALPS)处理后很安全,甚至“可以喝”,这样的表态无疑在愚弄大众。

  事实上,经过处理的核污水仍含有多种放射性物质,核污水一旦排放入海就无法回收,长期来看,将会给海洋生态带来难以估量的潜在威胁,最终危害人类健康。

  因此,核污水排海计划推出后,遭到日本民众强烈反对。日本《朝日新闻》2022年3月公布的问卷调查显示,福岛县、宫城县和岩手县受访的42个市町村长中,约六成反对东京电力公司福岛第一核电站核污水排放入海。日本全国渔业协会联合会也多次申明立场,反对该计划。

  日本政府认为,核污水排海是最便宜、最省事的解决方案,但此举却将周边国家乃至全世界置于核污染风险中。太平洋非日本一家之海,核污水会随着洋流流动,其影响势必会跨越国界,危害周边国家乃至整个国际社会的公共福祉和利益。

  《韩国经济新闻》发文称,相关研究认为,福岛核污水如果排放入海,约7个月后将到达济州等韩国海域,该国水产业和旅游业将遭受相当大的损失。

  德国南极海洋机构也曾发出警告,若日本将所有核污水排入海中,不到半年,整个太平洋都将面临高度辐射威胁,包括远在大洋另一端的美国。太平洋地区人民更是对日本该计划持反对意见。

  日本作为《联合国海洋法公约》缔约国,有义务保护海洋环境。然而,在核污水排海方案的正当性、核污水数据的可靠性、净化装置的有效性、环境影响的不确定性等问题上,日本未能作出科学、可信的说明。

  国际原子能机构技术工作组虽已三次赴日实地考察评估,但尚未就日排海方案的安全性给出结论,并且对日本提出诸多澄清要求和整改意见。在此情况下,日本仍执意推进核污水排海工程建设,这是极不负责任的行为。

  太平洋不是日本的下水道,日本必须正视各方合理关切,在与周边国家等相关利益方和国际原子能机构充分协商后,制定合理的核污水处理方案。日本也要着眼长远,若只顾眼前,执意将核污水排放入海,不仅其自身,周边国家乃至全世界都将为之买单,其后果必将会危害数代人。

  Fukushima water disposal by no means Japan’s own business

  By John Lee

  (ECNS) -- Japan has announced it will release treated wastewater from the wrecked Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean this year.

  Although Fukushima wastewater disposal affects global marine ecological environment protection and public health, Japan has turned a deaf ear to domestic and international opposition to dumping the contaminated water into the sea, treating the "global" matter as its own business.

  The Fukushima accident in 2011 had sent large quantities of radiation into the atmosphere and the Pacific Ocean, causing irreversible damage to the surrounding environment, and hundreds of thousands of people were forced to evacuate the area. South Korea still maintains its import ban on Japanese seafood from areas affected by the Fukushima nuclear disaster.

  On April 13, 2021, Japan announced it had decided to discharge contaminated radioactive wastewater in Fukushima Prefecture into the sea due to dwindling storage space, with the Japanese government and plant operator Tokyo Electric Power Company Holdings Inc. promoting the release plan over the past year.

  The Japanese government argues that the water treated by an advanced liquid processing system, or ALPS, is safe and drinkable, which is undoubtedly fooling the public.

  In fact, the treated wastewater still includes a variety of radioactive substances and can’t be recycled once discharged into the sea, which will pose a great threat to marine ecology and ultimately endanger human health in the long run.

  Therefore, the discharge plan has been strongly opposed in Japan. According to a questionnaire conducted by The Asahi Shimbun, nearly 60 percent of mayors of 42 municipalities in Iwate, Miyagi and Fukushima prefectures oppose the discharge plan. The National Fisheries Cooperative Federation of Japan has also repeatedly stated its opposition in public.

  The Japanese government believes that dumping Fukushima wastewater into the sea is the cheapest and most convenient solution, but neighboring countries and even the whole world will be at risk of nuclear pollution.

  The Pacific Ocean doesn’t belong to Japan and the wastewater flow along oceanic currents will surely break boundaries and endanger public welfare and the interests of neighboring countries and even the international community.

  The Korea Economic Daily reported that related research concluded that if contaminated water from Fukushima is released into the ocean, it would only take seven months for the contaminated water to reach the shores of Jeju Island, with the country's aquaculture and tourism suffering considerable losses.

  According to the calculation of a German marine scientific research institute, radioactive materials will spread to most of the Pacific Ocean within half a year from the date of discharge, and the U.S. and Canada will be affected by nuclear pollution. People in the Pacific region also oppose the discharge plan.

  As a participant of the United Nations Convention on the Law of the Sea, Japan has the obligation of protecting the marine environment.

  However, it hasn’t offered a full and convincing explanation on issues like the legitimacy of the discharge plan, the reliability of data on the nuclear-contaminated water, the efficacy of the treatment system or the uncertainty of environmental impact.

  Though the IAEA has yet to complete a comprehensive review after three investigations in Japan, the Japanese side has been pushing through the approval process for its discharge plan and even started building facilities for the discharge. It is rather irresponsible for Japan to act against public opinion at home and concerns abroad.

  The Pacific Ocean is not a private Japanese sewer. The country must seriously heed the voices of the international community and make a reasonable plan for the Fukushima wastewater disposal after full consultation with stakeholders and international agencies.

  If it only seeks instant interest and insists on discharging the contaminated water into the sea, not only itself, but also its neighboring countries and the entire world will pay for the decision and several generations will be forced to bear the consequence.

 

中国网客户端

国家重点新闻网站,9语种权威发布

正规网投地图