简书儿们大家好，日更进行时。之前分享了两篇nature解析的文章，读过的朋友可能发现了，这是按照论文的不同部分：abstract, introduction, methods...不同部分进行解析的。
这次分享的是nature一篇文章中methods部分的内容，希望能够给写作新手，或者想要提高语言表达的科研朋友们一点启示。关注微信公众号En Style了解更多paper写作的内容，有些困扰你的问题有涉及到欧～
本期分享的是《自然》2018年10月25日第7728期562卷关于应对食品系统对环境影响研究的论文Methods。为了解研究情况，在精读之前先看下摘要：
Options for keeping the food system within environmental limits
将食品系统保持在环境限制范围内的可行措施
The food system is a major driver of climate change, changes in land use, depletion of freshwater resources, and pollution of aquaticand terrestrial ecosystems through excessive nitrogen and phosphorusinputs. Here we show that between 2010 and 2050, as a result of expected changes in population and income levels, the environmental effects of the food system could increase by 50–90% in the absence of technological changes and dedicated mitigation measures, reaching levels that are beyond the planetary boundaries that define a safe operating space for humanity. We analyse several options for reducing the environmental effects of the food system, including dietary changes towards healthier, more plant-based diets, improvements in technologies and management, and reductions in food loss and waste. We find that no single measure is enough to keep these effects within all planetary boundaries simultaneously, and that a synergistic combination of measures will be needed to sufficiently mitigate the projected increase in environmental pressures.
由于氮和磷使用过多，粮食系统成为气候变化、土地使用变化、淡水资源枯竭、水和陆地生态系统污染的主要推动因素。本研究基于人口和收入水平的预期变化分析表明，若无任何科技和特定的减缓措施，从2010年至2050年，粮食系统对环境的影响将增加50-90%，超过人类在地球上特定的安全经营范围。研究分析了可以减少这种环境影响的几个选项，包括增加蔬菜比例、更为健康的饮食结构变化、促进科技发展和加强管理、减少食物损失和浪费。研究结果发现，以上任何单一措施，都难以控制这些影响超出地球所有的特定界限范围，有必要综合以上多种措施形成合力，充分减缓预期增加的环境压力。
摘要介绍了研究的背景、任务、结果和结论，其中提到的食品系统包括从食品生产、加工、运输到消费（农田到餐桌）的所有活动。
Nature写作指南之Methods
按照Nature的风格，在Methods部分，段落第一句提出整段主题（topic）。第一句后，如果方便，剩余部分可以全部使用被动语态。主动语态与被动语态的选择因主题和作者而异，有的主题相关的研究习惯用密集的被动语态。本文Methods部分主动语态和被动语态使用相当，更侧重于前者。
在Methods部分，作者通过Food-system model（食品系统模型）、Scenario analysis（情景分析）、Planetary boundaries（地球的特定界限）、Reporting summary（报告总结）四个方面进行论述。由于篇幅较长，本期节选了Food-system model的前两段，分析一些值得借鉴的知识点。
Methods精读
① Food-system model. For our analysis, we constructed a food-systems model that connects food consumption and production across regions (Supplementary Information). ② We distinguished several steps along the food chain: primary production (including non-food uses, for example, in industry, seed banks, and as biofuels); trade in primary commodities; processing to oils, oil cakes and refined sugar; use of feed for animals; and trade in processed commodities and animals (Extended Data Table 2). ③ We parameterized the model with data from the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) on current and future food production, processing factors, and feed requirements for 62 agricultural commodities and 159 countries. ④ Projections of future food consumption and production werebased on statistical association with changes in income and population, and were in line with other projections.
⑤ To assess the environmental impacts of the food system, we paired the food- system model with a set of country-specific environmental footprints related to GHG emissions, cropland use, bluewater use, and nitrogen and phosphorus appli- cation (Extended Data Table 3; data available upon request). ⑥ In line with projections of the allowable agricultural emissions budget, and our separate treatment of land use, we focused on the non-CO2 emissions of agriculture, in particular methane and nitrous oxide. ⑦ Data on GHG emissions were adopted from country-specific analyses of GHG emissions from crops and livestock. ⑧ Non-CO2 emissions of fish and seafood were calculated on the basis of feed requirements and feed-related emissions of aquaculture, and on projections of the ratio between wild-caught and farmed fish production. ⑨ Our baseline emissions estimate agrees well with existing ones that follow the same methodology.
①Food-system model. For our analysis, we constructed a food-systems model that connects food consumption and production across regions (Supplementary Information).
食品系统模型。为了进行分析，我们建立了食品系统模型，将不同区域的食品消费和生产联系起来（见补充信息）。
句型：前置成分+简单句+后置定语从句
◆ Methods段首主题句：For …, we constructed/developed/created…model that…
◆ construct同义替换create/build等，搭配Methods中的model/system等。
② We distinguished several steps along the food chain: primary production (including non-food uses, for example, in industry, seed banks, and as biofuels); trade in primary commodities; processing to oils, oil cakes and refined sugar; use of feed for animals; and trade in processed commodities and animals (Extended Data Table 2).
我们将食品链分为几个步骤：一次生产（包括非食品用途，比如工业中的此类应用、种子库以及生物燃料）；一次商品贸易；加工成油类、油糕和精制糖；动物饲料用途；加工商品和动物交易（扩展数据表2）。
句型：简单句+并列细节
◆ 多个成分并列的标点符号使用：本句使用的是分号，因为在并里的成分内，还有更小的并列（processing to oils, oil cakes and refined sugar），如果是单个的名词名列，可以直接用逗号；括号表示其它补充说明。
◆ distinguish v. 区分；使有别于；认出，听清；使出众。前两个意思平时用的多，比如distinguish on twin from the other（分辨双胞胎）、distinguishing marks（特殊标记）；后两个意思可以用于同义替换：
例：I could notdistinguish her words, but she sounded agitated.
我听不清她说的话，但是听得出她紧张不安。
She has already distinguished herselfas an actress.
作为演员，她已经享有盛名
③ We parameterized the model with data from the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) on current and future food production, processing factors, and feed requirements for 62 agricultural commodities and 159 countries.
我们基于国际农产品和贸易政策分析模型（IMPACT）关于当前和未来食品生产、加工要素和62种农业商品和159个国家食品供应需求的数据，对模型设置了参数。
句型：简单句+修饰细节
◆ 这个句子看起来很长，其实是简单的句子结构接一些细节，主要是最后的介词+多个并列名词修饰IMPACT。
◆ Parameterize sth with sth 用…设置参数; parameterize是parameter的动词形式，可以进行同义替换（代替动词+parameter）；尤其是with成分比较长时，可以避免冗余。比如：
There is currently no consensus on how best to parameterize the large volume of data produced in measuring the magnetic field (B), temperature (T) and strain (ε) dependence of the engineering critical current density (JE (B, T, ε)) for A15 superconducting strands. （Google Scholar）
◆ feed requirements这里可以理解为food supply requirements；feed也是动词，To feed a family or a community means to supply food for them。
④ Projections of future food consumption and production were based on statistical association with changes in income and population, and were in line with other projections.
我们基于收入和人口变化关联数据以及其它预测数据对于未来食品消费和生产进行预测。
句型：简单句+谓语并列；…were based on …and were in line with两个谓语成分并列。
◆ projection与estimate的区别见文末
◆ Statistical association with相当于data associated with，相对后者，前者把association变成了宾语的一部分，避免-ed结构密集出现（前面有based on）。
⑤ To assess the environmental impacts of the food system, we paired the food- system model with a set of country-specific environmental footprints related to GHG emissions, cropland use, bluewater use, and nitrogen and phosphorus appli- cation (Extended Data Table 3; data available upon request).
为了评估食品系统对环境的影响，我们将食品系统模型与各国一系列关于温室气体排放、农田使用、深海使用、氮和磷使用情况的环境足迹进行了配对（扩展数据表3；咨询获取数据）
句型：前置成分+简单句+后置修饰成分并列
◆ 并列：谓语直接用动词，将很长的并列成分放在句子的最后部分。
◆ Pair A with B:to put people or things into groups of two 搭配；配对；
例：Each blind studentwas paired witha sighted student.
每个盲人学员都配了一个有视力的学员。
◆ 同义替换：related to／connected／associated with
◆ bluewater 结合语境，这里采用的是wikepedia的解释之一：the global deep oceans（有更合适的解释，欢迎讨论）。cropland相当于farmland农田，耕地
⑥ In line with projections of the allowable agricultural emissions budget, and our separate treatment of land use, we focused on the non-CO2 emissions of agriculture, in particular methane and nitrous oxide.
我们考虑了可允许的农业排放预算预测数据，并且在研究中将土地使用情况单独进行处理，最终聚焦农业中的非二氧化碳排放，尤其是甲烷和一氧化二氮。
句型：前置成分+简单句+后置修饰
◆ 这句采用了典型的“悬念式”结构，铺垫后关键信息才来。翻译时需要还原中文的表达习惯，将悬念的部分尽完整表达。
◆ 同义替换：In line with/in accordance with；甲烷和一氧化二氮属于温室气体（greenhouse gasesGHG）
◆ Allowable：that is allowed, especially by law or by a set of rules （法律、规章等）允许的；同义替换词permissible。
例：The maximum allowable／permissible dosage is two tablets a day.
最大允许剂量是每天两片
◆ in particular／particularly+名词，尤其是
⑦ Data on GHG emissions were adopted from country-specific analyses of GHG emissions from crops and livestock.
温室气体排放数据来自各国关于农作物和家畜温室气体排放的分析报告。
句型：简单被动句
◆ 表达借鉴：adopt采用，可以adopt …approach/data/method/model；adopt也可以与use/utilize/employ/apply同义替换
◆ analysis作可数名词时，表示分析报告（复数形式analyses）
◆ Crop在农业领域表示庄稼（常复数crops）、收成（可数；相当于yield）
例：Rice farmers here still plant and harvest theircropsby hand.
这里的稻农仍用手工种植和收割庄稼。
A fine crop/yieldof coin玉米收成（产量）不错
⑧ Non-CO2 emissions of fish and seafood were calculated on the basis of feed requirements and feed-related emissions of aquaculture, and on projections of the ratio between wild-caught and farmed fish production.
鱼和海产食品非二氧化碳排放数据基于水产业食品供给需求以及供给相关的排放情况、野生和养殖鱼生产的比率预测进行计算。
句型：简单被动句+后置并列成分
◆ 并列表达细节：were calculated on the basis of….and…, and on projections of…
◆ 这里的后置并列主干有两个：on the basis of／on projections of；因为前面的并列部分有多个并列细节，所以第二个大的并列用and连接时，前面用逗号隔开。
◆ aquaculture水产养殖，水产业；wild-caughtadj.野外捕获的，联想：wildfish野生鱼，与farmedfish养殖鱼对应。
⑨ Our baseline emissions estimate agrees well with existing ones that follow the same methodology.
我们得出的基线排放预估数据与当前用同样方法得出的预估结果一致。
句型：简单句+定语从句
◆ 同义替换：agree with／to be the same as／be consistent with （与…）相符，一致；一致性表达在描述结果的时候常用到，可以灵活借鉴
比如：the figures do not agree／the figures are not the same/the figure are not consistent(inconsistent). 这些数据不一致
◆ 省略：existing ones=existing estimates；同一个句子中同一个名词出现两次，并且不影响意思清晰的情况下，第二个词可以省略。这里宾语和主语用到一样的词estimate，且为可数名词，第二个estimates用ones省略代替了。如果是单数指代，one变单数。
◆ projection n.与estimaten.的细微差别：
estimate一般是根据样本数据等得出的预测数据；projection是假设未来某个趋势会确切发生而推出的某个数据的预测情况。
比如Methods第一段中涉及projections的句子与estimate结论之前论述的区别：
Projections of future food consumption and production were based on statistical association withchanges in income and population, and were in line with other projections.
基于未来收入和人口变化数据
Non-CO2 emissions of fish and seafood were calculatedon the basis of feed requirements and feed-related emissions of aquaculture, and on projections of the ratio between wild-caught and farmed fish production
基于现有的样本数据和推测数据
总体来说，本期分享的Methods部分论述详细，常涉及各类并列；主动与被动语态灵活使用。密集的并列表达在Methods部分很常见；其它有的论文方法部分被动语态更为密集，也符合Nature的风格。遇到密集并列的情况时，注意选择恰当的动词，比如借鉴好的论文中用到的不错的词，避免表达冗余。并列时也需要注意标点符号细节，什么时候并列用分号合适，什么时候用逗号合适，什么时候需要括号补充说明。
若有建议、疑问或想法，欢迎留言讨论，你们的宝贵建议是语言降落伞更好的前进动力。
