喷施羧甲基纤维素铵对土壤水热效应及饲用苏丹草根系和产量的影响

【目的】研究喷施羧甲基纤维素铵（CMC-NH₄）对土壤含水量和温度及苏丹草根系和产量的影响，为解决宁夏引黄灌区热量紧缺问题、保障后茬作物稳产增产提供技术支撑。【方法】在宁夏引黄灌区，以小麦收获后复种的苏丹草为材料，采用大田试验，设置喷施0 kg/hm² (CK)、50 kg/hm² (T1)、100 kg/hm² (T2)、200 kg/hm² (T3)和300 kg/hm² (T4) CMC-NH₄ 5个处理，研究喷施CMC-NH₄对土壤含水量和温度，以及苏丹草根系特征、株高和干草产量的影响，并分析了CMC-NH₄喷施量与土壤含水量、温度及苏丹草生长指标和产量间的相关性。【结果】喷施CMC-NH₄处理土壤含水量较对照显著提高2.82%~29.19%(P＜0.05)，且随着CMC-NH₄喷施量的增加而增大。喷施CMC-NH₄处理土壤温度较对照显著提高5.14%~31.82%，且随着CMC-NH₄喷施量的增加而增大。在0~30 cm土层，与对照相比，喷施CMC-NH₄处理苏丹草的根长、根直径、根表面积和根体积分别显著提高16.35%~ 65.52%，7.69%~30.77%，42.40%~93.85%和120.76%~229.90%；0~10 cm土层苏丹草根长、根直径、根表面积和根体积占0~30 cm土层的比例均最高，根长、根直径、根表面积和根体积分别较对照提高了21.21%~74.76%，9.68%~58.06%，61.95%~136.13%和122.60%~273.18%。与对照相比，喷施CMC-NH₄处理苏丹草0~1.0 mm径级根长、根表面积和根体积显著提高，其中以0.6~1.0 mm径级根系增加幅度较大。喷施CMC-NH₄处理苏丹草株高和干草产量较对照分别显著增加了9.34%~22.52%和55.50%~110.55%。相关性分析结果表明，CMC-NH₄喷施量与土壤含水量、温度及苏丹草的根直径、体积和干草产量呈极显著正相关，与根长和根表面积呈显著正相关。【结论】在宁夏引黄灌区农田喷施CMC-NH₄能够改善土壤水温状况，促进苏丹草根系生长，提高干草产量，当CMC-NH₄喷施量为200 kg/hm²时效果最佳。     

常见菌材主要营养成分及内含物质的分析

为筛选适宜食用菌栽培的速生、优质菌材，以在黔北地区收集到的刺槐、肉桂、水青冈、山白树等13个科17个属共17种菌材木段为试材，测定各菌材样品中的碳素成分含量、矿质元素含量和其他内含物成分。经检测、分析得知：17种菌材纤维素含量为35%~53%，半纤维素含量为15%~29%，木质素含量为18%~30%，钾、钙、磷、镁、铜、锰、锌含量分别为602~3270、1080~7590、14~304、153~905、0.83~3.31、1.71~106.00、2.00~15 .00 mg/kg，pH值为4.24~6.72，果胶含量为5.78~12.40 g/kg，总黄酮含量为93.6~4262.8 mg/kg，单宁含量为0.01%~9.16%。木质纤维素及矿质元素有利于食用菌的生长发育，单宁、果胶、总黄酮和不适宜的pH值则抑制食用菌的生长。综合分析表明，枫香树、肉桂、山毛榉、枳椇树、苦郎树和水青冈比较适合作菌材，而马桑树、梨树和刺槐不适合用来栽培食用菌。     

中国竹浆造纸的潜力与发展

中国竹子资源丰富，分布广泛，发展竹材制浆造纸产业，对于缓解木浆原料短缺现状具有重要意义。根据对竹浆的理化性能分析，竹材是较好的造纸原料，竹材的纤维形态及化学组成表现出较好的制浆性能，仅次于针叶木，接近于阔叶木。从竹材应用于竹浆造纸的角度，综述了竹材的物理化学性能、现行的竹浆造纸工艺、竹浆造纸设备，并就竹浆造纸的发展潜力与发展方向提出了个性化观点，以期为探索绿色、低碳、环保的竹资源利用新途径，为开发高技术含量和高附加值竹产品提供借鉴，从而促进中国竹产业可持续发展。     

Development of Green Cellulose Ethers Thermotropic Material and Analysis of It’s Energy Efficient Performance

Hydroxypropylmethyl cellulose(HPMC), Sodium Chloride and pure water were adopted to develop green cellulose ethers thermotropic materials. And thermally induced switching temperature, visible and solar direct transmittance were measured under different mixing proportion. For energy consumption, DeST h was used to study the energy efficient effect of thermotropic double glazing windows with different mixing proportion. It was shown that the optimum mixing proportion of hydroxypropylmethyl cellulose(HPMC), Sodium Chloride and pure water was 2:15:100 by mass. And thermotropic double glazing window can reduce energy consumption by 3% and 8%, respectively, when compared with Low E double glazed window and common double glazed window in hot summer and cold winter zone.     

丙烯酰胺/羧甲基纤维素/生物炭复合水凝胶对烟苗镉胁迫的缓解效应研究

为缓解镉（Cd）对烟苗生长发育的毒害作用,考察新型丙烯酰胺/羧甲基纤维素/生物炭复合水凝胶（AM/CMC/B）对水溶液中Cd²⁺的去除效果,并通过盆栽试验探讨AM/CMC/B缓解烟苗Cd胁迫的效应。结果表明,AM/CMC/B可有效去除水中Cd²⁺,改善Cd胁迫下烟苗表型;AM/CMC/B处理下烟苗的最大叶长、最大叶宽、最大叶面积、总根长、总根表面积、平均根径、根尖数和根体积分别显著增加38.28%、30.01%、79.19%、83.31%、83.97%、54.44%、88.21%和261.56%;烟苗地上部分的鲜重和干重分别增加了98.39%和84.22%,地下部分的鲜重和干重分别增加了130.67%和231.82%,烟苗净光合速率、SPAD值和气孔导度显著增加62.03%、29.61%和84.42%,丙二醛含量显著降低36.61%,烟苗抗氧化活性和代谢物含量提高。可见,AM/CMC/B可以显著提高Cd胁迫下烟苗的耐受性。     

喷施羧甲基纤维素钾对宁夏引黄灌区土壤及其作物的影响

为探讨羧甲基纤维素钾(CMC-K)对农田土壤水温环境、土壤养分吸收和作物产量的影响，以宁夏引黄灌区为研究对象，饲草燕麦为供试作物CMC-K为供试材料，采用田间试验，设置CMC-K喷施量0 kg/hm²(CK)、50 kg/hm²(T1)、100 kg/hm²(T2)、200 kg/hm²(T3)和300 kg/hm²(T4)共5个处理，研究其对灌区土壤理化性质、土壤养分以及作物产量的影响。同时，测定不同处理中土壤含水量、温度、电导率、容重和土壤养分等，分析CMC-K对饲草燕麦产量的影响，以及分析CMC-K施用量与土壤理化性质、养分和饲草燕麦产量的相关性。结果表明:土壤含水量随着CMC-K的喷施量增大而增加，在作物拔节期可使土壤含水量提高39.78%~116.80%；CMC-K可以为作物生育期贡献积温48.4~114.4 ℃，能够显著提高土壤温度；喷施CMC-K有助于土壤养分保持，在0~10 cm土层能够提高全钾和速效钾含量28.31%~63.07%和34.72~95.45%，在10~20 cm土层可以提高全钾和速效钾含量12.30%~75.05%和25.65%~125.37%，对有效磷具有固持作用，同时对水解性氮影响明显，可以将水解性氮聚集在上层土壤；对饲草燕麦产量影响显著，提高18.80%~54.11%；CMC-K喷施量与土壤全钾、速效钾含量、土壤含水量以及燕麦产量表现显著正相关，相关系数分别达到0.917、0.982、0.676和0.983。综上所述，在本试验条件下，当CMC-K喷施量为200 kg/hm²时，可以显著提高土壤含水量、温度，影响土壤养分，有助于提升土壤全钾和速效钾含量，固持水解性氮，减少养分的淋溶，考虑其经济效益，推荐施用量为100 kg/hm²。     

Late sowing enhances lodging resistance of wheat plants by improving the biosynthesis and accumulation of lignin and cellulose

Delayed sowing mitigates lodging in wheat. However, the mechanism underlying the enhanced lodging resistance in wheat has yet to be fully elucidated. Field experiments were conducted to investigate the effects of sowing date on lignin and cellulose metabolism, stem morphological characteristics, lodging resistance, and grain yield. Seeds of Tainong 18, a winter wheat variety, were sown on October 8 (normal sowing) and October 22 (late sowing) during both of the 2015–2016 and 2016–2017 growing seasons. The results showed that late sowing enhanced the lodging resistance of wheat by improving the biosynthesis and accumulation of lignin and cellulose. Under late sowing, the expression levels of key genes (TaPAL, TaCCR, TaCOMT, TaCAD, and TaCesA1, 3, 4, 7, and 8) and enzyme activities (TaPAL and TaCAD) related to lignin and cellulose biosynthesis peaked 4–12 days earlier, and except for the TaPAL, TaCCR, and TaCesA1 genes and TaPAL, in most cases they were significantly higher than under normal sowing. As a result, lignin and cellulose accumulated quickly during the stem elongation stage. The mean and maximum accumulation rates of lignin and cellulose increased, the maximum accumulation contents of lignin and cellulose were higher, and the cellulose accumulation duration was prolonged. Consequently, the lignin/cellulose ratio and lignin content were increased from 0 day and the cellulose content was increased from 11 days after jointing onward. Our main finding is that the improved biosynthesis and accumulation of lignin and cellulose were responsible for increasing the stem-filling degree, breaking strength, and lodging resistance. The major functional genes enhancing lodging resistance in wheat that are induced by delayed sowing need to be determined.     

Root tensile strength of terrace hedgerow plants in the karst trough valleys of SW China: Relation with root morphology and fiber content

Root tensile strength is commonly affected by root morphology and fiber content, which combinedly affect the effectiveness of terrace hedgerow on controlling soil erosion in sloping farmland. However, the relationships between these root characteristics are still elusive. This study aimed to compare the root tensile strength, root morphologies, and root fiber contents, and quantify their differences among different plant species. Complete root systems of three terrace hedgerow plant species, i.e., O. bodinieri, V. villosa, and D. lablab L. were sampled for detecting root morphologies and fiber contents at different slope positions on a representative hillslope in karst trough valley. Single root specimens were collected to measure root tensile properties for these three plant species. Results showed that most root morphological parameters were the highest in O. bodinieri, followed by D. lablab L. Three plant species presented the same dominant diameter class as < 1.0 mm, and root volumes as < 1.50 cm³. Cellulose with contents closing to 50% was the main fiber type, and increased significantly linearly with the increasing root diameter in both O. bodinieri and V. villosa. The highest tensile strength and Young's modulus were found in D. lablab L., while the best ultimate tensile force and ultimate elongation were displayed in O. bodinieri. Root diameter showed negative power relationships with tensile strength and Young's modulus, a positive power relationship with ultimate tensile force, and a positive linear relationship with ultimate elongation. Our results will deepen the understanding of the terrace hedgerow functions for controlling soil erosion worldwide.     

Effects of carboxymethyl cellulose and chitosan bilayer edible coating on postharvest quality of citrus fruit

There is increasing public interest in development of edible natural biodegradable coatings to replace the currently used commercial synthetic waxes for maintaining postharvest quality of citrus fruit. We tested the efficacy of a newly developed polysaccharide-based edible bilayer coating comprising carboxymethyl cellulose (CMC) and chitosan in preserving postharvest quality of various citrus fruit, including ‘Or’ and ‘Mor’ mandarins, ‘Navel’ oranges, and ‘Star Ruby’ grapefruit after simulated storage and marketing. In all citrus species, it was found that the CMC/chitosan bilayer coating was equally effective as the commercial polyethylene wax in enhancing fruit gloss. Furthermore, the CMC/chitosan bilayer coating slightly increased fruit firmness, especially of oranges and grapefruit, but was mostly not effective in preventing post-storage weight loss. Both the CMC/chitosan bilayer coating and the commercial wax had no significant effects on juice total soluble solids and acidity levels, and had similar effects on gas permeability, as indicated by only slight increases in internal CO₂ levels and in juice ethanol accumulation after storage. Sensory analyses revealed that neither the CMC/chitosan bilayer coating nor the commercial wax coating had any deleterious effects on flavor preference of ‘Navel’ orange and ‘Star Ruby’ grapefruit. However, application of the commercial wax, and moreover the CMC/chitosan bilayer coating, resulted in a gradual decrease in flavor acceptability of ‘Or’ and ‘Mor’ mandarins because of increased perception of off-flavors. Overall, we showed that the CMC/chitosan bilayer edible coating sufficiently enhanced fruit gloss, but was not effective in preventing postharvest weight loss. Furthermore, flavor quality was slightly impaired in mandarins but not in oranges and grapefruit.     

纳米磁酶水酶法在磁流化床中提取大豆油脂的数值模拟及应用

为提高大豆油的提取率以及油的品质，该研究将游离纤维素酶固定在磁性高分子载体Fe3O4/SiOx-g-P（GMA）上，利用数值模拟确定磁流化床中水酶法提油的最佳参数，并将最佳参数应用在磁流化床中，通过单因素试验探究磁性固定化纤维素酶在磁流化床中水酶法提油的最佳工艺条件。结果表明：扫描电镜、粒径分析和红外光谱显示磁性固定化纤维素酶已固定在磁性高分子载体Fe3O4/SiOx-g-P（GMA）上，且具有较好的磁响应能力，与游离酶相比，磁性固定化纤维素酶提高了酶的耐热性和耐酸碱性。数值模拟得出磁场强度为0.034 T，流速为0.004 1 m/s时，磁酶在磁流化床中可与大豆料液充分接触，有利于提高大豆油提取率。磁流化床中水酶法提油较优工艺为：酶添加量为1.2 mg/g，pH值为5，温度为55 ℃，反应时间120 min，此时大豆油提取率较优为90.3%。磁性固定化纤维素酶在磁流化床中可以连续使用12 h。该研究提高了大豆油提取率，与间歇反应相比，磁流化床大豆油提取率增加了6.1%。研究结果为后续磁流化床水酶法提油提供了理论依据。