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高效液相色谱法用于氧化型染发产品中42种限用染发剂的筛查和定量分析
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作者 左雪 邸铮 +3 位作者 汪亚菁 杨玲 张华珺 柳青 《日用化学工业(中英文)》 CAS 北大核心 2024年第4期490-498,共9页
建立了一种利用高效液相色谱筛查和定量分析氧化型染发产品中42种限用染发剂的方法。染发产品经亚硫酸氢钠水溶液-乙醇超声提取后,以0.02 mol/L乙酸铵水溶液-乙腈为流动相,在TechMate AQUA-STIII色谱柱上进行梯度洗脱和分离,选择235和28... 建立了一种利用高效液相色谱筛查和定量分析氧化型染发产品中42种限用染发剂的方法。染发产品经亚硫酸氢钠水溶液-乙醇超声提取后,以0.02 mol/L乙酸铵水溶液-乙腈为流动相,在TechMate AQUA-STIII色谱柱上进行梯度洗脱和分离,选择235和280 nm作为检测波长,对42种染发剂进行一次性定性筛查,同时实现其中35种染发剂的定量分析,当筛查结果表明产品中含有2,6-二甲氧基-3,5-吡啶二胺盐酸盐、2-甲基-5-羟乙氨基苯酚等7种染发剂时,以0.02 mol/L乙酸铵水溶液-乙腈为流动相,在Waters Symmetry C_(18)色谱柱上进行等度洗脱,选择235 nm作为检测波长进行定量分析。结果表明:42种染发剂的方法检出限为10~101μg/g,定量限为33~337μg/g。在相应的线性范围内,42种染发剂色谱峰面积与质量浓度线性关系良好,相关系数(r)均大于0.9998。在4个不同含量水平下,各目标化合物的平均回收率在81.3%~119.6%之间,RSD不大于5%。 展开更多
关键词 高效液相色谱法 氧化型染发产品 限用染发剂 化妆品
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Green,Sustainable Architectural Bamboo with High Light Transmission and Excellent Electromagnetic Shielding as a Candidate for Energy-Saving Buildings 被引量:1
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作者 Jing wang Xinyu Wu +5 位作者 yajing wang Weiying Zhao Yue Zhao Ming Zhou Yan Wu Guangbin Ji 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第1期209-224,共16页
Currently,light-transmitting,energy-saving,and electromagnetic shielding materials are essential for reducing indoor energy consumption and improving the electromagnetic environment.Here,we developed a cellulose compo... Currently,light-transmitting,energy-saving,and electromagnetic shielding materials are essential for reducing indoor energy consumption and improving the electromagnetic environment.Here,we developed a cellulose composite with excellent optical transmittance that retained the natural shape and fiber structure of bamboo.The modified whole bamboo possessed an impressive optical transmittance of approximately 60%at 6.23 mm,illuminance of 1000 luminance(lux),water absorption stability(mass change rate less than 4%),longitudinal tensile strength(46.40 MPa),and surface properties(80.2 HD).These were attributed to not only the retention of the natural circular hollow structure of the bamboo rod on the macro,but also the complete bamboo fiber skeleton template impregnated with UV resin on the micro.Moreover,a multilayered device consisting of translucent whole bamboo,transparent bamboo sheets,and electromagnetic shielding film exhibited remarkable heat insulation and heat preservation performance as well as an electromagnetic shielding performance of 46.3 dB.The impressive optical transmittance,mechanical properties,thermal performance,and electromagnetic shielding abilities combined with the renewable and sustainable nature,as well as the fast and efficient manufacturing process,make this bamboo composite material suitable for effective application in transparent,energy-saving,and electromagnetic shielding buildings. 展开更多
关键词 Electromagnetic interference shielding Biomass material TRANSMITTANCE ENERGY-SAVING BAMBOO
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气相色谱法测定6种不同基质化妆品中水杨酸甲酯含量 被引量:1
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作者 汪亚菁 贾伯阳 +1 位作者 邬国庆 邸铮 《日用化学工业(中英文)》 CAS 北大核心 2023年第3期355-360,共6页
建立了气相色谱法(GC)测定6种基质化妆品中水杨酸甲酯的方法,并采用气相色谱-串联质谱法(GC-MS)对目标物进行定性确证。蜡基样品经乙酸乙酯-无水乙醇提取,其他基质样品经无水乙醇提取后,采用气相色谱-氢火焰离子化检测器进行测定。GC-M... 建立了气相色谱法(GC)测定6种基质化妆品中水杨酸甲酯的方法,并采用气相色谱-串联质谱法(GC-MS)对目标物进行定性确证。蜡基样品经乙酸乙酯-无水乙醇提取,其他基质样品经无水乙醇提取后,采用气相色谱-氢火焰离子化检测器进行测定。GC-MS采用全扫(SCAN)与选择离子监测(SIM)方式对结果进行确认。水杨酸甲酯质量浓度在5~500 mg/L范围内与其峰面积呈良好的线性关系(r=0.999 9);6种基质在高、中、低三个浓度加标的平均回收率为96.9%~108.2%,相对标准偏差(RSD)均≤2.9%(n=6);方法检出限为4μg/g,定量限为100μg/g;方法用于不同基质样品的分析,其中1批润唇膏检出水杨酸甲酯含量为0.083%,超出了欧盟对此类产品的限值要求。该方法快速、准确,适用于不同基质化妆品中水杨酸甲酯的定性定量分析,为化妆品中水杨酸甲酯的测定与筛查提供了技术支持。 展开更多
关键词 水杨酸甲酯 气相色谱法 气相色谱-串联质谱法 化妆品
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Detection and Analysis of Pesticide Residues in Chinese Chives and Risk Assessment of Dietary Intake 被引量:1
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作者 Lei wang Huihui LIU +9 位作者 Shuo YANG Ying wang Shuai wang Haitao ZHAO Huifang YAO yajing wang Liang ZHANG Yancheng ZHOU Sining TANG Yanhua YAN 《Agricultural Biotechnology》 CAS 2023年第1期87-93,共7页
[Objectives]This study was conducted to understand the status of pesticide residues and dietary intake risk of Chinese chives in Tangshan area. [Methods] Sixty eight kinds of pesticide residues in 415 Chinese chive sa... [Objectives]This study was conducted to understand the status of pesticide residues and dietary intake risk of Chinese chives in Tangshan area. [Methods] Sixty eight kinds of pesticide residues in 415 Chinese chive samples collected from Tangshan area were qualitatively and quantitatively determined by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) and gas chromatography(GC) in 2020. [Results] The results showed that 41 kinds of pesticide residues were detected in the 415 Chinese chive samples, and the detection rate was 69.4%(288/415), and there was a combination of pesticides in many samples. According to the National Food Safety Standard―Maximum Residue Limits of Pesticides in Food(GB 2763-2019), the residues of 12 pesticides exceeded the maximum residue limits(MRLs), and the unqualified rate was 38.07%(158/415). The highest detection rate of clothianidin was 41.20%(171/415), but there was no MRL in GB 2763-2019. The next was procymidone, the detection rate of which was 35.42%(147/415), and the over-standard rate was 30.12%(125/415). Forbidden and restricted pesticides were detected in some samples. According to the dietary exposure risk assessment, the NEDI/ADI values were all less than 1 and the intake risk was within acceptable range. In Tangshan area, the types of pesticides used in Chinese chive production are complex, and there are risks of multi-residue pollution and use of banned and restricted pesticides and unregistered pesticides. It is suggested that routine monitoring of pesticide residues and management of pesticide use should be strengthened to ensure the quality and safety of agricultural products. [Conclusions] This study provides a theoretical basis for the safe production of Chinese chive and the standardized and rational use of pesticides. 展开更多
关键词 Chinese chive Pesticide residues DETECTION Risk assessment
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The age at first consumption of forage in calves and its effect on growth and rumination in the short‑and long‑term
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作者 Jianxin Xiao Tianyu Chen +10 位作者 Rong Peng Gibson Maswayi Alugongo Hui Yang Muhammad Zahoor Khan Shuai Liu Yulin Ma Jingjun wang Wei wang yajing wang Shengli Li Zhijun Cao 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第5期2143-2157,共15页
Background Previous investigations into the effect of dietary forage on calf performance have been inconsistent,and there is a paucity of information exploring the effect of age on the growth performance and ruminatio... Background Previous investigations into the effect of dietary forage on calf performance have been inconsistent,and there is a paucity of information exploring the effect of age on the growth performance and rumination of calves.Eighty-four female Holstein calves(41.5±4.2 kg)were enrolled at birth,a subset of the calves were fed calf starter only(CON,n=21)while the rest(n=63)were classified into three treatment groups:the early(EHAY,n=26,5.1±0.8 d),the middle(MHAY,n=21,7.9±0.8 d)and the late(LHAY,n=16,12.1±1.4 d)hay consumers.The short-term effect of the age at first forage consump-tion(AFF)on calves’feed intake was monitored until d 84.In addition,the long-term effects of AFF on body weight,structural growth and rumination behavior were recorded until d 196.Rumen samples were collected on d 1,7,35,84 and 196 to ana-lyze the rumen fermentation,while fecal samples were collected from d 78 to 84 to estimate digestibility parameters.Results Treatment had no effect on feed intake.While,the EHAY calves tended to have lower BW and ADG compared to LHAY and CON calves.Several total-tract apparent digestibility parameters and digestible nutrients intake were significantly lower in EHAY calves compared with CON and LHAY calves.Calves in the EHAY group tended to begin ruminating ealier,while CON calves were the latest(12.3 vs.15.5 days of age).A treatment and time interaction was present for rumination time due to greater rumination in calves consuming hay compared to CON calves in week 10 to 12,the differences in rumination disappeared afterwards,no long-lasting significant differences in the rumina-tion and rumen fermentation parameters were found between treatments.Conclusions In conclusion,this study showed that hay consumption earlier in life(in the first week,around 5 days of life)could negatively affect the growth of the calf in the short and long term.Compared to consuming hay from the second week(around 12 days of life)or feeding concentrate only without hay,starting to consume hay from the first week could compromise nutrient digestibility and digestible nutrient intake independent of developing rumination behaviour and rumen fermentation. 展开更多
关键词 Age at first forage consumption Dairy calf GROWTH Nutrient digestibility Rumen fermentation RUMINATION
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A Tip-Inhibitor Interphase Embedded with Soluble Polysulfides for High-Voltage Li Metal Batteries
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作者 Xueyang Cui Jiancong Cheng +10 位作者 Chen Li Zongqiang Sun Kaixuan Li yajing wang Xiaoxiang Fan Shuai Tang Xiaodong Lin Ruming Yuan Bingwei Mao Mingsen Zheng Quanfeng Dong 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期157-165,共9页
The high-voltage battery has now become a goal in order to meet the demands for high energy density.However,the severe side reactions between Li metal and carbonate-based electrolytes in this system result in unstable... The high-voltage battery has now become a goal in order to meet the demands for high energy density.However,the severe side reactions between Li metal and carbonate-based electrolytes in this system result in unstable interphase,leading to non-uniform Li-ion flux and thus aggravating the dendrite growth of Li.The protect interphase,traditional solid electrolyte interface(SEI),is a loose solid layer consisted of many components,which generally does not possess the function of preventing the lithium budding.Herein,based on polysulfide solubility in ester,we proposed a strategy to eliminate the dendrite by constructing a unique SEI in which the dynamic polysulfides were in situ formed and encapsuled.For this purpose,a 2-fluorophenylsulfur pentafluoride(2-FSPF)was employed as an additive in carbonate-based electrolyte that can be decomposed electrochemically during battery operation to form such a polysulfide-rich interphase.These polysulfides with certain fluidity can adhere to dynamically the budding tip of Li metal,as a so-called tip-inhibitor,when the local current density of the tip rising,thus to hinder Li^(+)diffusion toward the tip,resulting in inhibiting the further growth of Li dendrites and leveling the Li deposition.At the current density of 1 mA cm^(-2),the average Coulombic efficiency of Li//Cu cells is as high as 98.39%during 600 cycles,and the stable cycling of Li//Li symmetric cell reaches 3500 h.Furthermore,due to the high anodic stability,the Li//high-voltage LiCoO_(2)(LCO)full cells and Li–O_(2)battery achieve excellent cycle performance with lean electrolyte. 展开更多
关键词 carbonate-based electrolyte free-dendrite high reversibility high-voltage battery lithium metal anode
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Effects of Seed Dressing with Microbial Inoculum on Nutrient Composition and Biological Yield of Silage Corn
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作者 Ruihuan DU Yanhua YAN +5 位作者 Lei wang Liang ZHANG Shuai wang Shuo YANG yajing wang Huihui CAO 《Agricultural Biotechnology》 CAS 2023年第5期52-54,58,共4页
[Objectives]This study was conducted to understand the effects of microbial inocula on the biological yield and nutritional components of corn.[Methods]Silage corn varieties suitable for planting in Hebei Province wer... [Objectives]This study was conducted to understand the effects of microbial inocula on the biological yield and nutritional components of corn.[Methods]Silage corn varieties suitable for planting in Hebei Province were selected,and set with an experimental group and a control check group each.Meanwhile,at the late stage of milk ripening of silage corn growth cycle,the nutritional components and indexes of silage corn were determined and analyzed by a near-infrared analyzer and the NIRS technique.Meanwhile,the biological yield of silage corn was determined at the maturation stage of its growth period,aiming at comprehensively evaluating the regulation effects of the microbial inoculum tested on silage corn from the aspects of basic nutritional components,mineral element contents,energy and related indexes of corn,combined with agronomic characters and biological yield.[Results]The microbial inoculum improved the biological yield and nutritional indexes of silage corn,and had a positive regulation effect on the growth of silage corn.[Conclusions]The results of this study provide a theoretical basis for popularizing the planting methods and cultivation methods of silage corn with high yield and high quality. 展开更多
关键词 Silage corn Microbial inoculum Near-infrared technology Energy index Nutritional quality analysis
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Multiple Pesticide Residues in Bananas Sold in Tangshan City and Dietary Risk Assessment
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作者 Lin LI Huihui LIU +8 位作者 Hefeng ZHANG Yancheng ZHOU Yuping LIU Zhenguo ZHANG Qianqian CONG Liang ZHANG yajing wang Ling ZHENG Baiqin ZHENG 《Agricultural Biotechnology》 2023年第6期52-57,共6页
[Objectives]This study was conducted to investigate the pesticide residue status of bananas in Tangshan area and the dietary intake risk of consumers.[Methods]High-performance liquid chromatography-tandem mass spectro... [Objectives]This study was conducted to investigate the pesticide residue status of bananas in Tangshan area and the dietary intake risk of consumers.[Methods]High-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)was applied to detect 70 pesticide residues in 191 batches of banana samples extracted from Tangshan area,and chronic and acute risk assessments were conducted.[Results]Among the 191 batches of bananas,172 batches of samples were detected to contain agrochemicals,with a detection rate of 90.05%.Seventeen agrochemicals were detected,accounting for 24.29%of the total agrochemicals tested.There was a phenomenon of multiple pesticide residues in a single sample,and high detection rates were found in carbendazim(49.21%),prochloraz(41.88%),pyraclostrobin(34.03%)and imidacloprid(30.37%).According to GB 2763-2021 National Food Safety Standards—Maximum Residue Limits for Pesticides in Food,the over-standard rate of imidacloprid was 17.8%;and the chronic and acute dietary risks of the 17 pesticide residues were all less than 100%.[Conclusions]The pesticide residues in bananas consumed by consumers on a daily basis do not pose unacceptable dietary risks. 展开更多
关键词 Bananas Pesticide residues Dietary intake Risk assessment
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黄杜中药漱口液对牙周病相关菌的影响及作用机理研究 被引量:1
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作者 王晓宇 王亚静 +3 位作者 赵鑫 王雁雯 王宇 黄赞扬 《日用化学工业》 CAS 北大核心 2022年第1期20-27,共8页
探究了黄杜中药漱口液对牙周病相关菌活性的影响及作用机理。分别以牙周病相关致病菌牙龈卟啉单胞菌(Porphyromonas gingivalis,P. gingivalis)和益生菌食窦魏斯氏菌(Weissella cibaria,W. cibaria)为受试菌,采用微量肉汤稀释法考察黄... 探究了黄杜中药漱口液对牙周病相关菌活性的影响及作用机理。分别以牙周病相关致病菌牙龈卟啉单胞菌(Porphyromonas gingivalis,P. gingivalis)和益生菌食窦魏斯氏菌(Weissella cibaria,W. cibaria)为受试菌,采用微量肉汤稀释法考察黄杜中药漱口液对P. gingivalis、W. cibaria活性的影响,结果显示其对致病菌P. gingivalis具有显著的抑制作用(稳定期生长率<20%),对益生菌W. cibaria基本无抑制(稳定期生长率>80%)。通过考察细胞壁、细胞膜的完整性及能量代谢酶的活性进一步探究黄杜中药漱口液对受试菌的作用机理,结果显示,P. gingivalis胞外碱性磷酸酶(AKP)、K^(+)、核酸、蛋白质含量显著升高(P<0.01),能量代谢酶琥珀酸脱氢酶(SDH)、苹果酸脱氢酶(MDH)活性显著下降(P<0.01),而对W. cibaria无显著影响(P>0.05)。推断出黄杜中药漱口液通过破坏致病菌P. gingivalis细胞膜、细胞壁完整性,扰乱能量代谢系统发挥抑菌作用,而对益生菌W. cibaria基本无影响,提示其可提高口腔益生菌的相对占比,改善口腔菌群,对牙周病的防治发挥积极作用。 展开更多
关键词 中药漱口液 牙周病 抑菌机理 牙龈卟啉单胞菌 食窦魏斯氏菌 益生菌
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Effects of feeding untreated, pasteurized and acidified waste milk and bunk tank milk on the performance, serum metabolic profiles, immunity, and intestinal development in Holstein calves 被引量:8
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作者 Yang Zou yajing wang +3 位作者 Youfei Deng Zhijun Cao Shengli Li Jiufeng wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第4期934-944,共11页
Background: The present experiment was performed to assess the effects of different sources of milk on the growth performance, serum metabolism, immunity, and intestinal development of calves. Eighty-four Holstein mal... Background: The present experiment was performed to assess the effects of different sources of milk on the growth performance, serum metabolism, immunity, and intestinal development of calves. Eighty-four Holstein male neonatal calves were assigned to one of the following four treatment groups: those that received bunk tank milk(BTM), untreated waste milk(UWM), pasteurized waste milk(PWM), and acidified waste milk(AWM) for 21 d.Results: Calves in the BTM and AWM groups consumed more starter(P < 0.05) than those in the UWM group.Average daily gain in the UWM group was the highest(P < 0.05). Calves exhibited the highest(P < 0.05) serum total protein, albumin, total cholesterol, high density lipoprotein, triglycerides, growth hormone, immunoglobulin(Ig) A and Ig M concentrations in the UWM group, highest malondialdehyde and tumor necrosis factor-α in the PWM group(P < 0.05), and highest glutathione peroxidase and Ig G in the BTM group(P < 0.05). The jejunum and ileum of the calves in all treatments presented a slight inflammatory response. The jejunal inflammation scores were higher(P < 0.05) in the UWM and AWM groups than the BTM group; the ileal inflammation scores increased more(P < 0.05) in the AWM group than the BTM group. Jejunal immunohistochemical scores(IHS) were higher(P < 0.05) in the PWM and AWM groups than the BTM group. Compared to the other three groups, calves feeding on BTM had lower(P < 0.05) ileal IHS. Jejunal interleukin(IL)-1β, IL-8, and IL-10 mRNA expression in the UWM group was the highest(P < 0.05). Calves fed AWM increased(P < 0.05) mRNA expression of IL-8 and toll like receptor 4(TLR-4) in the jejunum and IL-8, IL-1β, IL-6, IL-8, and IL-10 in the mesenteric lymph nodes.Conclusions: Overall, bunk tank milk is the best choice for calf raising compared to waste milk. The efficiency of feeding pasteurized and acidified waste milk are comparable, and the acidification of waste milk is an acceptable labor-saving and diarrhea-preventing feed for young calves. 展开更多
关键词 Acidified WASTE MILK CALF Intestinal development Pasteurized WASTE MILK SERUM metabolism WASTE MILK
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Review: Utilization of yeast of Saccharomyces cerevisiae origin in artificially raised calves 被引量:7
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作者 Gibson M.Alugongo Jianxin Xiao +3 位作者 Zhaohai Wu Shengli Li yajing wang Zhijun Cao 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第3期549-560,共12页
Yeast of Saccharomyces cerevisiae(SCY) origin has over long time been incorporated into domestic animal diets. In calves, several products have offered improved performance and health. Although several types of resear... Yeast of Saccharomyces cerevisiae(SCY) origin has over long time been incorporated into domestic animal diets. In calves, several products have offered improved performance and health. Although several types of research have been completed, the mode of action of SCY is not clear in calves. Under this review, we have highlighted the works available in the literature on the use of SCY in calves performance, health, immunity, and the gut environment. Both active live yeast and yeast culture have positive effects on growth, rumen, small intestines, immunity and general health of the calf. Specifically, SCY can improve DMI, growth, feed efficiency and reduce diarrhea in calves. Furthermore, subtle improvements are seen in rumen fermentation(increased butyrate production) and rumen papillae growth. These positive results are, however, more pronounced in calves that are under stress or exposed to significant levels of disease-causing agents. There is a need for further research in areas such as gut morphology, gut microbiology and immunity using latest molecular methods to fully understand how SCY helps the growth and development of calves. 展开更多
关键词 犊牛腹泻 酿酒酵母 人工饲养 分子生物学方法 免疫性能 生长发育 瘤胃发酵 酵母培养物
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Comparison of rumen bacteria distribution in original rumen digesta, rumen liquid and solid fractions in lactating Holstein cows 被引量:4
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作者 Shoukun Ji Hongtao Zhang +6 位作者 Hui Yan Arash Azarfar Haitao Shi Gibson Alugongo Shengli Li Zhijun Cao yajing wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第3期636-642,共7页
Background: Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions... Background: Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods: To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet(HFD) or a high energy diet(HED) were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results: Rumen bacterial diversity was mainly affected by diet and individual cow(P > 0.05) rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers(using LEf Se analysis) were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions: Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study. 展开更多
关键词 瘤胃细菌 液体 组分 固体 奶牛 细菌多样性 生物标志物 瘤胃内容物
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降雨强度、降雨历时对高速公路边坡稳定性的影响 被引量:2
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作者 李哲 王亚静 +1 位作者 黄帆 赵刘会 《青海交通科技》 2019年第2期60-63,71,共5页
为探究不同强度降雨在不同降雨历时下对边坡稳定性的影响,采用数值模拟软件Geo-studio的Seep/W和Slope/W模块,进行了边坡在四种不同降雨强度下的二维渗流与稳定性分析。将Seep/W计算所得孔隙水压力与体积含水率分布导入Slope/W,从而计... 为探究不同强度降雨在不同降雨历时下对边坡稳定性的影响,采用数值模拟软件Geo-studio的Seep/W和Slope/W模块,进行了边坡在四种不同降雨强度下的二维渗流与稳定性分析。将Seep/W计算所得孔隙水压力与体积含水率分布导入Slope/W,从而计算出边坡的稳定安全系数。数值计算结果显示:降雨历时、降雨强度对坡体稳定性均有不同程度的影响,在此基础上有针对性地提出了增设平台排水沟、植草灌等防排水及防冲刷措施。 展开更多
关键词 降雨强度 降雨入渗 基质吸力 边坡安全系数 植草灌
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N-carbamylglutamate restores nitric oxide synthesis and attenuates high altitudeinduced pulmonary hypertension in Holstein heifers ascended to high altitude 被引量:2
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作者 Shuxiang wang Arash Azarfar +2 位作者 yajing wang Zhijun Cao Shengli Li 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2018年第4期1000-1007,共8页
Background: High-altitude pulmonary hypertension(HAPH) is a life-threating condition for animals in high altitude,and disturbance of endothelial nitric oxide(NO) synthesis contributes to its pathogenesis. N-carbamylgl... Background: High-altitude pulmonary hypertension(HAPH) is a life-threating condition for animals in high altitude,and disturbance of endothelial nitric oxide(NO) synthesis contributes to its pathogenesis. N-carbamylglutamate(NCG), which enhances arginine synthesis, promotes endogenous synthesis of NO. In this study, we determined the effects of NCG on alleviating HAPH in Holstein heifers that ascended to Tibet(Lhasa, 3,658 m).Methods: Exp. 1, 2,000 Holstein heifers were transported from low elevation(1,027 m) to Lhasa. After being exposed to hypoxia for 1 yr, Holstein heifers were assigned to a healthy group(Control, n = 6) with mean pulmonary hypertension(mPAP) < 41 mmHg, and an HAPH affected group(HAPH, n = 6) with mPAP > 49 mmHg.Lung tissues were collected to evaluate histopathological changes and the expression of endothelial nitric oxide synthase(eNOS). Exp. 2, ten healthy heifers and 10 HAPH affected heifers were supplemented with NCG(20 g/d per heifer) for 4 wk. Physiological parameters were determined and blood samples were collected on d-1 and d 28 of the feeding trial.Results: Expression of e NOS in small pulmonary arteriole intima was higher in the healthy than HAPH group(P = 0.006), whereas HAPH group had significantly thicker media and adventitia than healthy group(all P < 0.05). The mRNA of eNOS and protein level of eNOS were higher in the lungs of heifers in the healthy group than in the HAPH group(both P < 0.001), whereas endothelin-1 protein levels were higher in HAPH group than in the healthy group(P = 0.025). NCG supplementation decreased mPAP and ammonia(both P = 0.001), whereas it increased the expression of eNOS, arginine, and plasma NO(all P < 0.05).Conclusions: The expression of eNOS was decreased in Holstein heifers with HAPH. NCG supplementation decreased m PAP through the restoration of eNOS and endogenous NO synthesis. 展开更多
关键词 HIGH-ALTITUDE PULMONARY hypertension HOLSTEIN HEIFERS N-carbamylglutamate TIBET
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Effect of reduced energy density of close-up diets on dry matter intake,lactation performance and energy balance in multiparous Holstein cows 被引量:1
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作者 Wenming Huang Yujia Tian +5 位作者 yajing wang Aminamu Simayi Amingguli Yasheng Zhaohai Wu Shengli Li Zhijun Cao 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2015年第1期47-54,共8页
Energy intake prepartum is critically important to health,milk performance,and profitability of dairy cows.The objective of this study was to determine the effect of reduced energy density of close-up diets on dry mat... Energy intake prepartum is critically important to health,milk performance,and profitability of dairy cows.The objective of this study was to determine the effect of reduced energy density of close-up diets on dry matter intake(DMI),lactation performance and energy balance(EB) in multiparous Holstein cows which were housed in a free-stall bam and fed for ad libitum intake.Thirty-nine dry cows were blocked and assigned randomly to three groups fed a high energy density diet[HD,n = 13;6.8 MJ of net energy for lactation(NE_L)/kg;14.0%crude protein(CP)],or a middle energy density diet(MD,n = 13;6.2 MJ NE_L/kg;14.0%CP),or a low energy density diet(LD,n = 13;5.4 MJ NE_L/kg;14.0%CP) from d 21 before expected day of calving.After parturition,all cows were fed the same lactation diet to d 70 in milk(DIM).The DMI and NE_L intake prepartum were decreased by the reduced energy density diets(P< 0.05).The LD group consumed 1.3 kg/d(DM) more diet compared with HD group in the last 24 h before calving.The milk yield and the postpartum DMI were increased by the reduced energy density diet prepartum(P< 0.05).The changes in BCS and BW prepartum and postpartum were not affected by prepartum diets.HD group had higher milk fat content and lower lactose content compared with LD group during the first 3 wk of lactation(P< 0.05).The energy consumption for HD,MD and LD groups were 149.8%,126.2%and 101.1%of their calculated energy requirements prepartum(P< 0.05),and 72.7%,73.1%and 75.2%during the first 4 wk postpartum,respectively.In conclusion,the low energy density prepartum diet was effective in controlling NE_L intake prepartum,and was beneficial in increasing DMI and milk yield,and alleviating negative EB postpartum. 展开更多
关键词 高能量密度 荷斯坦奶牛 能量平衡 泌乳性能 干物质采食量 日粮 干物质摄入量 自由采食量
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Heat stress on calves and heifers: a review 被引量:1
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作者 Jingjun wang Jinghui Li +5 位作者 Fengxia wang Jianxin Xiao yajing wang Hongjian Yang Shengli Li Zhijun Cao 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2020年第4期929-936,共8页
The current review is designed with aims to highlight the impact of heat stress(HS) on calves and heifers and to suggest methods for HS alleviation. HS occurs in animals when heat gain from environment and metabolism ... The current review is designed with aims to highlight the impact of heat stress(HS) on calves and heifers and to suggest methods for HS alleviation. HS occurs in animals when heat gain from environment and metabolism surpasses heat loss by radiation, convection, evaporation and conduction. Although calves and heifers are comparatively heat resistant due to less production of metabolic heat and more heat dissipation efficiency, they still suffer from HS to some degree. Dry matter intake and growth performance of calves and heifers are reduced during HS because of redistributing energy to heat regulation through a series of physiological and metabolic responses, such as elevated blood insulin and protein catabolism. Enhanced respiration rate and panting during HS accelerate the loss of CO2, resulting in altered blood acid-base chemistry and respiratory alkalosis. HS-induced alteration in rumen motility and microbiota affects the feed digestibility and rumen fermentation. Decreased luteinizing hormone, estradiol and gonadotrophins due to HS disturb the normal estrus cyclicity, depress follicular development, hence the drop in conception rate. Prenatal HS not only suppresses the embryonic development by the impaired placenta, which results in hypoxia and malnutrition, but also retards the growth, immunity and future milk production of newborn calves. Based on the above challenges, we attempted to describe the possible impacts of HS on growth, health, digestibility and reproduction of calves and heifers. Likewise, we also proposed three primary strategies for ameliorating HS consequences. Genetic development and reproductive measures, such as gene selection and embryo transfers, are more likely long-term approaches to enhance heat tolerance. While physical modification of the environment, such as shades and sprinkle systems, is the most common and easily implemented measure to alleviate HS. Additionally, nutritional management is another key approach which could help calves and heifers maintain homeostasis and prevent nutrient deficiencies because of HS. 展开更多
关键词 CALF Energy Heat stress HEIFER REPRODUCTION
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Weakening internal diffusion effect in selective hydrodesulfurization of FCC gasoline by novel designed eggshell CoMoS/Al_2O_3 catalysts 被引量:1
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作者 Bin Liu Yongming Chai +2 位作者 yajing wang Yunqi Liu Chenguang Liu 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第2期194-199,共6页
A simple method for preparation of presulfided eggshell CoMoS/γ-Al2O3 catalysts with sharp boundary is developed, through which the eggshell thicknesses of Co and Mo could be easily regulated by controlling the impre... A simple method for preparation of presulfided eggshell CoMoS/γ-Al2O3 catalysts with sharp boundary is developed, through which the eggshell thicknesses of Co and Mo could be easily regulated by controlling the impregnation time. According to the results characterized by EDS, XRD, HRTEM and FT-IR of adsorbed CO, the active component structures, the nature and/or the amount of active sites on the eggshell catalyst are similar to these on the uniform catalyst. The evaluation results of the catalytic performance in selective hydrodesulfurization (HDS) of FCC gasoline show the presence of significant internal diffusion inhibition effect on HDS of S-compounds especially in the uniform catalyst. Compared with uniform catalyst, the eggshell catalyst could remarkably reduce such an internal diffusion inhibition effect due to a shortened diffusion path of the reactants, thus showing higher HDS activity and selectivity. 展开更多
关键词 催化剂 FCC 蛋壳 扩散效应 加氢脱硫活性 弱化 内部扩散 X射线衍射
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Metal-organic framework-derived Ni doped Co_(3)S_(4) hierarchical nanosheets as a monolithic electrocatalyst for highly efficient hydrogen evolution reaction in alkaline solution
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作者 Jiankang wang yajing wang +1 位作者 Zhongping Yao Zhaohua Jiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第2期380-388,共9页
Hierarchical nanostructure construction and electronic structure engineering are commonly employed to increase the electrocatalytic activity of HER electrocatalysts.Herein,Ni doped Co_(3)S_(4) hierarchical nanosheets ... Hierarchical nanostructure construction and electronic structure engineering are commonly employed to increase the electrocatalytic activity of HER electrocatalysts.Herein,Ni doped Co_(3)S_(4) hierarchical nanosheets on Ti mesh(Ni doped Co_(3)S_(4) HNS/TM)were successfully prepared by using metal organic framework(MOF)as precursor which was synthesized under ambient condition.Characterization results confirmed this structure and Ni incorporation into Co_(3)S_(4) lattice as well as the modified electronic structure of Co_(3)S_(4) by Ni doping.Alkaline HER performance showed that Ni doped Co_(3)S_(4) HNS/TM presented outstanding HER activity with 173 m V overpotential at-10 m A·cm^(-2),surpassing most of metal sulfide-based electrocatalysts.The hierarchical structure,superior electrical conductivity and electronic structure modulation contributed to the accelerated water dissociation and enhanced intrinsic activity.This work provides a new avenue for synthesizing hierarchical nanostructure and simultaneously tuning the electronic structure to promote HER performance,which has potential application in designing highly efficient and cost-effective HER nanostructured electrocatalyst. 展开更多
关键词 Metal-organic framework Electronic structure Ni doped Co_(3)S_(4) ELECTROCHEMISTRY Catalysis Hydrogen production
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Spatial variability of soil moisture in a mining subsidence area of northwest China
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作者 Lu Bai yajing wang +4 位作者 Kai Zhang Yingming Yang Kaikai Bao Jiangang Zhao Xiaonan Li 《International Journal of Coal Science & Technology》 EI CAS CSCD 2022年第5期160-171,共12页
The current study investigated the impact of coal mining on deep soil moisture from the perspective of the absolute value of soil moisture.A combined classical statistics and multi-dimensional geo-statistics approach ... The current study investigated the impact of coal mining on deep soil moisture from the perspective of the absolute value of soil moisture.A combined classical statistics and multi-dimensional geo-statistics approach was employed to analyze the temporal and spatial changes in soil moisture from 0 to 10 m in the mining face of the Nalin River No.2 Mine in Northwest China from the perspective of spatial variability.The results of the study show that compared with the control area,the average value of soil moisture in 1-and 2-year subsidence areas decreased by 1.18%and 0.96%,respectively,whereas the coefcient of variation increased by 17.92%and 3.63%,respectively.Interpolation of soil moisture spatial distribution results showed that the spatial variability of soil moisture in the control area was less than that in the subsidence areas,and the spatial variability of soil moisture in the 2-year subsidence area was less than that in the 1-year subsidence area,indicating that mining increases the spatial variability of soil moisture and that the degree of spatial variability of soil moisture decreases as the subsidence enters the stable period.These results provide evidence for the mechanism by which coal mining subsidence afects soil moisture.Preferential fow caused by surface cracks,soil texture,the soil pore microstructure,and other factors in the coal mining subsidence area are the primary drivers of the increase in spatial variability of soil moisture. 展开更多
关键词 SOIL MOISTURE SUBSIDENCE
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Photosynthetic Characteristics in Two Near Isogenic Lines of Winter Wheat
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作者 Guirong HUANG Xinying ZHANG +3 位作者 yajing wang Fu FENG Xurong MEI Xiuli ZHONG 《Agricultural Biotechnology》 CAS 2019年第2期71-80,共10页
The development of near isogenic lines(NILs) is an important tool for physiological dissection of drought resistance in wheat. To better understand the potential for improving grain yield, a split-plot experiment was ... The development of near isogenic lines(NILs) is an important tool for physiological dissection of drought resistance in wheat. To better understand the potential for improving grain yield, a split-plot experiment was conducted under a mobile rain shelter using NILs of winter wheat with significant differences in the photosynthetic rate: the 908120 line with a high photosynthetic rate and the 908206 line with a low photosynthetic rate. The results indicated that the net photosynthesis rate(Pn), stomatal conductance, and transpiration rate in flag leaves in line 908120 were significantly higher than that in line 908206 under uniform water treatments during the reproductive phase in replicated pooled-culture trials. The maximum quantum yield Fv/Fm value and ribulose-1,5-bisphosphate carboxylase/oxygenase(RuBPCase) activity value were higher in line 908120 than that in line 908206, whereas the intercellular CO_2 and cell membrane permeability in line 908120 were lower than that in line 908206. Higher leaf Pn, transpiration rate, and RuBPCase activity and lower membrane ion leakage rate ensured the robustness of line 908120 during times of irrigation and drought, which contributed to the maintenance of its high grain yield. Drought had a negative effect on these factors, resulting in decreased yield, and the photosynthesis rate of flag leaves markedly affected the yield in NILs of winter wheat. NILs are an important strategy for wheat adaptation to drought stress, but might not be the only mechanism causing the significant grain yield increase. Collectively, the characteristics of line 908120 resulted in a higher grain yield compared with that of line 908206. Further dissection of the drought avoidance mechanisms in wheat, as well as analysis and identification of the genes involved may be necessary. 展开更多
关键词 NILs YIELD WINTER WHEAT DROUGHT PHOTOSYNTHESIS
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