海淀查获“甲醛水产品”

2月10日,大钟寺工商所与区卫生防疫站联合对大钟寺市场进行执法检查,发现农副产品批发大厅10号摊位正在出售用工业用火碱和甲醛(福尔马林)溶液浸泡过的虾仁共100多公斤;在其储存水产品的冷库内,工商人员又发现2袋标有“天津产片状氢氧化钠,含量96％”字样的化学物品和一桶约50公斤重无任何标记的发青的化学液体,后经卫生防疫人员检验,这是工业火碱和甲醛。 早在去年4月,海淀区工商局大钟寺工商所与区卫生防疫站就对大钟奇市场100多个水产摊位逐一进行过检查测试,防疫部门也为大钟奇市场派出一名专门检验人员。此后很长一段时间,

PVA缩甲醛吸水海绵在无创宫腔液取样和RNA检测中的安全性与可行性

目的:宫腔液RNA可用作检测子宫内膜容受性,但目前仍没有无创取样方法。聚乙烯醇(polyvinyl alcohol,PVA)缩甲醛吸水海绵作为一种医用生物吸水海绵,具有良好的吸水性和亲生物性,可用于开发新型无创宫腔液取样器。本研究旨在探讨PVA缩甲醛吸水海绵对子宫内膜上皮细胞的毒性及对宫腔液RNA测序(RNA sequencing,RNA-Seq)的影响。方法:使用PVA缩甲醛吸水海绵的细胞为实验组,包括0.005%、0.01%及0.02%(w/v)的悬液组以及0.01%、0.05%及0.1%(v/v)的浸提液组,对照组仅添加完全培养基,空白组无添加。采用体外细胞毒性实验测量每组细胞的存活率。招募2019年11月至2020年1月在中南大学湘雅医院生殖医学中心进行体外受精术的8例患者,采集患者的宫腔液,实验组将宫腔液用无菌PVA缩甲醛吸水海绵吸入后再置入RNA-later保存液中,对照组直接放入等量RNA-later保存液中,随后进行RNA-Seq及数据分析。结果:体外细胞毒性实验结果显示:0.005%浓度悬液组各培养时间的细胞存活率差异无统计学意义(P=0.255);0.01%和0.02%浓度悬液组在12 h内各培养时间的细胞存活率差异无统计学意义(均P>0.05),24 h与0 h相比细胞存活率下降(分别P<0.01,P<0.05)。在同一培养时间下,3个浓度梯度的悬液组细胞存活率均比对照组低(均P<0.05),其中0.005%浓度悬液组培养至24 h时细胞存活率下降幅度小于30%,0.01%浓度悬液组在12 h时细胞存活率下降幅度大于30%,0.02%浓度悬液组在0 h时下降幅度大于30%。0.01%浓度浸提液组在6 h内各培养时间的细胞存活率差异无统计学意义(均P>0.05),12 h、24 h与0 h组相比细胞存活率下降(均P<0.01);0.05%浓度浸提液组在12 h内各培养时间的细胞存活率差异无统计学意义(均P>0.05),24 h与0 h相比存活率下降(P<0.05);0.1%浓度浸提液组中各培养时间的细胞存活率差异无统计学意义(P=0.082)。在同一培养时间下,0.01%浓度浸提液组在0,3及24 h与对照组细胞存活率的差异均无统计学意义(均P>0.05);除了3 h之外,0.05%组与0.1%组的细胞存活率均较对照组下降(均P<0.05),下降幅度均小于30%。宫腔液RNA-Seq结果显示:实验组与对照组RNA的外显子率、基因检测数量、转录本检测数量差异均无统计学意义(均P>0.05)。结论:PVA缩甲醛吸水海绵对人子宫内膜上皮细胞的毒性作用符合国家要求的医用材料细胞毒性标准,用其进行宫腔液取样行RNASeq,不影响测序结果,表明PVA缩甲醛吸水海绵应用于无创宫腔液取样及RNA检测安全可行。

应用2100N型浊度计测定三聚氰胺浊度

探讨了应用浊度计法代替目视比浊法测定三聚氰胺甲醛水溶液浊度，并试验确定了浊度计量单位的换算系数，讨论了实验过程的影响因素。该方法误差小，定量准确，结果可靠。

锦16块深部液流转向驱油技术

辽河锦16块油井综合含水超过90%,近井地带调剖的效果已很差。研发了一种聚合物/酚醛成胶体系,该体系在30110℃下可在数小时到数天内形成储能模量G′在0.22.0Pa的可流动弱凝胶,与油基预交联聚合物J5(60120目)一起,用作深部液流转向剂。讨论了该弱凝胶的组成与配方。试验区有4口水井,15口油井。其中两口水井处理半径15m,分3个段塞注入J5颗粒量递增(5.08.0g/L)的1.5g/LHPAM溶液;另两口水井处理半径18m,第一段塞为HPAM溶液携带J5颗粒,第二、第三段塞分别为低、高交联的3.0g/L聚合物弱凝胶。注入后注水压力上升,10口可对比油井中3口井无效果,7口井见效,产液量减少,含水下降,产油量增大。

蛋白质过瘤胃保护技术的研究

蛋白质过瘤胃保护技术的研究王加启，冯仰廉（中国农业科学院畜牧研究所１０００９４）（北京农业大学畜牧系１００００９４）对反刍动物的蛋白质饲料进行保护，以增加过瘤胃蛋白质．有２个目的：（１）为生产力高的反刍动物提供足够的小肠可消化蛋白质．发挥其遗传潜力；...

浊度计法检测三聚氰胺产品的浊度

探讨了应用浊度计法代替目视比浊法测定三聚氰胺甲醛水溶液的浊度,并试验确定了浊度计量单位的换算系数,讨论了实验过程的影响因素。该方法误差小,定量准确,结果可靠。

肉鸡的饲养管理

肉鸡的饲养管理余佳胜，曾邦藩饲养肉鸡要获得最高的饲养效益和最佳的经济效益，选择优质的鸡苗和掌握科学的饲养方法至关重要，现谈谈饲养管理方面的体会：一、鸡舍应具有的条件１、建立鸡舍的地方，应选择水源充足、清洁、交通及用电方便；外界干扰少，有利于防疫，空气...

Efficient production of 5-hydroxymethylfurfural from hexoses using solid acid SO_4^(2-)/In_2O_3-ATP in a biphasic system

A natural attapulgite （ATP）‐based catalyst, sulfated In2O3‐ATP （SO42-/In2O3‐ATP）, was obtained by an impregnation‐calcination method and was used to efficiently and selectively produce the useful platform chemical 5‐hydroxymethylfurfural （HMF） from hexoses. Some important reaction param‐eters were studied, revealing that Lewis and Br-nsted acid sites on SO42-/In2O3‐ATP catalyze glu‐cose isomerization and fructose dehydration. The yields of HMF from glucose and fructose were 40.2%and 46.2%, respectively, using the optimal conditions of 180℃ for 60 min with 10 wt%of solid acid catalyst in a mixture of γ‐valerolactone‐water （9：1）.

三聚氰胺浊度和色度质检影响因素分析

根据GB/T 9567—1997《工业三聚氰胺》,分析检测三聚氰胺浊度、色度过程中的影响因素,主要有甲醛试剂的杂质、酸度控制、温度控制、保存时间等因素,并提出优化方案,保证试验方法的科学规范,定量准确,结果可靠。

Preparation of 5-Hydroxymethylfurfural from Cellulose via Fast Depolymerization and Consecutively Catalytic Conversion

The conversion of cellulose to 5-hydroxymethylfurfural （HMF） has been investigated by a one-pot consecutive reaction. At first, cellulose was depolymerised into glucose via a fast degradation of cellulose in molten ZnCI~ in the presence of hydrochloric acid, and the yield of glucose is 75% in 120 s at reaction temperature of 95 ℃. Then, DMSO was used as solvent and different kinds of metal chloride were added as catalysts, and the conversion was carried out continuously at 110-130 ℃ for 0.5-4 h. The yield of HMF was 53% when CrC13 were used as catalyst. The one-pot two steps conversion was carried out at atmosphere pressure, and it is a simple route to prepare HMF from lignocellulosic feedstock on a large scale.

Exploration of the active phase of the hydrotalcite-derived cobalt catalyst for HCHO oxidation

A series of Co-based oxide catalysts were prepared by calcining hydrotalcite precursors in different atmospheres and studied for HCHO catalytic oxidation. The N2-calcined catalyst exhibits enhanced HCHO oxidation and superior stability. On the basis of H2-TPR, X-ray photoelectron spectroscopy, and Raman characterizations, this can be ascribed to better redox ability, octahedrally coordinated Co2+ ions derived from the CoO phase, and other surface oxygen species, such as O2– or O–. The extra octahedrally coordinated Co2+ ions may reside in a more open framework site than the inactive tetrahedrally coordinated Co2+ ions. This species of Co2+ can easily make contact with oxygen and oxidize. The surface oxygen species, along with the octahedrally coordinated Co2+ ions, and a part of the Co3+ species constitute the Co2+-oxygen species-Co3+ sites, which enhance the catalytic activities. According to DRIFTS, Co2+-oxygen species-Co3+ makes oxidation of HCHO and conversion of DOM to formate easier.

STUDY ON THE TREATMENT OF 3—PHENOXY—BENZALDEHYDE INDUSTRIAL WASTEWATER WITH POLYMERIC ADSORBENT

In this paper the two effluents from PBA (3- phenoxy -benzaldehyde) productionprocess were treated by polymeric adsorbent CHA-lll. PBA or PBC(3-phenoxybenzoic acid) was recovered from the wastewater in the process of neutralization. As asecondary treatment method, adsorption with CHA-lll showed better efficency thanPhotocatalytic decomposition and solvent extraction. The optimal technologicalparameters were: adsorption: current velocity: 2.0 BV/hr(bed volume per hour), roomtemperature, desorption: current velocity:10 BV/hr 80℃8% sodium hydroxideaqueous solutions. In conclusion, 90.9% COD in the neutralizing wastewater and98. 4% COD in the hydrolysis wastewater are removed successfully.

Decomposition of Cellulose to Produce 5-Hydroxymethyl-Furaldehyde in Subcritical Water

A method for decomposition of cellulose to produce 5-hydroxymethyl-furaldehyde （5- HMF） in subcritical water-carbon dioxide binary system was proposed. A series of experiments were performed in a batch reaction vessel. Main products of the decomposition of cellulose are 5-HMF, furfural, levulinic acid and 1, 2, 4-benzenetrioI.The optimum condition for the preparation of 5-HMF was found as 523.15 K, 5.0% carbon dioxide mole fraction, and 30 min reaction time. The addition of carbon dioxide to water conduced to the decomposition of cellulose to 5-HMF. As can be seen from the distribution of the prod-ucts, the decomposition mechanism of cellulose is similar to the hydrothermal reaction of D-glucose and D-fructose.

Preparation of p-Hydroxybenzaldehyde by Hydrolysis of Diazonium Salts Using Rotating Packed Bed

A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.

Desulfurization of gasoline by condensation of thiophenes with formaldehyde in a biphasic system using aqueous phase of acids

Aqueous phase of acids as catalysts for the desulfurization of gasoline by condensation of thiophenes with form- aldehyde in a biphasic system was investigated. Two types of model gasoline with and without aromatics and olefins were employed in this work. The desulfurization rates were above 90% on these two types of model gasoline using formic acid and HaPW12O40 （0.8 mol·L-1）, indicating that the presence of aromatics and olefins has no effect on the desulfurization rate. High temperature （above 90 ℃） was more favorable to the process for desulfurization. Four hours was considered to be the proper treating time for the sulfur removal. In addition, aqueous phase of acids could be recycled at least 4 times without decreasing desulfurization rate. Finally, the possible process for the integration of condensation desulfurization into the existing refinery process for the production of gasoline with low sulfur content was proposed.

Effects of Lugol's iodine solution and formalin on cell volume of three bloom-forming dinoflagellates

Fixatives are traditionally used in marine ecosystem research. The bias introduced by fixatives on.the dimensions of plankton cells may lead to an overestimation or underestimation of the carbon biomass. To determine the impact of traditional fixatives on dinoflagellates during short- and long-term fixation, we analyzed the degree of change in three bloom-forming dinoflagellates （Prorocentrum rnicans, Scrippsiella trochoidea and Nocfiluca scintillans） brought about by Lugol＇s iodine solution （hereafter Lugol＇s） and formalin. The fixation effects were species-specific. P. micans cell volume showed no significant change following long-term preservation, and S. trochoidea swelled by approximately 8.06% in Lugol＇s and by 20.97% in formalin as a percentage of the live cell volume, respectively. N. scintillans shrank significantly in both fixatives. The volume change due to formalin in N. scintillans was not concentration-dependent, whereas the volume shrinkage ofN. scintillans cells fixed with Lugol＇s at a concentration of 2% was nearly six-fold that in cells fixed with Lugol＇s at a concentration of 0.6%-0.8%. To better estimate the volume of N. scintillans fixed in formalin at a concentration of 5%, we suggest that the conversion relationship was as follows： volume of live cell=volume of intact fixed cell/0.61. Apart from size change, damage induced by fixatives on N. scintillans was obvious. Lugol＇s is not a suitable fixative for N. scintillans due to high frequency of broken cells. Accurate carbon biomass estimate ofN. scintillans should be performed on live samples. These findings help to improve the estimate of phytoplankton cell volume and carbon biomass in marine ecosystem.

Mild and highly efficient transfer hydrogenation of aldehyde and ketone catalyzed by rubidium phosphate

Rubidium phosphate can be more conveniently obtained by extracting trace Rb+ from the salt lake brine. Rb_3PO_4 was found to be an excellent heterogeneous catalyst for transfer hydrogenation. Rb_3PO_4 lost 70% of its active sites after adsorbing water, but the remaining was not affected. The reductions of aldehydes and ketones, when promoted by Rb_3PO_4, were allowed at room temperature. The activities of substrates at room temperature followed a descending order of 2,6-dichlorobenzaldehyde> 4-bromobenzaldehyde>benzaldehyde>acetophenone>anisaldehyde>butanone. A new catalytic cycle postulating a six-membered cyclic transition state for the reductions of aldehydes and ketones was proposed. These results exploited the catalytic usage of Rb_3PO_4 and worth in industrial application.

Catalytic transformations of cellulose and its derived carbohydrates into 5-hydroxymethylfurfural, levulinic acid, and lactic acid

The catalytic transformation of cellulose into key building-block or platform chemicals such as 5-hydoxymethylfurfural(HMF),levulinic acid,and lactic acid under mild conditions,has attracted much attention in recent years,as these conversions can be operated without consumption of hydrogen or oxygen and thus are more economical compared to the hydrogenolysis or oxidation of cellulose.This review article highlights recent advances in the development of novel catalysts or catalytic processes for the conversion of cellulose and its derived carbohydrates into HMF,levulinic acid,and lactic acid or their esters under inert atmosphere.We also analyze efficient catalytic systems for HMF production,in particular Lewis acids combined with ionic liquid or biphasic systems.For the formations of levulinic and lactic acids or their esters,we focus on the reactions in aqueous and alcohol media catalyzed by multifunctional catalysts that combine the functions of hydrolysis,isomerization,and dehydration-rehydration or retro-aldol reactions.The reaction mechanism for each process will also be discussed to gain insights into the activation of C–O and C–C bonds in the absence of hydrogen or oxygen.

VBEFP/PCM: a QM/MM/PCM approach for valence-bond method and its application for the vertical excitations of formaldehyde and acetone in aqueous solution

In this paper, a combined QM/MM/PCM approach, named VBEFP/PCM, is presented for ab initio VB study with a solvent effect incorporated. In VBEFP/PCM, both short-range and long-range solvent effects are taken into account by effective fragment potential(EFP) and polarizable continuum model(PCM), respectively, while the solute molecules are described by valence bond(VB) wave function. Furthermore, VBEFP/PCM, along with VBPCM and VBEFP, is employed for the n??* vertical excitation of formaldehyde and acetone molecules in aqueous solution. The computational results show that VBEFP/PCM can provide the appropriate solvent shifts, whereas VBPCM underestimates the solvent shifts due to its lack of short-range solvent effect. The VBEFP results strongly rely upon the description of the short-range solvent effect. To explore the role of the solute's electronic structure in the solvent shift, resonance energy analysis during the excitation is performed. It was found that the solute's electronic polarization plays the most important role in the solvent shift. The ? resonance controls the variation of the solute's wave function during the n→?* vertical excitation, which leads to the blue solvent shifts.