提升烘梗丝工序出口水分稳定性研究

气流烘梗丝工序是制梗丝生产过程中的关键工序。本项目围绕提升烘梗丝出口水分稳定性,研究贮梗时间和天气情况对烘梗丝入口批间水分影响规律,通过梗丝加料补水或者调整梗丝回潮加水比例的方式,提升烘梗丝进料水分批间稳定性。在此基础上,进一步稳定烘梗丝机各项参数控制对当日烘梗批次对出口水分稳定性的影响以及烘梗丝机自身设备参数的影响,获取影响烘梗丝出口水分稳定性关键因素,提升烘梗丝工序工艺加工过程稳定性,达到提升烘梗机出口水分稳定性的目的。

基于田口方法提高回丝水分稳定性的设计

采用田口方法来进行回丝工艺参数设计,得到满足回丝水分稳定性控制要求的最优工艺参数。首先设置可控因子水平表,由极差分析确定较优试验条件组合;其次以信噪比和灵敏度作为稳健性指标,采用望目方案进行分析,得出最优试验条件组合;最后对最优组合进行验证,确认其可靠性。通过田口方法得到最佳试验条件组,使回丝水分合格率达到80%以上,回丝质量指标和稳定性显著提高,对回丝生产稳定性控制具有一定的指导意义。

松散回潮机出口水分稳定性研究

对于卷烟工业企业来说,制丝线的生产效率和烟丝质量直接影响到企业的经济效益,松散回潮作为卷烟制丝生产过程重要工序之一,由于处理对象为体积较大的叶片,处理后叶片质量尤其是出口水分的稳定性很难保证。文章通过对造成松散回潮机出口水分波动的原因排查分析,针对性地进行工艺设备改进,从而将松散回潮机出口水分Cpk值从0.8提高到了1.33以上,减小了出口水分波动,稳定了叶片在此工序过程的加工质量,取得了显著成效。

SH611P型滚筒烘丝设备的出口水分稳定性改进

为解决SH611P型滚筒烘丝设备烘丝出口水分长期异常波动问题,以提升烘后烟丝质量稳定性。本试验对烘丝筒转速、物料流量、热风风速、烘丝筒倾角等影响物料分布状态的关键工艺参数进行调整试验。结果表明:2.5°烘丝滚筒倾角与现行加工工序的不匹配是导致烘丝出口水分长期异常波动的根本原因,将2.5°倾角调整为3.5°能解决烘丝出口水分异常波动问题,且标偏更低、Cpk更大,有效提高烘丝出口水分稳定性和烘丝质量。

SMOS与SMAP过境时段表层土壤水分的稳定性研究

SMOS和SMAP都是为获取全球土壤水分信息而设计的专题卫星,均搭载了L波段辐射计。进行二者的横向对比是构建具有一致性的全球土壤水分数据集的关键基础。虽然SMAP、SMOS名义上的过境时刻是固定的,但二者的实际过境时刻随时间和空间发生变化,它们与地面实测数据三者之间难以匹配形成时序上严格统一的样本对,从而给土壤水分反演结果的精度评定带来困难。针对这一问题,以美国大陆地区为研究区,首先对2016~2017年SMOS、SMAP土壤水分数据的时间戳进行统计,判定二者过境的交叠时段;进而利用高观测频率、大空间尺度的实测数据,研究表层土壤水分在此时段内的自然变化特征。结果显示,按照全部、无降水、有降水3种条件,在样本量分别为98.14%、99.51%和88.49%的绝大多数情况下,表层土壤水分的变化量为0.007 m^3/m^3、0.007 m^3/m^3和0.012 m^3/m^3,远小于SMOS、SMAP的目标精度(0.04 m^3/m^3)。初步证实:①SMOS与SMAP的土壤水分反演结果(L2数据)可进行直接比对;②过境时刻差异对验证误差的影响可不计。

黄土丘陵沟壑区不同退耕模式的土壤水文性质影响对比

为系统评价黄土丘陵沟壑区在“退耕还林(草)”工程实施后不同退耕模式下的土壤水分涵养功能,选取0-200 cm土层的蓄水量、土壤含水量分层比、土壤水吸力和土壤含水量年际变化率作为土壤层水分蓄存、渗透、保持和稳定性的表征指标,分别对比了不同退耕模式下的土壤水文性质。结果表明:(1)各退耕模式下土壤蓄水量差异显著,撂荒模式的土壤蓄水量最高,为还灌和还乔模式下的1.6,1.7倍;(2)还乔模式下表层土壤水分的渗透性最优,深层土壤水分的渗透潜力最大;(3)各退耕模式的土壤持水性差异显著,还乔模式下土壤水分的保持能力突出;(4)撂荒模式土壤水分的稳定性最佳,各模式0-200 cm内土壤水分的稳定性在30年前后出现拐点,土壤含水量的年际变化率由负转正,并在120 cm以下土层较为稳定。

低温真空干燥对烟丝及卷烟品质的影响

为丰富烟草行业制丝加工方法,研究了低温真空干燥对烟草制品的水分影响规律,并与滚筒干燥方式加工的烟丝进行了物理质量、致香成分以及感官质量特点的分析检测。研究结果表明:①采用低温真空干燥加工后的烟丝致香成分相对含量为470.12μg/g,滚筒干燥后烟丝致香成分为 395.16μg/g。②批内、批间水分稳定性更好,批内真空干燥无干头干尾,水分标偏为0.06;滚筒干燥水分标偏为 0.23;③真空干燥后烟丝填充值为 4.02 cm^3/g、碎丝率为 7.58%;滚筒干燥后烟丝填充值为 4.57cm^3/g、碎丝率为 4.39%。相比于滚筒干燥,低温真空干燥处理在烟丝和卷烟品质方面具有一定优点。

焦炭预热干燥技术的应用

针对外购焦炭质量不稳定、水分波动大、影响高炉炉况顺行等问题,通过增设热风炉烟气主引风机及焦仓排气管轴流风机,改造供配电系统,完善自动化控制系统等措施,实现了焦炭水分的持续稳定,为高炉的生产顺行与低硅冶炼创造了有利条件,同时提高了热风炉废气综合利用率,显著提升了TRT发电量。

氢氧碳稳定同位素在植物水分利用策略研究中的应用

综述了氢氧碳稳定同位素的概念、示踪原理及其应用于定量确定植物水分来源、水分利用格局和水分利用效率等方面研究进展。同时展望了全球气候变化条件下,氢氧碳多种稳定同位素联合示踪先进技术在定量研究植物水分利用策略以及植被对全球气候变化的响应机制研究中的应用前景。

姬塬油田废弃钻井液处理技术研究

针对姬塬油田废弃钻井液的特点,研制了一套处理工艺流程,筛选适宜的化学脱稳剂,探讨了最佳使用条件,然后对钻井液固液分离出的钻井污水和固相分别进行深度处理和固化处理,通过试验筛选出了无机絮凝剂、有机助凝剂和固化剂,研究了最佳加量,深度处理的水质和固化后固体浸出物的水质均达到国家二级排放标准。

梗丝低速气流干燥机SH23B控制特点及应用存在问题

梗丝在线膨胀干燥技术在烟草行业普遍使用,文章系统介绍新型梗丝低速气流干燥机SH23B控制特点,有五个工艺控制点,采用六个工艺控制点,正常工作时均处于自动调节状态,形成闭环回路控制,能够使干燥后梗丝水分控制稳定均匀,造碎低,满足生产工艺需求。

Stable Isotope Technique——An Advanced Technology in Ascertaining Plant-Water Relations

Some key terms and relevant standard related with stable isotope tech- nique were introduced, and the determination of carbon, hydrogen and oxygen, the three stable isotopes in water, as well as their isotope effect was discussed. Appli- cations and advances of stable isotopes were stated mainly from plant water source, water use efficiency, the most active water adsorption region in root system and water resources utilization differences among different species in plant communi- ty. In addition, some existing problems in investigating the plant-water relations by using stable isotope technique were put forward. In this study, we aimed to promote the sustainable development of stable isotope technique in the research of plant water utilization and in the field of ecology in China.

Light Fraction Carbon and Water-Stable Aggregates in Black Soils

The distribution of light fraction carbon （LF-C） in the various size classes of aggregates and its relationship to water- stable aggregates as well as the influence of cultivation on the organic components in virgin and cultivated black soils were studied by wet sieving and density separation methods. The total organic carbon （TOC） and LF-C were significantly higher （P≤ 0.05） in the virgin soils than in the cultivated soils. The LF-C in aggregates of different size classes varied from 0.9 to 2.5 g kg^-1 in the cultivated soils and from 2.5 to 7.1 g kg^-1 in the virgin soils, whereas the ratio of LF-C to TOC varied from 1.9% to 7.3% and from 5.0% to 12.2%, respectively. After being incubated under constant temperature and controlled humidity for three months, the contribution of LF-C to TOC sharply decreased to an amount （1.7%4.5%） close to the level in soils that had been cultivated for 20 to 25 years （1.3%-8.8%）. As a result, the larger water-stable macro-aggregates （especially 〉 1 mm） decreased sharply, indicating that the LF-C pool in virgin soils declined quickly after cultivation, which reduced the water stability of soil aggregates.

Infiltration regulation and stability analysis of soil slope under sustained and small intensity rainfall

Rainfall infiltration depth and mode can severely influence slope stability.With the sustained rainfall,the influenced region of slope gradually expands.By using the Green-Ampt model to the soil slope,infiltration regulation was discussed under sustained and small intensity rainfall.And the infiltration rate of unsaturated soil was proposed according to the saturated infiltration theory.Because of the changing of initial moisture content in depth of slope,the saturated or unsaturated infiltration rate and depth could also be changeable with the sustained rainfall infiltration.Based on the principle of strength reduction,the calculation model of slope safety factor was established under different initial moisture contents and infiltration modes.Then,the slope stability was quantitatively analyzed through software FLAC3D.The calculation results of soil slope engineering show that there is a shorter period for slope stability under different initial moisture contents and unsaturated infiltration ways at the slope wetting front.The stability period of slope is 33.3%according to different initial moisture contents of wetting front less than that of the same initial moisture content of wetting front.And the slope is easier to fail under the unsaturated infiltration.The results agree well with the actual situation under sustained and small intensity rainfall.

A Successful Microbound Diet for the Larval Culture of Chinese Shrimp Fenneropenaeus chinensis

A 13-day feeding trial was carried out to evaluate the effectiveness of a microbound diet for rearing the larvae of Chinese shrimp Fenneropenaeus chinensis in comparison with the live foods that consist of Isochrysis galbana, Chlorella vulgaris, Tetraselrnis chuii, rotifer （Brachionus plicatilis） and Arternia sp. Larvae of 0 to 13d post-hatch （dph） were reared in a temperature-controlled semi-open culture system and stocked at a density of 100 larvae L^-1 in tanks, each containing 50 L sterilized seawater with salinity 30-32. Larvae were manually fed either the live foods or the microbound diet 6 times per day. At 13 dph, the growth of the larvae fed on the microbound diet was approximately 84% of that fed on the live foods. The survival rate of the larvae fed on the microbound diet was 44.29% at 13dph, which was not significantly different from that of larvae fed on live foods （63.55%）. The body length and development index （DI） of the larvae fed on the microbound diet were always lower than those of larvae fed on live foods. However, the differences reached significant levels only at 11 and 13 dph （P〈 0.05）. The mean dry weight loss of the microbound diet was 9.2% after 90 min immersion in seawater, indicating that this diet has a good water stability. The microbound diet contains 52.23% crude protein and 10.27% lipid and is easy to prepare. These characteristics of the diet suggest good potentials for its successful use in the larviculture of other penaeid and fish species.

On the hydrodynamic stability of a particle-laden flow in growing flat plate boundary layer

The parabolized stability equation (PSE) was derived to study the linear stability of particle-laden flow in growing Blasius boundary layer. The stability characteristics for various Stokes numbers and particle concentrations were analyzed after solving the equation numerically using the perturbation method and finite difference. The inclusion of the nonparallel terms produces a reduction in the values of the critical Reynolds number compared with the parallel flow. There is a critical value for the effect of Stokes number, and the critical Stokes number being about unit, and the most efficient instability suppression takes place when Stokes number is of order 10. But the presence of the nonparallel terms does not affect the role of the particles in gas. That is, the addition of fine particles (Stokes number is much smaller than 1) reduces the critical Reynolds number while the addition of coarse particles (Stokes number is much larger than 1) enhances it. Qualitatively the effect of nonparallel mean flow is the same as that for the case of plane parallel flows.

Stabilizing CuO photocathode with a Cu_(3)N protection shell

CuO,as a promising photocathode material,suffers from severe photocorrosion in photoelectrochemical water splitting applications.Herein,a Cu_(3)N protection shell was used to protect the CuO photocathode for the first time to effectively suppress the photocorrosion of CuO.Consequently,the Cu_(3)N‐protected CuO photocathode shows improved stability,retaining 80% of its initial current density in a 20‐min test,while only 10%of the initial current density can be retained for the bare photocathode.This work may provide an important strategy for using Cu_(3)N shells to stabilize unstable photocathodes.

Stability analysis of shallow tunnels subjected to seepage with strength reduction theory

Based on strength reduction theory,the stability numbers of shallow tunnels were investigated within the framework of upper and lower bound theorems of limit analysis. Stability solutions taking into account of water seepage were presented and compared with those without considering seepage. The comparisons indicate that the maximum difference does not exceed 3.7%,which proves the present method credible. The results show that stability numbers of shallow tunnels considering seepage are much less than those without considering seepage,and that the difference of stability numbers between considering seepage and without considering seepage increase with increasing the depth ratio. The stability numbers decrease with increasing permeability coefficient and groundwater depth. Seepage has significant effects on the stability numbers of shallow tunnels.

Effects of Tillage Management on Infiltration and Preferential Flow in a Black Soil, Northeast China

The impacts of no-tillage （NT） and moldboard plough （MP） managements on infiltration rate and preferential flow were characterized using a combined technique of double-ring device and dye tracer on a black soil （Mollisols） in Northeast China. The ob- jective of this study is to evaluate how tillage practices enhance soil water infiltration and preferential flow in favor of soil erosion con- trol in the study area. The steady infiltration rates under NT management are 1.6 and 2.1 times as high as those under MP management in the 6th and 8th years of the tillage management in place, while the infiltrated water amounts under NT management are 1.4 and 2.0 times as high as those under MP management, respectively. The depth of methylene blue penetrated into NT soil increases from 43 cm in the 6th year to 57 cm in the 8th year, which are 16 cm and 19 em deeper than those in MP soil, respectively. The results of morphol- ogic image show that more biological macro-pores occur in NT soil than in MP soil. These macro-pores play a key role in enhancing preferential flow in NT soil, which in turn promotes water infiltration through preferential pathways in NT soil. The results are helpful to policy-making in popularizing NT and have the implications for tillage management in regard to soil erosion control in black soil region of China.

Kinetics study and analysis of zeolite Y destruction

A series of zeolites,including USY zeolites without sodium,Na-USY at different Na contents,La-USY with different rare earth（RE） contents and La-Na-USY with RE and Na were prepared by an ion exchange method.They were investigated to understand the activation barriers for the destruction of Y zeolite structure under hydrothermal treatment and the effect of V using the solid-state kinetic model.The results showed that the pathways for Y zeolite destruction were dealumination,desiliconization and the disappearance of La-O bonds.Zeolites were destroyed by steam through acid hydrolysis,which was accelerated by V.In addition,Na and V exerted a synergistic effect on the framework destruction,and the formation of NaOH was the rate-determining step.The presence of RE elements decreased hydrolysis and stabilized the structure of the zeolites.The interaction between V and RE destroyed zeolite structure by eliminating the stabilizing La-O[RE-OH-RE]^（5＋）bridges in the sodalite cages.