光合细菌-膜生物反应器处理VB12废水的研究

利用光合细菌-膜生物反应器对VB12废水进行处理,经历了反应器的启动和试运行阶段后,对曝气量、水力停留时间、光合细菌菌种强弱、进水COD质量浓度4个影响因素进行了分析。结果显示:水力停留时间为35 h,试验温度为30℃左右,pH值为6~8,溶解氧质量浓度控制在0.5~1.0 mg/L范围内,COD去除率可达到90%以上。     

厌氧流化床处理红霉素废水启动实验研究

对中温(32±2℃)条件下颗粒活性炭(GAC)载体厌氧流化床(AFB)反应器处理红霉素废水启动方法进行了研究。实验表明:采用稳定进水COD基质浓度,控制红霉素废水与人工合成废水比例,以红霉素废水逐步取代人工合成废水的方法,达到了微生物的顺利驯化和反应器较快启动的目的。     

内循环生物流化床处理生活污水的实验研究

本技术采用自制的内循环生物流化床处理生活污水，以活性炭为载体进行挂膜实验。设备运行稳定后，通过控制进水流量和进气量，分析其对COD去除率的影响。实验结果表明：改进的快速排泥法可以保证内循环生物流化床的快速启动。在选择的实验条件下，当处理的生活污水COD值为300—600mg／L时，出水COD小于60mg／L，去除率为88．91％，达到生活污水排放标准GB18918—2002一级B排放标准。     

内循环三相流化床反应器处理味精废水的研究

研究以陶粒粒子为载体,采用快速排泥挂膜法,在内循环三相流化床反应器运行过程中逐渐加大进水量和进水浓度,使微生物适应高氨氮废水环境;研究了水力停留时间、NH4+-N浓度负荷冲击对NH4+-N去除率的影响.结果表明:内循环三相流化床可用于处理高NH4+-N废水;底物浓度越高水力停留时间越长;内循环三相流化床具有较好的抗负荷冲击能力,有利于解决实际废水水质不稳定难以达标排放的困难.     

新型内循环生物流化床处理油脂废水

针对油脂废水污染问题,对活性炭、沸石、烧结陶粒作为新型内循环生物流化床的载体处理油脂废水的性能进行比较.分别对各载体的投加率、水力停留时间、pH、表面活性剂、水力冲击和进水负荷进行了实验研究.结果表明:活性炭为最佳载体,其处理油脂废水的最佳操作条件为pH 6.8～7.8、水力停留时间为2.5～3.7 h、曝气量0.8～1.6 L/min.当油较大时,有必要适当添加表面活性剂增加其生物降解程度,此时油脂去除率＞90%.该生物流化床具有很强的抗水力负荷及油负荷冲击能力.     

异波折板水解酸化反应装置启动试验研究

在研究高效水解酸化工艺处理啤酒废水时,采用自然挂膜的方法启动异波折板高效水解酸化反应装置.通过深入系统研究,得出反应装置在启动过程中各阶段的水力停留时间(HRT)、pH值范围、进水COD浓度、容积负荷等最佳启动参数,使反应装置得以快速、稳定启动,并一直处于最佳运行状态.     

硅藻土改性载体加速移动床生物膜反应器启动研究

聚乙烯(polyethylene,简称PE)载体存在挂膜速度慢、附着生物膜活性低以及水处理效果差等缺点.通过添加硅藻土改善PE载体的亲水性,改性后载体的接触角由94.3°降低至77.8°.在移动床生物膜反应器(moving bed biofilm reactor,简称MBBR)工艺挂膜启动过程中,相同条件下,相比于PE载体,硅藻土改性载体表面附着的生物膜具有较高的蛋白质和多糖含量,表明附着在硅藻土改性载体上的生物膜生物活性较高.生物膜生长稳定后,反应器R1(填充硅藻土改性载体)内总生物量比反应器R2(填充PE载体)内总生物量高35.6%,硅藻土改性载体表面附着的生物膜量比PE载体的高62.3%.相应的,挂膜启动过程中,反应器R1的COD和氨氮去除率也高于反应器R2.上述硅藻土改性载体在挂膜性能和水处理性能方面的优势,缩短了反应器R1的启动时间.     

活性炭和石英砂在UASB系统中的应用研究

以活性炭和石英砂为微生物固定化材料,考察其在UASB系统中对COD的去除效果、体积负荷以及反应器的启动时间的影响,并与传统UASB反应器做了对比实验.结果表明:第1-40 d有机负荷为0.075～0.208 kg/m3;第1-10 d厌氧流化床未流化,UASB柱(R0)、活性炭柱(R1)、石英砂柱(R2)对COD的平均...     

膜生物反应器处理一种食品防腐剂生产废水的研究

利用浸没式膜生物反应器(SMBR)对某食品防腐剂生产废水处理进行了研究.重点考察了进水COD浓度、水力停留时间、溶解氧等各种因素对处理效果的影响.试验研究表明:当进水COD浓度小于3400mg/L,水力停留时间(HRT)不低于7h,同时保证温度不低于150C,DO不低于2.0mg/L时,SMBR对COD的平均去除率高于90%,出水COD均小于100ms/L,可基本实现达标排放.     

不同接种物对牛粪高温厌氧发酵的影响

研究了不同污泥培养的接种物对牛粪厌氧发酵启动时间、COD和BOD5降解情况、VFA及pH、产气量与产气速率的影响。结果表明:二沉池污泥培养的接种物厌氧细菌、产甲烷菌含量高,活性大,浓缩污泥培养的接种物次之,河床污泥培养的接种物各菌种数量及含量最少,且出现板结现象。接种物浓度一定条件下,用二沉池污泥培养的接种物接种,厌氧发酵体系启动速度快,COD、BOD5降解率高,产气量大且平稳。     

二元序列的翻转与对换排序

序列的翻转与对换的排序问题因在基因组比较中的应用而受到关注．考虑二元序列的翻转与对换的排序问题，分别给出了二元序列的翻转排序与对换排序的近似算法．     

Replication by human DNA polymerase-iota occurs by Hoogsteen base-pairing

Almost all DNA polymerases show a strong preference for incorporating the nucleotide that forms the correct Watson-Crick base pair with the template base. In addition, the catalytic efficiencies with which any given polymerase forms the four possible correct base pairs are roughly the same. Human DNA polymerase-iota (hPoliota), a member of the Y family of DNA polymerases, is an exception to these rules. hPoliota incorporates the correct nucleotide opposite a template adenine with a several hundred to several thousand fold greater efficiency than it incorporates the correct nucleotide opposite a template thymine, whereas its efficiency for correct nucleotide incorporation opposite a template guanine or cytosine is intermediate between these two extremes. Here we present the crystal structure of hPoliota bound to a template primer and an incoming nucleotide. The structure reveals a polymerase that is 'specialized' for Hoogsteen base-pairing, whereby the templating base is driven to the syn conformation. Hoogsteen base-pairing offers a basis for the varied efficiencies and fidelities of hPoliota opposite different template bases, and it provides an elegant mechanism for promoting replication through minor-groove purine adducts that interfere with replication.     

用修正学习曲线测算井段的钻井时间

将学习曲线与传统的分段方法结合起来,既克服了分段法中不考虑学习效果的缺陷,又克报了学习曲线中不能灵活调整的缺陷,形成两种方法的优点叠加．用学习曲线测算井段的钻井时间,其前提条件是：各井在该井段的钻头选型基本相同,井段直径相同,所穿过的地层相同,所属的井型相同．对钻井参数（钻压、转速、泵压、排量）、泥浆密度与性能、喷嘴直径与个数等时变性因素,不单独列出,而作为在钻井过程中通过逐步学习加以改善的对象．用塔北某地区１号构造上所钻井的二开井段（４４４．５ｍｍ）实际资料测算,得到的结果明显优于钻井监督的计划时间,测算的最大相对误差１１．８％,平均为８．８％,而监督组计划误差为４１．９％,平均误差率降低了一半以上．     

Self powered systems by nanogenerators and smart MEMS by piezotronics

Developing wireless nanodevices and nanosystems is of critical importance for sensing, medical science, environmental/infrastructure monitoring, defense technology and even personal electronics. It is highly desirable for wireless devices to be self powered without using battery, without which most of the sensor network may be impossible. The piezoelectric nanogenerators have the potential to serve as self sufficient power sources for micro/nano systems. For wurtzite structures that have non central symmetry, such as ZnO, GaN and InN, a piezoelectric potential (piezopotential) is created in the crystal by applying a strain. The nanogenerator is invented by using the piezopotential as the driving force for electrons to flow in respond to a dynamic straining of piezoelectric nanowires. A gentle straining can produce an output voltage of up to 20～50 V from an integrated nanogenerator. Furthermore, piezopotential in the wurtzite structure can serve as gate voltage that can effectively tune/control the charge transport across an interface/junction; electronics fabricated based on such a mechanism is coined as piezotronics, with applications in force/pressure triggered/controlled electronic devices, sensors, logic units and memory. By using the piezotronic effect, it is showed that the optoelectronic devices fabricated using wurtzite materials can have superior performance as solar cell, photon detector and light emitting diode. Piezotronic is likely to serve as “mechanosensation” for directly interfacing biomechanical action with silicon based technology and active flexible electronics. The paper gives a brief review about the basis of nanogenertors and piezotronics and their potential applications in smart MEMS (micro electro mechanical systems).