Folin-Ciocalteu法测定鱼腥草多酚的含量

目的：探索优化Folin-Ciocalteu 法测定鱼腥草中多酚含量。方法：运用不同的溶剂超声提取鱼腥草叶片,比较不同时间提取物用Folin-Ciocalteu 法测得的吸光度。并以乙醇2h 提取液为对象研究不同的碳酸钠溶液、Folin-Ciocalteu 显色剂加入量、反应温度及时间对吸光度大小及稳定性的影响。结果：甲醇提取效率最高,其次为乙醇、丙酮和水;提取时间2h;较适宜测定方法为采用0.5mL 提取液,加入2.0mL 20% 的碳酸钠缓冲液、1.5mLFolin-Ciocalteu 显色剂,蒸馏水定容至50.0mL,55℃保温1.5h,测定波长为760nm。结论：该方法比较快速、准确和稳定,适合推广。     

浅析电喷柴油发电机组使用与维修

对国外煤矿使用电喷柴油发电机组的原理作了简要介绍,同时结合多年对其使用及维修实践,提出了可借鉴的经验,具有一定的普遍性和操作实用性。     

Experimental investigation on thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger

The thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger was investigated to show its applicability in China. The effect on the performance of the collector of using a heat exchanger between the collector and the tank was analyzed. A “heat exchanger penalty factor” for the system was determined and energy balance equation in the system was presented. Outdoor tests of thermal performance of the thermosyphon flat-plate solar water heater with a mantle heat exchanger were taken in Kunming, China. Experimental results show that mean daily efficiency of the thermosyphon flat plate solar water heater with a mantle heat exchanger with 10 mm gap can reach up to 50%, which is lower than that of a thermosyphon flat-plate solar water heater without heat exchanger, but higher than that of a all-glass evacuated tubular solar water heater.     

熔融制样-X射线荧光光谱法测定锰矿中9种组分

探讨了熔融制样-X射线荧光光谱法测定锰矿中TMn、TFe、SiO₂、Al₂O₃、CaO、MgO、TiO₂ 、P₂O₅、K₂O等常见组分的分析方法。对试样进行烧损校正,采用国家标准物质和以国家标准物质为基体制备的校准样品,建立了基体校正后的校准曲线。通过试验确定以四硼酸锂为熔剂、硝酸铵为氧化剂、熔融中间和定型前分2次加入总量为0.15 g的NH4I脱模剂,采用1∶12.5的稀释比例高温熔融制样。方法用于锰矿标准样品与实际样品分析,标准样品的测定值与认定值一致,实际样品的分析结果与其他方法的结果吻合,满足了生产现场快速分析的需要。     

紫外光固化涂料对ABS力学性能的影响

从底漆、清漆、紫外光照射等因素研究了紫外光(UV)固化涂料对ABS塑料力学性能的影响.结果表明:UV固化涂料会使ABS力学性能发生变化,拉伸强度和弯曲模量几乎不变;弯曲强度升高了5.1%;冲击强度的保持率为原来的91.0%;断裂伸长率仅为原来的14.6%;塑料力学性能变化主要是底漆中复合溶剂和非溶剂组分、清漆中光引发剂以及固化过程中紫外光照射等因素作用引起的应力开裂、降解、交联等共同作用的结果;固化次数对ABS的断裂伸长率影响比较明显.     

Silicon nanowires with permanent electrostatic charges for nanogenerators

Electrets are dielectric materials possessing a quasi-permanent electric charge or dipole polarization. Frequently, the electrets are adversely affected by environmental temperature and humidity, leading to charge instability, which severely restricts applications. Here we show that silicon nanowires (SiNWs) via modified oxide-assisted growth can surprisingly serve as electrets with permanent electrostatic charges and surface potential up to 7.7 mV. Significantly, the extraordinary electret behavior of SiNWs is extremely robust, remaining stable against immersion in water for over 2 months. The SiNWs were utilized to fabricate a nanogenerator, which yielded an output electrical power of 2.19 × 10(-11) W with a conversion efficiency of 2.2%. The nanogenerator consists of only one movable part, giving highly sustainable and stable output signals, and thus holds promise for various self-powered applications. The permanent electrostatic charges on SiNWs are attributed to the formation of α-quartz in SiNWs.     

高速列车齿轮油性能要求与验证方法初探

分析了高速列车齿轮箱的润滑要求,指出了高速列车齿轮油相较于常规齿轮油需要强化的性能。结合国内高速列车齿轮箱的开发情况,初步探讨了高速列车齿轮油台架试验方法。     

环保型“金蝉”浸出剂处理金精矿的试验研究

针对某难处理金精矿进行了"金蝉"浸金试验研究。考察了"金蝉"用量、浸出时间、矿样粒度及类型等因素对金、银浸出效果的影响,以及"金蝉"浸金和常规氰化浸金的对比。其结果表明:在一定条件下,"金蝉"对金的浸出率优于常规氰化浸出,可达96%以上;但其试剂的消耗量略大,可采用置换后溶液调浆浸金降低"金蝉"消耗量,提高其同氰化法竞争的优势。     

食管支架术后支架贴壁不良综合征的初步探讨

目的探讨食管支架置入术后贴壁不良综合征（dys－seal syndrome ,DSS）的发生原因及相关处理。方法收集我科２００１年６月至２００８年６月行食管支架手术患者９８例,共置入９９枚金属支架。其中术后吻合口肿瘤复发狭窄１９例,术前有食管癌放疗病史２６例,伴食管－气管瘘３４例。结果术后７例患者出现DSS（发生率７．１％）。其中有放疗病史及梗阻上段食管明显扩张患者DSS发生率明显升高食管金属内支架是食管恶性和部分良性狭窄引起吞咽困难的有效治疗手段 ［１－２］ 。支架置入后常见的并发症包括胸痛、各种原因致支架再阻塞、支架移位、食管穿孔等 ［３－４］ ,也有相对较罕见并发症的报道,如消化道大出血、心肌梗死等 ［５－６］ 。我们在临床工作中发现部份患者食管支架置入术后支架位置良好,扩张满意,但患者诉吞咽疼痛并经常发生进食哽噎、嗳气,有明显的食物腐败味。而复查发现支架内对比剂尚可通过或仅有不畅,关键是可见支架上端与食管壁间不能完全贴壁而出现明显的空隙,有时可见食物残渣存留。可以得知食物残渣长期滞留、腐败引起炎症反应,继而使患者发生上述症状,严重时不得不将支架取出。我们将这一系列现象称之为“支架贴壁不良综合征”（dys－seal syndrome ,DSS）,现将我们治疗的９８例DSS总结报道如下。１材料与方法１．１材料收集我科２００１年６月至２００８年６月施行的食管支架恶性肿瘤患者９８例,其中男７６例,女２２例,年龄４６～８３岁,平均６２岁。９８例中原发病变为食管癌７５例、贲门癌２１例,纵隔淋巴结转移致食管外压性狭窄３例。支架置入术前有局部放疗病史２６例,伴发食管－气管瘘３４例。狭窄梗阻段位于食管上段２０例,中下段５９例,术后吻合口肿瘤复发１９例。共置入支架９９枚。置入支架类型包括南京微创覆膜食管支架（６７例）,Wallstent 裸支架（１２例）,Ultraflex裸支架（１０例）,韩国taewoong镍钛合金覆膜支架（１０例）。根据病变情况选择不同类型支架。一般情况下存在食管－气管瘘者必选用覆膜支架。其他情况下,梗阻上方食管明显扩张者选用喇叭口形支架,否则可选用直筒型支架。２００１－２００３年的病例选用裸支架为主,其后多用覆膜支架。１．２方法本组病例均在DSA机下操作完成。术前予咽部表面麻醉,患者仰卧,头偏向右侧,安放牙垫后在X线透视引导下以超滑导丝通过病灶狭窄阻塞段到达胃腔,沿导丝引入导管,注入对比剂证实后,更换（χ ２ ＝０．０１７,０．００５,P＝０．０３６,０．０１３）。经禁食,静脉输液或鼻饲等营养支持治疗后,１例患者逐渐恢复至进食半流质;１例于原支架上端再次置入较大直径支架,术后症状无缓解,后失访;２例改行鼻饲管置入;余３例内镜下取出支架。结论食管支架置入术后发生DDS为并发症之一,临床处理预后不良。取出已经置入的支架是较好的治疗措施。应在术前进行适当的评估以排除危险因素,选择合适的支架,加强围手术期管理等有助于DSS的预防。