磁化-去电子水对盐渍化土壤水盐运移特征影响

磁化与去电子等活化水处理技术在农业灌溉领域的应用受到人们广泛的关注,为了阐明磁化—去电子水入渗对土壤水盐运移的影响机制,利用自来水、去电子水、磁化水(0.4 T)、以及磁化—去电子水开展一维垂直入渗试验,研究了磁化—去电子活化水对土壤水盐运移特征及盐分淋洗效率的影响。结果表明:与对照相比,磁化—去电子活化处理能够有效促进土壤水分入渗,增加土壤含水率,降低土壤含盐量,提高灌溉水盐分淋洗效率,并且磁化—去电子水在入渗能力、土壤含水率、土壤含盐量、盐分淋洗效率较磁化或去电子方法有不同程度的提高,与去电子水相比,磁化—去电子水累积入渗量增加了28.0%,到达入渗终点用时减少了25.7%,15 cm深度土层的土壤含水率增加了7.9%,整体土壤脱盐率增加了13.9%;与磁化水相比,磁化—去电子水累积入渗量增加了6.7%,到达入渗终点用时减少了12.2%,15 cm深度土层的土壤含水率增加了3.2%,整体土壤脱盐率增加了4.7%。磁化—去电子水对土壤盐分淋洗有显著促进作用,并且比磁化水或去电子水的促进作用更明显,有利于为作物生长创造良好的水盐环境,为合理利用磁化-去电子水提供了参考。

去电子处理微咸水矿化度对土壤水盐运移特征的影响

为探究去电子处理微咸水对土壤水盐运移的影响,该文通过室内土柱试验,分析了不同矿化度微咸水(0.14、2、3、4、5 g/L)经去电子处理后土壤水分入渗及盐分分布规律。结果表明:不同矿化度去电子微咸水土壤入渗速率及湿润锋运移速率明显大于未处理微咸水,入渗时间为200 min时,累积入渗量和湿润锋运移深度在矿化度为4 g/L时增加幅度最大。相同矿化度去电子微咸水与未处理微咸水相比,Philip入渗公式吸渗率、Green-Ampt入渗公式饱和导水率及湿润锋处吸力均显著增加。去电子微咸水能够显著提高土壤的持水效率和上层土壤盐分的淋洗效果,矿化度为4 g/L时,相对淋盐率和Na+相对淋洗率最大。该研究表明去电子化处理能够改善土壤水盐运移特性,有利于微咸水安全利用。

去电子水灌溉对设施番茄产量、品质及水分利用率的影响

为了探究去电子水灌溉对设施番茄生长的影响,以‘毛粉802’为研究材料,分析不同去电子水灌溉量下番茄产量、品质及水分利用率的变化。结果表明,去电子水灌溉可明显促进设施番茄生长、提高水分利用率。与普通灌溉水(CK)相比,等量去电子水(T2)灌溉的设施番茄净光合速率(Pn)、气孔导度(Gs)、胞间二氧化碳(Ci)浓度、蒸腾速率(Tr)、单株产量、Vc含量、糖酸比、番茄红素含量及水分利用率分别显著提升9.56、14.29、4.75、7.52、11.99、13.28、7.80、6.76和7.96,可滴定酸含量显著降低5.88(P<0.05)。综合考虑设施番茄产量、品质及水分利用率,建议去电子水灌溉用量为3120 m^3/hm^2。

去电子水灌溉对冬小麦生长及其水分利用的影响

为探究去电子水灌溉对冬小麦生长及其水分利用的影响,选取关中平原典型灌区为研究区开展大田试验。以冬小麦"小偃22号"为供试作物,设置不同的灌水类型(普通水与去电子水)和灌溉量水平(60、120、180 mm与240 mm),分阶段对冬小麦的生长指标与光合指标进行测定,分析冬小麦的耗水特性、土壤水分变化状况及水分利用效率。结果表明,同一灌溉量水平(180 mm)下,与普通水灌溉相比,去电子水灌溉的冬小麦生长速率更快,同时耗水量较高,其籽粒产量与水分利用效率亦显著提高了17.8%与15.1%;与0 mm灌溉相比,去电子水灌溉的冬小麦增产46.9%,高于普通水灌溉处理(24.7%)。去电子水不同灌溉量处理中,灌溉量为180 mm时冬小麦的籽粒产量与水分利用效率均最高。因此,可以将去电子水灌溉180 mm作为关中平原冬小麦高效用水和高产的较优灌溉方案。

去电子水对牛粪秸秆好氧堆肥进程及细菌群落的影响

通过对普通水进行去电子处理,得到可利用性较强的去电子水,但其对好氧堆肥进程的影响还不明确.在牛粪秸秆好氧堆肥过程中添加去电子水,分析堆肥腐熟进程,并通过细菌群落结构变化揭示其作用的微生物学机理.研究结果表明去电子水处理堆肥的电导率(EC)、腐熟度(E4/E6)和C/N分别比对照组降低了48.7%、43.2%和27.9%,堆肥最高温度和种子发芽指数(GI)分别升高了17.5%、30.6%.同时去电子水提高了Glycomyces、Ammoniibacillus、Flavobacterium、Actinomadura和Geobacillus等优势属的相对丰度,改变了细菌群落的分布.冗余分析表明堆肥不同阶段的细菌优势菌属驱动着堆肥温度、pH、EC的变化,提高GI,促进堆肥腐熟.总之,加入去电子水有利于调节堆肥环境,缩短堆肥周期,并增加优势属的相对丰度,提高堆肥产品的稳定性.

活化水灌溉在农业生产中的应用研究进展

活化水技术可使水的理化性质发生显著改变,提升水分子活性,其中磁化、去电子、增氧等灌溉水活化技术能够改良土壤理化性质,提高水肥利用效率,促进农田作物生长及增产,并且因其具有低耗能、无毒无害且高效快速的特点已受到广泛关注。本文介绍了磁化、去电子、增氧三种较常见的灌溉水活化技术对普通水理化性质的改善效果,及其应用于农业生产过程中对土壤理化性质的改良作用;同时着重介绍了磁化水灌溉对作物生长的影响以及对土壤盐渍化的改良效果,并指出其中存在问题,以促进活化水灌溉技术在农业中的推广应用,这对正处于淡水资源短缺、土地质量下降的我国干旱半干旱区实现农业节水增效、可持续发展具有重要的理论和实践意义。

Clinical role of (18)~F-fluorodeoxyglucose positron emission tomography/computed tomography in post-operative follow up of gastric cancer: Initial results

AIM: To evaluate the clinical role of 18F-fluorodeo-xyglucose positron emission and computed tomography (18F-FDG PET/CT) in detection of gastric cancer recurrence after initial surgical resection. METHODS: In the period from January 2007 to May 2008, 23 patients who had previous surgical resection of histopathologically diagnosed gastric cancer underwent a total of 25 18F-FDG PET/CT scans as follow-up visits in our center. The standard of reference for tumor recurrence consisted of histopathologic confirmation or clinical follow-up information for at least 5 mo after PET/CT examinations. RESULTS: PET/CT was positive in 14 patients (61%) and negative in 9 (39%). When correlated with final diagnosis, which was confirmed by histopathologic evidence of tumor recurrence in 8 of the 23 patients (35%) and by clinical follow-up in 15 (65%), PET/CT was true positive in 12 patients, false positive in 2, true negative in 8 and false negative in 2. Overall, the accuracy of PET/CT was 82.6%, the negative predictive value (NPV) was 77.7%, and the positive predictive value (PPV) was 85.7%. The 2 false positive PET/CT findings were actually chronic inflammatory tissue lesions. For the two patients with false negativePET/CT, the f inal diagnosis was recurrence of mucinous adenocarcinoma in the anastomosis in one patient and abdominal wall metastasis in the other. Importantly, PET/CT revealed true-positive findings in 11 (47.8%) patients who had negative or no definite findings by CT. PET/CT revealed extra-abdominal metastases in 7 patients and additional esophageal carcinoma in one patient. Clinical treatment decisions were changed in 7 (30.4%) patients after introducing PET/CT into their conventional post-operative follow-up program. CONCLUSION: Whole body 18F-FDG PET/CT was highly effective in discriminating true recurrence in post-operative patients with gastric cancer and had important impacts on clinical decisions in a considerable portion of patients.

Acid Release from an Acid Sulfate Soil Sample Under Successive Extractions with Different Extractants

An acid sulfate soil sample was successively extracted with deionized water, 1 mol L-1 KCl and 0.000 5 mol L-l Ca(OH)2 solutions. The results showed that only very small amounts of acidity were extracted by deionized water, possibly through slow jarosite hydrolysis. Acid release through jarosite hydrolysis was greatly enhanced by Ca(OH)2 extraction at the expense of the added OH- being neutralized by the acid released. Successive extraction of the sample with KCl removed the largest amounts of acidity from the sample. However, it is likely that the major form of acidity released by KCl extraction was exchangeable acidity. The results also show the occurrence of low or non charged Al and Fe species in water and Ca(OH)2 extracts after first a few extractions. It appears that such a phenomenon was related to a decreasing EC value with increasing number of extractions.

On maximum power point tracking control strategy for variable speed constant frequency wind power generation

Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power.The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most.We presented a novel maximum power point tracking(MPPT)control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid.The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve,which had excellent dynamic and static performances and robustness.Simulation and experimental results testify the accuracy and validity of the control strategy.

Detection of Recurrent Cervical Cancer by Whole-body FDG PET Scans

OBJECTIVE To evaluate the role of whole-body {^18F} fluro-2- dexoxyglucose （FDG） positron emission tomography （PET） scans in the detection of recurrent cervical cancer. METHODS Between June, 2000 and January, 2006, 25 patients had undergone a PET scan at the Peking Union Medical College Hospital to evaluate possible recurrent cervical cancer. All the PET findings were reviewed and compared to available clinical data to classify each PET scan result as a true positive, true negative, false positive, or false negative. RESULTS A total of 38 PET scans were conducted on the 25 patients whose median age was 46 years. The Stage distributions were ⅠA （n = 1）, ⅠB （n = 11）, ⅡA （n =5）, ⅡB （n = 4）, ⅢB （n = 2）,ⅣB （n = 1）, and unknown Stage （n = 1）. There were 22 cases of squamous cell carcinoma and 3 cases of adenocarcinoma resulting in 9 true positive PET scans, 27 true negatives, 2 false positives and no false negatives. The sensitivity of the FDG PET scans for detecting recurrent cervical cancer was 100%, specificity 93.1%, positive predictive value 81.8%, and negative predictive value 100%. CONCLUSION The whole body FDG PET scans are a sensitive and specific imaging modality for the detection of recurrent cervical cancer. However the cost of PET scans is too high at this time. A large prospective study will determine whether this modality should be used routinely and take the place of other imaging methods in the early detection of recurrent cervical carcinoma.

Characterizations of Banana Peel and its Efficiency for Copper Adsorption

This research described the chemical and physical characterizations of banana （Musa sapientum Linn） peel for adsorption of copper. The FT-IR spectroscopy, BET （surface area） and SEM （scanning electron microscopy） coupled with EDX （energy dispersive X-ray） analysis were used for characterizations, while copper concentration was determined by ICP spectroscopy. The different parameters： pH values 3.0 to 9.0, banana dose （0.1 g to 0.7 g） and adsorption times （30 min to 180 min） were investigated for studying an adsorption efficient. It was found that banana peel （0.1 g） was a bio-adsorbent for copper adsorption under the suitable conditions at pH 7.0 and 90 min adsorption time. The sorption pattern was additionally found to be in linear form, according to the Freundlich and Langmuir equations with R2 = 0.966 and 0.994, respectively.

Electrolyte composition and removal mechanism of Cu electrochemical mechanical polishing

The optimization of electrolytes and the material removal mechanisms for Cu electrochemical mechanical planarization(ECMP)at different pH values including 5-methyl-1H-benzotriazole(TTA),hydroxyethylidenediphosphoric acid(HEDP),and tribasic ammonium citrate(TAC)were investigated by electrochemical techniques,X-ray photoelectron spectrometer(XPS)analysis,nano-scratch tests,AFM measurements,and polishing of Cu-coated blanket wafers.The experimental results show that the planarization efficiency and the surface quality after ECMP obtained in alkali-based solutions are superior to that in acidic-based solutions,especially at pH=8.The optimal electrolyte compositions(mass fraction)are 6% HEDP,0.3% TTA and 3% TAC at pH=8.The main factor affecting the thickness of the oxide layer formed during ECMP process is the applied potential.The soft layer formation is a major mechanism for electrochemical enhanced mechanical abrasion.The surface topography evolution before and after electrochemical polishing(ECP)illustrates the mechanism of mechanical abrasion accelerating electrochemical dissolution,that is,the residual stress caused by the mechanical wear enhances the electrochemical dissolution rate.This understanding is beneficial for optimization of ECMP processes.

Removal of reactive bright-red X-3B in water by Ti/13X molecular sieves

The compound materials （shorted by Ti/13X） of doping of TiO2 into 13X molecular sieves has-been achieved by methods namely impregnation. Technical parameters of preparation for Ti/13X were determined by removal efficiency of simulation dyeing wastewater containing reactive bright-red X-3B （shorted by X-3B）. In various preparation parameters, the influence of Ti loaded on 13X molecular sieves on X-3B removal efficiency is most important. The optimum condition for volume of TiCI4 loaded on 13X molecular sieves is 8 ml at 95.9%, produced sample referred as M8. M8 was characterized using X-Ray Diffraction （XRD）, Scanning Electron Microscope （SEM）. XRD patterns of M8 revealed the incorporation of titanium into framework of 13X molecular sieves, due to the presence ofTiO2 anatase phase. SEM image showed that M8 has a large number of wormhole-like channels, in comparison with that of 13X molecular sieves. The photocatalytic tests were carried out for degradation of X-3B. The results showed that the dosage of Ti/13X, reaction time, pH, and concentration of X-3B influence the X-3B removal efficiency. The optimum conditions of photodegradation as the following： MS/X-3B ratio, Conc. is 0.3 g/l, reaction time is 120 rain, pH is 2-6. The photodegradation reaction of Ti/13X with X-3B followed first order kinetics. The rate constants and t1/2 for M8 sample at 0.3 g/l M8/ X-3B solution ratio were 430 min^-1 and 16 min, respectively.

Characteristics of fulvic acid by high voltage pulse discharge plasma

High voltage pulse natural organic matter （NOM） toxic by-products. Fulvic acid discharge plasma can remove and produce no production of solution was treated by high voltage pulse discharge plasma in this paper. It was shown that： for the reason of thermolysis and oxidation, the pH and Oxidation Reduction Potential （ORP） of solution decreased gradually with the increase of peak voltage and fulvic acid solution concentration, meanwhile the temperature and turbidity of solution increased gradually. Adding hydrochlorid acid in the treatment could amplify the effect of plasma. When the concentration of NOM as the surrogate parameter, Ultraviolet Absorbancy Degree （UV254） increased slowly by the effect of plasma, while the degradation of Total Organic Carbon （TOC） was first-order reaction. The removal rate of TOC increased from 22.6% to 33.4% by high voltage pulse electrical field of 35 kv, and from 25.6% to 36.7% with the addition of hydrochlorid acid. This paper may provide some basis for the scale-up design of water treatment process by high voltage pulse discharge plasma with other technologies.

遍地肥羊(外二篇)

那天晚上,和老婆酣畅淋漓地缠绵后,老婆突然很心疼地对我说:老炳,那台老式大脑袋电脑别用了,太刺激眼睛,换一台液晶的吧。我说,好,谢谢老婆体恤。老婆又说,买台电脑好歹也要几千元,听说卖电脑的报价水分都很大,你找个熟悉卖电脑的朋友帮下忙,这样不至于被糊弄。我说行,正好我办公桌对面的小锋,有一个叫大亮的朋友,他在电子城卖电脑,通过小锋我们在一起喝过几次酒。老婆说,那明天你让小锋先陪你去电子城,探下路,回来再说。翌日,上班见到小锋后,我就把想买电脑的事对小锋讲了。小锋听后说,放心,这事包我身上了。大亮是我最好的哥们,肯定以最低价开给我们。午间,我和小锋在单位食堂吃过饭,便打车去了电子城。到了电子城。