Study on Water Resources Regulation and Reservoir Operating Prediction for Suppression of Salt Water Intrusion in the Pearl River Estuary

Salt water intrusion occurred frequently during dry season in Modaomen waterway of the Pearl River Estuary. With the development of region's economy and urbanization, the salt tides affect the region's water supply more and more seriously in recent years. Regulation and allocation of freshwater resources of the upper rivers of the estuary to suppress the salt tides is becoming important measures for ensuring the water supply security of the region in dry season. The observation data analysis showed that the flow value at the Wuzhou hydrometric station on the upper Xijiang river had a good correlation with the salinity in Modaomen estuary. Thus the flow rate of Wuzhou has been used as a control variable for suppression of salt tides in Modaomen estuary. However, the runoff at Wuzhou mainly comes from the discharge of Longtan reservoir on the upper reaches of Xijiang river and the runoff in the interval open valley between Longtan and Wuzhou sections. As the long distance and many tributaries as well as the large non-controlled watershed between this two sections, the reservoir water scheduling has a need for reasonable considering of interaction between the reservoir regulating discharge and the runoff process of the interval open watershed while the deployment of suppression flow at Wuzhou requires longer lasting time and high precision for the salt tide cycles. For this purpose, this study established a runoff model for Longtan - Wuzhou interval drainage area and by model calculations and observation data analysis, helped to understand the response patterns of the flow rate at Wuzhou to the water discharge of Longtan under the interval water basin runoff participating conditions. On this basis, further discussions were taken on prediction methods of Longtan reservoir discharge scheduling scheme for saline intrusion suppression and provided scientific and typical implementation programs for effective suppression flow process at the Wuzhou section.

核素131I胆道腔内辐照支架的制作和动物实验及临床应用研究

恶性梗阻性黄疸(malignant obstructive jaundice,MOJ)发现时多为晚期,如不治疗生存期仅3个月。由于肿瘤位置特殊、患者一般情况较差,仅5%～20%的患者可行外科切除和分流手术,并且手术死亡率相当高,分流术病死率高达10%～43%。1974年Molnar和Stocknm首先采用PTCD术（经皮肝胆管内外引流术，Percutaneous Transhepatic Cholangic Drainage,PTCD）,使MOJ患者的临床症状得到缓解, 获得进一步治疗的机会。1989年金属支架开始应用于胆道系统,恢复了胆汁的生理性引流,并使大多数患者拔除引流管,提高了生活质量,成为非手术治疗MOJ的首选方法。但肿瘤生长是造成支架堵塞、黄疸复发的主要原因。文献报道MOJ患者放置金属支架后,支架堵塞的概率达20%～86%,其中大多数由肿瘤生长通过支架网眼或超过支架边缘引起。因此,在支架置放的同时如何积极控制肿瘤生长成为提高疗效的关键问题。MOJ的局部治疗方法有多种,但都存在不足之处。国内学者采用动脉化疗栓塞结合PTCD或支架置放的方法治疗MOJ,使患者的生存期得到延长。但引起MOJ的胆管癌、淋巴结转移癌、胰腺癌、壶腹癌多为少血供肿瘤,而且由于血供特殊,大部分病例碘油沉积欠佳,因此动脉化疗栓塞对这类肿瘤的作用是有限的。外辐照治疗对胆管癌、淋巴结转移癌、胰腺癌、壶腹癌等引起MOJ的肿瘤有一定疗效,并与胆道引流术结合应用于上述肿瘤引起的MOJ。由于瘤体周围有肝脏、胰腺、胃肠道、肾脏等对射线敏感的器官, 限制了外辐照剂量,影响了疗效的提高。近几年,一种斩新的治疗手段正在应用于临床，就是通过PTCD手术时建立的通道再行腔内辐照治疗(核素内辐照治疗),可以较好的控制肿瘤继续生长，抑制支架再狭窄的发生,可使MOJ的治疗取得更好的效果。本研究的目的就是探索胆道内辐照支架制作的可行性，并设计特别的施源器，其具体方法可以简述为：以球囊扩张器扩张重度狭窄胆管+置入特制的二腔单囊管+腔内低剂量率放疗+腔内热频热疗+胆管引流等联合方法治疗。同时，就该二腔单囊管内辐照支架的安全性进行动物实验，从分子生物学、核医学的角度阐述了实验研究的机理和病理改变，同时进行了临床的应用研究，探讨胆道支架发生再阻塞的相关因素及对策，进一步提高（MOJ）患者的生存期。本工作结果总结如下： 1 对放射源和施源器均进行了改进，放射源为液态放射性核素131I，施源器为可调节的长柱形球囊，是专门设计的硅橡胶二腔单囊管，其功能为：中腔通接胆管腔（蓝色），具有引流胆汁作用；另一腔管连接球囊（绿色），是长柱状形可调节长短的球囊，囊内装填放射性液态核素131I；囊内还设置射频加热电极，能加热升温。另外，还可以根据肿瘤的大小和长度，来调节施源器的长度（长柱形球囊），一般照射长度超出支架两端1-2cm。二腔单囊管内辐照支架的特点：剂量分布合理，低剂量率效应，射线能量适中，放疗、热疗同步实施，引流、扩张和局部用药作用。与其他治疗方法比较，这一核医学治疗技术的最大优点是：大直径柱状液态源，近似面源，液囊适形病变胆管腔，均匀贴紧病灶壁，剂量分布合理，γ射线能量适中，低剂量率持续照射，同时联合射频温热治疗及胆道引流、局部用药对症处理等。 2 动物实验研究结果指出，囊装液态131I支架对胆管壁的放射性损伤随131I放射性活度的增加而逐渐加重,呈现明显的放射性活度效应关系。而普通支架组胆管壁无放射性损伤,但是胆管壁粘膜层和肌层增生较131I支架组重,胆管出现再狭窄倾向。本研究为临床合理应用131I支架治疗胆管癌及胆管良性狭窄选择合适的131I放射性活度,提供了必要的剂量学和基础研究依据。 3 动物实验研究结果表明,131I支架组犬胆管组织Fas表达较普通支架组明显,且其表达水平的变化与犬胆管壁平滑肌细胞凋亡的检测结果相同。131I支架组胆管腔面积比普通支架组明显增加,胆管狭窄程度比普通支架组轻。这主要是由于131I辐射促进Fas 基因表达,诱导增殖性平滑肌细胞凋亡,从而减轻胆管损伤后愈合过程中的管腔狭窄。 4． 胆道恶性梗阻胆道腔内囊装液态131I辐照治疗施源的直径为8mm时是胆管充分扩张的最低限度,根据近距离放疗的剂量学特点,它能保证胆管癌腔内辐照治疗时将施源管因素导致的放疗反应和局部肿瘤复发减至最低。并具有创伤小,操作简单,疗效明显,易被患者接受的特点。 5．囊装液态131I治疗恶性梗阻性黄疸（肝门部胆管癌18例），临床疗效满意，随访7～21个月,3个月生存率83.33 %(15/ 18)；6个月生存率72.22%(13/18)；9个月生存率56.25%(12/16)；12个月生存率46.15%(6/13),15个月生存率36.33%(4/11)；18个月生存率22.22%(2/9),21个月生存率28.57%(2/7)。4例发生并发症,其中2例为放射性胆管炎胆道出血,1例为胆汁性腹膜炎,另1例是胰瘘胰腺炎

2-D and 3-D processing and interpretation of multi-fold ground penetrating radar data:a case history from an archaeological site

A 2.5-D and 3-D multi-fold GPR survey was carried out in the Archaeological Park of Aquileia (northern Italy). The primary objective of the study was the identification of targets of potential archaeological interest in an area designated by local archaeological authorities. The second geophysical objective was to test 2-D and 3-D multi-fold methods and to study localised targets of unknown shape and dimensions in hostile soil conditions. Several portions of the acquisition grid were processed in common offset (CO), common shot (CSG) and common mid point (CMP) geometry. An 8×8 m area was studied with orthogonal CMPs thus achieving a 3-D subsurface coverage with azimuthal range limited to two normal components. Coherent noise components were identified in the pre-stack domain and removed by means of FK filtering of CMP records. Stack velocities were obtained from conventional velocity analysis and azimuthal velocity analysis of 3-D pre-stack gathers. Two major discontinuities were identified in the area of study. The deeper one most probably coincides with the paleosol at the base of the layer associated with activities of man in the area in the last 2500 years. This interpretation is in agreement with the results obtained from nearby cores and excavations. The shallow discontinuity is observed in a part of the investigated area and it shows local interruptions with a linear distribution on the grid. Such interruptions may correspond to buried targets of archaeological interest. The prominent enhancement of the subsurface images obtained by means of multi-fold techniques, compared with the relatively poor quality of the conventional single-fold georadar sections, indicates that multi-fold methods are well suited for the application to high resolution studies in archaeology.

应用输沙量推演流域侵蚀量的方法探讨

鉴于至今还没有一个有效获取流域侵蚀产沙量的方法,在分析悬移质泥沙与侵蚀泥沙之间的数量与粒配关系的基础上,阐述了应用输沙量推演流域侵蚀量在理论上的可能性,但却存在着难点,且主要表现在水文站数量不足与区域分布不均、流域内的生态环境复杂与区域差异大、水文站输沙量观测记录起始时间不同步、及新技术应用存在时空条件的局限性。结合与侵蚀产沙和泥沙输移比相关的定性与定量指标,提出了应用输沙量推演流域侵蚀量的方法,即"层次类剔法",来计算与评估流域侵蚀量和泥沙输移比,具体的操作过程是首先制作一幅流域地貌类型地块图,然后是逐类型、逐类型地块的侵蚀量计算和沟道流域泥沙输移比的判断,最终获取流域不同地块的侵蚀强度和流域泥沙输移比。本研究结果可为水土流失监测点的选择提供科学依据,同时对解决流域的泥沙问题也有重要的启迪作用。

地下滴灌的经济与环境效益研究综述

地下滴灌是一种新型的节水灌溉技术 ,具有诸多优点 ,不仅在技术和经济方面 ,而且在生态环境保护方面都是最有发展前途的节水灌溉技术。对地下滴灌技术的发展历史、经济与环境效益进行了综述 ,并讨论了存在的问题 ,对研究的开展提出了一些建议

黄土高原分形沟网研究

推测认为黄土高源沟网具有分形性。根据Hoton定律推导沟网分维计算式 ,确定沟网分形结构 ,分形理论求算得小流域沟网的分维D =1.9接近于平面空间时的D =2理论值。统计分析发现流域边界周长、长轴、短轴、长短轴比、汇合角等地貌指标随流域面积的变化。从而证明黄土高源流域的自相似性

地下滴灌埋管深度对冬小麦根冠生长及水分利用效率的影响

在试验室内 ,进行了地下滴灌埋管深度对不同生育时期冬小麦根系生长和地上部分生长影响的试验研究。结果表明 :2 0 cm和 4 0 cm埋管深度的水分分布特征 ,在生育早期抑制地上部分营养生长 ,促进冬小麦蹲苗 ;而中后期则促进生殖生长 ,产量和水分利用效率较高。不考虑犁底层影响时 ,在重壤土上 4 0 cm是冬小麦进行地下滴灌的较好埋深

基于CorelDRAW软件的小流域模型雨滴测量试验研究

降雨雨谱的观测,是了解降雨特性的一项重要工作。修建小流域模型,是对小流域进行各种试验研究的有效手段。该文基于相似率要求,在模型降雨雨滴较小,雨谱参数难以测定问题的基础上,运用CorelDRAW软件与传统色斑法相结合,探索出一种新的测量与数据处理方法,并得出不同情况下模型的雨谱特性。该法提高了测量精度,并减少了工作量。

Biodegradation of poly(L-lactide-co-glycolide) tube stents in bile

The objective of this study was to evaluate degradation behavior and the feasibility of biodegradable polymeric stents in common bile duct (CBD) repair and reconstruction. Various molar ratios of lactide (LA) and glycolide (GA) in poly(L-lactide-co-glycolide) (PLGA) were synthesized and processed into a circular tubing of similar to 10.0 mm outer diameter and a wall thickness of about 2.0 mm.

Feasibility of biodegradable PLGA common bile duct stents: An in vitro and in vivo study

The current study investigates the feasibility of using a biodegradable polymeric stent in common bile duct (CBD) repair and reconstruction. Here, poly(l-lactide-co-glycolide) (PLGA, molar ratio LA/GA = 80/20) was processed into a circular tube- and dumbbell-shaped specimens to determine the in vitro degradation behavior in bile. The morphology, weight loss, and molecular weight changes were then investigated in conjunction with evaluations of the mechanical properties of the specimen. Circular tube-shaped PLGA stents with X-ray opacity were subsequently used in common bile duct exploration (CBDE) and primary suturing in canine models. Next, X-ray images of CBD stents in vivo were compared and levels of serum liver enzymes and a histological analysis were conducted after stent transplantation. The results showed that the PLGA stents exhibited the required biomedical properties and spontaneously disappeared from CBDs in 4-5 weeks. The degradation period and function match the requirements in repair and reconstruction of CBDs to support the duct, guide bile drainage, and reduce T-tube-related complications.

Rare earth elements in bottom sediments of major rivers around the Yellow Sea: implications for sediment provenance

Rare earth elements (REEs) of 91 fine-grained bottom sediment samples from five major rivers in Korea (the Han, Keum, and Yeongsan) and China (the Changjiang and Huanghe) were studied to investigate their potential as source indicator for Yellow Sea shelf sediments, this being the first synthetic report on REE trends for bottom sediments of these rivers. The results show distinct differences in REE contents and their upper continental crust (UCC)-normalized patterns: compared to heavy rare earth elements (HREEs), light rare earth elements (LREEs) are highly enriched in Korean river sediments, in contrast to Chinese river sediments that have a characteristic positive Eu anomaly. This phenomenon is observed also in primary source rocks within the river catchments. This suggests that source rock composition is the primary control on the REE signatures of these river sediments, due largely to variations in the levels of chlorite and monazite, which are more abundant in Korean bottom river sediments. Systematic variations in I LREE pound/I HREE pound ratios, and in (La/Yb)-(Gd/Yb)(UCC) but also (La/Lu)-(La/Y)(UCC) and (La/Y)-(Gd/Lu)(UCC) relations have the greatest discriminatory power. These findings are consistent with, but considerably expand on the limited datasets available to date for suspended sediments. Evidently, the REE fingerprints of these river sediments can serve as a useful diagnostic tool for tracing the provenance of sediments in the Yellow Sea, and for reconstructing their dispersal patterns and the circulation system of the modern shelf, as well as the paleoenvironmental record of this and adjoining marginal seas.

Benthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough: dependance on water masses and food supply

Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Okinawa Trough is carried out. The results indicate that benthic foraminiferal abundance decreases rapidly with increasing water depth. Percentage frequencies of agglutinated foraminifera further confirm the modem shallow carbonate lysocline in the southern Okinawa Trough. From continental shelf edge to the bottom of Okinawa Trough, benthic foraminiferal fauna in the surface sediments can be divided into 5 assemblages: (1) Continental shelf break assemblage, dominated by Cibicides pseudoungerianus, corresponds to subsurface water mass of the Kuroshio Current; (2) upper continental slope assemblage, dominated by Cassidulina carinata, Globocassidulina subglobosa, corresponds to intermediate water mass of the Kuroshio Current; (3) intermediate continental slope assemblage, dominated by Uvigerina hispida, corresponds to the Okinawa Trough deep water mass above the carbonate lysocline; (4), lower continental slope - trough bottom assemblage, dominated by Pullenia bulloides, Epistominella exigua and Cibicidoides hyalinus, corresponds to deep water mass of the Okinawa Trough; and (5) trough bottom agglutinated assemblage, dominated by Rhabdammina spp., Bathysiphon flavidus, corresponds to I strongly dissolved environment of the trough bottom. The benthic foraminiferal fauna in the southern Okinawa Trough are controlled jointly by water masses and food supply. Water temperature, oxygen concentration and carbonate dissolution of the water masses are important controlling factors especially for the continental shelf break and trough bottom assemblages. The food supply also plays an important role in these benthic foraminiferal assemblages along the western slope. of the Okinawa Trough. Both the abundance and the 5 assemblages of benthic foraminifera correspond well to the organic matter supply along the continental slope and a lateral transport of TSM (total suspended matter) and POC (particulate organic carbon) from the shelf break to the deep water is also an important food supply for benthic fauna in this region.

Evolution and variability of the East Asian summer monsoon during the Pliocene: Evidence from clay mineral records of the South China Sea

The Late Pliocene is thought to be characterized by the simultaneous intensification of both the East Asian winter monsoon (EAWM) and East Asian summer monsoon (EASM). However, the evolution of the EASM during the Pliocene remains still controversial and only little is known about the dynamics of the EASM during the Pliocene on orbital time scales. Here we use clay mineral assemblages in sediments from Ocean Drilling Program (ODP) Site 1143 in the southern South China Sea (SCS) to obtain proxy records of past changes in the EASM climate during the Pliocene. Provenance analysis suggests that illite, chlorite and kaolinite originated mainly from the Mekong River drainage area. Smectite was derived mainly from the Indonesian islands. The kaolinite/illite ratio and the chemical index of alteration (CIA) of siliciclastic sediments allowed us to reconstruct the history of chemical weathering and physical erosion of the Mekong River drainage area and thus, the evolution of,the EASM during the Pliocene. Our clay minerals proxy data suggests a stronger EASM during the Early Pliocene than during the Late Pliocene. We propose that the long-term evolution of the EASM has been driven by global cooling rather than the uplift of the Tibetan Plateau. Spectral analysis of kaolinite/ illite ratio displays a set of strong periodicities at 100 ka, 30 ka, 28 ka, 25 ka, and 22 ka. with no clear obliquityrelated signal. Our study suggests that the Pliocene EASM intensity on orbital time scales is not only controlled by the Northern Hemisphere summer insolation, but also strongly influenced by equatorial Pacific ENSO-like ocean atmosphere dynamics. (C) 2010 Elsevier B.V. All rights reserved.

A moored underwater energy conservation system for profiling measurement

There is a need to obtain the hydrologic data including ocean current, wave, temperature and so on in the South China Sea. A new profiling instrument which does not suffer from the damage due to nature forces or incidents caused by passing ships, is under development to acquire data from this area. This device is based on a taut single point mid-water mooring system. It incorporates a small, instrumented vertically profiling float attached via an electromechanical cable to a winch integral with the main subsurface flotation. On a pre-set schedule, the instrument float with sensors is winched up to the surface if there is no strip passing by, which is defined by an on-board miniature sonar. And it can be immediately winched down to a certain depth if the sonar sensor finds something is coming. Since, because Of logistics, the area can only be visited once for a long time and a minimum of 10 times per day profiles are desired, energy demands are severe. To respond to these concerns, the system has been designed to conserve a substantial portion of the potential energy lost during the ascent phase of each profile and subsequently use this energy to pull the instrument down. Compared with the previous single-point layered measuring mode, it is advanced and economical. At last the paper introduces the test in the South China Sea.

Two modes of dipole events in tropical Indian Ocean

By analyzing the distributions of subsurface temperature and the surface wind stress anomalies in the tropical Pacific and Indian Oceans during the Indian Ocean Dipole (IOD) events, two major modes of the IOD and their formation mechanisms are revealed. (1) The subsurface temperature anomaly (STA) in the tropical Indian Ocean during the IOD events can be described as a "<" -shaped and west-east-oriented dipole pattern; in the east side of the "<" pattern, a notable tongue-like STA extends westward along the equator in the tropical eastern Indian Ocean; while in the west side of the "<" pattern, the STA has opposite sign with two centers (the southern one is stronger than the northern one in intensity) being of rough symmetry about the equator in the tropical mid-western Indian Ocean. (2) The IOD events are composed of two modes, which have similar spatial pattern but different temporal variabilities due to the large scale air-sea interactions within two independent systems. The first mode of the IOD event originates from the air-sea interaction on a scale of the tropical Pacific-Indian Ocean and coexists with ENSO. The second mode originates from the air-sea interaction on a scale of the tropical Indian Ocean and is closely associated with changes in the position and intensity of the Mascarene high pressure. The strong IOD event occurs when the two modes are in phase, and the IOD event weakens or disappears when the two modes are out of phase. Besides, the IOD events are normally strong when either of the two modes is strong. (3) The IOD event is caused by the abnormal wind stress forcing over the tropical Indian Ocean, which results in vertical transports, leading to the upwelling and pileup of seawater. This is the main dynamic processes resulting in the STA. When the anomalous easterly exists over the equatorial Indian Ocean, the cold waters upwell in the tropical eastern Indian Ocean while the warm waters pileup in the tropical western Indian Ocean, hence the thermocline in the tropical Indian Ocean is shallowed in the east and deepened in the west. The off-equator component due to the Coriolis force in the equatorial area causes the upwelling of cold waters and the shallowing of the equatorial India Ocean thermocline. On the other hand, the anomalous anticyclonic circulations and their curl fields located on both sides of the equator, cause the pileup of warm waters in the central area of their curl fields and the deepening of the equatorial Indian Ocean thermocline off the equator. The above three factors lead to the occurrence of positive phase IOD events. When anomalous westerly dominates over the tropical Indian Ocean, the dynamic processes are reversed, and the negative-phase IOD event occurs.